Luteinizing hormone releasing hormone-induced conditioned place-preference in male rats.
Conditioned place-preference induced by intraperitoneal injections of luteinizing hormone releasing hormone (LHRH) was studied in male rats. In Experiment 1, dose-dependent effects (doses: 0, 0.2, 1 and 5 micrograms/kg) were observed in gonadectomized males provided with a subcutaneous silastic implant containing testosterone. Animals injected with 1 or 5 micrograms LHRH developed reliable preference for the LHRH-associated compartment of a two-compartment preference box. The 0 and 0.2 microgram doses were without effect. Experiment 2 further studied the place-preference effects induced by 5 micrograms LHRH, by varying the sex steroid baseline condition of the animals. A significant effect of LHRH on place-preference was found in gonadectomized males with a testosterone or estradiol implant and in gonadally intact males. Differences between these groups were not found. However, in gonadectomized males without steroid substitution, LHRH did not induce place-preference. These data indicate that rewarding properties related to LHRH treatment can be observed in male rats, provided that the males are additionally exposed to sufficient levels of circulating sex steroids.
de Beun
R
R
Netherlands Institute for Brain Research, Amsterdam.
Geerts
N E
NE
Jansen
E
E
Slangen
J L
JL
van de Poll
N E
NE
D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology; D005246:Feedback; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009919:Orchiectomy; D010052:Ovariectomy; D051381:Rats; D011919:Rats, Inbred Strains; D013739:Testosterone / Q000097:blood
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D004958:Estradiol