Wang Z, Zhou L, Hulihan T J, Insel T R
Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, USA.
J Comp Neurol. 1996 Mar 18;366(4):726-37. doi: 10.1002/(SICI)1096-9861(19960318)366:4<726::AID-CNE11>3.0.CO;2-D.
The genus Microtus includes several closely related species of voles with diverse patterns of social organization. Comparative studies of these species have previously tested hypotheses related to the evolution of monogamy and affiliation. In earlier studies, monogamous voles have been reported to differ from closely related nonmonogamous voles in the neural distribution of oxytocin and vasopressin receptors. These receptors have also been implicated in the behavioral differences relevant to monogamy, as oxytocin and vasopressin influence pair-bond formation in the monogamous species. In the current study, two monogamous and two nonmonogamous vole species were compared for the distribution of oxytocin and vasopressin immunoreactivity. Contrary to our predictions, gender dimorphisms in vasopressin immunoreactivity were as evident in the monogamous as in the nonmonogamous species. Also, species differences in oxytocin and vasopressin staining were subtle relative to the profound species differences previously reported for receptor binding. These results are consistent with the hypothesis that neuroendocrine systems may evolve by changes in receptor distribution rather than by restructuring the presynaptic pathway.
田鼠属包括几种社会组织模式多样的近缘田鼠物种。此前，对这些物种的比较研究检验了与一夫一妻制和亲密关系进化相关的假说。在早期研究中，据报道，一夫一妻制田鼠与近缘的非一夫一妻制田鼠在催产素和加压素受体的神经分布上存在差异。这些受体也与一夫一妻制相关的行为差异有关，因为催产素和加压素会影响一夫一妻制物种中的配偶关系形成。在当前研究中，比较了两种一夫一妻制田鼠和两种非一夫一妻制田鼠的催产素和加压素免疫反应性分布。与我们的预测相反，加压素免疫反应性的性别二态性在一夫一妻制物种和非一夫一妻制物种中同样明显。此外，相对于先前报道的受体结合方面的显著物种差异，催产素和加压素染色的物种差异较为细微。这些结果与以下假说一致，即神经内分泌系统可能通过受体分布的变化而非通过重组突触前途径来进化。
