Diabetes is known to impair the cognitive health of people, but now scientists have identified one potential mechanism underlying these learning and memory problems.
A new National Institutes of Health (NIH) study in diabetic rodents finds that increased levels of a stress hormone produced by the adrenal gland disrupt the healthy functioning of the hippocampus, the region of the brain responsible for learning and short-term memory. Moreover, when levels of the adrenal glucocorticoid hormone corticosterone (also known as cortisol in humans) are returned to normal, the hippocampus recovers its ability to build new cells and regains the “plasticity” needed to compensate for injury and disease and adjust to change.
The study appears in the Feb. 17, 2008, issue of Nature Neuroscience and was conducted by the National Institute on Aging (NIA), part of the NIH. NIA's Mark Mattson, Ph.D., and colleagues in the Institute's Intramural Research Program performed the study with Alexis M. Stranahan, a graduate student at Princeton University in New Jersey.
“This research in animal models is intriguing, suggesting the possibility of novel approaches in preventing and treating cognitive impairment by maintaining normal levels of glucocorticoid,” said Richard J. Hodes, M.D., NIA director. “Further study will provide a better understanding of the often complex interplay between the nervous system, hormones and cognitive health.”