title: Gonadal status and pubertal age influence the responsiveness of the benzodiazepine/GABA receptor complex to environmental challenge in male rats.
abstract: Pubertal age and gonadal status in male rats influenced the functional response of the benzodiazepine (BZD)/GABA receptor chloride channel complex to an environmental challenge, i.e., encountering a stranger in familiar versus an unfamiliar environment. Chloride (Cl-) enhancement of [3H]flunitrazepam [( 3H]Flu) binding was facilitated by exposure to an unfamiliar environment relative to that measured in response to a familiar environment in gonadally intact adult rats but not in prepubertal rats (28 days). Enhancement of [3H]Flu by Cl- at 28 days was not differentially affected by the two environments and did not differ from that measured in non-handled control rats at this age. While a differential effect of the two environments on Cl- enhancement of [3H]Flu binding was also present in adult rats castrated as juveniles (at 19 days), the relationship of environmental challenge to Cl- facilitation was the reverse of that measured in intact adult rats. In addition. GABA-mediated 36Cl- uptake was facilitated in intact adult rats tested in either the familiar or unfamiliar environment relative to non-handled intact adult rats. This change in GABA-gated chloride channel function in response to environmental challenge, however, was not present in adult rats castrated as juveniles nor in 28-day-old rats. Therefore, both pubertal age and gonadal status influenced the responsiveness of the BZD/GABA receptor complex to environmental challenge. These findings suggest that pubertal development and adult hormonal status are important determinants of the functional responsiveness of the BZD/GABA receptor complex to environmental challenge.
authors.affiliation: Department of Psychology, University of Rochester, NY 14627.
authors.forename: R J
authors.initials: RJ
authors.lastname: Primus
authors.forename: C K
authors.initials: CK
authors.lastname: Kellogg
mesh_terms: D000375:Aging; D000818:Animals; D002540:Cerebral Cortex / Q000254:growth & development / Q000502:physiology*; D002712:Chlorides / Q000378:metabolism / Q000494:pharmacology; D005445:Flunitrazepam / Q000378:metabolism; D006234:Handling, Psychological; D008297:Male; D009919:Orchiectomy; D051381:Rats; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D012016:Reference Values; D012741:Sexual Maturation; D013315:Stress, Psychological / Q000503:physiopathology*; D014316:Tritium
chemical_list: D002712:Chlorides; D011963:Receptors, GABA-A; D014316:Tritium; D005445:Flunitrazepam