Arquivo da tag: Visceralidade

Our Microbiome May Be Looking Out for Itself (New York Times)

15/08/2014UncategorizedEvolucionismo, Intestinos, Microbiota, Pós-humano, Visceralidaderenzotaddei

AUG. 14, 2014

A highly magnified view of Enterococcus faecalis, a bacterium that lives in the human gut. Microbes may affect our cravings, new research suggests.CreditCenters for Disease Control and Prevention

Carl Zimmer

Your body is home to about 100 trillion bacteria and other microbes, collectively known as your microbiome. Naturalists first became aware of our invisible lodgers in the 1600s, but it wasn’t until the past few years that we’ve become really familiar with them.

This recent research has given the microbiome a cuddly kind of fame. We’ve come to appreciate how beneficial our microbes are — breaking down our food, fighting off infections and nurturing our immune system. It’s a lovely, invisible garden we should be tending for our own well-being.

But in the journal Bioessays, a team of scientists has raised a creepier possibility. Perhaps our menagerie of germs is also influencing our behavior in order to advance its own evolutionary success — giving us cravings for certain foods, for example.

Maybe the microbiome is our puppet master.

“One of the ways we started thinking about this was in a crime-novel perspective,” said Carlo C. Maley, an evolutionary biologist at the University of California, San Francisco, and a co-author of the new paper. “What are the means, motives and opportunity for the microbes to manipulate us? They have all three.”

The idea that a simple organism could control a complex animal may sound like science fiction. In fact, there are many well-documented examples of parasites controlling their hosts.

Some species of fungi, for example, infiltrate the brains of ants and coax them to climb plants and clamp onto the underside of leaves. The fungi then sprout out of the ants and send spores showering onto uninfected ants below.

How parasites control their hosts remains mysterious. But it looks as if they release molecules that directly or indirectly can influence their brains.

Our microbiome has the biochemical potential to do the same thing. In our guts, bacteria make some of the same chemicals that our neurons use to communicate with one another, such as dopamine and serotonin. And the microbes can deliver these neurological molecules to the dense web of nerve endings that line the gastrointestinal tract.

A number of recent studies have shown that gut bacteria can use these signals to alter the biochemistry of the brain. Compared with ordinary mice, those raised free of germs behave differently in a number of ways. They are more anxious, for example, and have impaired memory.

Adding certain species of bacteria to a normal mouse’s microbiome can reveal other ways in which they can influence behavior. Some bacteria lower stress levels in the mouse. When scientists sever the nerve relaying signals from the gut to the brain, this stress-reducing effect disappears.

Some experiments suggest that bacteria also can influence the way their hosts eat. Germ-free mice develop more receptors for sweet flavors in their intestines, for example. They also prefer to drink sweeter drinks than normal mice do.

Scientists have also found that bacteria can alter levels of hormones that govern appetite in mice.

Dr. Maley and his colleagues argue that our eating habits create a strong motive for microbes to manipulate us. “From the microbe’s perspective, what we eat is a matter of life and death,” Dr. Maley said.

Different species of microbes thrive on different kinds of food. If they can prompt us to eat more of the food they depend on, they can multiply.

Microbial manipulations might fill in some of the puzzling holes in our understandings about food cravings, Dr. Maley said. Scientists have tried to explain food cravings as the body’s way to build up a supply of nutrients after deprivation, or as addictions, much like those for drugs like tobacco and cocaine.

But both explanations fall short. Take chocolate: Many people crave it fiercely, but it isn’t an essential nutrient. And chocolate doesn’t drive people to increase their dose to get the same high. “You don’t need more chocolate at every sitting to enjoy it,” Dr. Maley said.

Perhaps, he suggests, the certain kinds of bacteria that thrive on chocolate are coaxing us to feed them.

John F. Cryan, a neuroscientist at University College Cork in Ireland who was not involved in the new study, suggested that microbes might also manipulate us in ways that benefited both them and us. “It’s probably not a simple parasitic scenario,” he said.

Research by Dr. Cryan and others suggests that a healthy microbiome helps mammals develop socially. Germ-free mice, for example, tend to avoid contact with other mice.

That social bonding is good for the mammals. But it may also be good for the bacteria.

“When mammals are in social groups, they’re more likely to pass on microbes from one to the other,” Dr. Cryan said.

“I think it’s a very interesting and compelling idea,” said Rob Knight, a microbiologist at the University of Colorado, who was also not involved in the new study.

If microbes do in fact manipulate us, Dr. Knight said, we might be able to manipulate them for our own benefit — for example, by eating yogurt laced with bacteria that would make us crave healthy foods.

“It would obviously be of tremendous practical importance,” Dr. Knight said. But he warned that research on the microbiome’s effects on behavior was “still in its early stages.”

The most important thing to do now, Dr. Knight and other scientists said, was to run experiments to see if microbes really are manipulating us.

Mark Lyte, a microbiologist at the Texas Tech University Health Sciences Center who pioneered this line of research in the 1990s, is now conducting some of those experiments. He’s investigating whether particular species of bacteria can change the preferences mice have for certain foods.

“This is not a for-sure thing,” Dr. Lyte said. “It needs scientific, hard-core demonstration.”

Bactéria pode aumentar inteligência (Exame)

06/08/2014UncategorizedBactérias, Microbiota, Saúde mental, Visceralidaderenzotaddei

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.

Political attitudes derive from body and mind: ‘Negativity bias’ explains difference between liberals and conservatives (Science Daily)

01/08/2014UncategorizedCiência política, Corpo, Política, Visceralidaderenzotaddei

Date: July 31, 2014

Source: University of Nebraska-Lincoln

Summary: Neither conscious decision-making or parental upbringing fully explain why some people lean left and others lean right, researchers say. A mix of deep-seated psychology and physiological responses are at the core of political differences.

Pictured are University of Nebraska-Lincoln political scientists Kevin Smith, left, and John Hibbing, right. Credit: University Communications, University of Nebraska-Lincoln/Craig Chandler

Do people make a rational choice to be liberal or conservative? Do their mothers raise them that way? Is it a matter of genetics?

Two political scientists from the University of Nebraska-Lincoln and a colleague from Rice University say that neither conscious decision-making nor parental upbringing fully explain why some people lean left while others lean right.

A growing body of evidence shows that physiological responses and deep-seated psychology are at the core of political differences, the researchers say in the latest issue of the journal Behavioral and Brain Sciences.

“Politics might not be in our souls, but it probably is in our DNA,” says the article written by political scientists John Hibbing and Kevin Smith of UNL and John Alford of Rice University.

“These natural tendencies to perceive the physical world in different ways may in turn be responsible for striking moments of political and ideological conflict throughout history,” Alford said.

Using eye-tracking equipment and skin conductance detectors, the three researchers have observed that conservatives tend to have more intense reactions to negative stimuli, such as photos of people eating worms, burning houses or maggot-infested wounds.

Combining their own results with similar findings from other researchers around the world, the team proposes that this so-called “negativity bias” may be a common factor that helps define the difference between conservatives, with their emphasis on stability and order, and liberals, with their emphasis on progress and innovation.

“Across research methods, samples and countries, conservatives have been found to be quicker to focus on the negative, to spend longer looking at the negative, and to be more distracted by the negative,” the researchers wrote.

The researchers caution that they make no value judgments about this finding. In fact, some studies show that conservatives, despite their quickness to detect threats, are happier overall than liberals. And all people, whether liberal, conservative or somewhere in between, tend to be more alert to the negative than to the positive — for good evolutionary reasons. The harm caused by negative events, such as infection, injury and death, often outweighs the benefits brought by positive events.

“We see the ‘negativity bias’ as a common finding that emerges from a large body of empirical studies done not just by us, but by many other research teams around the world,” Smith explained. “We make the case in this article that negativity bias clearly and consistently separates liberals from conservatives.”

The most notable feature about the negativity bias is not that it exists, but that it varies so much from person to person, the researchers said.

“Conservatives are fond of saying ‘liberals just don’t get it,’ and liberals are convinced that conservatives magnify threats,” Hibbing said. “Systematic evidence suggests both are correct.”

Many scientists appear to agree with the findings by Hibbing, Smith and Alford. More than 50 scientists contributed 26 peer commentary articles discussing the Behavioral and Brain Sciences article.

Only three or four of the articles seriously disputed the negativity bias hypothesis. The remainder accepted the general concept, while suggesting modifications such as better defining and conceptualizing a negativity bias; more deeply exploring its nature and origins; and more clearly defining liberalism and conservatism across history and culture.

Journal Reference:

John R. Hibbing, Kevin B. Smith, John R. Alford. Differences in negativity bias underlie variations in political ideology. Behavioral and Brain Sciences, 2014; 37 (03): 297 DOI: 10.1017/S0140525X13001192

Learning the smell of fear: Mothers teach babies their own fears via odor, animal study shows (Science Daily)

30/07/2014UncategorizedAnimais, Inteligência animal, Medo, Odores, Socialidade animal, Visceralidaderenzotaddei

Date: July 28, 2014

Source: University of Michigan Health System

Summary: Babies can learn what to fear in the first days of life just by smelling the odor of their distressed mothers’, new research suggests. And not just “natural” fears: If a mother experienced something before pregnancy that made her fear something specific, her baby will quickly learn to fear it too — through her odor when she feels fear.

Even when just the odor of the frightened mother was piped in to a chamber where baby rats were exposed to peppermint smell, the babies developed a fear of the same smell, and their blood cortisol levels rose when they smelled it. Credit: Image courtesy of University of Michigan Health System

Babies can learn what to fear in the first days of life just by smelling the odor of their distressed mothers, new research suggests. And not just “natural” fears: If a mother experienced something before pregnancy that made her fear something specific, her baby will quickly learn to fear it too — through the odor she gives off when she feels fear.

In the first direct observation of this kind of fear transmission, a team of University of Michigan Medical School and New York University studied mother rats who had learned to fear the smell of peppermint — and showed how they “taught” this fear to their babies in their first days of life through their alarm odor released during distress.

In a new paper in the Proceedings of the National Academy of Sciences, the team reports how they pinpointed the specific area of the brain where this fear transmission takes root in the earliest days of life.

Their findings in animals may help explain a phenomenon that has puzzled mental health experts for generations: how a mother’s traumatic experience can affect her children in profound ways, even when it happened long before they were born.

The researchers also hope their work will lead to better understanding of why not all children of traumatized mothers, or of mothers with major phobias, other anxiety disorders or major depression, experience the same effects.

“During the early days of an infant rat’s life, they are immune to learning information about environmental dangers. But if their mother is the source of threat information, we have shown they can learn from her and produce lasting memories,” says Jacek Debiec, M.D., Ph.D., the U-M psychiatrist and neuroscientist who led the research.

“Our research demonstrates that infants can learn from maternal expression of fear, very early in life,” he adds. “Before they can even make their own experiences, they basically acquire their mothers’ experiences. Most importantly, these maternally-transmitted memories are long-lived, whereas other types of infant learning, if not repeated, rapidly perish.”

Peering inside the fearful brain

Debiec, who treats children and mothers with anxiety and other conditions in the U-M Department of Psychiatry, notes that the research on rats allows scientists to see what’s going on inside the brain during fear transmission, in ways they could never do in humans.

He began the research during his fellowship at NYU with Regina Marie Sullivan, Ph.D., senior author of the new paper, and continues it in his new lab at U-M’s Molecular and Behavioral Neuroscience Institute.

The researchers taught female rats to fear the smell of peppermint by exposing them to mild, unpleasant electric shocks while they smelled the scent, before they were pregnant. Then after they gave birth, the team exposed the mothers to just the minty smell, without the shocks, to provoke the fear response. They also used a comparison group of female rats that didn’t fear peppermint.

They exposed the pups of both groups of mothers to the peppermint smell, under many different conditions with and without their mothers present.

Using special brain imaging, and studies of genetic activity in individual brain cells and cortisol in the blood, they zeroed in on a brain structure called the lateral amygdala as the key location for learning fears. During later life, this area is key to detecting and planning response to threats — so it makes sense that it would also be the hub for learning new fears.

But the fact that these fears could be learned in a way that lasted, during a time when the baby rat’s ability to learn any fears directly was naturally suppressed, is what makes the new findings so interesting, says Debiec.

The team even showed that the newborns could learn their mothers’ fears even when the mothers weren’t present. Just the piped-in scent of their mother reacting to the peppermint odor she feared was enough to make them fear the same thing.

And when the researchers gave the baby rats a substance that blocked activity in the amygdala, they failed to learn the fear of peppermint smell from their mothers. This suggests, Debiec says, that there may be ways to intervene to prevent children from learning irrational or harmful fear responses from their mothers, or reduce their impact.

From animals to humans: next steps

The new research builds on what scientists have learned over time about the fear circuitry in the brain, and what can go wrong with it. That work has helped psychiatrists develop new treatments for human patients with phobias and other anxiety disorders — for instance, exposure therapy that helps them overcome fears by gradually confronting the thing or experience that causes their fear.

In much the same way, Debiec hopes that exploring the roots of fear in infancy, and how maternal trauma can affect subsequent generations, could help human patients. While it’s too soon to know if the same odor-based effect happens between human mothers and babies, the role of a mother’s scent in calming human babies has been shown.

Debiec, who hails from Poland, recalls working with the grown children of Holocaust survivors, who experienced nightmares, avoidance instincts and even flashbacks related to traumatic experiences they never had themselves. While they would have learned about the Holocaust from their parents, this deeply ingrained fear suggests something more at work, he says.

Going forward, he hopes to work with U-M researchers to observe human infants and their mothers — including U-M psychiatrist Maria Muzik, M.D. and psychologist Kate Rosenblum, Ph.D., who run a Women and Infants Mental Health clinic and research program and also work with military families. The program is currently seeking women and their children to take part in a range of studies.

Journal Reference:

Jacek Debiec and Regina Marie Sullivan. Intergenerational transmission of emotional trauma through amygdala-dependent mother-to-infant transfer of specific fear. PNAS, July 28, 2014 DOI: 10.1073/pnas.1316740111

Diet affects males’ and females’ gut microbes differently (Science Daily)

30/07/2014UncategorizedFlora intestinal, Gênero, Microbiota, Microorganismos, Visceralidaderenzotaddei

Date: July 29, 2014

Source: University of Texas at Austin

Summary: The microbes living in the guts of males and females react differently to diet, even when the diets are identical, according to a new study. These results suggest that therapies designed to improve human health and treat diseases through nutrition might need to be tailored for each sex.

Illustration by Marianna Grenadier and Jenna Luecke. Credit: Image courtesy of University of Texas at Austin

The microbes living in the guts of males and females react differently to diet, even when the diets are identical, according to a study by scientists from The University of Texas at Austin and six other institutions published this week in the journal Nature Communications. These results suggest that therapies designed to improve human health and treat diseases through nutrition might need to be tailored for each sex.

The researchers studied the gut microbes in two species of fish and in mice, and also conducted an in-depth analysis of data that other researchers collected on humans. They found that in fish and humans diet affected the microbiota of males and females differently. In some cases, different species of microbes would dominate, while in others, the diversity of bacteria would be higher in one sex than the other.

These results suggest that any therapies designed to improve human health through diet should take into account whether the patient is male or female.

Only in recent years has science begun to completely appreciate the importance of the human microbiome, which consists of all the bacteria that live in and on people’s bodies. There are hundreds or even thousands of species of microbes in the human digestive system alone, each varying in abundance.

Genetics and diet can affect the variety and number of these microbes in the human gut, which can in turn have a profound influence on human health. Obesity, diabetes, and inflammatory bowel disease have all been linked to low diversity of bacteria in the human gut.

One concept for treating such diseases is to manipulate the microbes within a person’s gut through diet. The idea is gaining in popularity because dietary changes would make for a relatively cheap and simple treatment.

Much has to be learned about which species, or combination of microbial species, is best for human health. In order to accomplish this, research has to illuminate how these microbes react to various combinations of diet, genetics and environment. Unfortunately, to date most such studies only examine one factor at a time and do not take into account how these variables interact.

“Our study asks not just how diet influences the microbiome, but it splits the hosts into males and females and asks, do males show the same diet effects as females?” said Daniel Bolnick, professor in The University of Texas at Austin’s College of Natural Sciences and lead author of the study.

While Bolnick’s results identify that there is a significant difference in the gut microbiota for males and females, the dietary data used in the analysis are organized in complex clusters of disparate factors and do not easily translate into specific diet tips, such as eating more vegetables or less meat.

“To guide people’s behavior, we need to know what microbes are desirable for people,” said Bolnick. “Diet and sex do interact to influence the microbes, but we don’t yet know what a desirable target for microbes is. Now we can go in with eyes open when we work on therapies for gut microbe problems, as many involve dietary changes. We can walk into those studies looking for something we weren’t aware of before. All along we treated diet as if it works the same for men and women. Now we’ll be approaching studies of therapies in a different way.”

Why men and women would react differently to changes in diet is unclear, but there are a couple of possibilities. The hormones associated with each sex could potentially influence gut microbes, favoring one strain over another. Also, the sexes often differ in how their immune systems function, which could affect which microbes live and die in the microbiome.

One notable exception in Bolnick’s results was in the mice. Although there was a tiny difference between male and female mice, for the most part the microbiota of each sex reacted to diet in the same manner. Because most dietary studies are conducted on mice, this result could have a huge effect on such research, and it raises questions about how well studies of gut microbes in lab mice can be generalized to other species, particularly humans.

“This means that most of the research that’s being done on lab mice — we need to treat that with kid gloves,” said Bolnick.

Bolnick’s co-authors are Lisa Snowberg (UT Austin); Philipp Hirsch (University of Basel and Uppsala University); Christian Lauber and Rob Knight (University of Colorado, Boulder); Elin Org, Brian Parks and Aldons Lusis (University of California, Los Angeles); J. Gregory Caporaso (Northern Arizona University and Argonne National Laboratory); and Richard Svanbäck (Uppsala University).

This research was funded by the Howard Hughes Medical Institute, the David and Lucile Packard Foundation and the Swedish Research Council.

Journal Reference:

Daniel I. Bolnick, Lisa K. Snowberg, Philipp E. Hirsch, Christian L. Lauber, Elin Org, Brian Parks, Aldons J. Lusis, Rob Knight, J. Gregory Caporaso, Richard Svanbäck. Individual diet has sex-dependent effects on vertebrate gut microbiota. Nature Communications, 2014; 5 DOI: 10.1038/ncomms5500

DESPRET: “TENER UN CUERPO ES APRENDER A AFECTARSE” (Networks & Matters)

29/07/2014UncategorizedCorpo, Despret, Perspectivismo, Teoria Ator-Rede, Visceralidaderenzotaddei

07.25.14

por Tomás Sánchez Criado

Pensando en el activismo encarnado y la relación con la experiencia, creo que puede ser enormemente útil algunos de estos fragmentos de Despret que traduzco para activar el debate…

La postura que caracteriza a Despret y su particular lectura de William James (en castellano véase también el texto “El cuerpo de nuestros desvelos: Figuras de la antropozoogénesis“, incluído en el volumen 1 de la compilación Tecnogénesis) fue resumida brillantemente por Latour en un texto conmemorativo de la postura de Stengers-Despret (titulado How to talk about the body?): “[…] tener un cuerpo es aprender a afectarse, esto es a ‘efectuarse’, a ser movido, puesto en movimiento por otras entidades, humanas o no humanas”(p. 205, traducción propia).

Despret, V., & Galetic, S. (2007). Faire de James un “lecteur anachronique” de Von Uexküll: esquisse d’un perpectivisme radical. In D. Debaise (Ed.),Vie et Expérimentation: Peirce, James, Dewey (pp. 45–76). Paris: Vrin.

“[…] apelamos a [William] James y le reclutamos como lector anacrónico del naturalista [Von Uexküll]: él nos permite prolongar el interés de la práctica de von Uexküll, seguir los actos que crean los accesos a los mundos, que tejen la continuidad de las experiencias, sin recurrir a principios que escaparían a toda experiencia. Al subjetivismo que parecía imponer en teoría lo sustituimos por lo que llamamos un perspectivismo radical” (p.53)

“[La perspectiva] es a la vez una manera de ser afectado –esto es, cómo el mundo me toca–, una disponibilidad a ‘hacerse afectar’ –esto es, las pasiones que tengo que acoger– y una afectación voluntaria –esto es, éste es el mundo que querría habitar–. Es del orden del sentir como del actuar; cada una de estas vías nos conducirían al mismo punto de convergencia: el mundo es una perspectiva del cuerpo” (pp.56-57)

“El perspectivismo se reencuentra con el mundo que el subjetivismo había extraviado: nuestro cuerpo merece nuestra confianza. Porque él confía en el mundo; porque las cosas del mundo no son inertes, sino que actúan sobre él, porque le tocan en lo más íntimo, porque reivindican una importancia y una significación; porque el cuerpo es, sin duda, el que más puede reconocer ‘esa vida pública de las cosas’, esa actualidad presente por la que ellas nos confrontan [cita a W. James]’” (p.59)

“[…] Es a partir de la construcción de una comunidad de experiencia que cada cosa que experimentamos puede convertirse en mundo común” (p.61)

“La perspectiva no puede confundirse con el punto de vista: lugar de paso, promontorio [surplomb] transitorio. Estamos en el interior de un domus, por lo que se plantea la cuestión de cómo amueblarlo; y son las puertas que nos hemos dejado abiertas las que constituyen la perspectiva. De ahí el rol que pudiéramos atribuir al conflicto: el de ser una pragmática de la perspectiva. Un rol doble, de hecho: por una parte el de multiplicar las perspectivas; por otra, el de discriminarlas en función de su capacidad de acogida – ¿Estaremos bien ‘en casa’? ¿Con qué seres? ¿Qué debemos dejarnos fuera? Entonces, multipliquemos las perspectivas: porque qué hace el conflicto si no poblar la escena de actores, naturalezas, fragmentos del universo y dejarlos desplegar sus propuestas” (pp. 66-67)

“Tantos afectos, tantos mundos. Con el conflicto [la polémique] no son tanto sistemas explicativos lo que se pone en juego, sino proposiciones de mundos a habitar, mundos afectados: perspectivas que están en conflicto [la polémique]” (p.68)

“[La perspectiva] es una actitud, es decir, una disposición a ser afectado y una manera de afectar. […] El mundo es una perspectiva del cuerpo. Porque es de él del que todo parte y al que todo vuelve. Él es a través del que el mundo nos toca. Él es el que, actuando, constituye un mundo común. Él es el garante de nuestra confianza. Una perspectiva […] es una manera de habitar el mundo” (p.70)

“[…] la perspectiva es el lugar a partir del cual el mundo se hace nuestro. […] Es a partir de las acciones, es decir, de las relaciones particulares que mantenemos con las cosas de la realidad, relaciones en las que esas cosas nos confrontan, que constituimos un mundo común” (p.71)

“El mundo común se constituye a la vez en el compartir y en la multiplicación de intereses o, más bien, debiéramos decir acción a acción” (p.74)

Ancient Man Used “Super-Acoustics” to Alter Consciousness (… and speak with the dead?) (Phys.Org)

20/06/2014UncategorizedAntropologia física, Arqueologia, Corpo, Espiritualidade, Malta, Religião, Tecnologias do corpo, Visceralidaderenzotaddei

June 16th, 2014 Linda Eneix

Ancient Man Used “Super-Acoustics” to Alter Consciousness (... and speak with the dead?)

Research team members enter the “Oracle Room” of the Hal Saflieni Hypogeum, Malta (ca. 3600 BCE)

A prehistoric necropolis yields clues to the ancient use of sound and its effect on human brain activity.Researchers detected the presence of a strong double resonance frequency at 70Hz and 114Hz inside a 5,000-years-old mortuary temple on the Mediterranean island of Malta. The Ħal Saflieni Hypogeum is an underground complex created in the Neolithic (New Stone Age) period as a depository for bones and a shrine for ritual use. A chamber known as “The Oracle Room” has a fabled reputation for exceptional sound behavior.

During testing, a deep male voice tuned to these frequencies stimulated a resonance phenomenon throughout the hypogeum, creating bone-chilling effects. It was reported that sounds echoed for up to 8 seconds. Archaeologist Fernando Coimbra said that he felt the sound crossing his body at high speed, leaving a sensation of relaxation. When it was repeated, the sensation returned and he also had the illusion that the sound was reflected from his body to the ancient red ochre paintings on the walls. One can only imagine the experience in antiquity: standing in what must have been somewhat odorous dark and listening to ritual chant while low light flickered over the bones of one’s departed loved ones.

Sound in a Basso/Baritone range of 70 – 130 hz vibrates in a certain way as a natural phenomenon of the environment in the Hypogeum, as it does in Newgrange passage tomb, megalithic cairns and any stone cavity of the right dimensions. At these resonance frequencies, even small periodic driving forces can produce large amplitude oscillations, because the system stores vibrational energy. Echoes bounce off the hard surfaces and compound before they fade. Laboratory testing indicates that exposure to these particular resonant frequencies can have a physical effect on human brain activity.

In the publication from the conference on Archaeoacoustics which sparked the study, Dr. Paolo Debertolis reports on tests conducted at the Clinical Neurophysiology Unit at the University of Trieste in Italy: “…each volunteer has their own individual frequency of activation, …always between 90 and 120 hz. Those volunteers with a frontal lobe prevalence during the testing received ideas and thoughts similar to what happens during meditation, whilst those with occipital lobe prevalence visualized images.” He goes on to state that under the right circumstances, “Ancient populations were able to obtain different states of consciousness without the use of drugs or other chemical substances.”

Hal Saflieni (ca. 3600 BCE)

Credit: Mediterranean Institute of Ancient CivilizationsWriting jointly, Anthropologist, Dr. Ezra Zubrow, Archaeologist and Psychologist, Dr. Torill Lindstrom state: “We regard it as almost inevitable that people in the Neolithic past in Malta discovered the acoustic effects of the Hypogeum, and experienced them as extraordinary, strange, perhaps even as weird and “otherworldly”.

What is astounding is that five thousand years ago the builders exploited the phenomenon, intentionally using architectural techniques to boost these “super-acoustics”. Glenn Kreisberg, a radio frequency spectrum engineer who was with the research group, observed that in the Hypogeum, “The Oracle Chamber ceiling, especially near its entrance from the outer area, and the elongated inner chamber itself, appears to be intentionally carved into the form of a wave guide.”

Project organizer Linda Eneix points to other features: “The carving of the two niches which concentrate the effect of sound, the curved shape of the Oracle Chamber with its shallow “shelf” cut high across the back, the corbelled ceilings and concave walls in the finer rooms are all precursors of todays’ acoustically engineered performance environments.” She says, “If we can accept that these developments were not by accident, then it’s clear that Ħal Saflieni’s builders knew how to manipulate a desired human psychological and physiological experience, whether they could explain it or not.”

Why?

It was demonstrated at the conference that special sound is associated with the sacred: from prehistoric caves in France and Spain to musical stone temples in India; from protected Aztec codexes in Mexico to Eleusinian Mysteries and sanctuaries in Greece to sacred Elamite valleys in Iran. It was human nature to isolate these hyper-acoustic places from mundane daily life and to place high importance to them because abnormal sound behavior implied a divine presence.

In the same conference publication Emeritus Professor Iegor Reznikoff suggests that Ħal Saflieni is a link between Palaeolithic painted caves and Romanesque chapels … “That people sang laments or prayers for the dead in the Hypogeum is certain, for a) it is a universal practice in all oral traditions we know, b) at the same period, around 3,000 BC, we have the Sumerian or Egyptian inscriptions mentioning singing to the Invisible, particularly in relationship with death and Second Life, and finally c) the resonance is so strong in the Hypogeum already when simply speaking, that one is forced to use it and singing becomes natural.”

Drs. Lindstrom and Zubrow hint at a more hierarchal purpose for the manipulation of sound. “The Neolithic itself was characterized by cultures focused on new invention…enormous collective collaborations over extended periods of time. For these large-scale projects of agriculture and building, social cohesion and compliance was absolutely necessary.”

The same people who created Ħal Saflieni also engineered a complete solar calendar with solstice and equinox sunrise alignments that still function today in one of their above-ground megalithic structures. There is no question that a sophisticated school of architectural, astronomic and audiologic knowledge was already in place a thousand years before the Egyptians started building pyramids. Eneix believes that Malta’s Ħal Saflieni Hypogeum is a remnant of a rich cultural tradition carried by the Neolithic migrations that spanned thousands of years and thousands of miles.

US Scientists, Oil Giant Stole Indigenous Blood (Common Dreams)

19/06/2014UncategorizedÍndios, ciência, Direitos humanos, Equador, Genética, Sangue, Visceralidaderenzotaddei

Published on Wednesday, June 18, 2014 by Common Dreams

For years, scientists working with Maxus Energy took blood samples from hundreds of Amazonian tribal members

– Max Ocean, editorial intern

Members of the Ecuadorean indigenous group known as the Huaorani (Credit: Jean-François Renaud/cc/flickr)

U.S. scientists working together with oil company Maxus Energy took around 3,500 blood samples from the indigenous Amazonian tribe known as the Huaorani, Ecuador charged on Monday.

The Huaorani are known for a unique genetic makeup that makes them immune to certain diseases.

René Ramírez, the head of the Ecuadorian Ministry of Higher Education, Science and Technology, told Ecuador state TV on Monday that samples were taken from around 600 Huaorani, and that multiple pints of blood were taken from many members of the tribe. Ramírez said that it is not yet known whether the samples have resulted in any commercial gains, but that samples were sold for scientific research.

According to an initial investigation two years ago, “It was demonstrated that the Coriell Institute has in its stores samples (from the Huaorani) and that it sells genetic material from the Huaorani people.” Harvard University was among the purchasers. Specifically, the 2012 report found that since 1994, seven cell cultures and 36 blood samples were distributed to eight different countries.

In the same report the Huaorani said that scientists had tricked them into allowing their blood to be taken between 1990 and 1991; however, President Rafael Correa said that there is now evidence that samples were taken as far back as the 1970s “in complicity with the oil company operating in the area.”

The Huaorani allegedly agreed to give the blood samples because scientists lied to them about why the samples were being taken. They were told the samples were being taken for medical tests, but never received results.

According to the website Hispanically Speaking News, in his weekly radio address on Saturday, President Correa said that at least 31 research papers were written between 1989 and 2012 based on the blood samples obtained––all without the consent of the Huaorani or the royalty payments normally required.

The taking of the samples was illegal, as Ecuador’s constitution bans the use of scientific research including genetic material in violation of human rights.

According to AFP, when the allegations first emerged in 2012, the U.S. Embassy said it was not aware of the case, and they did not immediately issue a response after Ecuador brought the charges on Monday.

Life-style determines gut microbes (Max-Planck-Gesellschaft)

19/04/2014UncategorizedBactérias, Ecologia, Flora intestinal, Visceralidaderenzotaddei

An international team of researchers has for the first time deciphered the intestinal bacteria of present-day hunter-gatherers

April 15, 2014

The gut microbiota is responsible for many aspects of human health and nutrition, but most studies have focused on “western” populations. An international collaboration of researchers, including researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has for the first time analysed the gut microbiota of a modern hunter-gatherer community, the Hadza of Tanzania. The results of this work show that Hadza harbour a unique microbial profile with features yet unseen in any other human group, supporting the notion that Hadza gut bacteria play an essential role in adaptation to a foraging subsistence pattern. The study further shows how gut microbiota may have helped our ancestors adapt and survive during the Paleolithic.

Hadza women roasting tubers. © Alyssa Crittenden

Bacterial populations have co-evolved with humans over millions of years, and have the potential to help us adapt to new environments and foods. Studies of the Hadza offer an especially rare opportunity for scientists to learn how humans survive by hunting and gathering, in the same environment and using similar foods as our ancestors did.

The research team, composed of anthropologists, microbial ecologists, molecular biologists, and analytical chemists, and led in part by Stephanie Schnorr and Amanda Henry of the Max Planck Institute for Evolutionary Anthropology, compared the Hadza gut microbiota to that of urban living Italians, representative of a “westernized” population. Their results, published recently in Nature Communications, show that the Hadza have a more diverse gut microbe ecosystem, i.e. more bacterial species compared to the Italians. “This is extremely relevant for human health”, says Stephanie Schnorr. “Several diseases emerging in industrialized countries, like IBS, colorectal cancer, obesity, type II diabetes, Crohn’s disease and others, are significantly associated with a reduction in gut microbial diversity.”

The Hadza gut microbiota is well suited for processing indigestible fibres from a plant-rich diet and likely helps the Hadza get more energy from the fibrous foods that they consume. Surprisingly, Hadza men and women differed significantly in the type and amount of their gut microbiota, something never before seen in any other human population. Hadza men hunt game and collect honey, while Hadza women collect tubers and other plant foods. Though they share these foods, each sex eats slightly more of the foods they target. “The differences in gut microbiota between the sexes reflects this sexual division of labour”, says Stephanie Schnorr. “It appears that women have more bacteria to help process fibrous plant foods, which has direct implications for their fertility and reproductive success.” These findings support the key role of the gut microbiota as adaptive partners during the course of human evolution by aligning with differing diets.

Hadza digging for plant foods. © MPI f. Evolutionary Anthropology

Finally, the Hadza gut microbe community is a unique configuration with high levels of bacteria, like Treponema, that in western populations are often considered signs of disease, and low levels of other bacteria, likeBifidobacterium, that in western populations are considered “healthy”. However, the Hadza experience little to no autoimmune diseases that would result from gut bacteria imbalances. Therefore, we must redefine our notions of “healthy” and “unhealthy” bacteria, since these distinctions are clearly dependent on the environment we live in. Genetic diversity of bacteria is likely the most important criterion for the health and stability of the gut microbiome.

“Co-resident microbes are our ‘old friends’ that help us adapt to different lifestyles and environments”, says Amanda Henry, leader of the Max Planck Research Group on Plant Foods in Hominin Dietary Ecology. “Through this analysis of the Hadza gut microbiota, we have increased our knowledge of human-microbiome adaptations to life in a savanna environment and improved our understanding of how gut microbiota may have helped our ancestors adapt and survive during the Paleolithic.”

The Way to a Chimpanzee’s Heart Is Through Its Stomach (Science Daily)

17/01/2014UncategorizedChimpanzés, Socialidade animal, Visceralidaderenzotaddei

Jan. 16, 2014 — The ability to form long-term cooperative relationships between unrelated individuals is one of the main reasons for human’s extraordinary biological success, yet little is known about its evolution and mechanisms. The hormone oxytocin, however, plays a role in it.

After hunting, chimpanzees share the meat of a red colobus monkey amongst them. (Credit: © Roman M. Wittig / Taï Chimpanzee Project)

Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, measured the urinary oxytocin levels in wild chimpanzees after food sharing and found them to be elevated in both donor and receiver compared to social feeding events without sharing. Furthermore, oxytocin levels were higher after food sharing than after grooming, another cooperative behavior, suggesting that food sharing might play a more important role in promoting social bonding. By using the same neurobiological mechanisms, which evolved within the context of building and strengthening the mother-offspring bond during lactation, food sharing might even act as a trigger for cooperative relationships in related and unrelated adult chimpanzees.

Humans and a few other social mammals form cooperative relationships between unrelated adults that can last for several months or years. According to recent studies the hormone oxytocin, which facilitates bonding between mother and offspring, likely plays a role in promoting these relationships. In chimpanzees, for instance, increased urinary oxytocin levels are linked to grooming between bonding partners, whether or not they are genetically related to each other.

To examine the ways in which oxytocin is associated with food sharing, Roman Wittig and colleagues of the Max Planck Institute for Evolutionary Anthropology in Leipzig have collected and analyzed 79 urine samples from 26 wild chimpanzees from Budongo Forest in Uganda within one hour after the chimpanzees either shared food or socially fed without sharing. The result: A chimpanzee’s urine contained significantly higher levels of oxytocin after sharing food with another group member than just after feeding socially regardless whether the animal was the donor or the receiver of the food. “Increased urinary oxytocin levels were independent of whether subjects gave or received food, shared with kin or non-kin, shared with an established bond partner or not, or shared meat or other food types,” says Roman Wittig.

In addition, the researchers found that the oxytocin levels associated with food sharing were higher than those associated with grooming, indicating that the rarer food sharing has a stronger bonding effect than the more frequently occurring grooming. “Food sharing may be a key behavior for social bonding in chimpanzees,” says Wittig. “As it benefits receivers and donors equally, it might even act as a trigger and predictor of cooperative relationships.”

The researchers further suggest that food sharing likely activates neurobiological mechanisms that originally evolved to support mother-infant bonding during lactation. “Initially, this mechanism may have evolved to maintain bonds between mother and child beyond the age of weaning,” says Wittig. “It may then have been hitch-hiked and is now also promoting bond formation and maintenance in non-kin cooperative relationships.”

The Latin roots of the word companion (‘com = with’ and ‘panis = bread’) may indicate a similar mechanism to build companionship in humans. Whether human urinary oxytocin levels also increase after sharing a meal with others will be a subject for future studies.

Journal Reference:

R. M. Wittig, C. Crockford, T. Deschner, K. E. Langergraber, T. E. Ziegler, K. Zuberbuhler. Food sharing is linked to urinary oxytocin levels and bonding in related and unrelated wild chimpanzees. Proceedings of the Royal Society B: Biological Sciences, 2014; 281 (1778): 20133096 DOI: 10.1098/rspb.2013.3096

Altering the Community of Gut Bacteria Promotes Health and Increases Lifespan (Science Daily)

17/01/2014UncategorizedEcologia, Intestinos, Visceralidaderenzotaddei

Jan. 16, 2014 — Scientists at the Buck Institute for Research on Aging have promoted health and increased lifespan in Drosophila by altering the symbiotic, or commensal, relationship between bacteria and the absorptive cells lining the intestine. The research, appearing in the January 16, 2014 edition of Cell, provides a model for studying many of the dysfunctions that are characteristic of the aging gut and gives credence to the growing supposition that having the right balance of gut bacteria may be key to enjoying a long healthy life.

Even though recent research in humans has linked the composition of gut flora with diet and health in the elderly and the list of age-related diseases associated with changes in gut bacteria include cancer, diabetes, and inflammatory bowel disease, lead author and Buck faculty Heinrich Jasper, PhD, says there is no systematic understanding of how we go from having a young, healthy gut to one that is old and decrepit. “Our study explores age-related changes in the gut that include increased oxidative stress, inflammation, impaired efficiency of the immune response, and the over-proliferation of stem cells,” said Jasper. “It puts these changes into a hierarchical, causal relationship and highlights the points where we can intervene to rescue the negative results of microbial imbalance.”

Jasper says the bacterial load in fly intestines increases dramatically with age, resulting in an inflammatory condition. The imbalance is driven by chronic activation of the stress response gene FOXO (something that happens with age), which suppresses the activity of a class of molecules (PGRP-SCs, homologues of PGLYRPs in humans) that regulate the immune response to bacteria. PGRP-SC suppression deregulates signaling molecules (Rel/NFkB) that are important to mount an effective immune response to gut bacteria. The resulting immune imbalance allows bacterial numbers to expand, triggering an inflammatory response that includes the production of free radicals. Free radicals, in turn, cause over-proliferation of stem cells in the gut, resulting in epithelial dysplasia, a pre-cancerous state.

Jasper said the most exciting result of their study occurred when his group increased the expression of PGRP-SC in epithelial cells of the gut, which restored the microbial balance and limited stem cell proliferation. This enhancement of PGRP-SC function, which could be mimicked by drugs, was sufficient to increase lifespan of flies. “If we can understand how aging affects our commensal population — first in the fly and then in humans — — our data suggest that we should be able to impact health span and life span quite strongly, because it is the management of the commensal population that is critical to the health of the organism.”

Journal Reference:

Linlin Guo, Jason Karpac, Susan L. Tran, Heinrich Jasper.PGRP-SC2 Promotes Gut Immune Homeostasis to Limit Commensal Dysbiosis and Extend Lifespan. Cell, 2014; 156 (1-2): 109 DOI: 10.1016/j.cell.2013.12.018

Neuroscientists Pinpoint Location of Fear Memory in Amygdala (Science Daily)

01/02/2013UncategorizedMediação tecnológica, Medo, Memória, neurociências, Visceralidaderenzotaddei

Jan. 27, 2013 — A rustle of undergrowth in the outback: it’s a sound that might make an animal or person stop sharply and be still, in the anticipation of a predator. That “freezing” is part of the fear response, a reaction to a stimulus in the environment and part of the brain’s determination of whether to be afraid of it.

An image showing neurons in the lateral subdivision of the central amygdala (CeL). In red are somatostain-positive (SOM+) neurons, which control fear; in green are another set of neurons known as PKC-delta cells. (Credit: Image courtesy of Bo Li)

A neuroscience group at Cold Spring Harbor Laboratory (CSHL) led by Assistant Professor Bo Li Ph.D., together with collaborator Professor Z. Josh Huang Ph.D., have just released the results of a new study that examines the how fear responses are learned, controlled, and memorized. They show that a particular class of neurons in a subdivision of the amygdala plays an active role in these processes.

Locating fear memory in the amygdala

Previous research had indicated that structures inside the amygdalae, a pair of almond-shaped formations that sit deep within the brain and are known to be involved in emotion and reward-based behavior, may be part of the circuit that controls fear learning and memory. In particular, a region called the central amygdala, or CeA, was thought to be a passive relay for the signals relayed within this circuit.

Li’s lab became interested when they observed that neurons in a region of the central amygdala called the lateral subdivision, or CeL, “lit up” in a particular strain of mice while studying this circuit.

“Neuroscientists believed that changes in the strength of the connections onto neurons in the central amygdala must occur for fear memory to be encoded,” Li says, “but nobody had been able to actually show this.”

This led the team to further probe into the role of these neurons in fear responses and furthermore to ask the question: If the central amygdala stores fear memory, how is that memory trace read out and translated into fear responses?

To examine the behavior of mice undergoing a fear test the team first trained them to respond in a Pavlovian manner to an auditory cue. The mice began to “freeze,” a very common fear response, whenever they heard one of the sounds they had been trained to fear.

To study the particular neurons involved, and to understand them in relation to the fear-inducing auditory cue, the CSHL team used a variety of methods. One of these involved delivering a gene that encodes for a light-sensitive protein into the particular neurons Li’s group wanted to look at.

By implanting a very thin fiber-optic cable directly into the area containing the photosensitive neurons, the team was able to shine colored laser light with pinpoint accuracy onto the cells, and in this manner activate them. This is a technique known as optogenetics. Any changes in the behavior of the mice in response to the laser were then monitored.

A subset of neurons in the central amygdala controls fear expression

The ability to probe genetically defined groups of neurons was vital because there are two sets of neurons important in fear-learning and memory processes. The difference between them, the team learned, was in their release of message-carrying neurotransmitters into the spaces called synapses between neurons. In one subset of neurons, neurotransmitter release was enhanced; in another it was diminished. If measurements had been taken across the total cell population in the central amygdala, neurotransmitter levels from these two distinct sets of neurons would have been averaged out, and thus would not have been detected.

Li’s group found that fear conditioning induced experience-dependent changes in the release of neurotransmitters in excitatory synapses that connect with inhibitory neurons — neurons that suppress the activity of other neurons — in the central amygdala. These changes in the strength of neuronal connections are known as synaptic plasticity.

Particularly important in this process, the team discovered, were somatostatin-positive (SOM+) neurons. Somatostatin is a hormone that affects neurotransmitter release. Li and colleagues found that fear-memory formation was impaired when they prevent the activation of SOM+ neurons.

SOM+ neurons are necessary for recall of fear memories, the team also found. Indeed, the activity of these neurons alone proved sufficient to drive fear responses. Thus, instead of being a passive relay for the signals driving fear learning and responses in mice, the team’s work demonstrates that the central amygdala is an active component, and is driven by input from the lateral amygdala, to which it is connected.

“We find that the fear memory in the central amygdala can modify the circuit in a way that translates into action — or what we call the fear response,” explains Li.

In the future Li’s group will try to obtain a better understanding of how these processes may be altered in post-traumatic stress disorder (PTSD) and other disorders involving abnormal fear learning. One important goal is to develop pharmacological interventions for such disorders.

Li says more research is needed, but is hopeful that with the discovery of specific cellular markers and techniques such as optogenetics, a breakthrough can be made.

Journal Reference:

Haohong Li, Mario A Penzo, Hiroki Taniguchi, Charles D Kopec, Z Josh Huang, Bo Li. Experience-dependent modification of a central amygdala fear circuit. Nature Neuroscience, 2013; DOI: 10.1038/nn.3322

Primates, Too, Can Move in Unison (Science Daily)

01/02/2013UncategorizedAnimais, Corpo, Interação humanos-animais, Multidão, Socialidade animal, Visceralidaderenzotaddei

Jan. 28, 2013 — Japanese researchers show for the first time that primates modify their body movements to be in tune with others, just like humans do. Humans unconsciously modify their movements to be in synchrony with their peers. For example, we adapt our pace to walk in step or clap in unison at the end of a concert. This phenomenon is thought to reflect bonding and facilitate human interaction. Researchers from the RIKEN Brain Science Institute report that pairs of macaque monkeys also spontaneously coordinate their movements to reach synchrony.

Monkey training (A), and experimental setting (B and C). (Credit: Image courtesy of RIKEN)

This research opens the door to much-needed neurophysiological studies of spontaneous synchronization in monkeys, which could shed light into human behavioral dysfunctions such as those observed in patients with autism spectrum disorders, echopraxia and echolalia — where patients uncontrollably imitate others.

In the research, recently published in the journal Scientific Reports, the team led by Naotaka Fujii developed an experimental set-up to test whether pairs of Japanese macaque monkeys synchronize a simple push-button movement.

Before the experiment, the monkeys were trained to push a button with one hand. In a first experiment the monkeys were paired and placed facing each other and the timing of their push-button movements was recorded. The same experiment was repeated but this time each monkey was shown videos of another monkey pushing a button at varying speeds. And in a last experiment the macaques were not allowed to either see or hear their video-partner.

The results show that the monkeys modified their movements — increased or decreased the speed of their push-button movement — to be in synchrony with their partner, both when the partner was real and on video. The speed of the button pressing movement changed to be in harmonic or sub-harmonic synchrony with the partners’ speed. However, different pairs of monkeys synchronized differently and reached different speeds, and the monkeys synchronized their movements the most when they could both see and hear their partner.

The researchers note that this behavior cannot have been learnt by the monkeys during the experiment, as previous research has shown that it is extremely difficult for monkeys to learn intentional synchronization.

They add: “The reasons why the monkeys showed behavioral synchronization are not clear. It may be a vital aspect of other socially adaptive behavior, important for survival in the wild.”

The study was partly supported by Grant-in-Aid for Scientific Research on Innovative Areas ‘Neural creativity for communication’ (22120522 and 24120720) of MEXT, Japan.

Journal Reference:

Yasuo Nagasaka, Zenas C. Chao, Naomi Hasegawa, Tomonori Notoya, Naotaka Fujii. Spontaneous synchronization of arm motion between Japanese macaques. Scientific Reports, 2013; 3 DOI:10.1038/srep01151

Digestão bloqueada, praga controlada (Revista Fapesp)

30/01/2013UncategorizedAnimais, Direitos animais, Economia, Incerteza, Interação humanos-animais, Saúde, Visceralidaderenzotaddei

[Curioso que tanto receio exista com relação à geoengenharia, e tão pouco direcionado a esse tipo de zooengenharia.]

Pesquisa da função intestinal de insetos aumenta o conhecimento da fisiologia desses animais e pode ajudar a criar métodos inovadores de combater doenças e controlar pragas da lavoura (estrutura 3D da catepsina L2)

30/01/2013

Por Fábio Reynol

Agência FAPESP – Diversas enfermidades humanas, como dengue, doença de chagas e leishmaniose, e pragas que destroem lavouras de algodão, cana-de-açúcar e bananeira são problemas que têm como ponto comum o fato de serem provocadas por insetos.

Uma extensa pesquisa feita no Instituto de Química (IQ) da Universidade de São Paulo (USP) ampliou o conhecimento sobre diferentes insetos por meio de uma abordagem peculiar: a investigação da função intestinal. Com isso, abriu espaço para métodos inovadores de controle.

O trabalho compôs o projeto “A digestão dos insetos: uma abordagem molecular, celular, fisiológica e evolutiva”, conduzido de 2008 a 2012 e apoiado pela FAPESP por meio da modalidade Auxílio à Pesquisa – Projeto Temático.

O projeto, coordenado por Walter Ribeiro Terra, professor titular do IQ-USP – com a professora Clelia Ferreira como investigadora principal e vice-coordenadora –, é uma continuação de Temáticos sobre o mesmo tema desenvolvidos desde 1991. O novo projeto teve início em 2012 com conclusão prevista para 2017.

Entre as principais descobertas do projeto concluído este ano foi a de que mosquitos hematófagos da ordem Díptera têm em comum tripsinas especiais, fundamentais para a digestão de proteínas. “Essa informação torna esse tipo de tripsina um possível alvo de controle para todos os mosquitos desse grupo”, disse Terra.

Trata-se de um alvo bastante relevante, uma vez que a ordem Díptera engloba os gênerosAnopheles, Aedes e Culex, os quais agrupam insetos vetores de importantes doenças como malária, febre amarela, dengue e filariose.

Segundo Terra, inibir a tripsina poderia ser um método eficaz de controle dessas doenças, uma vez que bloquearia o processo de digestão dos insetos. Para isso, o trabalho também envolveu a busca por inibidores químicos das enzimas encontradas.

O método utilizado foi o da modelagem computacional a partir de imagens tridimensionais dessas moléculas. Em um modelo digital em 3D da enzima a ser inibida são testadas virtualmente moléculas inibidoras que se encaixam no maior número possível de reentrâncias, ou sítios funcionais.

“Em quanto mais sítios funcionais o reagente atracar, mais forte será a ligação e mais eficiente será o inibidor”, disse Terra à Agência FAPESP, explicando que a modelagem molecular 3D é amplamente usada na indústria farmacêutica.

A enzima bloqueada não consegue se recombinar e cumprir sua função no processo de digestão, o de quebrar outras moléculas. Sem conseguir absorver os nutrientes de que precisam, os mosquitos morrem.

O estudo da fisiologia do barbeiro Rhodnius prolixus, vetor da doença de chagas, sempre foi difícil e a observação de sua função intestinal um obstáculo para os pesquisadores.

A equipe de Terra contornou o problema encontrando um inseto similar, o Dysdercus peruvianus, percevejo que ataca o algodão. Transcriptomas (partes do genoma que codificam proteínas) desse inseto mostraram detalhes que podem ser válidos também para o barbeiro, podendo gerar alvos de controle naquele inseto.

O agronegócio da cana-de-açúcar também poderá se beneficiar do estudo. A catepsina L, enzima digestiva típica de muitos besouros, foi isolada no Sphenophorus levis, besouro cuja fase larval ataca o sistema radicular da cana. Essa enzima foi clonada, expressa e caracterizada com substratos sintéticos e inibidores. A mesma enzima encontrada no Tenebrio molitor, besouro conhecido como bicho-da-farinha, teve sua estrutura tridimensional resolvida.

“O maior desafio em identificar a estrutura tridimensional é a cristalização da proteína, porque se ela não cristaliza não conseguimos obter o modelo”, disse Terra, esclarecendo que várias proteínas não conseguem formar cristais, inviabilizando a sua visualização tridimensional.

Estrutura do desenvolvimento

Uma estrutura particular do sistema intestinal dos insetos recebeu atenção especial no Projeto Temático conduzido no IQ-USP: a membrana peritrófica.

Em formato de um minúsculo tubo, sabe-se que seu papel está ligado à eficiência digestiva, porém suas funções ainda não são totalmente conhecidas pela ciência. Algumas dessas funções hipotéticas foram testadas em insetos modelos e descobriu-se que ela possui participação preponderante no desenvolvimento dos insetos.

Insetos cujas membranas peritróficas foram inibidas tiveram o seu desenvolvimento prejudicado. Ao mesmo tempo, algumas plantas possuem reagentes naturais que atacam essa membrana, o que as protege de serem devoradas por insetos. “Essas informações tornam essa estrutura um importante alvo para processos inovadores de controle”, observou Terra.

O Projeto Temático também promoveu avanços consideráveis no conhecimento da evolução das espécies. Além de possível alvo de controle das moscas domésticas, a enzima catepsina D também está presente em humanos e em outros animais que possuem sistemas digestivos muito ácidos voltados a processar alimentos ricos em bactérias.

“O interessante dessa descoberta foi constatar que a mesma adaptação evolutiva ocorreu duas vezes e de maneira independente na mosca e na espécie humana”, disse Terra.

Outro avanço importante foi sobre a morfofisiologia dos insetos. Um estudo com o percevejoPodisus nigrispinus, predador de outros insetos, mostrou que a então chamada digestão extraoral daquele inseto é uma dispersão dos tecidos da presa por ação de uma substância salivar. A digestão propriamente dita ocorre no interior do intestino do inseto.

A descoberta, publicada no Journal of Insect Physiology, provocou uma menção especial de um parecerista da revista. “Ele escreveu que a partir desse trabalho deve-se repensar os conceitos de digestão fora do corpo”, disse Terra, salientando que a equipe recebeu com muito orgulho esse reconhecimento.

O projeto ainda identificou a lisozima como uma enzima crítica na digestão de moscas que atacam frutas, a trealase é crucial para lagartas pragas de lavouras e as beta-glucanases, ausentes nos mamíferos, estão relacionadas à digestão e ao sistema imunológico de insetos. Todas elas são potenciais alvos de controle dos insetos envolvidos.

Mais de 1,3 mil citações

Os resultados dos quatro anos de estudos estão registrados em 20 publicações e quatro capítulos de livros e os trabalhos de laboratório do projeto foram citados 1.357 vezes na literatura científica mundial nesse período.

No âmbito do Projeto Temático foram desenvolvidas três dissertações de mestrado, seis teses de doutorado e duas de pós-doutorado. O projeto contou com cinco Bolsas FAPESP de Iniciação Científica, uma de Doutorado e as duas de Pós-Doutorado.

O Temático ainda promoveu trabalhos em parcerias com diversas instituições nacionais como a Universidade Federal de Santa Catarina (UFSC), a Universidade Federal de Lavras (UFL), a Universidade Federal de São Carlos (UFSCar), o Instituto Nacional de Ciência e Tecnologia (INCT) de Entomologia Molecular do qual o IQ-USP faz parte e a Escola Superior de Agricultura Luiz de Queiroz (Esalq) também da USP.

O grupo ainda participa de um consórcio internacional para o sequenciamento do genoma do barbeiro Rhodnius prolixus cujos resultados ainda estão em análise e, de acordo com Terra, ainda devem gerar diversas aplicações práticas.

Are Bacteria Making You Hungry? (Science Daily)

20/12/2012UncategorizedCognição, Descentralização, neurociências, Neurofisiologia, Sistema nervoso entérico, Visceralidaderenzotaddei

Dec. 19, 2012 — Over the last half decade, it has become increasingly clear that the normal gastrointestinal (GI) bacteria play a variety of very important roles in the biology of human and animals. Now Vic Norris of the University of Rouen, France, and coauthors propose yet another role for GI bacteria: that they exert some control over their hosts’ appetites. Their review was published online ahead of print in the Journal of Bacteriology.

Are bacteria making you hungry? Over the last half decade, it has become increasingly clear that the normal gastrointestinal (GI) bacteria play a variety of very important roles in the biology of human and animals. (Credit: © fabiomax / Fotolia)

This hypothesis is based in large part on observations of the number of roles bacteria are already known to play in host biology, as well as their relationship to the host system. “Bacteria both recognize and synthesize neuroendocrine hormones,” Norris et al. write. “This has led to the hypothesis that microbes within the gut comprise a community that forms a microbial organ interfacing with the mammalian nervous system that innervates the gastrointestinal tract.” (That nervous system innervating the GI tract is called the “enteric nervous system.” It contains roughly half a billion neurons, compared with 85 billion neurons in the central nervous system.)

“The gut microbiota respond both to both the nutrients consumed by their hosts and to the state of their hosts as signaled by various hormones,” write Norris et al. That communication presumably goes both ways: they also generate compounds that are used for signaling within the human system, “including neurotransmitters such as GABA, amino acids such as tyrosine and tryptophan — which can be converted into the mood-determining molecules, dopamine and serotonin” — and much else, says Norris.

Furthermore, it is becoming increasingly clear that gut bacteria may play a role in diseases such as cancer, metabolic syndrome, and thyroid disease, through their influence on host signaling pathways. They may even influence mood disorders, according to recent, pioneering studies, via actions on dopamine and peptides involved in appetite. The gut bacterium,Campilobacter jejuni, has been implicated in the induction of anxiety in mice, says Norris.

But do the gut flora in fact use their abilities to influence choice of food? The investigators propose a variety of experiments that could help answer this question, including epidemiological studies, and “experiments correlating the presence of particular bacterial metabolites with images of the activity of regions of the brain associated with appetite and pleasure.”

Journal Reference:

V. Norris, F. Molina, A. T. Gewirtz. Hypothesis: bacteria control host appetites. Journal of Bacteriology, 2012; DOI:10.1128/JB.01384-12

Social Synchronicity: Research Finds a Connection Between Bonding and Matched Movements (Science Daily)

17/12/2012UncategorizedCorpo, Interatividade, Visceralidaderenzotaddei

A new study finds that body-movement synchronization between two participants increases following a short session of cooperative training, suggesting that our ability to synchronize body movements is a measurable indicator of social interaction. (Credit: © Yuri Arcurs / Fotolia)

Dec. 12, 2012 — Humans have a tendency to spontaneously synchronize their movements. For example, the footsteps of two friends walking together may synchronize, although neither individual is consciously aware that it is happening. Similarly, the clapping hands of an audience will naturally fall into synch. Although this type of synchronous body movement has been observed widely, its neurological mechanism and its role in social interactions remain obscure. In a new study, led by cognitive neuroscientists at the California Institute of Technology (Caltech), researchers found that body-movement synchronization between two participants increases following a short session of cooperative training, suggesting that our ability to synchronize body movements is a measurable indicator of social interaction.

“Our findings may provide a powerful tool for identifying the neural underpinnings of both normal social interactions and impaired social interactions, such as the deficits that are often associated with autism,” says Shinsuke Shimojo, Gertrude Baltimore Professor of Experimental Psychology at Caltech and senior author of the study.

Shimojo, along with former postdoctoral scholar Kyongsik Yun, and Katsumi Watanabe, an associate professor at the University of Tokyo, presented their work in a paper published December 11 inScientific Reports, an online and open-access journal from the Nature Publishing Group.

For their study, the team evaluated the hypothesis that synchronous body movement is the basis for more explicit social interaction by measuring the amount of fingertip movement between two participants who were instructed to extend their arms and point their index fingers toward one another — much like the famous scene in E.T. between the alien and Elliott. They were explicitly instructed to keep their own fingers as stationary as possible while keeping their eyes open. The researchers simultaneously recorded the neuronal activity of each participant using electroencephalography, or EEG, recordings. Their finger positions in space were recorded by a motion-capture system.

The participants repeated the task eight times; the first two rounds were called pretraining sessions and the last two were posttraining sessions. The four sessions in between were the cooperative training sessions, in which one person — a randomly chosen leader — made a sequence of large finger movements, and the other participant was instructed to follow the movements. In the posttraining sessions, finger-movement correlation between the two participants was significantly higher compared to that in the pretraining sessions. In addition, socially and sensorimotor-related brain areas were more synchronized between the brains, but not within the brain, in the posttraining sessions. According to the researchers, this experiment, while simple, is novel in that it allows two participants to interact subconsciously while the amount of movement that could potentially disrupt measurement of the neural signal is minimized.

“The most striking outcome of our study is that not only the body-body synchrony but also the brain-brain synchrony between the two participants increased after a short period of social interaction,” says Yun. “This may open new vistas to study the brain-brain interface. It appears that when a cooperative relationship exists, two brains form a loose dynamic system.”

The team says this information may be potentially useful for romantic or business partner selection.

“Because we can quantify implicit social bonding between two people using our experimental paradigm, we may be able to suggest a more socially compatible partnership in order to maximize matchmaking success rates, by preexamining body synchrony and its increase during a short cooperative session” explains Yun.

As part of the study, the team also surveyed the subjects to rank certain social personality traits, which they then compared to individual rates of increased body synchrony. For example, they found that the participants who expressed the most social anxiety showed the smallest increase in synchrony after cooperative training, while those who reported low levels of anxiety had the highest increases in synchrony. The researchers plan to further evaluate the nature of the direct causal relationship between synchronous body movement and social bonding. Further studies may explore whether a more complex social interaction, such as singing together or being teamed up in a group game, increases synchronous body movements among the participants.

“We may also apply our experimental protocol to better understand the nature and the neural correlates of social impairment in disorders where social deficits are a common symptom, as in schizophrenia or autism,” says Shimojo.

The title of the Scientific Reports paper is “Interpersonal body and neural synchronization as a marker of implicit social interaction.” Funding for this research was provided by the Japan Science and Technology Agency’s CREST and the Tamagawa-Caltech gCOE (global Center Of Excellence) programs.

Journal Reference:

Kyongsik Yun, Katsumi Watanabe, Shinsuke Shimojo.Interpersonal body and neural synchronization as a marker of implicit social interaction. Scientific Reports, 2012; DOI: 10.1038/srep00959

What do chimps and humans have in common? Gut bacteria (MSNBC)

14/11/2012UncategorizedEvolução, Evolucionismo, Intestinos, Macacos, Primatas, Primatologia, Saúde, Visceralidaderenzotaddei

It’s nearly identical, and suggests patterns evolved before the two split and went own ways

Chimpanzees at Gombe Stream National Park in Tanzania have a lot in common with humans. And they both like to eat, apparently. Photo: Ian Gilby

By Stephanie Pappas

updated 11/13/2012 3:30:35 PM ET

Humans share about 99 percent of our genomes with chimpanzees. Now, research finds we share something else: gut bacteria.

The bacterial colonies that populate the chimpanzee intestinal tract are mirror images of those found in the human gut, researchers report Tuesday in the journal Nature Communications. The findings suggest gut bacteria patterns evolved before chimps and humans split and went their evolutionarily separate ways.

Human gut bacteria are crucial to health, with infants relying on healthy microbe populations to influence the developing immune system. Problems with microbe populations may also contribute to obesity and inflammatory bowel diseases.

Three intestinal ecosystems

In 2011, researchers learned that everyone’s gut bacteria fall into one of three different types, almost analogous to blood types. In each type, certain bacteria dominate. These types weren’t linked to any personal characteristics such as geographic area, age or gender. Researchers dubbed these distinct bacterial ecosystems “enterotypes.” (“Entero” means gut or intestine.)

“No one really knows why these three enterotypes exist,” said study researcher Andrew Moeller, a doctoral student at Yale University.

Along with his adviser Howard Ochman and their colleagues, Moeller wants to understand how these enterotypes arose. They could be distinctly human, he told LiveScience, which would suggest they arose relatively recently, perhaps in response to the development of agriculture. Or they could be ancient, shared among our closest primate relatives.

The researchers analyzed gut bacteria samples from 35 chimpanzees from Gombe Stream National Park in Tanzania. The chimpanzees were all in the subspecies Pan troglodytes schweinfurthii, the eastern chimpanzee, which arose about the same time as Homo sapiens.

Shared bacteria

The researchers found that, just like humans, chimps’ guts harbor one of three distinct types of bacterial colonies. Even more intriguingly, these enterotypes matched humans’ precisely. In type 1, for example, both humans and chimps show a predominance of Bacteroides,Faecalibacterium and Parabacteroides.

There were some differences. For example, in humans and chimps, enterotype 2 is marked by an overabundance of bacteria called Lachnospiraceae. In humans, the bacteria Prevotellae is also prevalent in type 2. In chimps, Prevotellae appears in significant numbers in all three enterotypes, perhaps because it is associated with a high-carbohydrate diet.

Other differences could help explain certain human health issues. By comparing human and chimpanzee gut bacteria, the researchers found many of the bacteria present only in humans are linked to diseases such as inflammatory bowel diseases, conditions that cause pain, diarrhea and vomiting.

Seven of the chimps in the study were tested repeatedly over eight years, and their gut microbes were found to change from type to type over that time period. No one has ever tested humans for changes over a period longer than two weeks, Moeller said, but the results suggest our enterotypes may shift over time, too.

Our shared history

The similarities between chimp and human colonies suggest enterotypes predate our species, which in turn suggests that none of the three ecosystems are better than the others, Moeller said.

“Before we found this in chimpanzees, there was a possibility that enterotypes were a product of modernization, which could mean they have some negative effects on health,” he said. “I don’t think there’s any reason to think one enterotype is going to have an effect on health that’s going to be better” than the others.

Moeller and his colleagues are now examining gorilla fecal samples to find out where they stand as slightly more distant primate relatives to humans.

“The next step is to try to find out the processes and mechanisms responsible for producing these three community states,” Moeller said, “which is kind of a lofty goal, but I think more sampling will actually reveal why these communities exist.”

Vídeo: Gente do Terra Madre

22/10/2012UncategorizedAgricultura familiar, Agricultura orgânica, Cidadania, Economia, participatividade, Reconexão com a terra, Saúde, Slow food, sociedade civil, Sustentabilidade, Visceralidaderenzotaddei

Neste vídeo você pode ver um panorama das pessoas e idéias que se entrecruzam no “Terra Madre – encontro mundial das comunidades do alimento” (terramadre.org). Evento que, a cada dois anos, reúne na Itália cerca de 7mil pessoas vindas de 150 países, entre pequenos produtores, agricultores, pescadores artesanais, cozinheiros, pesquisadores e ativistas do Slow Food (slowfood.com). Pessoas comprometidas em defender e promover modos de produção que respeitam o meio-ambiente, atentos aos recursos naturais do planeta, à conservação da biodiversidade e justiça social.

Saiba mais:
http://terramadre.slowfoodbrasil.com

Uma (in)certa antropologia

An (un)certain anthropology

Arquivo da tag: Visceralidade

Our Microbiome May Be Looking Out for Itself (New York Times)

Bactéria pode aumentar inteligência (Exame)

Political attitudes derive from body and mind: ‘Negativity bias’ explains difference between liberals and conservatives (Science Daily)

Learning the smell of fear: Mothers teach babies their own fears via odor, animal study shows (Science Daily)

Diet affects males’ and females’ gut microbes differently (Science Daily)

DESPRET: “TENER UN CUERPO ES APRENDER A AFECTARSE” (Networks & Matters)

Ancient Man Used “Super-Acoustics” to Alter Consciousness (… and speak with the dead?) (Phys.Org)

US Scientists, Oil Giant Stole Indigenous Blood (Common Dreams)

Life-style determines gut microbes (Max-Planck-Gesellschaft)

The Way to a Chimpanzee’s Heart Is Through Its Stomach (Science Daily)

Altering the Community of Gut Bacteria Promotes Health and Increases Lifespan (Science Daily)

Neuroscientists Pinpoint Location of Fear Memory in Amygdala (Science Daily)

Primates, Too, Can Move in Unison (Science Daily)

Digestão bloqueada, praga controlada (Revista Fapesp)

30/01/2013

Are Bacteria Making You Hungry? (Science Daily)

Social Synchronicity: Research Finds a Connection Between Bonding and Matched Movements (Science Daily)

What do chimps and humans have in common? Gut bacteria (MSNBC)

Vídeo: Gente do Terra Madre