Posts tagged Neuroscience 2012

Scientists are presenting new research on how the brain develops during the dynamic and vulnerable transition period from childhood to adulthood. The findings underscore the uniqueness of adolescence, revealing factors that may influence depression, decision-making, learning, and social relationships.

The findings were presented at Neuroscience 2012, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health.

The brain’s “reward system,” those brain circuits and structures that mediate the experience and pursuit of pleasure, figured prominently in several studies. The studies shed light on adolescents’ ability to control impulsivity and think through problems; reveal physical changes in the “social brain;” document connections between early home life and brain function in adolescence; and examine the impact of diet on depressive-like behavior in rodents.

Today’s new findings show that:

• Adolescents can throw impulsivity out the window when big rewards are at stake. The bigger the reward, the more thoughtful they can be, calling on important brain regions to gather and weigh evidence, and make decisions that maximize gains (BJ Casey, PhD).
• Rodents that receive an omega-3 fatty acid in their diets, from gestation through their early development, appear less vulnerable to depressive-like behaviors during adolescence (Christopher Butt, PhD).
• Depression in older adolescent boys may be associated with changes in communication between regions of the brain that process reward. At the same time, the study found possible connections between early emotional attachments — particularly with mothers — and later reward system function (Erika Forbes, PhD).
• Early cognitive stimulation appears to predict the thickness of parts of the human cortex in adolescence, and experiences at age four appear to have a greater impact than those at age eight (Martha Farah, PhD).
• During the span of adolescence, the volume of the “social brain” — those areas that deal with understanding other people — changes substantially, with notable gender differences (Kathryn Mills, BA).

"Advances in neuroscience continue to delve deeper and deeper into the unique and dynamically changing biology of the adolescent brain," said press conference moderator Jay Giedd, MD, of the National Institute of Mental Health, an expert on childhood and adolescent brain development. "The insights are beginning to elucidate the mechanisms that make the teen years a time of particular vulnerabilities but also a time of great opportunity."

(Source: sciencedaily.com)

A study by researchers from Emory University and Indiana University found that the beneficial effects daily exercise can have on the regeneration of nerves also require androgens such as testosterone in both males and females. It is the first report of both androgen-dependence of exercise on nerve regeneration and of an androgenic effect of exercise in females.

"The findings will provide a basis for the development of future treatment strategies for patients suffering peripheral nerve injuries," said Dale Sengelaub, professor in the Department of Psychological and Brain Sciences at IU. "And they underscore the need to tailor those treatments differently for men and women."

The researchers discussed the study on Monday at the Neuroscience 2012 scientific meeting in New Orleans.

Injuries to peripheral nerves are common. Hundreds of thousands of Americans are victims of traumatic injuries each year, and non-traumatic injuries, such as carpal tunnel syndrome, are found in even higher numbers. The researchers previously showed that two weeks of moderate daily exercise substantially improves regeneration of cut nerves and leads to functional recovery in mice, though different types of exercise are required to produce the effect in males and females. They now report that these beneficial effects of exercise require androgens such as testosterone in both males and females.

In the study they conducted, they exercised three groups of male and female mice. Nerves of the three groups were cut and surgically repaired. Once group received the drug flutamide, which blocks the androgen receptor. A second group received a placebo treatment. The third group was unexercised. Regenerating nerve fibers in the placebo group grew to more than twice the length of those in unexercised mice in both males and females. In flutamide-treated mice, the effects of exercise were blocked completely in both sexes.

The Society of Neuroscience is promoting the study (“Enhancement of peripheral axon regeneration by exercise requires androgen receptor signaling in both male and female mice”) to media covering the conference as a “Hot Topic.”

(Source: eurekalert.org)

(Credit: Oleg Zabielin / Shutterstock)

A new study in animals shows that chronic stress during pregnancy prevents brain benefits of motherhood, a finding that researchers suggest could increase understanding of postpartum depression.

Rat mothers showed an increase in brain cell connections in regions associated with learning, memory and mood. In contrast, the brains of mother rats that were stressed twice a day throughout pregnancy did not show this increase.

The researchers were specifically interested in dendritic spines – hair-like growths on brain cells that are used to exchange information with other neurons.

Previous animal studies conducted by lead author Benedetta Leuner of Ohio State University showed that an increase of dendritic spines in new mothers’ brains was associated with improved cognitive function on a task that requires behavioral flexibility – in essence, enabling more effective multitasking. The dendritic spines increased by about 20 percent in these brain regions in new mothers, according to her findings.

The stress in this new study negated those brain benefits of motherhood, causing the stressed rats’ brains to match brain characteristics of animals that had no reproductive or maternal experience.

The stressed rats also had less physical interaction with their babies than did unstressed rats, a behavior observed in human mothers who experience postpartum depression.

“Animal mothers in our research that are unstressed show an increase in the number of connections between neurons. Stressed mothers don’t,” said Leuner, assistant professor of psychology and neuroscience at Ohio State and lead author of the study. “We think that makes the stressed mothers more vulnerable. They don’t have the capacity for brain plasticity that the unstressed mothers do, and somehow that’s contributing to their susceptibility to depression.”

(Source: newswise.com)

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