Article date: 1989/9/1
PubMed ID: 2552344
Journal name: Neuroendocrinology (ISSN: 0028-3835)
The regulation of 3H-muscimol binding to high-affinity GABAa receptors by estradiol (E) and by progesterone (P) was studied within discrete brain regions using in vitro quantitative autoradiography. Treatment of ovariectomized and adrenalectomized female rats with E resulted in a decrease of muscimol binding only in specific estrogen-sensitive brain regions like the ventromedial nuclei (VMN) of the hypothalamus, the arcuate nucleus (ARC), the medial amygdala and the midbrain central grey (MCG). When administered alone, P had no effect. However, in estrogen-primed females, P increased muscimol binding in both VMN and MCG to levels seen in control animals. Thus, E and P exert opposite effects on the GABAa receptor within these two nuclei. As both hormones facilitate female reproductive behavior as well as the release of luteinizing hormone, present results suggest that E and P affect muscimol binding by different mechanisms.
Author List: Schumacher M, Coirini H, McEwen B S
Publication Types: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.
Substances mentioned in the article: Receptors, GABA-A; Muscimol; Progesterone; Estradiol;
Mesh terms: Adrenalectomy; Amygdala/drug effects; Animals; Arcuate Nucleus of Hypothalamus/drug effects; Brain/drug effects; Estradiol/pharmacology; Female; Mesencephalon/drug effects; Muscimol/metabolism; Ovariectomy; Progesterone/pharmacology; Rats; Rats, Inbred Strains; Receptors, GABA-A/drug effects; Ventromedial Hypothalamic Nucleus/drug effects;