EFFECT OF PSYCHOLOGICAL STRESS ON [S-35] TBPS BINDING IN RAT-BRAIN

This study was designed to determine whether psychological stress alte rs the function of the GABAergic synapse, examined as biochemical chan ges of [S-35]t-butylbicyclophosphorothionate ([S-35]TBPS) binding, in unwashed membranes of rat cerebral cortex. Psychological stress increa sed the number of [S-35]TBPS binding sites by 22%. This enhancement wa s very similar to that after acute foot shock (24%). Psychological str ess was induced very rapidly, because only 1 day after previous foot s hock exposure, [S-35]TBPS binding was increased by 23%. Diazepam [3 mg /kg intraperitoneally (subcutaneously)] and ipsapirone (5 mg/kg subcut aneously), injected 30 min before psychological stress, antagonized th e enhancement of [S-35]TBPS binding. This result suggests that psychol ogical stress is a good animal model for investigating the various bio chemical changes related to stress, avoiding the physical components a ssociated with most of the normally used stressors and mimicking only emotional state alterations. (C) 1997 Elsevier Science Inc.