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Natural Brain Chemical Manages Despair

BrainScientists have identified a brain chemical that appears to help animals cope with ‘behavioral despair’ caused by inescapable stress.

Researchers studying the brains of mice identified a gene-regulating protein that triggers the animals’ ability to cope with anguish hopelessness and associated with inescapable stress.

They said their studies have yielded an animal model of resilience that they will use to explore how antidepressants work on the brain circuitry involved in such stress response.

Led by Eric Nestler, the researchers published their findings in the journal Neuron, published by Cell Press.

In earlier studies, Nestler and his colleagues showed that exposure to repeated stress caused an increase in a protein called ∆FosB in the brain. This protein is a “transcription factor,” a regulatory protein that controls the activity of multiple target genes.

In the new experiments, they sought to explore the role of ∆FosB in regulating adaptation to stress. Their approach involved first exposing mice to random shocks from which the animals could not escape. Such repeated exposure to inescapable stress tends to increase the lag time for mice to escape subsequent shocks, when they are given the chance to escape.

Measuring this lag time, or the complete failure to escape, gave the researchers a measure of “behavioral despair.” This experimental approach has long been used as an animal model of human “affective disorders” such as depression, posttraumatic stress disorder, and bipolar disorder. As in humans with such disorders, this behavioral despair in mice responds to antidepressants.

Nestler and colleagues discovered that the mice that showed the smallest lag in escape times also had higher levels of ∆FosB in a brain region involved in processing of pain signals and defensive responses. In contrast, animals with either longer escape lag times or failure to escape showed lower ∆FosB levels.

What’s more, when the researchers introduced higher levels of the gene for ∆FosB into mice, they found it reduced the level of behavioral despair as reflected in their readiness to escape shocks.

The researchers also established that increased ∆FosB levels in the mice decreased the activity of the gene for a protein called “substance P¡” known to regulate processes such as mood, pain sensitivity, anxiety, and stress.

“Our present results provide a fundamentally novel and testable model for the mechanisms of resilience,” concluded the researchers.

“Our future studies will test the hypothesis that antidepressant treatments may enhance resilience by stimulating these same adaptive processes which occur spontaneously in some, but not all, of the individuals in a population exposed to chronic stress,” they wrote.

Source: Cell Press

Natural Brain Chemical Manages Despair

Rick Nauert PhD

Rick Nauert, PhDDr. Rick Nauert has over 25 years experience in clinical, administrative and academic healthcare. He is currently an associate professor for Rocky Mountain University of Health Professionals doctoral program in health promotion and wellness. Dr. Nauert began his career as a clinical physical therapist and served as a regional manager for a publicly traded multidisciplinary rehabilitation agency for 12 years. He has masters degrees in health-fitness management and healthcare administration and a doctoral degree from The University of Texas at Austin focused on health care informatics, health administration, health education and health policy. His research efforts included the area of telehealth with a specialty in disease management.

APA Reference
Nauert PhD, R. (2015). Natural Brain Chemical Manages Despair. Psych Central. Retrieved on August 17, 2018, from https://psychcentral.com/news/2007/07/20/natural-brain-chemical-manages-despair/1037.html

 

Scientifically Reviewed
Last updated: 6 Oct 2015
Last reviewed: By John M. Grohol, Psy.D. on 6 Oct 2015
Published on PsychCentral.com. All rights reserved.