DiBenedictis Brett T, Nussbaum Elizabeth R, Cheung Harry K, Veenema Alexa H
Neurobiology of Social Behavior Laboratory, Department of Psychology, Boston College, Chestnut Hill, Massachusetts.
J Comp Neurol. 2017 Aug 1;525(11):2549-2570. doi: 10.1002/cne.24216. Epub 2017 May 8.
The neuropeptides vasopressin (AVP) and oxytocin (OT) have been implicated in the regulation of numerous social behaviors in adult and juvenile animals. AVP and OT signaling predominantly occur within a circuit of interconnected brain regions known collectively as the "social behavior neural network" (SBNN). Importantly, AVP and OT signaling within the SBNN has been shown to differentially regulate diverse social behaviors, depending on the age and/or sex of the animal. We hypothesized that variation in the display of these behaviors is due in part to age and sex differences in AVP and OT synthesis within the SBNN. However, a thorough characterization of AVP and OT-immunoreactive (ir) fibers and cell bodies across age and sex within the SBNN has been lacking in rats. We therefore quantified AVP- and OT-ir fibers and cell bodies in 22 subregions of the forebrain SBNN in juvenile and adult, male and female rats. We found numerous age (16 subregions) and sex (10 subregions) differences in AVP-ir fiber fractional areas, and AVP-ir cell body numbers, which were mainly observed in the medial amygdala/bed nucleus of the stria terminalis to lateral septum circuit. In contrast to AVP, we observed no age or sex differences in OT-ir fiber fractional areas or cell bodies in any of the 22 subregions of the forebrain SBNN. Thus, unlike the static pattern observed for OT, AVP innervation of the forebrain SBNN appears to undergo developmental changes, and is highly sexually dimorphic, which likely has significant functional consequences for the regulation of social behavior.
神经肽血管加压素（AVP）和催产素（OT）参与调控成年和幼年动物的多种社会行为。AVP和OT信号主要发生在一组相互连接的脑区回路中，这些脑区统称为“社会行为神经网络”（SBNN）。重要的是，已表明SBNN内的AVP和OT信号根据动物的年龄和/或性别差异调节不同的社会行为。我们推测这些行为表现的差异部分归因于SBNN内AVP和OT合成的年龄和性别差异。然而，大鼠中缺乏对SBNN内不同年龄和性别的AVP和OT免疫反应性（ir）纤维及细胞体的全面表征。因此，我们对幼年和成年雄性及雌性大鼠前脑SBNN的22个亚区域中的AVP和OT-ir纤维及细胞体进行了定量分析。我们发现AVP-ir纤维分数面积和AVP-ir细胞体数量存在大量年龄（16个亚区域）和性别（10个亚区域）差异，主要出现在终纹床核内侧杏仁核到外侧隔区回路。与AVP不同，在前脑SBNN的22个亚区域中的任何一个中，我们均未观察到OT-ir纤维分数面积或细胞体存在年龄或性别差异。因此，与OT呈现的静态模式不同，前脑SBNN的AVP神经支配似乎经历了发育变化，且具有高度性别二态性，这可能对社会行为的调节产生重大功能影响。
