brain plasticity

New discoveries on depression

depressed woman

Image: iStockphoto

During depression, the brain becomes less plastic and adaptable, and thus less able to perform certain tasks, like storing memories. Researchers at the Swedish medical university Karolinska Institutet have now traced the brain’s lower plasticity to reduced functionality in its support cells, and believe that learning more about these cells can pave the way for radical new therapies for depression. “We were able to cure memory dysfunction in ‘depressed’ rats by giving them doses of D-serine,” says Mia Lindskog, biologist and Assistant Professor at Karolinska Institutet’s Department of Neuroscience.

Dr Lindskog and her team used FSL rats, which are rats that have been specially bred with a disposition for ‘depression’. The rats were first put through two tests to confirm that they had the symptoms that are also characteristic of human depression. In the first, the rats’ memories were checked by repeatedly being exposed to different objects; in the second, the team assessed their level of apathy by releasing them in a container of water and observing whether they merely stayed floating in the container or immediately tried to climb out (non of the rats had to stay in the water for more than five minutes). In both cases the FSL rats’ results were compared with normal laboratory rats, and memory disorders and apathy could be confirmed.

The researchers then injected the rats with D-serine. This substance improved their memories but had no effect on the apathy. “We have shown that there are two symptoms here that can be influenced independently of one another, which means they could be treated in tandem in patients with depression,” says Dr Lindskog. The researchers also studied the synaptic activity in the hippocampus of the rats, a part of the brain which plays an important part in the memory. [continue reading…]

Volunteer service, such as tutoring children, can help older adults delay or reverse declining brain function, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health. Using functional magnetic resonance imaging (fMRI), the researchers found that seniors participating in a youth mentoring program made gains in key brain regions that support cognitive abilities important to planning and organizing one’s daily life. The study is the first of its kind to demonstrate that valuable social service programs, such as Experience Corps—a program designed to both benefit children and older adults’ health—can have the added benefits of improving the cognitive abilities of older adults, enhancing their quality of life. The study is published in the December issue of the Journals of Gerontology: Medical Sciences.

About 78 million Americans were born from 1946 to 1964. Individuals of retirement age are the fastest-growing sector of the U.S. population, so there is great interest in preserving their cognitive and physical abilities, especially given the societal cost of the alternative. [continue reading…]