Neuroscientists at the University of Pittsburgh have identified the neural networks that connect the cerebral cortex to the adrenal medulla, which is responsible for the body’s rapid response in stressful situations. These findings, reported in the online Early Edition of the journal Proceedings of the National Academy of Sciences (PNAS), provide evidence for the neural basis of a mind-body connection.
Specifically, the findings shed new light on how stress, depression and other mental states can alter organ function, and show that there is a real anatomical basis for psychosomatic illness. The research also provides a concrete neural substrate that may help explain why meditation and certain exercises such as yoga and Pilates can be so helpful in modulating the body’s responses to physical, mental and emotional stress.
“Our results turned out to be much more complex and interesting than we imagined before we began this study,” said senior author Peter L. Strick, Ph.D., Thomas Detre Chair of the Department of Neurobiology and scientific director of the University of Pittsburgh Brain Institute.
In their experiments, the scientists traced the neural circuitry that links areas of the cerebral cortex to the adrenal medulla (the inner part of the adrenal gland, which is located above each kidney). The scientific team included lead author Richard P. Dum, Ph.D., research associate professor in the Department of Neurobiology; David J. Levinthal, M.D., Ph.D., assistant professor in the Department of Medicine; and Dr. Strick.
The PNAS study also revealed that the areas of the cortex that are active when we sense conflict, or are aware that we have made an error, are a source of influence over the adrenal medulla. “This observation,” said Dr. Strick, “raises the possibility that activity in these cortical areas when you re-imagine an error, or beat yourself up over a mistake, or think about a traumatic event, results in descending signals that influence the adrenal medulla in just the same way as the actual event.” These anatomical findings have relevance for therapies that deal with post-traumatic stress.
Additional links with the adrenal medulla were discovered in cortical areas that are active during mindful mediation and areas that show changes in bipolar familial depression. “One way of summarizing our results is that we may have uncovered the stress and depression connectome,” says Dr. Strick.
Overall, these results indicate that circuits exist to link movement, cognition and affect to the function of the adrenal medulla and the control of stress. This circuitry may mediate the effects of internal states like chronic stress and depression on organ function and, thus, provide a concrete neural substrate for some psychosomatic illness. Source: University of Pittsburgh Schools of the Health Sciences./Science Daily