GABA[A] receptor level changes in female hamster forebrain following in vivo estrogen progesterone and benzodiazepine treatment: a quantitative autoradiography analysis.

Article date: 1989/1/1

PubMed ID: 2994118

Journal name: Experimental brain research (ISSN: 0014-4819)


The levels of gamma amino butyric acid (GABAA) receptors (i.e. 3H-Muscimol binding sites) were determined by quantitative neurotransmitter receptors autoradiography in ovariectomized (OVX), OVX-estradiolo (E), OVX-progesterone (P), OVX-E + P, diazepam (DZ) and DZ + Ro15-1788 treated female hamsters. The various hormonal treatments altered 3H muscimol binding in many brain areas, whereas DZ and DZ + Ro15-1788 had little influence on GABAA receptor levels at the onset of the blocked aggressive behavioral activity. For example, E, P and E + P all significantly increased 3H muscimol binding in medial preoptic area, ventromedial hypothalamic nuclei, and vertical diagonal bandmedial septal nucleus, whereas P treatment increased binding in the caudate-putamen and decreased it in reuniens nucleus of the thalamus. E and E + P treatments increased 3H muscimol binding in the corticomedial amygdala nucleus and hippocampus. Diazepam treatment decreased the GABAA receptor binding in the caudate-putamen and basolateral amygdala, while having no effect in the other brain regions where hormone treatment was effective. In vitro incubation of brain sections with micromolar concentrations of E or P did not change muscimol binding. These results suggest that ovarian steroids, and benzodiazepines to a lesser extent, modulate 3H muscimol binding but do so in different brain regions. The hormone effects on 3H muscimol binding in the critical reproductive centres at a time period that coincides with the onset of its behavioral effect is consistent with a genomic controlled activity.

Author List: Canonaco M, O'Connor L H, Pfaff D W, McEwen B S

Publication Types: Journal Article; Research Support, Non-U.S. Gov't

Substances mentioned in the article: Receptors, GABA-A; Benzodiazepines; Muscimol; Flumazenil; Progesterone; Estradiol; Diazepam;

Mesh terms: Animals; Autoradiography; Benzodiazepines/pharmacology; Cricetinae; Diazepam/pharmacology; Estradiol/pharmacology; Female; Flumazenil/pharmacology; Frontal Lobe/drug effects; Muscimol/metabolism; Ovariectomy; Progesterone/pharmacology; Receptors, GABA-A/drug effects;

Citations: - 6115648

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