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An international team of scientists, led by researchers at the University of California, San Diego School of Medicine, reports that abnormal sequences of DNA known as rare copy number variants, or CNVs, appear to play a significant role in the risk for early onset bipolar disorder. The findings will be published in the December 22 issue of the journal Neuron.

Most cases of autism are not caused by a single genetic mutation. However, several disorders with autism-like symptoms, including the rare Fragile X syndrome, can be traced to a specific mutation. Several years ago, MIT neuroscientist Mark Bear discovered that this mutation leads to overproduction of proteins found in brain synapses — the connections between neurons that allow them to communicate with each other.

Potential clues to how autism miswires the brain are emerging from a study of a rare, purely genetic form of the disorders that affects fewer than 20 people worldwide. Using cutting-edge “disease-in a-dish” technology, researchers funded by the National Institutes of Health have grown patients’ skin cells into neurons to discover what goes wrong in the brain in Timothy Syndrome. Affected children often show symptoms of autism spectrum disorders along with a constellation of physical problems. Included in this report is a video summary of the study results.

A major study of recent international data on school mathematics performance casts doubt on some common assumptions about gender and math achievement — in particular, the idea that girls and women have less ability due to a difference in biology. “We tested some recently proposed hypotheses that try to explain a supposed gender gap in math performance and found they were not supported by the data,” says Janet Mertz, senior author of the study and a professor of oncology at the University of Wisconsin-Madison.

Pediatric researchers analyzing genetic influences in attention-deficit/hyperactivity disorder (ADHD) have found alterations in specific genes involved in important brain signaling pathways. The study raises the possibility that drugs acting on those pathways might offer a new treatment option for patients with ADHD who have those gene variants – potentially, half a million U.S. children.

roblems like anxiety and depression are caused by psychological and environmental factors, and are known to be influenced by genetic proclivities. However, it is still not clear how each factor affects the brain’s functions to induce anxious and depressive symptoms. To shed light on these interactions, a team from the Centre Émotion-Remédiation et Réalité Virtuelle (Center for Emotion Remediation and Virtual Reality, CNRS / UPMC / CHU Pitié Salpêtrière) has investigated the amygdala, a part of the brain that is hyperactive in individuals suffering from anxiety and depression.

A study by researchers at UC Davis has found that pregnant women with a particular gene variation are more likely to produce autoantibodies to the brains of their developing fetuses and that the children of these mothers are at greater risk of later being diagnosed with autism. The finding is the first to demonstrate a genetic mechanism at play in the development of the neurodevelopmental disorder among some children – offering the possibility of a genetic test for some women at risk for having a child with autism, said Judy Van de Water, an immunologist and the study’s co-principal investigator.
Young genes that appeared since the primate branch split from other mammal species are expressed in unique structures of the developing human brain, a new analysis finds. The correlation suggests that scientists studying the evolution of the human brain should look to genes considered recent by evolutionary standards and early stages of brain development.

The study found that stress experienced by young female rats can impair their future offspring, but can also improve resilience. The study also showed that providing the young stressed females with an enriched environment (often used to model therapy), can indeed ameliorate some of the effects. “The similarities between rats and humans raise the question of whether similar effects might transpire in humans; for example, exposure to war or natural disasters might have heritable effects,” explains Prof. Micah Leshem who headed the study.

A study using mice provides insight into how a specific receptor subtype in the brain could play a role in increasing a person’s risk for attention-deficit hyperactivity disorder (ADHD). The research, conducted by the Intramural Research Program (IRP) at the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health, could also help explain how stimulants work to treat symptoms of ADHD.