Neuroscience Institute, Center for Behavioral Neuroscience, Georgia State University, PO Box 5030, Atlanta, GA 30302-5030, USA.
Physiol Behav. 2010 Dec 2;101(5):685-92. doi: 10.1016/j.physbeh.2010.08.007. Epub 2010 Aug 17.
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.
在叙利亚仓鼠（Mesocricetus auratus）中，求偶前行为，如阴道气味标记，对于吸引合适的配偶至关重要。阴道标记依赖于大脑前区，这些区域涉及啮齿动物生殖行为的神经调节，包括中脑前视前区/下丘脑前部（MPOA-AH）。在 MPOA-AH 中，神经肽催产素（OT）作用于促进交配（摆尾），以及对雄性的超声波发声。然而，尚不清楚该区域的 OT 是否也有助于阴道标记。在本研究中，将特定的催产素受体拮抗剂（OTA）注射到完整雌性叙利亚仓鼠的 MPOA-AH 中，以确定该区域的催产素受体依赖性信号是否对雄性、雌性和清洁气味引起的正常阴道标记表达至关重要。与载体注射相比，OTA 注射显著抑制了对雄性气味的阴道标记。OTA 对雌性或清洁气味的标记没有影响。当注射到终纹床核（BNST）时，这是 MPOA-AH 附近的一个区域，OTA 同样有效地减少了标记。最后，OTA 的作用似乎是特异性的阴道标记，因为 MPOA-AH 或 BNST 中的 OTA 注射不会改变一般的运动活动、侧腹标记或社会气味调查。综上所述，这些结果表明 MPOA-AH 和/或 BNST 中的 OT 通常促进雄性气味诱导的阴道标记，进一步证明 OT 通常支持同种动物之间的亲社会互动。
