Blocking oxytocin receptors inhibits vaginal marking to male odors in female Syrian hamsters.
In Syrian hamsters (Mesocricetus auratus), precopulatory behaviors such as vaginal scent marking are essential for attracting a suitable mate. Vaginal marking is dependent on forebrain areas implicated in the neural regulation of reproductive behaviors in rodents, including the medial preoptic/anterior hypothalamus (MPOA-AH). Within MPOA-AH, the neuropeptide oxytocin (OT) acts to facilitate copulation (lordosis), as well as ultrasonic vocalizations towards males. It is not known, however, if OT in this area also facilitates vaginal marking. In the present study, a specific oxytocin receptor antagonist (OTA) was injected into MPOA-AH of intact female Syrian hamsters to determine if oxytocin receptor-dependent signaling is critical for the normal expression of vaginal marking elicited by male, female, and clean odors. OTA injections significantly inhibited vaginal marking in response to male odors compared with vehicle injections. There was no effect of OTA on marking in response to either female or clean odors. When injected into the bed nucleus of the stria terminalis (BNST), a nearby region to MPOA-AH, OTA was equally effective in decreasing marking. Finally, the effects of OTA appear to be specific to vaginal marking, as OTA injections in MPOA-AH or BNST did not alter general locomotor activity, flank marking, or social odor investigation. Considered together, these results suggest that OT in MPOA-AH and/or BNST normally facilitates male odor-induced vaginal marking, providing further evidence that OT generally supports prosocial interactions among conspecifics.
Martinez
Luis A
LA
Neuroscience Institute, Center for Behavioral Neuroscience, Georgia State University, PO Box 5030, Atlanta, GA 30302-5030, USA. lmartinez10@student.gsu.edu
Albers
H Elliott
HE
Petrulis
Aras
A
D000704:Analysis of Variance; D000819:Animal Communication; D000818:Animals; D006224:Cricetinae; D030762:Estrous Cycle; D005260:Female; D007032:Hypothalamus, Anterior / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008647:Mesocricetus; D008845:Microinjections; D009812:Odorants; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000494:pharmacology; D011301:Preoptic Area / Q000187:drug effects / Q000378:metabolism*; D018045:Receptors, Oxytocin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D012903:Smell / Q000502:physiology; D012919:Social Behavior
D018045:Receptors, Oxytocin; D010121:Oxytocin