Article date: 1990/1/15
PubMed ID: 2302578
Journal name: Brain research (ISSN: 0006-8993)
The role of gamma-aminobutyric acid (GABA) in mediation of lordosis in the rat has been unclear. We report here that GABA plays a dual role in the mediation of lordosis and has differential effects in the medial hypothalamus (MH) and preoptic area/anterior hypothalamus continuum (POA-AH). Bilateral infusion of the GABAA antagonist bicuculline into the MH of cannulated females primed with estradiol benzoate and progesterone (EB + P) resulted in a marked and transient inhibition of ongoing lordosis. A similar pattern of inhibition was seen in females treated with EB only. In contrast, infusion of the same dose of bicuculline into the POA-AH of sexually receptive females had no effect on lordosis whereas infusion of the GABAA agonist muscimol into this site resulted in a short-term inhibition of lordosis. Furthermore, when females were treated with subthreshold doses of EB + P to induce a low level of lordosis responding, infusion of muscimol into the MH resulted in a significant enhancement of lordosis; infusion of bicuculline into the POA-AH also enhanced lordosis responding as compared to saline-infused controls. These data indicate that increased GABAergic neurotransmission in the MH facilitates lordosis whereas increased GABAergic activity in the POA-AH inhibits this behavior.
Author List: McCarthy M M, Malik K F, Feder H H
Publication Types: Journal Article; Research Support, U.S. Gov't, P.H.S.
Substances mentioned in the article: Muscimol; gamma-Aminobutyric Acid; Bicuculline;
Mesh terms: Animals; Bicuculline/pharmacology; Female; Hypothalamus, Middle/drug effects; Muscimol/pharmacology; Posture; Preoptic Area/drug effects; Rats; Rats, Inbred Strains; Sexual Behavior, Animal/drug effects; gamma-Aminobutyric Acid/physiology;