GABAA receptors mediate the changes produced by stress on GABA function and locomotor activity.

(1) This study shows the effects of bicuculline pretreatment on the GABAergic system in certain areas of the rat brain after acute ether and cold stress. (2) The spontaneous locomotor activity was diminished by either ether stress or cold stress or bicuculline. (3) Acute ether stress enhanced GABA concentration in the hypothalamus (69%) and in the frontal cerebral cortex (26%). Bicuculline prevented the increase in GABA levels induced by ether stress in both areas. (4) Acute cold stress decreased GABA concentration in the corpus striatum (29%). Bicuculline prevented the decrease in GABA levels induced by cold stress. (5) It is concluded that there is a GABAA receptor involved in stress induced changes on endogenous GABA levels as well as on locomotor activity.