Research on stress hormone effects on the brain reveals unexpected findings

Stress is a common problem often resulting in poor health and mental disorders. New research has revealed that current concepts on how stress hormones act on the brain may need to be reassessed. It is thought that disturbances in the action of stress hormones play a key role in causing mental disorders, like major depression and post-traumatic stress disorder (PTSD). Learning to cope with stressful events is known to require changes in the expression of genes in the hippocampus, a limbic brain region involved in learning and memory. Such changes in gene expression are brought about by stress-induced glucocorticoid hormones acting via receptors that can directly bind to genes and alter their expression. A BBSRC -funded study, published in the international journal Proceedings of the National Academy of Sciences (PNAS), has found that the action of mineralocorticoid receptors (MRs) at the neuronal genome cannot be predicted based solely on receptor occupancy by glucocorticoid hormone. As a result the concept on tonic and feedback action, which over the past few decades has been cited in textbooks, may require some adjustment.