Role of the oxytocin system in amygdala subregions in the regulation of social interest in male and female rats.
Role of the oxytocin system in amygdala subregions in the regulation of social interest in male and female rats.
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DOI：
10.1016/j.neuroscience.2016.05.036
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发表时间：
2016-08-25
期刊：
影响因子：
3.3
通讯作者：
Veenema AH
中科院分区：
文献类型：
--
作者：
Dumais KM;Alonso AG;Bredewold R;Veenema AH
我们之前发现，雄性大鼠内侧杏仁核（MeA）的催产素（OT）受体（OTR）结合密度与社会兴趣（即调查同一个体的动机）呈正相关，而雌性大鼠中央杏仁核（CeA）的催产素（OT）受体结合密度与社会兴趣呈负相关。在这里，我们通过在社会兴趣测试（同性青少年接触4分钟）前注射OTR拮抗剂（5ng /0.5 μ l/侧）或OT （100pg /0.5 μ l/侧），确定了OTR在MeA和CeA中对成年大鼠社会兴趣的性别特异性调节的因果关系。在CeA中阻断OTR会降低男性的社交兴趣，但对女性没有影响，而所有其他治疗对行为没有影响。为了进一步探讨在社会利益中，OT系统在CeA中的性别特异性参与，我们使用体内微透析来确定在社会利益中CeA内源性OT释放的可能性别差异。有趣的是，男性和女性在基线和社交兴趣期间表现出相似的细胞外OT释放水平，这表明除了局部OT释放外，还有其他因素介导了CeA-OTR在社交兴趣中的性别特异性作用。此外，我们发现女性CeA-OT释放与社会调查时间呈正相关。这进一步反映在社交兴趣低的女性与社交兴趣高的女性相比，在社交兴趣低的女性中，CeA-OT释放减少。我们讨论的可能性是，这种减少的OT释放可能是暴露于社会刺激的结果，而不是原因。总的来说，我们的研究结果首次表明，在男性和女性之间，CeA的细胞外OT释放是相似的，并且CeA中的OTR在男性对幼鱼同种的社会兴趣的调节中起着因果作用。
We previously found that oxytocin (OT) receptor (OTR) binding density in the medial amygdala (MeA) correlated positively with social interest (i.e., the motivation to investigate a conspecific) in male rats, while OTR binding density in the central amygdala (CeA) correlated negatively with social interest in female rats. Here, we determined the causal involvement of OTR in the MeA and CeA in the sex-specific regulation of social interest in adult rats by injecting an OTR antagonist (5 ng/0.5 µl/side) or OT (100 pg/0.5 µl/side) before the social interest test (4-min same-sex juvenile exposure). OTR blockade in the CeA decreased social interest in males but not females, while all other treatments had no behavioral effect. To further explore the sex-specific involvement of the OT system in the CeA in social interest, we used in vivo microdialysis to determine possible sex differences in endogenous OT release in the CeA during social interest. Interestingly, males and females showed similar levels of extracellular OT release at baseline and during social interest, suggesting that factors other than local OT release mediate the sex-specific role of CeA-OTR in social interest. Moreover, we found a positive correlation between CeA-OT release and social investigation time in females. This was further reflected by reduced CeA-OT release during social interest in females that expressed low compared to high social interest. We discuss the possibility that this reduction in OT release may be a consequence, rather than a cause, of exposure to a social stimulus. Overall, our findings show for the first time that extracellular OT release in the CeA is similar between males and females and that OTR in the CeA plays a causal role in the regulation of social interest towards juvenile conspecifics in males.