A Blind Circadian Clock in Cavefish Reveals that Opsins Mediate Peripheral Clock Photoreception

The circadian clock is synchronized with the day-night cycle primarily by light. Fish represent fascinating models for deciphering the light input pathway to the vertebrate clock since fish cell clocks are regulated by direct light exposure. Here we have performed a comparative, functional analysis of the circadian clock involving the zebrafish that is normally exposed to the day-night cycle and a cavefish species that has evolved in perpetual darkness. Our results reveal that the cavefish retains a food-entrainable clock that oscillates with an infradian period. Importantly, however, this clock is not regulated by light. This comparative study pinpoints the two extra-retinal photoreceptors Melanopsin (Opn4m2) and TMT-opsin as essential upstream elements of the peripheral clock light input pathway.

Study suggests L-DOPA therapy for Angelman syndrome may have both benefits and unanticipated effects

Last year a clinical trial of L-DOPA — a mainstay of Parkinson’s disease therapy — was launched for Angelman syndrome, a rare intellectual disorder that shares similar motor symptoms such as tremors and difficulty with balance. The clinical trial is based on a 10-year-old case report showing benefit with the drug, but few studies since have explored the neurological justification for using L-DOPA to treat parkinsonian features in Angelman syndrome.

New research from the University of North Carolina School of Medicine, conducted in animal models of the disorder, now provides justification for this therapeutic approach. The study, published online ahead of print on Nov. 12 by the Journal of Clinical Investigation, suggests that L-DOPA could compensate for a loss of the neurochemical dopamine in the brain’s motor pathways and improve motor symptoms. However, it also indicates that the drug could add to an already increased amount of dopamine in the brain’s reward pathways and thus have unanticipated consequences on emotion and attention.

“The results were extremely surprising, because we don’t know of any other disorder where dopamine is affected one way in one brain pathway and the opposite way in another,” said Benjamin D. Philpot, PhD, associate professor of cell biology and physiology at UNC.

“If what we see in humans mirrors what we see in mice, then it does provide some optimism that L-DOPA might provide benefit for tremor,” said C.J. Malanga, MD, PhD, associate professor of neurology at UNC. “But it also raises caution that researchers might want to consider assessing other aspects of Angelman syndrome that might be affected by dopamine — not just motor symptoms but also other neuropsychiatric features.”  Malanga and Philpot are senior authors of the study.

Seeing someone yawn or hearing someone laugh makes you likely to follow suit. The same goes for scratching an itch. Now, for the first time, researchers have investigated the neural basis of contagious itch, identifying several brain regions whose activity predicts how susceptible people are to feeling itchy when they see someone else scratch.

Researchers in the United Kingdom showed volunteers video clips of people scratching an arm or a spot on their chest. Sure enough, subjects reported feeling more itchy, and most scratched themselves at least once during the experiment. When a subset of the volunteers watched the videos inside an functional magnetic resonance imaging scanner, the scans revealed activity in several of the same brain regions known to fire up in response to an itch-inducing histamine injection.

Activity in three of these areas correlated with subjects’ self-reported itchiness, the team reports online in the Proceedings of the National Academy of Sciences. Personality tests suggest that the trait that best predicts susceptibility to contagious itch is neuroticism, not empathy, as some researchers have suggested.

Meditation appears to produce enduring changes in emotional processing in the brain

A new study has found that participating in an 8-week meditation training program can have measurable effects on how the brain functions even when someone is not actively meditating. In their report in the November issue of Frontiers in Human Neuroscience, investigators at Massachusetts General Hospital (MGH), Boston University (BU), and several other research centers also found differences in those effects based on the specific type of meditation practiced.

"The two different types of meditation training our study participants completed yielded some differences in the response of the amygdala – a part of the brain known for decades to be important for emotion – to images with emotional content," says Gaëlle Desbordes, PhD, a research fellow at the Athinoula A. Martinos Center for Biomedical Imaging at MGH and at the BU Center for Computational Neuroscience and Neural Technology, corresponding author of the report. "This is the first time that meditation training has been shown to affect emotional processing in the brain outside of a meditative state."

Several previous studies have supported the hypothesis that meditation training improves practitioners’ emotional regulation. While neuroimaging studies have found that meditation training appeared to decrease activation of the amygdala – a structure at the base of the brain that is known to have a role in processing memory and emotion – those changes were only observed while study participants were meditating. The current study was designed to test the hypothesis that meditation training could also produce a generalized reduction in amygdala response to emotional stimuli, measurable by functional magnetic resonance imaging (fMRI).

Brain-damaged man ‘aware’ of scientists’ questions

A crash victim thought to have been in a vegetative state for more than a decade has used the power of thought to tell scientists he is not in pain.

Canadian Scott Routley, from London, Ontario, communicated with researchers via a brain scan, proving that he is conscious and aware. It is the first time such a severely brain-damaged patient has been able to provide clinically relevant information to doctors.

British neuroscientist Professor Adrian Owen, who leads the research team at the Brain and Mind Institute of Western Ontario, said: “Scott has been able to show he has a conscious, thinking mind. We have scanned him several times and his pattern of brain activity shows he is clearly choosing to answer our questions. We believe he knows who and where he is.”

Prof Owen was speaking on a BBC Panorama programme to be broadcast on Tuesday night.

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Research suggests that humans are slowly but surely losing intellectual and emotional abilities

Human intelligence and behavior require optimal functioning of a large number of genes, which requires enormous evolutionary pressures to maintain. A provocative hypothesis published in a recent set of Science and Society pieces published in the Cell Press journal Trends in Genetics (1, 2) suggests that we are losing our intellectual and emotional capabilities because the intricate web of genes endowing us with our brain power is particularly susceptible to mutations and that these mutations are not being selected against in our modern society.

"The development of our intellectual abilities and the optimization of thousands of intelligence genes probably occurred in relatively non-verbal, dispersed groups of peoples before our ancestors emerged from Africa," says the papers’ author, Dr. Gerald Crabtree, of Stanford University. In this environment, intelligence was critical for survival, and there was likely to be immense selective pressure acting on the genes required for intellectual development, leading to a peak in human intelligence.

Bluebrain is a ten-year documentary film-in-the-making about the twenty-first century race to reverse engineer the human brain. Such is the goal of The Blue Brain Project, based in Lausanne, Switzerland, one of the highest-profile neuroscience projects in the world today. Blue Brain’s audacious leader is Henry Markram, who publicly announced in 2009 that he seeks to reverse-engineer a human brain with digital simulations of all the physical properties of every neuron, powered by IBM supercomputers, by 2020. Director Noah Hutton began shooting in 2009, focusing exclusively on Markram’s Blue Brain Project— but starting in Year 3, the scope of the film has expanded to include the work of other prominent projects and labs seeking to understand the brain through different methods, including Sebastian Seung of M.I.T., Rafael Yuste of Columbia University, and Jeff Lichtman of Harvard University.

The film will continue to survey the work of other projects and their leaders in years to come, with yearly shorts released ahead of a full re-edit into a documentary feature due for completion in 2020. As the Blue Brain simulation is built over the course of this decade, so too will this documentary about a historic quest in human history. Through yearly updates from Blue Brain and other prominent scientists, philosophers, and ethicists, Bluebrain will track a crucial decade in the human mind’s relentless drive to understand itself.

Early stress may sensitize girls’ brains for later anxiety

High levels of family stress in infancy are linked to differences in everyday brain function and anxiety in teenage girls, according to new results of a long-running population study by University of Wisconsin-Madison scientists.

The study highlights evidence for a developmental pathway through which early life stress may drive these changes. Here, babies who lived in homes with stressed mothers were more likely to grow into preschoolers with higher levels of cortisol, a stress hormone. In addition, these girls with higher cortisol also showed less communication between brain areas associated with emotion regulation 14 years later. Last, both high cortisol and differences in brain activity predicted higher levels of adolescent anxiety at age 18.

The young men in the study did not show any of these patterns.

"We wanted to understand how stress early in life impacts patterns of brain development which might lead to anxiety and depression,” says first author Dr. Cory Burghy of the Waisman Laboratory for Brain Imaging and Behavior. "Young girls who, as preschoolers, had heightened cortisol levels, go on to show lower brain connectivity in important neural pathways for emotion regulation — and that predicts symptoms of anxiety during adolescence."

To test this, scans designed by Dr. Rasmus Birn, assistant professor of psychiatry in the UW School of Medicine and Public Health, showed that teenage girls whose mothers reported high levels of family stress when the girls were babies show reduced connections between the amygdala or threat center of the brain and the ventromedial prefrontal cortex, a part of the brain responsible for emotional regulation. Birn used a method called resting-state functional connectivity (fcMRI), which looks at the brain connections while the brain is at a resting state.

The study was published in Nature Neuroscience.

Stanford’s touch-sensitive plastic skin heals itself

Nobody knows the remarkable properties of human skin like the researchers struggling to emulate it. Not only is our skin sensitive – sending the brain precise information about pressure and temperature – but it also heals efficiently to preserve a protective barrier against the world. Combining these two features in a single synthetic material presented an exciting challenge for Stanford chemical engineering Professor Zhenan Bao and her team.

Now, they have succeeded in making the first material that can both sense subtle pressure and heal itself when torn or cut. Their findings will be published Nov. 11 in the journal Nature Nanotechnology.

In the last decade, there have been major advances in synthetic skin, said Bao, the study’s principal investigator, but even the most effective self-healing materials had major drawbacks. Some had to be exposed to high temperatures, making them impractical for day-to-day use. Others could heal at room temperature, but repairing a cut changed their mechanical or chemical structure, so they could heal themselves only once. Most important, no self-healing material was a good bulk conductor of electricity, a crucial property.

"To interface this kind of material with the digital world, ideally you want it to be conductive," said Benjamin Chee-Keong Tee, a researcher on the project.

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