Arquivo da tag: Drosófila

Flies possess more sophisticated cognitive abilities than previously known (Science Daily)

18/02/2022UncategorizedAnimais, Animismo, Cognição, Consciência, Drosófila, Inteligência animalrenzotaddei

Immersive virtual reality and real-time brain activity imaging showcase Drosophila’s capabilities of attention, working memory and awareness

Date: February 17, 2022

Source: University of California – San Diego

Summary: Common flies feature more advanced cognitive abilities than previously believed. Using a custom-built immersive virtual reality arena, neurogenetics and real-time brain activity imaging, researchers found attention, working memory and conscious awareness-like capabilities in fruit flies.

Fruit fly (stock image). *Credit: © Arif_Vector / stock.adobe.com*

As they annoyingly buzz around a batch of bananas in our kitchens, fruit flies appear to have little in common with mammals. But as a model species for science, researchers are discovering increasing similarities between us and the miniscule fruit-loving insects.

In a new study, researchers at the University of California San Diego’s Kavli Institute for Brain and Mind (KIBM) have found that fruit flies (Drosophila melanogaster) have more advanced cognitive abilities than previously believed. Using a custom-built immersive virtual reality environment, neurogenetic manipulations and in vivo real-time brain-activity imaging, the scientists present new evidence Feb. 16 in the journal Nature of the remarkable links between the cognitive abilities of flies and mammals.

The multi-tiered approach of their investigations found attention, working memory and conscious awareness-like capabilities in fruit flies, cognitive abilities typically only tested in mammals. The researchers were able to watch the formation, distractibility and eventual fading of a memory trace in their tiny brains.

“Despite a lack of obvious anatomical similarity, this research speaks to our everyday cognitive functioning — what we pay attention to and how we do it,” said study senior author Ralph Greenspan, a professor in the UC San Diego Division of Biological Sciences and associate director of KIBM. “Since all brains evolved from a common ancestor, we can draw correspondences between fly and mammalian brain regions based on molecular characteristics and how we store our memories.”

To arrive at the heart of their new findings the researchers created an immersive virtual reality environment to test the fly’s behavior via visual stimulation and coupled the displayed imagery with an infra-red laser as an averse heat stimulus. The near 360-degree panoramic arena allowed Drosophila to flap their wings freely while remaining tethered, and with the virtual reality constantly updating based on their wing movement (analyzed in real-time using high-speed machine-vision cameras) it gave the flies the illusion of flying freely in the world. This gave researchers the ability to train and test flies for conditioning tasks by allowing the insect to orient away from an image associated with the negative heat stimulus and towards a second image not associated with heat.

They tested two variants of conditioning, one in which flies were given visual stimulation overlapping in time with the heat (delay conditioning), both ending together, or a second, trace conditioning, by waiting 5 to 20 seconds to deliver the heat after showing and removing the visual stimulation. The intervening time is considered the “trace” interval during which the fly retains a “trace” of the visual stimulus in its brain, a feature indicative of attention, working memory and conscious awareness in mammals.

The researchers also imaged the brain to track calcium activity in real-time using a fluorescent molecule they genetically engineered into their brain cells. This allowed the researchers to record the formation and duration of the fly’s living memory since they saw the trace blinking on and off while being held in the fly’s short-term (working) memory. They also found that a distraction introduced during training — a gentle puff of air — made the visual memory fade more quickly, marking the first time researchers have been able to prove such distractedness in flies and implicating an attentional requirement in memory formation in Drosophila.

“This work demonstrates not only that flies are capable of this higher form of trace conditioning, and that the learning is distractible just like in mammals and humans, but the neural activity underlying these attentional and working memory processes in the fly show remarkable similarity to those in mammals,” said Dhruv Grover, a UC San Diego KIBM research faculty member and lead author of the new study. “This work demonstrates that fruit flies could serve as a powerful model for the study of higher cognitive functions. Simply put, the fly continues to amaze in how smart it really is.”

The scientists also identified the area of the fly’s brain where the memory formed and faded — an area known as the ellipsoid body of the fly’s central complex, a location that corresponds to the cerebral cortex in the human brain.

Further, the research team discovered that the neurochemical dopamine is required for such learning and higher cognitive functions. The data revealed that dopamine reactions increasingly occurred earlier in the learning process, eventually anticipating the coming heat stimulus.

The researchers are now investigating details of how attention is physiologically encoded in the brain. Grover believes the lessons learned from this model system are likely to directly inform our understanding of human cognition strategies and neural disorders that disrupt them, but also contribute to new engineering approaches that lead to performance breakthroughs in artificial intelligence designs.

The coauthors of the study include Dhruv Grover, Jen-Yung Chen, Jiayun Xie, Jinfang Li, Jean-Pierre Changeux and Ralph Greenspan (all affiliated with the UC San Diego Kavli Institute for Brain and Mind, and J.-P. Changeux also a member of the Collège de France).

Journal Reference:

Dhruv Grover, Jen-Yung Chen, Jiayun Xie, Jinfang Li, Jean-Pierre Changeux, Ralph J. Greenspan. Differential mechanisms underlie trace and delay conditioning in Drosophila. Nature, 2022; DOI: 10.1038/s41586-022-04433-6

Understanding fruit fly behavior may be next step toward autonomous vehicles (Science Daily)

07/04/2021UncategorizedAutomóveis autônomos, Cibernética, Drosófila, Inteligência animal, Inteligência artificial, Modelagemrenzotaddei

Could the way drosophila use antennae to sense heat help us teach self-driving cars make decisions?

Date: April 6, 2021

Source: Northwestern University

Summary: With over 70% of respondents to a AAA annual survey on autonomous driving reporting they would fear being in a fully self-driving car, makers like Tesla may be back to the drawing board before rolling out fully autonomous self-driving systems. But new research shows us we may be better off putting fruit flies behind the wheel instead of robots.

With over 70% of respondents to a AAA annual survey on autonomous driving reporting they would fear being in a fully self-driving car, makers like Tesla may be back to the drawing board before rolling out fully autonomous self-driving systems. But new research from Northwestern University shows us we may be better off putting fruit flies behind the wheel instead of robots.

Drosophila have been subjects of science as long as humans have been running experiments in labs. But given their size, it’s easy to wonder what can be learned by observing them. Research published today in the journal Nature Communications demonstrates that fruit flies use decision-making, learning and memory to perform simple functions like escaping heat. And researchers are using this understanding to challenge the way we think about self-driving cars.

“The discovery that flexible decision-making, learning and memory are used by flies during such a simple navigational task is both novel and surprising,” said Marco Gallio, the corresponding author on the study. “It may make us rethink what we need to do to program safe and flexible self-driving vehicles.”

According to Gallio, an associate professor of neurobiology in the Weinberg College of Arts and Sciences, the questions behind this study are similar to those vexing engineers building cars that move on their own. How does a fruit fly (or a car) cope with novelty? How can we build a car that is flexibly able to adapt to new conditions?

This discovery reveals brain functions in the household pest that are typically associated with more complex brains like those of mice and humans.

“Animal behavior, especially that of insects, is often considered largely fixed and hard-wired — like machines,” Gallio said. “Most people have a hard time imagining that animals as different from us as a fruit fly may possess complex brain functions, such as the ability to learn, remember or make decisions.”

To study how fruit flies tend to escape heat, the Gallio lab built a tiny plastic chamber with four floor tiles whose temperatures could be independently controlled and confined flies inside. They then used high-resolution video recordings to map how a fly reacted when it encountered a boundary between a warm tile and a cool tile. They found flies were remarkably good at treating heat boundaries as invisible barriers to avoid pain or harm.

Using real measurements, the team created a 3D model to estimate the exact temperature of each part of the fly’s tiny body throughout the experiment. During other trials, they opened a window in the fly’s head and recorded brain activity in neurons that process external temperature signals.

Miguel Simões, a postdoctoral fellow in the Gallio lab and co-first author of the study, said flies are able to determine with remarkable accuracy if the best path to thermal safety is to the left or right. Mapping the direction of escape, Simões said flies “nearly always” escape left when they approach from the right, “like a tennis ball bouncing off a wall.”

“When flies encounter heat, they have to make a rapid decision,” Simões said. “Is it safe to continue, or should it turn back? This decision is highly dependent on how dangerous the temperature is on the other side.”

Observing the simple response reminded the scientists of one of the classic concepts in early robotics.

“In his famous book, the cyberneticist Valentino Braitenberg imagined simple models made of sensors and motors that could come close to reproducing animal behavior,” said Josh Levy, an applied math graduate student and a member of the labs of Gallio and applied math professor William Kath. “The vehicles are a combination of simple wires, but the resulting behavior appears complex and even intelligent.”

Braitenberg argued that much of animal behavior could be explained by the same principles. But does that mean fly behavior is as predictable as that of one of Braitenberg’s imagined robots?

The Northwestern team built a vehicle using a computer simulation of fly behavior with the same wiring and algorithm as a Braitenberg vehicle to see how closely they could replicate animal behavior. After running model race simulations, the team ran a natural selection process of sorts, choosing the cars that did best and mutating them slightly before recombining them with other high-performing vehicles. Levy ran 500 generations of evolution in the powerful NU computing cluster, building cars they ultimately hoped would do as well as flies at escaping the virtual heat.

This simulation demonstrated that “hard-wired” vehicles eventually evolved to perform nearly as well as flies. But while real flies continued to improve performance over time and learn to adopt better strategies to become more efficient, the vehicles remain “dumb” and inflexible. The researchers also discovered that even as flies performed the simple task of escaping the heat, fly behavior remains somewhat unpredictable, leaving space for individual decisions. Finally, the scientists observed that while flies missing an antenna adapt and figure out new strategies to escape heat, vehicles “damaged” in the same way are unable to cope with the new situation and turn in the direction of the missing part, eventually getting trapped in a spin like a dog chasing its tail.

Gallio said the idea that simple navigation contains such complexity provides fodder for future work in this area.

Work in the Gallio lab is supported by the NIH (Award No. R01NS086859 and R21EY031849), a Pew Scholars Program in the Biomedical Sciences and a McKnight Technological Innovation in Neuroscience Awards.

Story Source:

Materials provided by Northwestern University. Original written by Lila Reynolds. Note: Content may be edited for style and length.