BENZODIAZEPINE RECEPTORS IN THE BRAIN AS AFFECTED BY DIFFERENT EXPERIMENTAL STRESSES - CHANGES ARE SMALL AND NOT UNDIRECTIONAL

Rats and mice were exposed to several different stress situations to investigate whether brain benzodiazepine receptors were sensitive to altered external or internal environmental circumstances. All stresses were applied for several days. Electrical foot shock and post-natal isolation of newborn pups resulted in small (7-25%) decreases in benzodiazepine receptor binding in some cerebral cortex or hippocampal areas while immobilization stress resulted in a small(9%) increase in frontal cortex. Other brain areas (i.e., striatum, cerebellum, pons-medulla and occipital cortex) and other stress forms (isolation of male mice, forced swimming in cold water or chronic amphetamine intoxication) did not change receptor binding. The effect of prolonged stress on benzodiazepine receptors is complex and not very pronounced.