title: Progesterone enhances inhibitory responses of cerebellar Purkinje cells mediated by the GABAA receptor subtype.
abstract: Previous studies from this laboratory have indicated that the sex steroid progesterone (P) is able to augment inhibitory responses of cerebellar Purkinje cells to the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the urethane anesthetized adult female rat. Because both GABAA and GABAB receptors are localized in this CNS area, agonist/antagonists for these receptors were utilized in the present evaluation in order to delineate the specific receptor subtype involved in P-GABA interactions. Systemically administered P was found to augment GABA-mediated inhibition by an average of 80%. Concomitant application of the GABAA blocker, bicuculline, greatly reduced this modulatory effect of the steroid. In contrast, P administration had no effect on baclofen-induced inhibition. These data suggest that P effects on GABA physiology are mediated predominantly at the GABAA receptor.
authors.affiliation: Department of Anatomy, Hahnemann University, Philadelphia, PA 19102-1192.
authors.forename: S S
authors.initials: SS
authors.lastname: Smith
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D005260:Female; D009433:Neural Inhibition / Q000187:drug effects*; D011374:Progesterone / Q000494:pharmacology*; D011689:Purkinje Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology*
chemical_list: D011963:Receptors, GABA-A; D011374:Progesterone; D001640:Bicuculline