Friday, April 29, 2011

Prairie voles aid in search for autism treatment

Researchers at Emory’s Center for Translational Social Neuroscience (CTSN) are focusing on prairie voles as a new model to screen the effectiveness of drugs to treat autism.

They are starting with D-cycloserine, a drug Emory researchers have shown enhances behavioral therapy for phobias and also promotes pair bonding among prairie voles. Giving female voles D-cycloserine, which is thought to facilitate learning and memory, can encourage them to bond with a new male more quickly than usual. The findings will be published in Biological Psychiatry.

“The prairie vole model has enabled us to learn about complex neural pathways in social areas of the brain,” says Larry Young (at left) director of the CTSN. “We believe these insights will be useful in identifying drugs that enhance social cognition and learning. Drugs with these properties, particularly when combined with behavioral therapies, may be beneficial in the treatment of autism spectrum disorders.”

The prairie vole is one of the few species in nature that is monogamous and that creates deep social bonds while mating. The basic mechanisms of voles’ and humans’ social learning are similar enough that the learning that occurs during voles’ pair bonding can model complex human social interactions. Young and his colleagues have used voles to show the importance for social interactions of hormones such as oxytocin, which has also been proposed as a treatment for autism spectrum disorders.

The first author of the paper is Emory graduate student Meera Modi. She showed that D-cycloserine promotes pair bonding in prairie voles when it is injected peripherally. By infusing the drug directly into specific regions of the brain, she also showed the importance of two regions linked to social learning and reward, the nucleus accumbens and amygdala.

"We think D-cycloserine interacts with the brain's social information processing circuits to enhance the natural learning processes that occur there,” Modi says.

Emory researchers have shown D-cycloserine can be used to treat psychiatric diseases such as phobias and social anxiety. It is now in clinical trials for treatment of post-traumatic stress disorder. D-cycloserine is thought to enhance learning by acting on receptors for the neurotransmitter glutamate.

Autism spectrum disorders affect one in 110 children in the United States, according to the Centers for Disease Control and Prevention. Currently there are no drugs that specifically target social deficits found in individuals with autism, Young notes. Most drugs now prescribed for individuals with autism were originally developed for other disorders such as depression or schizophrenia.

The research was supported by a fellowship from Autism Speaks and by the National Institutes of Health.

Related:
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Mapping the social brain
Anxious kids confuse mad and sad

Thursday, April 28, 2011

Monkey memory mirrors that of humans

"For the first time, monkeys can actually tell us what they recollect," psychologist Ben Basile says of the new computer touchscreen method of testing memory. Photo and video (below) by Ben Basile.

By Carol Clark

Like humans, monkeys can recall and reproduce simple shapes from memory, a new study clearly shows for the first time.

The finding by Emory University psychologists Ben Basile and Robert Hampton was published today in Current Biology. The psychologists developed a computer touchscreen method to test the recall power of rhesus monkeys, drawing on the resources of Yerkes National Primate Research Center.

“Our observations of recall in Old World monkeys suggests that it may have been adaptive in primates for more than 30 million years, and that it does not depend on language or anything else that is uniquely human,” Basile says.

“We believe we have found a new method for testing animals that opens a whole new window into the world of non-human memory research,” Basile adds. “For the first time, monkeys can actually tell us what they recollect, and their test results are directly comparable to human tests.”

Humans have many different forms of memory that can be used in different ways. Recognition, for instance, demonstrates your ability to identify your house when shown a picture of it. Recall shows your ability to draw or describe your house, based solely on your memory of it.

In humans, recognition and recall tests can be supported by two different types of memory. This difference is most clearly seen in some rare cases of amnesia, where patients can easily recognize objects that are before them, but have lost the ability to recall those same objects when they are out of sight.

Previous research has established the ability of monkeys and many other animals to recognize objects. The problem of language, however, has thwarted efforts to test recall in non-humans.
video
The Emory scientists overcame the language barrier by teaching the rhesus monkeys to “draw.” The monkeys were shown simple shapes on a computer screen. Later, they were presented with a computer touchscreen that allowed them to recreate those shapes by touching the corresponding areas of a grid. The monkeys learned through trial and error that reproducing the shapes they had seen previously would bring a food reward. Once trained, the monkeys were able to transfer their memory skill to novel shapes.

The performance of the monkeys on the computer touchscreen paralleled that of humans using the Rey-Osterrieth Complex Figure Test, a standard human recall test, in which subjects draw a complicated shape from memory.

Related: Visit the Laboratory of Comparative Primate Cognition, and watch demonstrations of more experiments.

“Humans certainly recall more complex and sophisticated things over longer time periods,” Basile says. “But we’ve shown that for simple shapes, monkeys have a pattern of performance for recognition and recall that mirrors that of humans. And their ability to immediately transfer their performance to new shapes suggests that we’re tapping into some general cognitive capacity.”

Different types of memory may have evolved to solve a range of problems. Recognizing something as familiar, for instance, is quick and might allow for rapid responses to sightings of food and predators. Recollecting absent information is slower, and might support a more detailed and flexible use of memory, possibly knowledge of distant food locations or past social interactions for planning future behavior.

Related:
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Wednesday, April 27, 2011

Is it ethical to study dolphins in captivity?

iStockphoto.com

How smart are dolphins? Recent research suggests that some species of dolphins, particularly the bottlenose, may even be brighter than our closest living primate relative, the chimpanzee.

Does dolphin intelligence have ethical implications for how we interact with them?

You can join in a live "Science Now" discussion of the ethics of studying dolphins in captivity on Thursday, April 28, at 3 pm.

UPDATED, 4 pm on April 28: The full transcript of the dolphin debate is now available, click here.

Emory neuroscientist Lori Marino, who specializes in the neuroanatomy of dolphins, will be talking with Richard Conner, a biologist from the University of Massachusetts School of Marine Sciences who studies dolphin behavior.

Click here to join the live chat, hosted by Science, the journal of the American Society for the Advancement of Science.

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Monday, April 25, 2011

If a tree falls, learn from it


By Kelly Gray

Emory is reusing its dead or fallen trees as wood supplies for new kiosks that will help guide visitors in the campus' Lullwater Preserve.

The kiosks will be part of "Emory as Place," an educational initiative about the breadth and diversity of life within the campus and bioregion. From each kiosk, visitors will be able to synch their smartphones to Emory's sustainability map and learn more about the history and ecology of Lullwater.

"Tours of Lullwater provide an introduction to the history, ecosystems and ethical responsibilities in Lullwater that support our institutional legacy. The reuse of these trees is another interesting component in that history," says Ciannat Howett, director of sustainability intitiatives.



Most trees that die in Lullwater are left standing to allow for natural decomposition and to provide habitat for wildlife. But a white oak and two red oaks were recently harvested because they were a potential hazard for pedestrians.

Typically most large commercial lumber yards will not accept urban trees, which often have hidden metal objects in their tree trunks that can damage commercial band saws and shut down production lines.

Mississippi Wood Trader, however, is a unique lumber mill in Atlanta that provides wood for institutional and private customers. The large trees the urban mill processes are typically 80-100 years old, and are used for flooring, beams, molding, table and bar tops.

Related:
Windstorm reshapes Atlanta forests

Research takes flight in digital age

Nancy Seideman, Emory’s executive director of media relations, writes in the Academic Exchange:

The decision to enter a scholarly manuscript into the public sphere used to be more of a deliberate one.

Today there is no choice to make. Boundaries between academia and broader society have blurred considerably. Within academia, the pace of dissemination of scholarly work has quickened with the proliferation of electronic and open-access publication, coupled with the tremendous growth of social media and Internet channels of dissemination and the transformation of the still influential and far-reaching mainstream media.

Photo credit: iStockphoto.com.

It’s the job of today’s scholars to take the time to master communications skills and media tools in order to fulfill their civic responsibility to help translate and make accessible research that means something to people. In doing so, we need to resist the frequent pressure from the media and the general public to make a leap from fundamental research to application or revelation.

"Meaning something,” after all, can take many forms: inviting people to share in the thrill of discovery, unearthing the brittle piece of paper in an archive that provides a clue in an historical mystery, uncovering a family ledger that reveals how a famous author developed his characters, identifying a molecule that just might have help in treatment of an intractable disease. People hunger for knowledge, for experiencing that sense of wonder and excitement of exploration that only the academic world can provide.

Read more.

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Monday, April 18, 2011

Dengue fever's growing range and virulence


Emory disease ecologist Gonzalo Vazquez-Prokopec writes about the growing threat of the dengue virus, for the journal Future Microbiology:

We are still losing our global battle against dengue virus (DENV). After half a century since the beginning of its rampant spread, and despite decades of continued vector control efforts, DENV has re-emerged to become the most important human mosquito-borne viral infection. Currently, approximately 70–100 million cases of classic DENV infection are reported every year (most of them in tropical and subtropical countries), with an estimated 2.1 million cases of life-threatening disease in the form of Dengue Hemorrhagic Fever/Dengue Shock Syndrome. Over the last two decades, the number of dengue fever epidemics has increased exponentially, and the dramatic range expansion of the endemic and hyper-endemic areas is indisputable. Moreover, the global incidence of Dengue Hemorrhagic Fever and Dengue Shock Syndrome has increased 30-fold since the 1950s, and both severe manifestations are a leading cause of hospitalization in parts of Southeast Asia.

Increases in human population, rapid and unplanned urbanization, and human travel have contributed to the resurgence and spread of DENV infections. However, it is the inadequacy of our current tools to combat the virus carrying mosquito vectors and the virus itself, together with our limited understanding of the biological, social and behavioral dimensions of virus transmission that have contributed most to our inability to contain this dengue pandemic. New approaches, tools, and methods for dengue control and prevention are desperately needed.

Read the whole article in Future Microbiology.

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Thursday, April 14, 2011

Passionate ecologist seeks outdoorsy date


Emory biology student Tom Quigley wants a date, and he wants it bad. Can you recommend him?

He’s wooing the Sierra Club’s Best Internship on Earth. Quigley is among 25 semifinalists from across the country vying for $5,000 in gear and cash, and a summer job making videos of Sierra Club outings.

Check out his video application, above. (Don’t miss this bonus track of him playing acoustic guitar and singing "Little Lion Man.”)

If you think Quigley’s got what it takes to treat nature right, go to the Sierra Club site and leave a comment for him.

Monday, April 11, 2011

Psychologists closing in on claustrophobia



By Carol Clark

We all move around in a protective bubble of “near space,” more commonly known as “personal space.” But not everyone’s bubble is the same size. People who project their personal space too far beyond their bodies, or the norm of arm’s reach, are more likely to experience claustrophobic fear, a new study finds.

The study, to be published in the journal Cognition, is one of the first to focus on the perceptual mechanisms of claustrophobic fear.

“We’ve found that people who are higher in claustrophobic fear have an exaggerated sense of the near space surrounding them,” says Emory psychologist Stella Lourenco, who led the research. “At this point, we don’t know whether it’s the distortion in spatial perception that leads to the fear, or vice versa. Both possibilities are likely.”

Everyone experiences claustrophobic fear to some extent, but there is a wide range of individual differences. About 4 percent of people are estimated to suffer from full-blown claustrophobia, which can cause them to have panic attacks when traveling through a tunnel or riding in an elevator. Some people seek medical treatment for the condition.

Photo: iStockphoto.com

“Increasing our understanding of the factors that contribute to claustrophobia may help clinicians develop more effective therapies for what can be a highly debilitating fear,” says Matthew Longo, one of the study’s co-authors and a psychologist at Birkbeck, University of London.

Claustrophobia is often associated with a traumatic experience, such as getting stuck in an elevator for a long period. “However, we know that some people who experience traumatic events in restricted spaces don’t develop full-blown claustrophobia,” Lourenco says. “That led us to ask whether other factors might be involved. Our results show a clear relation between claustrophobic fear and basic aspects of spatial perception.”

Neural and behavioral evidence shows that we treat space that is within arm’s reach differently from space that is farther away. “It makes adaptive sense to be more aware of things that are closer to the body, for both utilitarian purposes and defensive ones,” Lourenco says. “It also makes adaptive sense to be afraid of things that are too far away from you on the vertical dimension, since there can be a great cost to falling.”

In ongoing work, Lourenco and Longo are investigating how the range of individual differences in spatial perception relates to fear. They are asking normal research subjects, who are not seeking treatment for claustrophobia or acrophobia (the fear of heights), to estimate various distances.

While the subjects who have higher levels of claustrophobic fear underestimate horizontal distances, those who have more acrophobic fear overestimate vertical distances. “One intriguing possibility is that these two types of fear may form opposite ends of a single spatial-perceptual continuum,” Lourenco says.

Related:
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Friday, April 8, 2011

Get ready to flash your intelligence

You’re working late in a downtown Atlanta skyscraper. You realize that you are all alone in the building. You glance out the window: Below you see hordes of people start moving chaotically, then spontaneously flow together into an orderly stream.

Don’t be a bystander. It’s time to put on some sensible shoes and listen to those voices in your head. Sign-up to join a science flash mob of hundreds of people demonstrating how molecules evolve and self-assemble.

The first “Group Intelligence” flash mob begins on the Emory Quad next Thursday, April 14 at 7 pm. Group Intelligence will spread to downtown Atlanta’s Woodruff Park the following week. From there, it’s going national and to Europe.

It’s all part of the daring convergence of science and art brought to you by Out of Hand Theater and the Center for Chemical Evolution. The center is a collaboration of Emory and Georgia Tech, funded by the NSF and NASA.

Click here to join Group Intelligence. Remember: It takes a diversity of molecules, and people, to ensure our survival.

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Windstorm reshapes Atlanta forests


Atlanta is known for its mammoth trees, which create a forest atmosphere in some metro areas. Monday’s violent storm felled many of these giants in and around the city, killing six people, damaging property and taking out power.

The storm took down 40 trees on the Emory campus. The university has some of the best-preserved hardwood forests in the Piedmont province of the Southeast. When large trees are downed by storms, it’s part of a natural process of clearing out old growth, explains Carl Brown, adjunct faculty in environmental studies.

Hal Jacobs, who writes the blog Quad Talk, spoke with Brown next to Mizell Bridge and the Carlos Museum. Check out the beautiful scenes of campus forest in his video, above, including a great shot of a hawk.

Related:
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How a hike led to a math 'Eureka!'

Thursday, April 7, 2011

What makes yawns contagious?

Bored with your friends? Perhaps it's evolutionary. New research shows that chimpanzees are more likely to "catch" yawns from familiar chimpanzees than strangers. Photo: iStockPhoto.com.

Contagious yawning is not just a marker of sleepiness or boredom. For chimpanzees, it may actually be a sign of a social connection between individuals.

Scientists at Emory’s Yerkes National Primate Research Center discovered that chimpanzees yawn more after watching familiar chimpanzees yawn than after watching strangers yawn. Their findings, published today in the Public Library of Science One (PLoS ONE), may help scientists understand empathy, the mechanism thought to underlie contagious yawning, in both chimpanzees and humans. The research also may help show how social biases strengthen or weaken empathy.

Yerkes researchers Matthew Campbell and Frans de Waal propose that when yawning spreads between chimpanzees, it reflects an underlying empathy between them.

“The idea is that yawns are contagious for the same reason that smiles, frowns and other facial expressions are contagious,” they write. “Our results support the idea that contagious yawning can be used as a measure of empathy, because the biases we observed were similar to empathy biases previously seen in humans.”

They studied 23 adult chimpanzees that were housed in two separate groups. The chimpanzees viewed several nine-second video clips of other chimpanzees, in both groups, either yawning or doing something else. They yawned 50 percent more frequently in response to seeing members of their group yawn compared to seeing others yawn.

In humans, scientists have identified certain parts of the brain that are activated both when someone experiences pain and when they see someone else experiencing pain. In these experiments, people tend to show more sensitivity for members of the same social group.

The results raise the question of whether contagious yawning among humans shows the same biases: favoring members of the same social group over different social groups.

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Tuesday, April 5, 2011

Chimps, bonobos yield clues to social brain

The social behaviors of the chimpanzee (left) and the bonobo (right) "mirror individual differences within the human population," says anthropologist James Rilling. Photos, copyright by Frans de Waal.

By Carol Clark

It’s been a puzzle why our two closest living primate relatives, chimpanzees and bonobos, have widely different social traits, despite belonging to the same genus. Now, a comparative analysis of their brains shows neuroanatomical differences that may be responsible for these behaviors, from the aggression more typical of chimpanzees to the social tolerance of bonobos.

“What’s remarkable is that the data appears to match what we know about the human brain and behavior,” says Emory anthropologist James Rilling, who led the analysis. “The neural circuitry that mediates anxiety, empathy and the inhibition of aggression in humans is better developed in bonobos than in chimpanzees.”

The journal of Social Cognitive and Affective Neuroscience published the results, the most comprehensive comparative analysis to date of the neural systems of chimpanzees and bonobos.

“By contributing to our basic understanding of how brain anatomy relates to social behavior, this study may provide clues to the brain dysfunction underlying human social behavioral disorders like psychopathy and autism,” Rilling says.

Chimpanzees and bonobos diverged from a common ancestor with humans about six million years ago, and from each other just one-to-two million years ago. Despite this relatively brief separation in evolutionary terms, the two species exhibit significant differences in social behavior. Compared with chimpanzees, bonobos are more anxious, less aggressive, more socially tolerant, more playful, more sexual and perhaps more empathic.

“Chimpanzees tend to resolve conflict by using aggression, while bonobos are more likely to use behavioral mechanisms like sex and play to diffuse tension,” Rilling says. “The social behaviors of the two species mirror individual differences within the human population.”
Neuroanatomical differences between the brain of the chimpanzee (left) and the bonobo (right) match what we know about the human brain and behavior. Images by James Rilling.

Rilling heads Emory’s Laboratory for Darwinian Neuroscience, a leader in the use of non-invasive neuro-imaging technology to compare the neurobiology of humans and other primates. The anthropology department lab draws on resources of Emory’s Yerkes National Primate Research Center.

“In addition to exploring links between neuroanatomy and different social behaviors, we’re mapping the underlying biology for how species evolve and differentiate,” Rilling says.

A range of imaging and analytical techniques were used in the chimpanzee-bonobo study. Voxel-based morphometry compared the gray matter in standard structural scans of the brains. Diffusion tensor imaging (DTI) captured the white matter connections, to compare the fiber tracts that “wire” the brain.

The results showed that bonobos have more developed circuitry for key nodes within the limbic system, the so-called emotional part of the brain, including the amygdala, the hypothalamus and the anterior insula. The anterior insula and the amygdala are both implicated in human empathy.

“We also found that the pathway connecting the amygdala and the prefrontal cortex is larger in bonobos than chimpanzees,” Rilling says. “When our amygdala senses that our actions are causing someone else distress, we may use that pathway to adjust our behavior in a prosocial direction.”

Chimpanzees have better developed visual system pathways, according to the analysis. Previous research has suggested that those pathways are important for tool use, a skill which chimpanzees appear better at than bonobos.

Rilling conducted the research with Yerkes neuroscientist Todd Preuss; DTI experts Timothy Behrens and Jan Scholz from Oxford University; Emory graduate student Bhargav Errangi; and former Emory student Matthew Glasser.

Related:
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