EFFECTS OF ESTROGEN ON POTASSIUM-STIMULATED ACETYLCHOLINE-RELEASE IN THE HIPPOCAMPUS AND OVERLYING CORTEX OF ADULT-RATS

In vivo microdialysis techniques were used to examine the effects of e strogen on potassium-stimulated acetylcholine release in the hippocamp us and overlying cortex of adult, ovariectomized rats. Estrogen treatm ent resulted in a significant increase in the percent change in acetyl choline release induced by potassium relative to controls, particularl y after prolonged (90 min) exposure to high potassium. The data sugges t that estrogen may help to maintain cholinergic function under condit ions where cholinergic afferents to the hippocampal formation and cort ex are challenged or impaired.