Arquivo da tag: Saúde mental

Casos de esquizofrenia poderiam ser evitados se fosse possível prevenir infecção por parasita, diz estudo (SBMT)

Proliferação do parasita, que também está relacionado a outros transtornos mentais, é mais comum em países tropicais

Cerca de 30% da população mundial está infectada com um dos parasitas que mais intriga a ciência, o Toxoplasma gondii. Apesar de inofensivo para a maioria das pessoas saudáveis, pesquisas científicas comprovaram que o protozoário é capaz de alterar o comportamento de seres humanos e animais, além de possível ligação com a esquizofrenia. Recentemente, um estudo produzido nos Estados Unidos foi além, sugerindo que cerca de um quinto dos casos de esquizofrenia entre os norte-americanos pode envolver o parasita. Nos países mais pobres, esse índice tende a ser ainda maior.

O estudo, publicado na revista Preventive Veterinary Medicine, foi conduzido pelo médico veterinário e professor Gary Smith, na Seção de Epidemiologia e Saúde Pública da Escola de Medicina Veterinária da Universidade da Pensilvânia. Smith elaborou um cálculo que mede o quão importante é o fator de risco à infecção, que aumenta com a idade.

“Há cada vez mais evidências por meio de estudos de que pessoas infectadas por Toxoplasma têm um risco aumentado para esquizofrenia”, explica o pesquisador. A partir desse pressuposto, o desafio foi descobrir qual a proporção de casos do transtorno mental poderia ser evitada se fosse possível para prevenir a infecção humana com o parasita.

Pelos cálculos feitos em um programa de computador, esse índice seria de 21,4% para países como os Estados Unidos e os da Europa Ocidental, em que a incidência de infecção pelo T. gondiinão varia com a idade. “O resultado, no entanto, seria diferente para muitos países da América do Sul, porque a não incidência de infecção é claramente maior nos grupos etários mais jovens, especialmente entre os mais pobres”, disse.

Só no Brasil – País que tem o maior índice mundial de infectados (66,7%), cerca de 126 milhões de pessoas são hospedeiras do parasita. A proliferação deste, aliás, é mais comum nos países de clima tropical, principalmente nas nações mais pobres, onde há grandes concentrações urbanas e sem saneamento básico.

O mal é transmitido tanto pela ingestão de carne crua e terra contaminada quanto por meio do contato direto com secreções e fezes de gato. Também pode ser repassada ao feto durante a gravidez através da placenta – sendo recomendado, inclusive, que mulheres grávidas evitem contatos com gatos durante o período de gestação. Apesar de ser uma infecção comum tanto em pessoas quanto em animais, o Toxoplasma afeta especialmente os gatos – únicos seres onde o parasita consegue se reproduzir.

Suicídio

Pesquisas feitas em diversos países têm demonstrado como o T. gondii pode estar relacionado a problemas neurológicos, como a depressão, principalmente em pessoas do sexo feminino. Segundo reportagem da revista Scientific American, um desses estudos, desenvolvido no Instituto de Pesquisas Médicas Stanley, em Maryland (EUA), concluiu que mulheres infectadas com quantidades altas de Toxoplasma apresentavam maior tendência a ter filhos esquizofrênicos.

Outro trabalho, produzido por cientistas dinamarqueses obteve um resultado ainda mais alarmante. Segundo a pesquisa, as mulheres que tinham infecções do parasita apresentaram tendência 54% maior de tentarem o suicídio. Em geral, as tentativas eram violentas, utilizando armas brancas e de fogo. Entre aquelas sem histórico de doenças mentais, o índice também foi alto: 56% tinham mais chances de cometerem atentado contra a própria vida.

A preocupação quanto os efeitos do protozoário no organismo são também evidentes em ratos. De acordo com pesquisas, o parasita pode alterar o comportamento desses animais, fazendo-os, por exemplo, perder o medo do cheiro de gatos – alguns chegam até mesmo a sentir atração sexual com o odor. Além disso, pesquisadores descobriram que ratos infectados conseguem recuperar o comportamento normal tanto com remédios antiparasitários quanto com antipsicóticos.

Já se descobriu que a infecção aumenta os níveis do neurotransmissor conhecido como dopamina, que é um dos fatores da esquizofrenia quando em altas doses. Isso porque oToxoplasma possui um gene que codifica uma enzima fundamental para a produção de dopamina, sendo este o método de influência sobre o cérebro de seres humanos e animais. Os cientistas, agora, tentam entender de forma clara como o parasita se comporta no cérebro.

(Newsletter da SBMT)

http://sbmt.org.br/portal/casos-de-esquizofrenia-poderiam-ser-evitados-se-fosse-possivel-prevenir-infeccao-por-parasita-diz-estudo/?locale=pt-BR

The Surprising Link Between Gut Bacteria And Anxiety (Huff Post)

 |  By

Posted: 01/04/2015 10:05 am EST 

GUT BACTERIA

In recent years, neuroscientists have become increasingly interested in the idea that there may be a powerful link between the human brain and gut bacteria. And while a growing body of research has provided evidence of the brain-gut connection, most of these studies so far have been conducted on animals.

Now, promising new research from neurobiologists at Oxford University offers some preliminary evidence of a connection between gut bacteria and mental health in humans. The researchers found that supplements designed to boost healthy bacteria in the gastrointestinal tract (“prebiotics”) may have an anti-anxiety effect insofar as they alter the way that people process emotional information.

While probiotics consist of strains of good bacteria, prebiotics are carbohydrates that act as nourishment for those bacteria. With increasing evidence that gut bacteria may exert some influence on brain function and mental health, probiotics and prebiotics are being increasingly studied for the potential alleviation of anxiety and depression symptoms.

“Prebiotics are dietary fibers (short chains of sugar molecules) that good bacteria break down, and use to multiply,” the study’s lead author, Oxford psychiatrist and neurobiologist Dr. Philip Burnet, told The Huffington Post. “Prebiotics are ‘food’ for good bacteria already present in the gut. Taking prebiotics therefore increases the numbers of all species of good bacteria in the gut, which will theoretically have greater beneficial effects than [introducing] a single species.”

To test the efficacy of prebiotics in reducing anxiety, the researchers asked 45 healthy adults between the ages of 18 and 45 to take either a prebiotic or a placebo every day for three weeks. After the three weeks had passed, the researchers completed several computer tests assessing how they processed emotional information, such as positive and negatively-charged words.

The results of one of the tests revealed that subjects who had taken the prebiotic paid less attention to negative information and more attention to positive information, compared to the placebo group, suggesting that the prebiotic group had less anxiety when confronted with negative stimuli. This effect is similar to that which has been observed among individuals who have taken antidepressants or anti-anxiety medication.

The researchers also found that the subjects who took the prebiotics had lower levels of cortisol — a stress hormone which has been linked with anxiety and depression — in their saliva when they woke up in the morning.

While previous research has documented that altering gut bacteria has a similarly anxiety-reducing effect in mice, the new study is one of the first to examine this phenomenon in humans. As of now, research on humans is in its early stages. A study conducted last year at UCLA found that women who consumed probiotics through regularly eating yogurt exhibited altered brain function in both a resting state and when performing an emotion-recognition task.

“Time and time again, we hear from patients that they never felt depressed or anxious until they started experiencing problems with their gut,” Dr. Kirsten Tillisch, the study’s lead author, said in a statement. “Our study shows that the gut–brain connection is a two-way street.”

So are we moving towards a future in which mental illness may be able to be treated (or at least managed) using targeted probiotic cocktails? Burnet says it’s possible, although they’re unlikely to replace conventional treatment.

“I think pre/probiotics will only be used as ‘adjuncts’ to conventional treatments, and never as mono-therapies,” Burnet tells HuffPost. “It is likely that these compounds will help to manage mental illness… they may also be used when there are metabolic and/or nutritional complications in mental illness, which may be caused by long-term use of current drugs.”

The findings were published in the journal Psychopharmacology.

Ghost illusion created in the lab (Science Daily)

Date: November 6, 2014

Source: Ecole Polytechnique Fédérale de Lausanne

Summary: Patients suffering from neurological or psychiatric conditions have often reported ‘feeling a presence’ watching over them. Now, researchers have succeeded in recreating these ghostly illusions in the lab.

This image depicts a person experiencing the ghost illusion in the lab. Credit: Alain Herzog/EPFL

Ghosts exist only in the mind, and scientists know just where to find them, an EPFL study suggests. Patients suffering from neurological or psychiatric conditions have often reported feeling a strange “presence.” Now, EPFL researchers in Switzerland have succeeded in recreating this so-called ghost illusion in the laboratory.

On June 29, 1970, mountaineer Reinhold Messner had an unusual experience. Recounting his descent down the virgin summit of Nanga Parbat with his brother, freezing, exhausted, and oxygen-starved in the vast barren landscape, he recalls, “Suddenly there was a third climber with us… a little to my right, a few steps behind me, just outside my field of vision.”

It was invisible, but there. Stories like this have been reported countless times by mountaineers, explorers, and survivors, as well as by people who have been widowed, but also by patients suffering from neurological or psychiatric disorders. They commonly describe a presence that is felt but unseen, akin to a guardian angel or a demon. Inexplicable, illusory, and persistent.

Olaf Blanke’s research team at EPFL has now unveiled this ghost. The team was able to recreate the illusion of a similar presence in the laboratory and provide a simple explanation. They showed that the “feeling of a presence” actually results from an alteration of sensorimotor brain signals, which are involved in generating self-awareness by integrating information from our movements and our body’s position in space.

In their experiment, Blanke’s team interfered with the sensorimotor input of participants in such a way that their brains no longer identified such signals as belonging to their own body, but instead interpreted them as those of someone else. The work is published in Current Biology.

Generating a “Ghost”

The researchers first analyzed the brains of 12 patients with neurological disorders — mostly epilepsy — who have experienced this kind of “apparition.” MRI analysis of the patients’s brains revealed interference with three cortical regions: the insular cortex, parietal-frontal cortex, and the temporo-parietal cortex. These three areas are involved in self-awareness, movement, and the sense of position in space (proprioception). Together, they contribute to multisensory signal processing, which is important for the perception of one’s own body.

The scientists then carried out a “dissonance” experiment in which blindfolded participants performed movements with their hand in front of their body. Behind them, a robotic device reproduced their movements, touching them on the back in real time. The result was a kind of spatial discrepancy, but because of the synchronized movement of the robot, the participant’s brain was able to adapt and correct for it.

Next, the neuroscientists introduced a temporal delay between the participant’s movement and the robot’s touch. Under these asynchronous conditions, distorting temporal and spatial perception, the researchers were able to recreate the ghost illusion.

An “Unbearable” Experience

The participants were unaware of the experiment’s purpose. After about three minutes of the delayed touching, the researchers asked them what they felt. Instinctively, several subjects reported a strong “feeling of a presence,” even counting up to four “ghosts” where none existed. “For some, the feeling was even so strong that they asked to stop the experiment,” said Giulio Rognini, who led the study.

“Our experiment induced the sensation of a foreign presence in the laboratory for the first time. It shows that it can arise under normal conditions, simply through conflicting sensory-motor signals,” explained Blanke. “The robotic system mimics the sensations of some patients with mental disorders or of healthy individuals under extreme circumstances. This confirms that it is caused by an altered perception of their own bodies in the brain.”

A Deeper Understanding of Schizophrenia

In addition to explaining a phenomenon that is common to many cultures, the aim of this research is to better understand some of the symptoms of patients suffering from schizophrenia. Such patients often suffer from hallucinations or delusions associated with the presence of an alien entity whose voice they may hear or whose actions they may feel. Many scientists attribute these perceptions to a malfunction of brain circuits that integrate sensory information in relation to our body’s movements.

“Our brain possesses several representations of our body in space,” added Giulio Rognini. “Under normal conditions, it is able to assemble a unified self-perception of the self from these representations. But when the system malfunctions because of disease — or, in this case, a robot — this can sometimes create a second representation of one’s own body, which is no longer perceived as ‘me’ but as someone else, a ‘presence’.”

It is unlikely that these findings will stop anyone from believing in ghosts. However, for scientists, it’s still more evidence that they only exist in our minds.

Watch the video: http://youtu.be/GnusbO8QjbE


Journal Reference:

  1. Olaf Blanke, Polona Pozeg, Masayuki Hara, Lukas Heydrich, Andrea Serino, Akio Yamamoto, Toshiro Higuchi, Roy Salomon, Margitta Seeck, Theodor Landis, Shahar Arzy, Bruno Herbelin, Hannes Bleuler, Giulio Rognini. Neurological and Robot-Controlled Induction of an Apparition. Current Biology, 2014; DOI:10.1016/j.cub.2014.09.049

Parasite-schizophrenia connection: One-fifth of schizophrenia cases may involve the parasite T. gondii (Science Daily)

Date: October 29, 2014

Source: University of Pennsylvania

Summary: Many factors, both genetic and environmental, have been blamed for increasing the risk of a diagnosis of schizophrenia. Some, such as a family history of schizophrenia, are widely accepted. Others, such as infection with Toxoplasma gondii, a parasite transmitted by soil, undercooked meat and cat feces, are still viewed with skepticism. A new study used epidemiological modeling methods to determine the proportion of schizophrenia cases that may be attributable to T. gondii infection. The work suggests that about one-fifth of cases may involve the parasite.

The parasite T. gondii has been shown to alter behavior in rodents. Smith’s study supports a link to schizophrenia in humans. Credit: Image courtesy of University of Pennsylvania

Many factors, both genetic and environmental, have been blamed for increasing the risk of a diagnosis of schizophrenia. Some, such as a family history of schizophrenia, are widely accepted. Others, such as infection with Toxoplasma gondii, a parasite transmitted by soil, undercooked meat and cat feces, are still viewed with skepticism.

A new study by Gary Smith, professor of population biology and epidemiology at the University of Pennsylvania’s School of Veterinary Medicine, used epidemiological modeling methods to determine the proportion of schizophrenia cases that may be attributable to T. gondii infection. The work, published in the journal Preventive Veterinary Medicine, suggests that about one-fifth of cases may involve the parasite.

“Infection with Toxoplasma is very common, so, even if only a small percentage of people suffer adverse consequences, we could be talking about problems that affect thousands and thousands of people,” Smith said.

In the United States, just over a fifth of the population is infected with T. gondii. The vast majority aren’t aware of it. But there are some populations that need to be concerned. For example, if a woman becomes infected for the first time during pregnancy, her fetus can die or suffer serious developmental problems. People with HIV or other diseases that weaken the immune system are susceptible to a complication of T. gondii infection called toxoplasmic encephalitis, which can be deadly.

Though the medical community has long believed that most healthy people suffer no adverse effects from a T. gondii infection, recent studies have found evidence of worrisome impacts, including an association with schizophrenia because the parasite is found in in the brain as well as in muscles. Other work has shown that some antipsychotic drugs can stop the parasite from reproducing. In addition, field and laboratory studies in mice, rats and people have shown that infection with T. gondiitriggers changes in behavior and personality.

To further investigate this connection, Smith sought to calculate the population attributable fraction, or PAF, a metric epidemiologists use to determine how important a risk factor might be. In this case, Smith explained that the PAF is “the proportion of schizophrenia diagnoses that would not occur in a population if T. gondii infections were not present.”

The usual method of calculating the PAF was not well suited to examining the link between schizophrenia and T. gondii, because some of the variables are constantly in flux. For example, the proportion of people infected by T. gondii increases with age. Using a standard epidemiological modeling format, but taking into account all of the age-related changes in the relevant factors, Smith found the average PAF during an average lifetime to be 21.4 percent.

“In other words, we ask, if you could stop infections with this parasite, how many cases could you prevent?” Smith said. “Over a lifetime, we found that you could prevent one-fifth of all cases. That, to me, is significant.”

Smith noted that in some countries, the prevalence of T. gondii infection is much higher than in the U.S., and these countries also have a higher incidence of schizophrenia.

People with schizophrenia have greatly reduced life expectancies, and many are unable to work. Family members may also leave the workforce to care for relatives with the disease. For these reasons and others, schizophrenia acts as a large drain on the economy, responsible for $50 to $60 billion in health-care expenditures in the U.S. each year.

“By finding out how important a factor T. gondii infection is, this work might inform our attitude to researching the subject,” Smith said. “Instead of ridiculing the idea of a connection between T. gondii and schizophrenia because it seems so extraordinary, we can sit down and consider the evidence. Perhaps then we might be persuaded to look for more ways to reduce the number of people infected with Toxoplasma.”

The study was supported by the University of Pennsylvania School of Veterinary Medicine.


Journal Reference:

  1. Gary Smith. Estimating the population attributable fraction for schizophrenia when Toxoplasma gondii is assumed absent in human populations.Preventive Veterinary Medicine, 2014; DOI: 10.1016/j.prevetmed.2014.10.009

Should the Japanese give nuclear power another chance? (Science Daily)

Date: October 23, 2014

Source: ResearchSEA

Summary: On September 9, 2014, the Japan Times reported an increasing number of suicides coming from the survivors of the March 2011 disaster. In Minami Soma Hospital, which is located 23 km away from the power plant, the number of patients experiencing stress has also increased since the disaster. What’s more, many of the survivors are now jobless and therefore facing an uncertain future.


On September 9, 2014, the Japan Times reported an increasing number of suicides coming from the survivors of the March 2011 disaster. In Minami Soma Hospital, which is located 23 km away from the power plant, the number of patients experiencing stress has also increased since the disaster. What’s more, many of the survivors are now jobless and therefore facing an uncertain future.

This is not the first time that nuclear power has victimized the Japanese people. In 1945, atomic bombs exploded in Hiroshima and Nagasaki, creating massive fears about nuclear power in the Japanese population. It took 20 years for the public to erase the trauma of these events. It was then — in the mid 1960s(?) — that the Fukushima Daiichii Nuclear Power Plant was built.

According to Professor Tetsuo Sawada, Assistant Professor in the Laboratory of Nuclear Reactors at Tokyo University, it took a lot of effort to assure people that nuclear power was safe and beneficial. The first step was a legal step: In 1955, the Japanese government passed a law decreeing that nuclear power could only be used for peaceful purposes.

“But that law was not enough to assure people to accept the establishment of nuclear power,” said Prof. Sawada.

He explained that the economy plays an important role in public acceptance of nuclear power. Through the establishment of nuclear power plants, more jobs were created, which boosted the economy of the Fukushima region at that time.

“Before the Fukushima disaster, we could find many pro-nuclear people in the area of nuclear power plants since it gave them money,” said Prof. Sawada.

Now, more than forty years have passed and the public’s former confidence has evolved into feelings of fear about nuclear power and distrust toward the government.

According to a study conducted by Noriko Iwai from the Japanese General Social Survey Research Center, the Fukushima nuclear accident has heightened people’s perception of disaster risks, fears of nuclear accident, and recognition of pollution, and has changed public opinion on nuclear energy policy.

“Distance from nuclear plants and the perception of earthquake risk interactively correlate with opinions on nuclear issues: among people whose evaluation of earthquake risk is low, those who live nearer to the plants are more likely to object to the abolishment of nuclear plants,” said Iwai.

This finding is in line with the perception of Sokyu Genyu, a chief priest in Fukujuji temple, Miharu Town, Fukushima Prefecture. As a member of the Reconstruction Design Council in Response to the Great East Japan Earthquake, he argued that both the Fukushima Daiichi and Daini nuclear power plants should be shut down in response to the objection of 80% of Fukushima residents.

However, the Japanese government, local scientists and international authorities have announced that Fukushima is safe. Radiation levels are below 1mSv/y, a number that, according to them, we should not be worried about. But the public do not believe in numbers.

But Genyu was not saying that these numbers are scientifically false. Rather, he argues that the problem lies more in the realm of social psychology. Despite the announcement about low-radiation levels, the Japanese people are still afraid of radiation.

“It is reasonable for local residents in Fukushima to speak out very emotionally. Within three months of the disaster, six people had committed sucide. They were homeless and jobless, ” said Genyu.

It is heart-breaking to know that victims of the Fukushima Daiichi nuclear accident died not because of radiation, but instead because of depression. Besides the increasing number of suicides, the number ofpatients suffering from cerebrovascular disease (strokes)has also risen. In Minami-Soma Hospital, the population of stroke patients increased by more than 100% after the disaster.

Local doctors and scientists are now actively educating students in Fukushima, convincing them that the radiation will not affect their health.

Dr. Masaharu Tsubokura, a practicing doctor at Minami-Soma Hospital, has been informing students that Fukushima is safe. But sadly, their responses are mostly negative and full of apathy.

“I think the Fukushima disaster is not about nuclear radiation but is rather a matter of public trust in the technology ,” said Dr. Tsubokura.

Dr. Tsubokura has given dosimeters, a device used to measure radiation, to children living in Minami-Soma city. But apparently, this was not enough to eliminate people’s fears.

In 2012, Professor Ryogo Hayano, a physicist from the University of Tokyo, joined Dr. Tsubokura in Minami-Soma Hospital and invented BABYSCAN technology, a whole-body scanning to measure radiation in small children as well as to allay the fears of Fukushima parents.

“BABYSCAN is unnecessary but necessary. It is unnecessary because we know that the radiation is low. But it is necessary to assure parents that their children are going to be okay,” said Prof. Hayano.

After witnessing the fears of the Fukushima people, Prof. Hayano thinks that nuclear power is no longer appropriate for Japan. He believes that the government should shut down nuclear power plants.

“As a scientist, I know that nuclear power is safe and cheap. But looking at the public’s fear in Fukushima, I think it should be phased out,” said Prof. Hayano.

But, does the government care about the public when it comes to politics?

It has only been three years since the disaster and Prime Minister Shinzo Abe has been keen to revive the country’s nuclear power plants. The operations of more than 50 nuclear power plants in Japan have been suspended because of the Daiichi power plant meltdown.

Last month, Japan’s Nuclear Regulation Authority approved the reopening of a power plant in Sendai for 2015.

Treating mental illness by changing memories of things past (Science Daily)

Date: August 12, 2014

Source: Elsevier

Summary: Author Marcel Proust makes a compelling case that our identities and decisions are shaped in profound and ongoing ways by our memories. This truth is powerfully reflected in mental illnesses, like posttraumatic stress disorder (PTSD) and addictions. In PTSD, memories of traumas intrude vividly upon consciousness, causing distress, driving people to avoid reminders of their traumas, and increasing risk for addiction and suicide. In addiction, memories of drug use influence reactions to drug-related cues and motivate compulsive drug use.

 

“Memory reconsolidation is probably among the most exciting phenomena in cognitive neuroscience today. It assumes that memories may be modified once they are retrieved which may give us the great opportunity to change seemingly robust, unwanted memories,” explains Dr. Lars Schwabe of Ruhr-University Bochum in Germany. Credit: Image courtesy of Elsevier

In the novel À la recherche du temps perdu (translated into English as Remembrance of Things Past), Marcel Proust makes a compelling case that our identities and decisions are shaped in profound and ongoing ways by our memories.

This truth is powerfully reflected in mental illnesses, like posttraumatic stress disorder (PTSD) and addictions. In PTSD, memories of traumas intrude vividly upon consciousness, causing distress, driving people to avoid reminders of their traumas, and increasing risk for addiction and suicide. In addiction, memories of drug use influence reactions to drug-related cues and motivate compulsive drug use.

What if one could change these dysfunctional memories? Although we all like to believe that our memories are reliable and permanent, it turns out that memories may indeed be plastic.

The process for modifying memories, depicted in the graphic, is called memory reconsolidation. After memories are formed and stored, subsequent retrieval may make them unstable. In other words, when a memory is activated, it also becomes open to revision and reconsolidation in a new form.

“Memory reconsolidation is probably among the most exciting phenomena in cognitive neuroscience today. It assumes that memories may be modified once they are retrieved which may give us the great opportunity to change seemingly robust, unwanted memories,” explains Dr. Lars Schwabe of Ruhr-University Bochum in Germany. He and his colleagues have authored a review paper on the topic, published in the current issue of Biological Psychiatry.

The idea of memory reconsolidation was initially discovered and demonstrated in rodents.

The first evidence of reconsolidation in humans was reported in a study in 2003, and the findings have since continued to accumulate. The current report summarizes the most recent findings on memory reconsolidation in humans and poses additional questions that must be answered by future studies.

“Reconsolidation appears to be a fundamental process underlying cognitive and behavioral therapies. Identifying its roles and mechanisms is an important step forward to fully harnessing the reconsolidation process in psychotherapy,” said Dr. John Krystal, Editor of Biological Psychiatry.

The translation of the animal data to humans is a vital step for the potential application of memory reconsolidation in the context of mental disorders. Memory reconsolidation could open the door to novel treatment approaches for disorders such as PTSD or drug addiction.


Journal Reference:

  1. Lars Schwabe, Karim Nader, Jens C. Pruessner. Reconsolidation of Human Memory: Brain Mechanisms and Clinical Relevance. Biological Psychiatry, 2014; 76 (4): 274 DOI: 10.1016/j.biopsych.2014.03.008

Bactéria pode aumentar inteligência (Exame)

Microbiologia | 24/05/2010 15:50

Cientistas acreditam que espécie também tem capacidades antidepressivas por aumentar níveis de serotonina no cérebro

Célio Yano 

São Paulo – Uma espécie de bactéria que os cientistas já acreditavam ter capacidades antidepressivas pode também deixar pessoas mais inteligentes. A descoberta foi apresentada hoje no 110º Encontro Geral da Sociedade Americana de Microbiologia (ASM, na sigla em inglês), realizado em San Diego, nos Estados Unidos.

“A Mycobacterium vaccae é uma bactéria de solo natural, que as pessoas geralmente ingerem ou respiram quando passam algum tempo na natureza”, disse Dorothy Matthews, que conduziu a pesquisa junto com Susan Jenks. Espécie não-patogênica, a M. vaccae tem esse nome por ter sido encontrada pela primeira vez em fezes de vaca.

De acordo com a ASM, estudos anteriores já haviam mostrado que bactérias da espécie mortas injetadas em ratos estimulam o crescimento de alguns neurônios que resultam no aumento de níveis de serotonina e reduzem a ansiedade.

Como a serotonina, tipo de neurotransmissor, desempenha um papel importante no aprendizado, Dorothy e Susan imaginaram que a M. vaccae vivas poderiam aumentar a capacidade de aprendizado do rato. Elas então alimentaram as cobaias com bactérias vivas e testaram a habilidade dos roedores para percorrer um labirinto. Conforme as pesquisadoras, os ratos que se alimentaram da bactéria atravessaram o labirinto duas vezes mais rápido e com menor índice de ansiedade que ratos que não haviam recebido o tratamento.

Em um segundo experimento, as bactérias foram removidas da dieta dos animais e eles foram testados novamente. Embora os ratos percorressem o labirinto mais lentamente do que haviam feito quando ingeriram a bactéria, eles ainda eram mais rápidos que os ratos que não haviam ingerido M. vaccae em nenhum momento. Após três semanas de descanso, os ratos ainda percorriam o labirinto mais rapidamente que os demais, mas os resultados já não eram mais estatisticamente significantes, o que sugere que o efeito foi temporário.

“Esta pesquisa mostra que M. vaccae pode ter uma função na ansiedade e aprendizado de mamíferos”, disse Dorothy. “É interessante imaginarmos que criar ambientes de aprendizado nas escolas que incluam momentos ao ar livre, onde M. vaccae esteja presente, pode baixar a ansiedade e aumentar a capacidade de aprender novas tarefas”, complementou.

Does That Cat Have O.C.D.? (New York Times)

It was love at first pet when Laurel Braitman and her husband adopted a 4-year-old Bernese mountain dog, a 120-pound bundle of fur named Oliver.

The first few months were blissful. But over time, Oliver’s troubled mind slowly began to reveal itself. He snapped at invisible flies. He licked his tail until it was wounded and raw. He fell to pieces when he spied a suitcase. And once, while home alone, he ripped a hole in a screen and jumped out of a fourth-floor window. To everyone’s astonishment, he survived.

Oliver’s anguish devastated Dr. Braitman, a historian of science, but it also awakened her curiosity and sent her on an investigation deep into the minds of animals. The result is the lovely, big-hearted book “Animal Madness,” in which Dr. Braitman makes a compelling case that nonhuman creatures can also be afflicted with mental illness and that their suffering is not so different from our own.

In the 17th century, Descartes described animals as automatons, a view that held sway for centuries. Today, however, a large and growing body of research makes it clear that animals have never been unthinking machines.

ANIMAL MADNESS How Anxious Dogs, Compulsive Parrots and Elephants in Recovery Help Us Understand Ourselves. By Laurel Braitman. Simon & Schuster. 384 pages. $28.CreditSonny Figueroa/The New York Times

We now know that species from magpies to elephants can recognize themselves in the mirror, which some scientists consider a sign of self-awareness. Rats emit a form of laughter when they’re tickled. And dolphins, parrots and dogs show clear signs of distress when their companions die. Together, these and many other findings demonstrate what any devoted pet owner has probably already concluded: that animals have complex minds and rich emotional lives.

Unfortunately, as Dr. Braitman notes, “every animal with a mind has the capacity to lose hold of it from time to time.”

Take Gigi, a female gorilla who developed what looked like panic attacks after being terrorized by a younger male. Whenever she saw her tormentor, she “seemed to shut down, rocking and trembling,” Dr. Braitman writes. Many other beasts round out the miserable menagerie, including Sunita, a tiger with stress-induced facial tics; Charlie, a macaw who plucked out all her feathers; and Gus, a polar bear who swam endless figure eights — for as many as 12 hours a day — in his pool at the Central Park Zoo.

Dr. Braitman and the experts she consults are careful about how they interpret this behavior. For example, although a dog’s nonstop tail-licking may resemble the endless hand-washing of a human with obsessive-compulsive disorder, one veterinary behaviorist points out that because she cannot prove that dogs are having obsessive thoughts, she prefers a diagnosis of “compulsive disorder” instead.

Still, it’s clear that the animals are suffering, and the triggers are often the same sorts of stress and trauma that can cause breakdowns in humans: a natural disaster, abuse, the loss of a loved one. And we’re not the only species that bears the burden of war; some of the military dogs that served in Iraq and Afghanistan display the same PTSD-like symptoms that afflict their human colleagues.

Dr. Braitman does not shy away from controversial topics — most notably, the question of whether animals can commit suicide. Charlie, the feather-plucking macaw, died when she fell out of a tree and onto a metal stake in the ground, prompting her owner to wonder if the bird had deliberately brought about her own demise. “Suicide” is a loaded word, and Charlie’s story is unconvincing, but animals can certainly engage in self-harming behaviors, from repeatedly banging their heads against walls to simply refusing to eat.

Animals “may have fewer tools available to them to inflict mortal wounds and also lack humanity’s sophisticated cognitive abilities to plan their own ends, but they can and do harm themselves,” Dr. Braitman writes. “Sometimes they die.”

Throughout the book, she argues that anthropomorphism — or the assignment of human traits to other species — can serve a useful purpose, especially if we “anthropomorphize well.” She writes, “Instead of self-centered projection, anthropomorphism can be a recognition of bits and pieces of our human selves in other animals and vice versa.”

Though we may never know for sure what parrots or polar bears are feeling, “making educated guesses about animal emotions” is often the first step in alleviating their pain. Healing troubled animal minds is now a bona fide industry, populated with dog behaviorists, cat whisperers, elephant monks and horse massagers.

For some animals, behavioral therapy, environmental enrichment or companionship is enough to ease the agony. Others may need a pharmaceutical assist — from Prozac, Valium, Thorazine or one of the many psychiatric drugs now available to creatures throughout the animal kingdom.

“Prozac Nation has been offering citizenship to nonhumans for decades,” Dr. Braitman writes. Gigi, the terrorized gorilla, received a round of Xanax and Paxil and eventually recovered (mostly) with the help of a psychiatrist and a zookeeper who never gave up on her.

Though humans are a leading cause of animal unhappiness — captivity alone causes many problems, even in the absence of outright neglect or abuse — “Animal Madness” is also brimming with compassion and the tales of the many, many humans who devote their days to making animals well.

Boosting depression-causing mechanisms in brain increases resilience, surprisingly (Science Daily)

Date: April 17, 2014

Source: Mount Sinai Medical Center

Summary: New research uncovers a conceptually novel approach to treating depression. Instead of dampening neuron firing found with stress-induced depression, researchers demonstrated for the first time that further activating these neurons opens a new avenue to mimic and promote natural resilience.

Researchers produced antidepressant-like behavioral effects by reversing out-of-balance electrical activity in reward circuit neurons of susceptible mice exposed to social stress. Further increasing an excitatory current (lh potentiation) triggered a compensatory increase in a potassium channel current (K’ current) — as did activating the potassium channel (K+ current) using pulses of light in mice with brain circuitry genetically engineered to respond to it (optogenetic excessive activation). Credit: Ming-Hu Han, Ph.D., Icahn School of Medicine at Mount Sinai

A new study points to a conceptually novel therapeutic strategy for treating depression. Instead of dampening neuron firing found with stress-induced depression, researchers demonstrated for the first time that further activating these neurons opens a new avenue to mimic and promote natural resilience. The findings were so surprising that the research team thinks it may lead to novel targets for naturally acting antidepressants.

Results from the study are published online April 18 in the journal Science.

Researchers from the Icahn School of Medicine at Mount Sinai point out that in mice resilient to social defeat stress (a source of constant stress brought about by losing a dispute or from a hostile interaction), their cation channel currents, which pass positive ions in dopamine neurons, are paradoxically elevated to a much greater extent than those of depressed mice and control mice. This led researchers to experimentally increase the current of cation channels with drugs in susceptible mice, those prone to depression, to see whether it would enhance coping and resilience. They found that such boosting of cation channels in dopamine neurons caused the mice to tolerate the increased stress without succumbing to depression-related symptoms, and unexpectedly the hyperactivity of the dopamine neurons was normalized.

Allyson K. Friedman, PhD, Postdoctoral Fellow in Pharmacology and Systems Therapeutics at the Icahn School of Medicine at Mount Sinai, and the study’s lead author said: “To achieve resiliency when under social stress, the brain must perform a complex balancing act in which negative stress-related changes in the brain actively trigger positive changes. But that can only happen once the negative changes reach a tipping point.”

The research team used optogenetics, a combination of laser optics and gene virus transfer, to control firing activity of the dopamine neurons. When light activation or the drug lamotrigine is given to these neurons, it drives the current and neuron firing higher. But at a certain point, it triggers compensatory mechanisms, normalizes neuron firing, and achieves a kind of homeostatic (or balanced) resilience.

“To our surprise, we found that resilient mice, instead of avoiding deleterious changes in the brain, experience further deleterious changes in response to stress, and use them beneficially,” said Ming-Hu Han, PhD, at Icahn School of Medicine at Mount Sinai, who leads the study team as senior author.

Drs. Friedman and Han see this counterintuitive finding as stimulating research in a conceptually novel antidepressant strategy. If a drug could enhance coping and resilience by pushing depressed (or susceptible) individuals past the tipping point, it potentially might have fewer side effects, and work as a more naturally acting antidepressant.

Eric Nestler, MD, PhD, at the Icahn School of Medicine at Mount Sinai praised the study. “In this elegant study, Drs. Friedman and Han and their colleagues reveal a highly novel mechanism that controls an individual’s susceptibility or resilience to chronic social stress. The discoveries have important implications for the development of new treatments for depression and other stress-related disorders.”

The study, “Enhancing Depression Mechanisms in Midbrain Dopamine Neurons Achieves Homeostatic Resilience,” was also coauthored by J.J. Walsh, B. Juarez, S.M. Ku, D. Chaudhury, J. Wang, X. Li, D.M. Dietz, N. Pan, V.F. Vialou, Z. Yue, from the Icahn School of Medicine at Mount Sinai in New York and R. L. Neve at Massachusetts Institute of Technology in Cambridge MA.

National Institute of Mental Health Grant R01 MH092306 and F32 MH096464 provided support for this research.

Journal Reference:

  1. A. K. Friedman, J. J. Walsh, B. Juarez, S. M. Ku, D. Chaudhury, J. Wang, X. Li, D. M. Dietz, N. Pan, V. F. Vialou, R. L. Neve, Z. Yue, M.-H. Han. Enhancing Depression Mechanisms in Midbrain Dopamine Neurons Achieves Homeostatic ResilienceScience, 2014; 344 (6181): 313 DOI:10.1126/science.1249240

Discurso sobre o sonho pode ajudar no diagnóstico de doenças mentais (Fapesp)

Pesquisadores brasileiros desenvolvem técnica de análise matemática de relatos sobre sonhos, capaz de auxiliar na identificação de sintomas de esquizofrenia e bipolaridade (imagem: divulgação)

17/03/2014

Por Elton Alisson

Agência FAPESP – A pista dada por Sigmund Freud (1856-1939) no livro “A intepretação dos sonhos, de 1899, de que “os sonhos são a estrada real para o inconsciente”, chave para a Psicanálise, também pode ser útil na Psiquiatria, no diagnóstico clínico de transtornos mentais, como a esquizofrenia e a bipolaridade, entre outras.

A constatação é de um grupo de pesquisadores do Instituto do Cérebro da Universidade Federal do Rio Grande do Norte (UFRN), em colaboração com colegas do Departamento de Física da Universidade Federal de Pernambuco (UFPE) e do Centro de Pesquisa, Inovação e Difusão em Neuromatemática (Neuromat) – um dos CEPIDs da FAPESP.

Eles desenvolveram uma técnica de análise matemática de relatos de sonhos que poderá, no futuro, auxiliar no diagnóstico de psicoses.

A técnica foi descrita em um artigo publicado em janeiro na Scientific Reports, revista de acesso aberto do grupo Nature.

“A ideia é que a técnica, relativamente simples e barata, seja utilizada como ferramenta para auxiliar os psiquiatras no diagnóstico clínico de pacientes com transtornos mentais de forma mais precisa”, disse Mauro Copelli, professor da UFPE e um dos autores do estudo, à Agência FAPESP.

De acordo com Copelli – que realizou mestrado e doutorado parcialmente com Bolsa da FAPESP –, apesar dos esforços seculares para aumentar a precisão da classificação dos transtornos mentais, o atual método de diagnóstico de psicoses tem sido duramente criticado.

Isso porque ele ainda peca pela falta de objetividade e pelo fato de a maioria dos transtornos mentais não contar com biomarcadores (indicadores biométricos) capazes de auxiliar os psiquiatras a diagnosticá-los com maior exatidão.

Além disso, pacientes com esquizofrenia ou transtorno bipolar muitas vezes apresentam sintomas psicóticos comuns, como alucinações, delírios, hiperatividade e comportamento agressivo – o que pode comprometer a precisão do diagnóstico.

“O diagnóstico dos sintomas psicóticos é altamente subjetivo”, afirmou Copelli. “Por isso mesmo, a última versão do Manual Diagnóstico e Estatístico de Transtornos Mentais [publicado pela Associação Americana de Psiquiatria em 2013] foi muito atacada”, avaliou.

A fim de desenvolver um método quantitativo para avaliar sintomas psiquiátricos, os pesquisadores gravaram, com o consentimento dos envolvidos, os relatos dos sonhos de 60 pacientes voluntários, atendidos no ambulatório de psiquiatria de um hospital público em Natal (RN).

Alguns dos pacientes já tinham recebido o diagnóstico de esquizofrenia, outros de bipolaridade e os demais, que formaram o grupo de controle, não apresentavam sintomas de transtornos mentais.

Os relatos dos sonhos dos pacientes, feitos à psiquiatra Natália Bezerra Mota, doutoranda na URFN e primeira autora do estudo, foram transcritos.

As frases dos discursos dos pacientes foram transformadas por um software desenvolvido por pesquisadores do Instituto do Cérebro em grafos – estruturas matemáticas similares a diagramas nas quais cada palavra dita pelo paciente foi representada por um ponto ou nó, como o feito em uma linha de crochê.

Ao analisar os grafos dos relatos dos sonhos dos três grupos de pacientes os pesquisadores observaram que há diferenças muito claras entre eles.

O tamanho, em termos de quantidade de arestas ou links, e a conectividade (relação) entre os nós dos grafos dos pacientes diagnosticados com esquizofrenia, bipolaridade ou sem transtornos mentais apresentaram variações, afirmaram os pesquisadores.

“Os pacientes com esquizofrenia, por exemplo, fazem relatos que, quando representados por grafos, possuem menos ligações do que os demais grupos de pacientes”, disse Mota.

Diferenças de discursos

Segundo os pesquisadores, a diferenciação de pacientes a partir da análise dos grafos de relatos dos sonhos foi possível porque suas características de fala também são bastante diversificadas.

Os pacientes esquizofrênicos costumam falar de forma lacônica e com pouca digressão (desvio de assunto) – o que explica por que a conectividade e a quantidade de arestas dos grafos de seus relatos são menores em comparação às dos bipolares.

Por sua vez, pacientes com transtorno bipolar tendem a apresentar um sintoma oposto ao da digressão, chamado logorreia ou verborragia, falando atabalhoadamente frases sem sentido – chamado na Psiquiatria de “fuga de ideias”.

“Encontramos uma correlação importante dessas medidas feitas por meio das análises dos grafos com os sintomas negativos e cognitivos medidos por escalas psicométricas utilizadas na prática clínica da Psiquiatria”, afirmou Mota.

Ao transformar essas características marcantes de fala dos pacientes em grafos é possível dar origem a um classificador computacional capaz de auxiliar os psiquiatras no diagnóstico de transtornos mentais, indicou Copelli.

“Todas as ocorrências no discurso dos pacientes com transtornos mentais que no grafo têm um significado aparentemente geométrico podem ser quantificadas matematicamente e ajudar a classificar se um paciente é esquizofrênico ou bipolar, com uma taxa de sucesso comparável ou até mesmo melhor do que as escalas psiquiátricas subjetivas utilizadas para essa finalidade”, avaliou.

O objetivo dos pesquisadores é avaliar um maior número de pacientes e calibrar o algoritmo (sequência de comandos) do software desenvolvido para transformar os relatos dos sonhos em grafos que possam ser usados em larga escala na prática clínica de Psiquiatria.

Apesar de utilizada inicialmente para o diagnóstico de psicoses, a técnica poderá ser expandida para diversas outras finalidades, contou Mota.

“Ela poderá ser utilizada, por exemplo, para buscar mais informações sobre estrutura de linguagem aplicadas à análise de relatos de pessoas não apenas com sintomas psicóticos, mas também em diferentes situações de declínio cognitivo, como demência, ou em ascensão, como durante o aprendizado e o desenvolvimento da fala e escrita”, indicou a pesquisadora.

Papel dos sonhos

Os pesquisadores também desenvolveram e analisaram, durante o estudo, os grafos de relatos sobre atividades realizadas pelos pacientes voluntários na véspera do sonho.

Os grafos desses relatos do dia a dia, chamados de “relatos de vigília”, não foram tão indicativos do tipo de transtorno mental sofrido pelo paciente como outros, disse Copelli.

“Conseguimos distinguir esquizofrênicos dos demais grupos usando a análise dos grafos dos relatos de vigília, mas não conseguimos distinguir bem os bipolares do grupo de controle dessa forma”, contou.

Os pesquisadores ainda não sabem por que os grafos dos discursos sobre o sonho são mais informativos sobre psicose do que os grafos da vigília.

Algumas hipóteses esmiuçadas na pesquisa de doutorado de Mota estão relacionadas a mecanismos fisiológicos de formação de memória.

“Acreditamos que, por serem memórias mais transitórias, os sonhos podem ser mais demandantes cognitivamente e ter maior impacto afetivo do que as memórias relacionadas ao cotidiano, e isso pode tornar seus relatos mais complexos”, contou a pesquisadora.

“Outra hipótese é que o sonho está relacionado a um evento vivenciado exclusivamente por uma pessoa, sem ser compartilhado com outras, e por isso talvez seja mais complexo de ser explicado do que uma atividade relacionada ao cotidiano”, disse.

Para testar essas hipóteses, os pesquisadores pretendem ampliar a coleta de dados aplicando questionários em pacientes com registro de primeiro surto psicótico, com o objetivo de esclarecer se outros tipos de relatos, como de memórias antigas, podem se equiparar ao sonho em termos de informação psiquiátrica. Eles também querem verificar se podem usar o método para identificar sinais ou grupo de sintomas (pródromo) e acompanhar efeitos de medicações.

“Pretendemos investigar em laboratório, com eletroencefalografia de alta densidade e diversas técnicas de mensuração de distâncias semânticas e análise de estrutura de grafos, de que forma os estímulos recebidos imediatamente antes de dormir influenciam os relatos de sonhos produzidos ao despertar”, disse Sidarta Ribeiro, pesquisador do Instituto do Cérebro da UFRN.

“Estamos particularmente interessados nos efeitos distintos de imagens com valor afetivo”, afirmou Ribeiro, que também é pesquisador associado do Neuromat.

O artigo Graph analysis of dream reports is especially informative about psychosis (doi: 10.1038/srep03691), de Mota e outros, pode ser lido na revista Scientific Reports emwww.nature.com/srep/2014/140115/srep03691/full/srep03691.html.

Japanese Town: Half the survivors of mega-earthquake, tsunami, have PTSD symptoms (Science Daily)

Date: March 6, 2014

Source: Brigham Young University

Summary: A new study shows that more than half the survivors in one Japanese town exhibited ‘clinically concerning’ symptoms of PTSD following the country’s mega-earthquake and tsunami. Two-thirds of survivors also reported symptoms of depression. Having work to do has proven important in increasing resilience.

Though just two of Hirono’s 5,418 residents lost their lives in Japan’s mega-earthquake and tsunami, a new study shows that the survivors are struggling to keep their sanity.

One year after the quake, Brigham Young University professor Niwako Yamawaki and scholars from Saga University evaluated the mental health of 241 Hirono citizens. More than half of the people evaluated experienced “clinically concerning” symptoms of post-traumatic stress disorder. Two-thirds of the sample reported symptoms of depression.

Those rates exceed levels seen in the aftermath of other natural disasters, but what happened in Japan wasn’t just a natural disaster. Leaked radiation from nuclear power plants forced residents of Hirono to relocate to temporary housing far from home.

“This was the world’s fourth-biggest recorded earthquake, and also the tsunami and nuclear plant and losing their homes — boom boom boom boom within such a short time,” said Yamawaki, a psychology professor at BYU. “The prevalence one year after is still much higher than other studies of disasters that we found even though some time had passed.”

Yamawaki got the idea for this study while shoveling mud from a damaged Japanese home one month after the tsunami flooded coastal towns. She had just arrived for a previously scheduled fellowship at Saga University. During her off-time, she traveled to the affected area and volunteered in the clean-up effort. One seemingly stoic homeowner broke down in tears when Yamawaki and her husband thanked her for the chance to help.

“She said ‘This is the first time I have cried since the disaster happened,'” Yamawaki said. “She just said ‘Thank you. Thank you for letting me cry.'”

Back at Saga University, Yamawaki collaborated with Hiroko Kukihara to conduct a study on the mental health and resilience of survivors. Their report appears in the journal Psychiatry and Clinical Neurosciences.

Participants in the study lived in temporary housing provided by the Japanese government when Hirono was evacuated. With an average age of 58, the people are noticeably older than the populations of normal Japanese towns. Yamawaki suspects that young people were more likely to permanently relocate elsewhere in Japan following the disaster.

The researchers didn’t just measure the rates of mental illness; they also performed a statistical analysis to learn what fostered resilience among the survivors. Eating right, exercising regularly and going to work all promoted resilience and served as a buffer against mental illness.

“Having something to do after a disaster really gives a sense of normalcy, even volunteer work,” Yamawaki said.

As the researchers got to know survivors, they heard from so many that they missed seeing their former neighbors. The mass relocation outside the radiation zone broke up many neighborhood ties.

“Japanese are very collectivistic people and their identity is so intertwined with neighbors,” Yamawaki said. “Breaking up the community has so much impact on them.”

While it’s hard to fathom the scope of the devastation in the coastal region of Fukushima, most survivors believe something like this will happen again. If so, this new study provides a blueprint for how to help them put their lives back together again.

Journal Reference:

  1. Hiroko Kukihara, Niwako Yamawaki, Kumi Uchiyama, Shoichi Arai, Etsuo Horikawa. Trauma, depression, and resilience of earthquake/tsunami/nuclear disaster survivors of Hirono, Fukushima, Japan.Psychiatry and Clinical Neurosciences, 2014; DOI: 10.1111/pcn.12159

New research helps explain how social understanding is performed by the brain (Science Daily)

Date:

February 24, 2014

Source: Aarhus University

Summary: An important question has been answered about how social understanding is performed in the brain. The findings may help us to attain a better understanding of why people with autism and schizophrenia have difficulties with social interaction. Using magnetic stimulation to temporarily disrupt normal processing of the areas of the human brain involved in the production of actions of human participants, it is demonstrated that these areas are also involved in the understanding of actions. The study is the first to demonstrate a clear causal effect, whereas earlier studies primarily have looked at correlations, which are difficult to interpret.

A new study from Aarhus University, Denmark, helps us understand why people with autism and schizophrenia have difficulties with social interaction. Credit: © styleuneed / Fotolia

In a study to be published in Psychological Science, researchers from Aarhus University and the University of Copenhagen demonstrate that brain cells in what is called the mirror system help people make sense of the actions they see other people perform in everyday life.

Using magnetic stimulation to temporarily disrupt normal processing of the areas of the human brain involved in the production of actions of human participants, it is demonstrated that these areas are also involved in the understanding of actions. The study is the first to demonstrate a clear causal effect, whereas earlier studies primarily have looked at correlations, which are difficult to interpret.

One of the researchers, John Michael, explains the process: “There has been a great deal of hype about the mirror system, and now we have performed an experiment that finally provides clear and straightforward evidence that the mirror system serves to help people make sense of others’ actions,” says John Michael.

Understanding autism and schizophrenia

The study shows that there are areas of the brain that are involved in the production of actions. And the researchers found evidence that these areas contribute to understanding others’ actions. This means that the same areas are involved in producing actions and understanding others’ actions. This helps us in everyday life, but it also holds great potential when trying to understand why people with autism and schizophrenia have difficulties with social interaction.

“Attaining knowledge of the processes underlying social understanding in people in general is an important part of the process of attaining knowledge of the underlying causes of the difficulties that some people diagnosed with autism and schizophrenia experience in sustaining social understanding. But it is important to emphasize that this is just one piece of the puzzle.”

“The findings may be interesting to therapists and psychiatrists who work with patients with schizophrenia or autism, or even to educational researchers,” adds John Michael.

Facts about the empirical basis

The participants (20 adults) came to the lab three times. They were given brain scans on the first visit. On the second and third, they received stimulation to their motor system and then performed a typical psychological task in which they watched brief videos of actors pantomiming actions (about 250 videos each time). After each video they had to choose a picture of an object that matched the pantomimed video. For example, a hammer was the correct answer for the video of an actor pretending to hammer.

This task was intended to gauge their understanding of the observed actions. The researchers found that the stimulation interfered with their performance of this task.

Innovative method

The researchers used an innovative technique for magnetically stimulating highly specific brain areas in order to temporarily disrupt normal processing in those areas. The reason for using this technique (called continuous theta-burst stimulation) in general is that it makes it possible to determine which brain areas perform which functions. For example, if you stimulate (and thus temporarily impair) area A, and the participants subsequently have difficulty with some specific task (task T), then you can infer that area A usually performs task T. The effect goes away after 20 minutes, so this is a harmless and widely applicable way to identify which tasks are performed by which areas.

With continuous theta-burst stimulation, you can actually determine that the activation of A contributes as a cause to people performing T. This method thus promises to be of great use to neuroscientists in the coming years.

Journal Reference:

  1. J. Michael, K. Sandberg, J. Skewes, T. Wolf, J. Blicher, M. Overgaard, C. D. Frith.Continuous Theta-Burst Stimulation Demonstrates a Causal Role of Premotor Homunculus in Action UnderstandingPsychological Science, 2014; DOI: 10.1177/0956797613520608

Cientistas identificam gene que relaciona estrutura cerebral à inteligência (O Globo)

JC e-mail 4892, de 11 de fevereiro de 2014

Descoberta pode ter implicações importantes para a compreensão de transtornos psiquiátricos como esquizofrenia e autismo

Cientistas do King’s College London identificaram, pela primeira vez, um gene que relaciona a espessura da massa cinzenta do cérebro à inteligência. O estudo foi publicado nesta terça-feira na revista “Molecular Psychiatry” e pode ajudar a entender os mecanismos biológicos por trás de determinados danos intelectuais.

Até agora já se sabia que a massa cinzenta tinha um papel importante para a memória, atenção, pensamento, linguagem e consciência. Estudos anteriores também já mostravam que a espessura do córtex cerebral tinha a ver com a habilidade intelectual, mas nenhum gene tinha sido identificado.

Um time internacional de cientistas, liderado pelo King´s College, analisou amostras de DNA e exames de ressonância magnética por imagem de 1.583 adolescentes saudáveis de 14 anos, que também se submeteram a uma série de testes para determinar inteligência verbal e não verbal.

– Queríamos descobrir como diferenças estruturais no cérebro tinham a ver com diferenças na habilidade intelectual. Identificamos uma variação genética relacionada à plasticidade sináptica, de como os neurônios se comunicam – explica Sylvane Desrivières, principal autora do estudo, pelo Instituto de Psiquiatria do King’s College London. – Isto pode nos ajudar a entender o que acontece em nível neuronal com certas formas de comprometimento intelectual, onde a habilidade de comunicação dos neurônios é, de alguma forma, comprometida.

Ela acrescenta que é importante apontar que a inteligência é influenciada por muitos fatores genéticos e ambientais. O gene que identificamos só explica uma pequena proporção das diferenças nas habilidades intelectuais e não é, de forma alguma, “o gene da inteligência”.

Os pesquisadores observaram 54 mil possíveis variações envolvidas no desenvolvimento cerebral. Em média, adolescentes com uma variante genética particular tinham um córtex mais fino no hemisfério cerebral esquerdo, particularmente nos lobos frontal e temporal, e executavam bem testes de capacidade intelectual. A variação genética afeta a expressão do gene NPTN, que codifica uma proteína que atua nas sinapses neuronais e, portanto, afeta a forma como as células do cérebro se comunicam.

Para confirmar as suas conclusões, os pesquisadores estudaram o gene NPTN em células de camundongo e do cérebro humano. Os pesquisadores verificaram que o gene NPTN tinha uma atividade diferente nos hemisférios esquerdo e direito do cérebro, o que pode fazer com que o hemisfério esquerdo seja mais sensível aos efeitos das mutações NPTN. Os resultados sugerem que algumas diferenças na capacidade intelectual podem resultar da diminuição da função do gene NPTN em determinadas regiões do hemisfério esquerdo do cérebro.

A variação genética identificada neste estudo representa apenas uma estimativa de 0,5% da variação total em inteligência. No entanto, as descobertas podem ter implicações importantes para a compreensão dos mecanismos biológicos subjacentes de vários transtornos psiquiátricos, como esquizofrenia e autismo, nas quais a capacidade cognitiva é uma característica fundamental da doença.

http://oglobo.globo.com/ciencia/cientistas-identificam-gene-que-relaciona-estrutura-cerebral-inteligencia-11563313#ixzz2t1amCUSy

Climate change rattles mental health of Inuit in Labrador (CBC)

‘Grief, mourning, anger, frustration’ over environmental changes

CBC News Posted: Jan 10, 2014 5:22 PM ET Last Updated: Jan 10, 2014 5:58 PM ET

This photo supplied by researcher Ashlee Cunsolo Willox shows cabins in Double Mer just outside of Rigolet in Nunatsiavut, Labrador. Climate change has caused ice to break up or not form at all, making it difficult for Inuit populations to access the cabins they use as a base for hunting and trapping.This photo supplied by researcher Ashlee Cunsolo Willox shows cabins in Double Mer just outside of Rigolet in Nunatsiavut, Labrador. Climate change has caused ice to break up or not form at all, making it difficult for Inuit populations to access the cabins they use as a base for hunting and trapping. (Couresty My Word: Storytelling & Digital Media Lab)

Researchers studying the mental health and well-being of Inuit populations in coastal Labrador say rising temperatures are having damaging psychological effects on people in traditional communities.

‘Many people said they also felt very depressed about not being able to get out there on the land’– Ashlee Cunsolo Willox, researcher for Inuit Mental Health Adaptation to Climate Change project

In an interview airing on CBC Radio’s Quirks & Quarks on Saturday, Dr. Ashlee Cunsolo Willox, who has been working in partnership with Inuit communities in Nunatsiavut since 2009, describes intense feelings of isolation among people there following temperature changes that have caused disruptions in how the ice and snow are interacting.

“The North Labrador Coast is one of the fastest-changing and fastest-warming areas anywhere in the world,” she told host Bob McDonald. “In particular, rising temperatures have led to a real decrease in sea ice.”

There were strong emotional reactions to that loss among all 120 people interviewed by researchers behind the community-based Inuit Mental Health Adaptation to Climate Change project.

The feelings included a sense of grief, mourning, anger, frustration, sadness, and many people said they also felt very depressed about not being able to get out there on the land,” Cunsolo Willox said.

Traditional routes no longer safe

Wildlife and vegetation have changed, with caribou and moose moving further north, and traditional berries have been failing to grow when they have in the past.

“In some cases, they’re getting less snow than before, which makes it very difficult to travel inland by Ski-Doo or by dog team,” added Cunsolo Willox, who holds the Canada Research Chair in Determinants of Healthy Communities at Cape Breton University.

She and her colleagues interviewed people in the communities of Nain, Hopedale, Postville, Makkovik and Rigolet, and their work is run in partnership with the Rigolet Inuit Community Government. The majority of those interviewed are Inuit.

“People describe themselves as land people, as people of the snow and the ice, and would say that going out on the land and hunting and trapping and fishing [is] just as much part of their life as breathing,” Cunsolo Willox said.

The full interview will be broadcast on Saturday’s program at noon.

LSD and Other Psychedelics Not Linked With Mental Health Problems (Science Daily)

Aug. 19, 2013 — The use of LSD, magic mushrooms, or peyote does not increase a person’s risk of developing mental health problems, according to an analysis of information from more than 130,000 randomly chosen people, including 22,000 people who had used psychedelics at least once.

Researchers found no link between the use of psychedelic drugs and a range of mental health problems. Instead they found some significant associations between the use of psychedelic drugs and fewer mental health problems. (Credit: © Zerbor / Fotolia)

Researcher Teri Krebs and clinical psychologist Pål-Ørjan Johansen, from the Norwegian University of Science and Technology’s (NTNU) Department of Neuroscience, used data from a US national health survey to see what association there was, if any, between psychedelic drug use and mental health problems.

The authors found no link between the use of psychedelic drugs and a range of mental health problems. Instead they found some significant associations between the use of psychedelic drugs and fewer mental health problems.

The results are published in the journal PLOS ONE and are freely available online after 19 August.

Symptoms and mental health treatment considered

The researchers relied on data from the 2001-2004 National Survey on Drug Use and Health, in which participants were asked about mental health treatment and symptoms of a variety of mental health conditions over the past year. The specific symptoms examined were general psychological distress, anxiety disorders, mood disorders, and psychosis.

Armed with this information, Krebs and Johansen were able to examine if there were any associations between psychedelic use and general or specific mental health problems. They found none.

“After adjusting for other risk factors, lifetime use of LSD, psilocybin, mescaline or peyote, or past year use of LSD was not associated with a higher rate of mental health problems or receiving mental health treatment,” says Johansen.

Could psychedelics be healthy for you?

The researchers found that lifetime use of psilocybin or mescaline and past year use of LSD were associated with lower rates of serious psychological distress. Lifetime use of LSD was also significantly associated with a lower rate of outpatient mental health treatment and psychiatric medicine prescription.

The design of the study makes it impossible to determine exactly why the researchers found what they found.

“We cannot exclude the possibility that use of psychedelics might have a negative effect on mental health for some individuals or groups, perhaps counterbalanced at a population level by a positive effect on mental health in others,” they wrote.

Nevertheless, “recent clinical trials have also failed to find any evidence of any lasting harmful effects of psychedelics,” the researchers said, which supports the robustness of the PLOS ONE findings.

In fact, says Krebs, “many people report deeply meaningful experiences and lasting beneficial effects from using psychedelics.”

“Other studies have found no evidence of health or social problems among people who had used psychedelics hundreds of times in legally-protected religious ceremonies,” adds Johansen.

What’s the bottom line on psychedelic use?

Psychedelics are different than most other recreational drugs. Experts agree that psychedelics do not cause addiction or compulsive use, and they are not known to harm the brain.

When evaluating psychedelics, as with any activity, it is important to take an objective view of all the evidence and avoid being biased by anecdotal stories either of harm or benefit, the researchers say.

“Everything has some potential for negative effects, but psychedelic use is overall considered to pose a very low risk to the individual and to society,” Johansen says, “Psychedelics can elicit temporary feelings of anxiety and confusion, but accidents leading to serious injury are extremely rare.”

“Early speculation that psychedelics might lead to mental health problems was based on a small number of case reports and did not take into account either the widespread use of psychedelics or the not infrequent rate of mental health problems in the general population,” Krebs explains.

“Over the past 50 years tens of millions of people have used psychedelics and there just is not much evidence of long-term problems,” she concludes.

Both researchers were supported by the Research Council of Norway.

Journal Reference:

  1. Teri S. Krebs, Pål-Ørjan Johansen. Psychedelics and Mental Health: A Population StudyPLoS ONE, 2013; 8 (8): e63972 DOI: 10.1371/journal.pone.0063972

Doença de Alzheimer revertida pela primeira vez (Ciência Hoje)

Investigadores canadianos usaram técnica de estimulação cerebral profunda

2013-06-28

Foram aplicados pequenos impulsos eléctricos perto do fórnix

Foram aplicados pequenos impulsos eléctricos perto do fórnix

A doença de Alzheimer foi revertida pela primeira vez. Uma equipa de investigadores canadianos, da Universidade de Toronto, liderada por Andres Lozano, usou uma técnica de estimulação cerebral profunda, directamente no cérebro de seis pacientes, conseguindo travar a doença há agora já mais de um ano.

Em dois destes pacientes, a deterioração da área do cérebro associada à memória não só parou de encolher como voltou a crescer. Nos outros quatro, o processo de deterioração parou por completo.

Nos portadores de Alzheimer, a região do hipocampo é uma das primeiras a encolher. O centro de memória funciona nessa área cerebral, convertendo as memórias de curto prazo em memórias de longo prazo. Sendo assim, a degradação do hipocampo revela alguns dos primeiros sintomas da doença, como a perda de memória e a desorientação.Imagens cerebrais revelam que o lobo temporal, onde está o hipocampo e o cingulado posterior, usam menos glicose do que o normal, sugerindo que estão desligadas e ambas têm um papel importante na memória.

Para tentar reverter esse quadro degenerativo, Lozano e sua equipa recorreram à estimulação cerebral – enviar impulsos eléctricos para o cérebro através de eléctrodos implantados.

O grupo instalou os dispositivos perto do fórnix – um aglomerado de neurónios que enviam sinais para o hipocampo – dos pacientes diagnosticados com Alzheimer há pelo menos um ano. Os investigadores aplicaram pequenos impulsos eléctricos 130 vezes por segundo.

Testes realizados um ano depois mostram que a redução da glicose foi revertida nas seis pessoas. Esta descoberta pode levar a novos caminhos para tratamentos de Alzheimer, uma vez que é a primeira vez que foi revertida.

Os cientistas admitem, no entanto, que a técnica ainda não é conclusiva e que necessita de mais investigação. A equipa vai agora iniciar um novo teste que envolve 50 pessoas.

São Paulo é a cidade com maior índice de perturbações mentais no mundo (Revista Fórum)

Publicado em 10 de julho de 2013 às 6:05 pm

Segundo pesquisadores, elevada incidência de transtornos é consequência da alta urbanização associada com privações sociais

Da Redação

São Paulo representou o Brasil no estudo (Foto: Andre Deak / Flickr)

O relatório São Paulo Megacity Mental Health Surve mostrou que a região metropolitana de São Paulo possui a maior incidência de perturbações mentais no mundo. O estudo feito pela OMS (Organização Mundial de Saúde) revela que 29,6% dos paulistanos, e moradores da região metropolitana, sofrem de algum tipo de perturbação mental. O levantamento pesquisou 24 grandes cidades em diferentes países.

Entre os problemas mais comuns apontados no estudo estão a ansiedade, mudanças comportamentais e abuso de substâncias químicas. Dentre eles, a ansiedade é o mais comum, afetando 19,9% das 5.037 pessoas pesquisadas.

Depois de São Paulo, cidade que representa o Brasil no estudo, os EUA aparece em segundo lugar, com aproximadamente 25% de incidência de perturbações mentais. A cidade norte-americana utilizada no levantamento da OMS não foi revelada.

Além de ser a cidade com maior incidência de perturbações mentais, São Paulo também aparece na liderança do ranking de casos graves, com 10% da população afetada. Neste ponto, a capital paulista também é seguida pelos EUA, que possui uma incidência de casos graves de 5,7%

De acordo com os pesquisadores responsáveis pelo estudo, a alta incidência de perturbações mentais é causada pela alta urbanização associada com privações sociais. Segundo eles, os grupos mais vulneráveis são homens migrantes e mulheres que residem em regiões de alta vulnerabilidade social.

Em São Paulo, a pesquisa da OMS foi financiada pela Fapesp (Fundação de Amparo à Pesquisa do Estado de São Paulo), sob a coordenação da Profa. Laura Helena Andrade, professora do Departamento e Instituto de Psiquiatria da Faculdade de Medicina da USP, e da Profa. Maria Carmen Viana, professora do Departamento de Medicina Social da Universidade Federal do Espírito Santo.

Com informações do Jornal de Notícias.

Robo-Pets May Contribute to Quality of Life for Those With Dementia (Science Daily)

June 24, 2013 — Robotic animals can help to improve the quality of life for people with dementia, according to new research.

Professor Glenda Cook with PARO seal Glenda Cook with PARO seal. (Credit: Image courtesy of Northumbria University)

A study has found that interacting with a therapeutic robot companion made people with mid- to late-stage dementia less anxious and also had a positive influence on their quality of life.

The pilot study, a collaboration led by Professor Wendy Moyle from Griffith University, Australia and involving Northumbria University’s Professor Glenda Cook and researchers from institutions in Germany, investigated the effect of interacting with PARO — a robotic harp seal — compared with participation in a reading group. The study built on Professor Cook’s previous ethnographic work carried out in care homes in North East England.

PARO is fitted with artificial intelligence software and tactile sensors that allow it to respond to touch and sound. It can show emotions such as surprise, happiness and anger, can learn its own name and learns to respond to words that its owner uses frequently.

Eighteen participants, living in a residential aged care facility in Queensland, Australia, took part in activities with PARO for five weeks and also participated in a control reading group activity for the same period. Following both trial periods the impact was assessed, using recognised clinical dementia measurements, for how the activities had influenced the participants’ quality of life, tendency to wander, level of apathy, levels of depression and anxiety ratings.

The findings indicated that the robots had a positive, clinically meaningful influence on quality of life, increased levels of pleasure and also reduced displays of anxiety.

Research has already shown that interaction with animals can have a beneficial effect on older adults, increasing their social behaviour and verbal interaction and decreasing feelings of loneliness. However, the presence of animals in residential care home settings can place residents at risk of infection or injury and create additional duties for nursing staff.

This latest study suggests that PARO companions elicit a similar response and could potentially be used in residential settings to help reduce some of the symptoms — such as agitation, aggression, isolation and loneliness — of dementia.

Prof Cook, Professor of Nursing at Northumbria University, said: “Our study provides important preliminary support for the idea that robots may present a supplement to activities currently in use and could enhance the life of older adults as therapeutic companions and, in particular, for those with moderate or severe cognitive impairment.

“There is a need for further research, with a larger sample size, and an argument for investing in interventions such as PARO robots which may reduce dementia-related behaviours that make the provision of care challenging as well as costly due to increased use of staff resources and pharmaceutical treatment.”

The researchers of the pilot study have identified the need to undertake a larger trial in order to increase the data available. Future studies will also compare the effect of the robot companions with live animals.

Journal Reference:

  1. Wendy Moyle, Marie Cooke, Elizabeth Beattie, Cindy Jones, Barbara Klein, Glenda Cook, Chrystal Gray. Exploring the Effect of Companion Robots on Emotional Expression in Older Adults with Dementia: A Pilot Randomized Controlled TrialJournal of Gerontological Nursing, 2013; 39 (5): 46 DOI: 10.3928/00989134-20130313-03

Mice Give New Clues to Origins of Obsessive-Compulsive Disorder (Science Daily)

June 10, 2013 — Columbia Psychiatry researchers have identified what they think may be a mechanism underlying the development of compulsive behaviors. The finding suggests possible approaches to treating or preventing certain characteristics of OCD.

Using a new technology in a mouse model, the researchers found that repeated stimulation of specific circuits linking the brain’s cortex and striatum produces progressive repetitive behavior. (Credit: Image courtesy of Columbia University Medical Center)

OCD consists of obsessions, which are recurrent intrusive thoughts, and compulsions, which are repetitive behaviors that patients perform to reduce the severe anxiety associated with the obsessions. The disorder affects 2-3 percent of people worldwide and is an important cause of illness-related disability, according to the World Health Organization.

Using a new technology in a mouse model, the researchers found that repeated stimulation of specific circuits linking the brain’s cortex and striatum produces progressive repetitive behavior. By targeting this region, it may be possible to stop abnormal circuit changes before they become pathological behaviors in people at risk for obsessive-compulsive disorder (OCD). The study, which was led by Susanne Ahmari, MD, PhD, assistant professor of clinical psychiatry at Columbia Psychiatry and the New York State Psychiatric Institute, was published in the June 7 issue of Science.

While the obsessions and compulsions that are the hallmarks of OCD are thought to be centered in the cortex, which controls thoughts, and the striatum, which controls movements, little is known about how abnormalities in these brain regions lead to compulsive behaviors in patients.

To simulate the increased activity that takes place in the brains of OCD patients, Dr. Ahmari and her colleagues used a new technology called optogenetics, in which light-activated ion channels are expressed in subsets of neurons in mice, and neural circuits are then selectively activated using light delivered through fiberoptic probes.

“What we found was really surprising,” said Dr. Ahmari. “That activation of cortico-striatal circuits did not lead directly to repetitive behaviors in the mice. But if we repeatedly stimulated for multiple days in a row for only five minutes a day, we saw a progressive development of repetitive behaviors — in this case, repetitive grooming behavior — that persisted up to two weeks after the stimulation was stopped.”

She added, “And not only that, when we treated the mice with fluoxetine, one of the most common medications used for OCD, their behavior went back to normal.” The current study, as well as others currently being performed by Dr. Ahmari and her team, may ultimately provide clues for new treatment targets in terms of both novel drug development and direct stimulation techniques, including deep brain stimulation (DBS).

The study was supported by grants from NIMH (K08MH087718; K24 MH091555), the Louis V. Gerstner, Jr. Scholars Program, the Irving Institute for Clinical and Translational Research, the Gray Matters Foundation, the Leon Levy Foundation, and a NARSAD Young Investigator Award.

Journal Reference:

  1. S. E. Ahmari, T. Spellman, N. L. Douglass, M. A. Kheirbek, H. B. Simpson, K. Deisseroth, J. A. Gordon, R. Hen.Repeated Cortico-Striatal Stimulation Generates Persistent OCD-Like BehaviorScience, 2013; 340 (6137): 1234 DOI: 10.1126/science.1234733

‘Belief in Science’ Increases in Stressful Situations (Science Daily)

June 5, 2013 — A faith in the explanatory and revealing power of science increases in the face of stress or anxiety, a study by Oxford University psychologists suggests.

The researchers argue that a ‘belief in science’ may help non-religious people deal with adversity by offering comfort and reassurance, as has been reported previously for religious belief.

‘We found that being in a more stressful or anxiety-inducing situation increased participants’ “belief in science”,’ says Dr Miguel Farias, who led the study in the Department of Experimental Psychology at Oxford University. ‘This belief in science we looked at says nothing of the legitimacy of science itself. Rather we were interested in the values individuals hold about science.’

He explains: ‘While most people accept science as a reliable source of knowledge about the world, some may hold science as a superior method for gathering knowledge, the only way to explain the world, or as having some unique and fundamental value in itself. This is a view of science that some atheists endorse.’

As well as stressing that investigating a belief in science carries no judgement on the value of science as a method, the researchers point out that drawing a parallel between the psychological benefits of religious faith and belief in science doesn’t necessarily mean that scientific practice and religion are also similar in their basis.

Instead, the researchers suggest that their findings may highlight a basic human motivation to believe.

‘It’s not just believing in God that is important for gaining these psychological benefits, it is belief in general,’ says Dr Farias. ‘It may be that we as humans are just prone to have belief, and even atheists will hold non-supernatural beliefs that are reassuring and comforting.’

The researchers report their findings in the Journal of Experimental Social Psychology.

There is evidence from previous studies that suggests religious belief helps individuals cope with stress and anxiety. The Oxford University group wondered if this was specific to religious belief, or was a more general function of holding belief.

The researchers developed a scale measuring a ‘belief in science’ in which people are asked how much they agree or disagree with a series of 10 statements, including:

  • ‘Science tells us everything there is to know about what reality consists of.’
  • ‘All the tasks human beings face are soluble by science.’
  • ‘The scientific method is the only reliable path to knowledge.’

This scale was used first with a group of 100 rowers, of whom 52 were about to compete in a rowing regatta and the other 48 were about to do a normal training session. Those about to row in competition would be expected to be at a higher stress level.

Those who were competing in the regatta returned scores showing greater belief in science than those in the training group. The difference was statistically significant.

Both groups of rowers reported a low degree of commitment to religion and as expected, those rowers about to compete did say they were experiencing more stress.

In a second experiment, a different set of 60 people were randomly assigned to two groups. One group was asked to write about the feelings aroused by thinking about their own death, while the other was asked to write about dental pain. A number of studies have used an exercise on thinking about your own death to induce a certain amount of ‘existential anxiety’.

The participants who had been asked to think about their own death scored higher in the belief in science scale.

The researchers say their findings are consistent with the idea that belief in science increases when secular individuals are placed in threatening situations. They go on to suggest that a belief in science may help non-religious people deal with adverse conditions.

Dr Farias acknowledges however that they have only shown this in one direction — that stress or anxiety increases belief in science. They suggest other experiments should be done to examine whether affirming a belief in science might then reduce subsequent experience of stress or anxiety.

Journal Reference:

  1. Miguel Farias, Anna-Kaisa Newheiser, Guy Kahane, Zoe de Toledo. Scientific faith: Belief in science increases in the face of stress and existential anxietyJournal of Experimental Social Psychology, 2013; DOI:10.1016/j.jesp.2013.05.008

Depression Linked to Telomere Enzyme, Aging, Chronic Disease (Science Daily)

May 23, 2013 — The first symptoms of major depression may be behavioral, but the common mental illness is based in biology — and not limited to the brain. In recent years some studies have linked major, long-term depression with life-threatening chronic disease and with earlier death, even after lifestyle risk factors have been taken into account.

The first symptoms of major depression may be behavioral, but the common mental illness is based in biology — and not limited to the brain. In recent years some studies have linked major, long-term depression with life-threatening chronic disease and with earlier death, even after lifestyle risk factors have been taken into account. (Credit: © diego cervo / Fotolia)

Now a research team led by Owen Wolkowitz, MD, professor of psychiatry at UC San Francisco, has found that within cells of the immune system, activity of an enzyme called telomerase is greater, on average, in untreated individuals with major depression. The preliminary findings from his latest, ongoing study will be reported today at the annual meeting of the American Psychiatric Association in San Francisco.

Telomerase is an enzyme that lengthens protective end caps on the chromosomes’ DNA, called telomeres. Shortened telomeres have been associated with earlier death and with chronic diseases in population studies.

The heightened telomerase activity in untreated major depression might represent the body’s attempt to fight back against the progression of disease, in order to prevent biological damage in long-depressed individuals, Wolkowitz said.

The researchers made another discovery that may suggest a protective role for telomerase. Using magnetic resonance imaging (MRI), they found that, in untreated, depressed study participants, the size of the hippocampus, a brain structure that is critical for learning and memory, was associated with the amount of telomerase activity measured in the white blood cells. Such an association at a single point in time cannot be used to conclude that there is a cause-and-effect relationship with telomerase helping to protect the hippocampus, but it is plausible, Wolkowitz said.

Remarkably, the researchers also found that the enzyme’s activity went up when some patients began taking an antidepressant. In fact, depressed participants with lower telomerase activity at baseline — as well as those in whom enzyme activity increased the most with treatment — were the most likely to become less depressed with treatment.

“Our results are consistent with the beneficial effect of telomerase when it is boosted in animal studies, where it has been associated with the growth of new nerve cells in the hippocampus and with antidepressant-like effects, evidenced by increased exploratory behavior,” Wolkowitz said. Wolkowitz cautions that his new findings are preliminary due to the small size of the study and must be confirmed through further research.

The researchers also measured telomere length in the same immune cells. Only very chronically depressed individuals showed telomere shortening, Wolkowitz said.

“The longer people had been depressed, the shorter their telomeres were,” he said. “Shortened telomere length has been previously demonstrated in major depression in most, but not all, studies that have examined it. The duration of depression may be a critical factor.”

The 20 depressed participants enrolled in the study had been untreated for at least six weeks and had an average lifetime duration of depression of about 13 years. After baseline evaluation and laboratory measures, 16 of the depressed participants were treated with sertraline, a member of the most popular class of anti-depressants, the serotonin-selective-reuptake-inhibitors (SSRIs), and then evaluated again after eight weeks. There were 20 healthy participants who served as controls.

The ongoing study still is accepting depressed participants who are not now taking antidepressants. Wolkowitz’s team also studies chronic inflammation and the biochemical phenomenon of oxidative stress, which he said have often been reported in major depression. Wolkowitz is exploring the hypothesis that inflammation and oxidative stress play a role in telomere shortening and accelerated aging in depression.

“New insights into the mechanisms of these processes may well lead to new treatments — both pharmacological and behavioral — that will be distinctly different from the current generation of drugs prescribed to treat depression,” he said. “Additional studies might lead to simple blood tests that can measure accelerated immune-cell aging.”

Wolkowitz’s research is funded by the National Institutes of Health. He is on the scientific advisory board of Telome Health, Inc., a private biotechnology company.

Story Source:

The above story is reprinted from materials provided byUniversity of California, San Francisco (UCSF). The original article was written by Jeffrey Norris.

Schizophrenia Symptoms Eliminated in Animal Model (Science Daily)

May 22, 2013 — Overexpression of a gene associated with schizophrenia causes classic symptoms of the disorder that are reversed when gene expression returns to normal, scientists report. 

Overexpression of a gene associated with schizophrenia causes classic symptoms of the disorder that are reversed when gene expression returns to normal, scientists report. Pictured are (left to right) Drs. Lin Mei, Dongmin Yin and Yongjun Chen, Medical College of Georgia at Georgia Regents University. (Credit: Phil Jones, Georgia Regents University Photographer)

They genetically engineered mice so they could turn up levels of neuregulin-1 to mimic high levels found in some patients then return levels to normal, said Dr. Lin Mei, Director of the Institute of Molecular Medicine and Genetics at the Medical College of Georgia at Georgia Regents University.

They found that when elevated, mice were hyperactive, couldn’t remember what they had just learned and couldn’t ignore distracting background or white noise. When they returned neuregulin-1 levels to normal in adult mice, the schizophrenia-like symptoms went away, said Mei, corresponding author of the study in the journal Neuron.

While schizophrenia is generally considered a developmental disease that surfaces in early adulthood, Mei and his colleagues found that even when they kept neuregulin-1 levels normal until adulthood, mice still exhibited schizophrenia-like symptoms once higher levels were expressed. Without intervention, they developed symptoms at about the same age humans do.

“This shows that high levels of neuregulin-1 are a cause of schizophrenia, at least in mice, because when you turn them down, the behavior deficit disappears,” Mei said. “Our data certainly suggests that we can treat this cause by bringing down excessive levels of neuregulin-1 or blocking its pathologic effects.”

Schizophrenia is a spectrum disorder with multiple causes — most of which are unknown — that tends to run in families, and high neuregulin-1 levels have been found in only a minority of patients. To reduce neuregulin-1 levels in those individuals likely would require development of small molecules that could, for example, block the gene’s signaling pathways, Mei said. Current therapies treat symptoms and generally focus on reducing the activity of two neurotransmitters since the bottom line is excessive communication between neurons.

The good news is it’s relatively easy to measure neuregulin-1 since blood levels appear to correlate well with brain levels. To genetically alter the mice, they put a copy of the neuregulin-1 gene into mouse DNA then, to make sure they could control the levels, they put in front of the DNA a binding protein for doxycycline, a stable analogue for the antibiotic tetracycline, which is infamous for staining the teeth of fetuses and babies.

The mice are born expressing high levels of neuregulin-1 and giving the antibiotic restores normal levels. “If you don’t feed the mice tetracycline, the neuregulin-1 levels are always high,” said Mei, noting that endogenous levels of the gene are not affected. High-levels of neuregulin-1 appear to activate the kinase LIMK1, impairing release of the neurotransmitter glutamate and normal behavior. The LIMK1 connection identifies another target for intervention, Mei said.

Neuregulin-1 is essential for heart development as well as formation of myelin, the insulation around nerves. It’s among about 100 schizophrenia-associated genes identified through genome-wide association studies and has remained a consistent susceptibility gene using numerous other methods for examining the genetics of the disease. It’s also implicated in cancer.

Mei and his colleagues were the first to show neuregulin-1’s positive impact in the developed brain, reporting in Neuron in 2007 that it and its receptor ErbB4 help maintain a healthy balance of excitement and inhibition by releasing GABA, a major inhibitory neurotransmitter, at the sight of inhibitory synapses, the communication paths between neurons. Years before, they showed the genes were also at excitatory synapses, where they also could quash activation. In 2009, the MCG researchers provided additional evidence of the role of neuregulin-1 in schizophrenia by selectively deleting the gene for its receptor, ErbB4 and creating another symptomatic mouse.

Schizophrenia affects about 1 percent of the population, causing hallucinations, depression and impaired thinking and social behavior. Babies born to mothers who develop a severe infection, such as influenza or pneumonia, during pregnancy have a significantly increased risk of schizophrenia.

Journal Reference:

  1. Dong-Min Yin, Yong-Jun Chen, Yi-Sheng Lu, Jonathan C. Bean, Anupama Sathyamurthy, Chengyong Shen, Xihui Liu, Thiri W. Lin, Clifford A. Smith, Wen-Cheng Xiong, Lin Mei.Reversal of Behavioral Deficits and Synaptic Dysfunction in Mice Overexpressing Neuregulin 1.Neuron, 2013; 78 (4): 644 DOI:10.1016/j.neuron.2013.03.028

Nos últimos 150 anos, já tentaram de tudo para a ‘cura gay’, diz livro (Folha de S.Paulo)

14/05/2013 – 16h32

da Livraria da Folha

A tentativa de transformar homossexuais em héteros usando métodos “científicos” já tem mais de 150 anos. A medicina, segundo os pesquisadores James Naylor Green e Ronaldo Polito, já tentou de tudo para “curá-los”.

“Confinamento, choques elétricos, medicação pesada, tratamento psicológico ou psiquiátrico, psicanálise individual, de grupo e familiar, camisa de força, transplante de testículos, eis aí algumas das “técnicas” de intervenção no corpo e na mente dos homens que preferem se relacionar afetiva e sexualmente com outros homens”, contam em “Frescos Trópicos”.

O título faz parte da coleção “Baú de Histórias”, coordenada pela historiadora Mary Del Priore, autora “Histórias Íntimas”“Ancestrais: Uma Introdução à História da África Atlântica”“A Família no Brasil Colonial”“500 Anos Brasil: Histórias e Reflexões“Festas e Utopias no Brasil Colonial” e“Matar para Não Morrer” e do recém-lançado “O Castelo de Papel”.

No livro, os autores examinam o período entre as décadas de 1870 e 1980, fundamentados em informações publicadas nessa época. Abaixo, leia trecho de “Frescos Trópicos”.

 

Acompanha o surgimento lento de uma consciência sobre a homossexualidade “Pode-se dizer que a medicina, nos últimos 150 anos, já tentou ou propôs de tudo para a “cura” dos homossexuais. Confinamento, choques elétricos, medicação pesada, tratamento psicológico ou psiquiátrico, psicanálise individual, de grupo e familiar, camisa de força, transplante de testículos, eis aí algumas das “técnicas” de intervenção no corpo e na mente dos homens que preferem se relacionar afetiva e sexualmente com outros homens.

Entre inúmeros exemplos do passado, citemos Pires de Almeira, em “Homossexualismo”, de 1906, que propõe um tratamento específico para os invertidos. Mas, primeiro, vamos entender o que ele chama de “invertido”: “é aquele que, de nascença, é já invertivo, e que, em toda a associação sexual, representa o papel de macho: é, pois, um macho mais macho, se se trata de um homem”. “Invertidos”, portanto, nascem homossexuais, diferentemente dos “pervertidos” que, segundo o autor, “depois de terem sido já sexuais normais, se tornaram invertidos por qualquer motivo”.

Para Pires de Almeida, o tratamento dos “pervertidos” é somente um pouco mais simples do que dos “invertidos”. Para estes ele recomenda, entre outros procedimentos:

“O invertido deveria ser acompanhado desde a infância, vigiado por uma espécie de tutor que, à feição de um aparelho ortopédico moral, fosse-lhe obstáculo ao desvio, trabalhando pertinentemente para que a consolidação se efetue em absoluto. (…)

Antes de tudo, devemos lembrar que tais desregramentos são puramente moléstias mentais; e, por isso, aconselharei, quando não tenhamos acompanhando o indivíduo desde a infância, e hajamos iniciado o tratamento em idade tardia, medicá-lo pela estética sugestiva; isto é, por meio do magnetismo e da sugestão combinados: bem orientar-lhe o espírito, dirigindo sua atenção para a beleza das formas femininas, cercá-lo de modelos célebres em pintura, na estatuária principalmente, e obrigá-lo à leitura de obras românticas em que tais belezas despertem as paixões tumultuosas. Facilitar-se-lhe-á o encontro com mulheres plasticamente sensuais, fáceis às carícias, graciosas, faceiras; não se hesitará até diante de certos subterfúrgios a princípio, tal como, por exemplo, o de provocar o coito do invertido com mulheres vestidas de homem; ou mesmo obrigá-lo a pernoitar com mulheres completamente nuas, ainda que não as goze.

Se, porém, existe, da parte do doente, repulsão invencível para as sociedades ambíguas, recorrer-se-á à convivência em outro meio: mulheres atraentes, sim, porém puras, puríssimas, virtuosas: o seio perfumado das famílias.”

“Frescos Trópicos”
Autores: Ronald Polito, James Naylor Green
Editora: José Olympio
Páginas: 196
Quanto: R$ 23,90 (preço promocional*)
Onde comprar: pelo telefone 0800-140090 ou pelo site da Livraria da Folha

Homofobia deve ser tratada como doença, diz analista
‘Amor entre Meninas’ fala sobre o momento de ‘sair do armário’
Leia relato de adolescente transgênero

Major Depression: Great Success With Pacemaker Electrodes, Small Study Suggests (Science Daily)

Apr. 9, 2013 — Researchers from the Bonn University Hospital implanted pacemaker electrodes into the medial forebrain bundle in the brains of patients suffering from major depression with amazing results: In six out of seven patients, symptoms improved both considerably and rapidly. The method of Deep Brain Stimulation had already been tested on various structures within the brain, but with clearly lesser effect.

The medial forebrain bundle is highlighted in green. (Credit: Volker Arnd Coenen/Uni Freiburg)

The results of this new study have now been published in the international journal Biological Psychiatry.

After months of deep sadness, a first smile appears on a patient’s face. For many years, she had suffered from major depression and tried to end her life several times. She had spent the past years mostly in a passive state on her couch; even watching TV was too much effort for her. Now this young woman has found her joie de vivre again, enjoys laughing and travelling. She and an additional six patients with treatment resistant depression participated in a study involving a novel method for addressing major depression at the Bonn University Hospital.

Considerable amelioration of depression within days

Prof. Dr. Volker Arnd Coenen, neurosurgeon at the Department of Neurosurgery (Klinik und Poliklinik für Neurochirurgie), implanted electrodes into the medial forebrain bundles in the brains of subjects suffering from major depression with the electrodes being connected to a brain pacemaker. The nerve cells were then stimulated by means of a weak electrical current, a method called Deep Brain Stimulation. In a matter of days, in six out of seven patients, symptoms such as anxiety, despondence, listlessness and joylessness had improved considerably. “Such sensational success both in terms of the strength of the effects, as well as the speed of the response has so far not been achieved with any other method,” says Prof. Dr. Thomas E. Schläpfer from the Bonn University Hospital Department of Psychiatry und Psychotherapy (Bonner Uniklinik für Psychiatrie und Psychotherapie).

Central part of the reward circuit

The medial forebrain bundle is a bundle of nerve fibers running from the deep-seated limbic system to the prefrontal cortex. In a certain place, the bundle is particularly narrow because the individual nerve fibers lie close together. “This is exactly the location in which we can have maximum effect using a minimum of current,” explains Prof. Coenen, who is now the new head of the Freiburg University Hospital’s Department of Stereotactic and Functional Neurosurgery (Abteilung Stereotaktische und Funktionelle Neurochirurgie am Universitätsklinikum Freiburg). The medial forebrain bundle is a central part of a euphoria circuit belonging to the brain’s reward system. What kind of effect stimulation exactly has on nerve cells is not yet known. But it obviously changes metabolic activity in the different brain centers.

Success clearly increased over that of earlier studies

The researchers have already shown in several studies that deep brain stimulation shows an amazing and-given the severity of the symptoms- unexpected degree of amelioration of symptoms in major depression. In those studies, however, the physicians had not implanted the electrodes into the medial forebrain bundle but instead into the nucleus accumbens, another part of the brain’s reward system. This had resulted in clear and sustainable improvements in about 50 percent of subjects. “But in this new study, our results were even much better,” says Prof. Schläpfer. A clear improvement in complaints was found in 85 percent of patients, instead of the earlier 50 percent. In addition, stimulation was performed with lower current levels, and the effects showed within a few days, instead of after weeks.

Method’s long-term success

“Obviously, we have now come closer to a critical structure within the brain that is responsible for major depression,” says the psychiatrist from the Bonn University Hospital. Another cause for optimism among the group of physicians is that, since the study’s completion, an eighth patient has also been treated successfully. The patients have been observed for a period of up to 18 month after the intervention. Prof. Schläpfer reports, “The anti-depressive effect of deep brain stimulation within the medial forebrain bundle has not decreased during this period.” This clearly indicates that the effects are not temporary. This method gives those who suffer from major depression reason to hope. However, it will take quite a bit of time for the new procedure to become part of standard therapy.

Journal Reference:

  1. Thomas E. Schlaepfer, Bettina H. Bewernick, Sarah Kayser, Burkhard Mädler, Volker A. Coenen. Rapid Effects of Deep Brain Stimulation for Treatment-Resistant Major DepressionBiological Psychiatry, 2013; DOI:10.1016/j.biopsych.2013.01.034