Department of Psychology, Cornell University, Ithaca, NY 14853, USA.
Department of Psychology, Cornell University, Ithaca, NY 14853, USA.
Horm Behav. 2018 Mar;99:14-24. doi: 10.1016/j.yhbeh.2018.01.006. Epub 2018 Feb 3.
Although prairie vole (Microtus ochrogaster) social behavior is well-characterized in adults, surprisingly little is known about the development of social behavior in voles. Further, the overwhelming majority of studies in prairie voles examine social behavior in a reproductive context. Here, we examine developmental plasticity in affiliation and aggression and their underlying neural correlates. Using sexually naïve males, we characterized interactions with an age-matched, novel, same-sex conspecific in four different age groups that span pre-weaning to adulthood. We found that prosocial behavior decreased and aggression increased as males matured. Additionally, pre-weaning males were more prosocial than nonsocial, whereas post-weaning males were more nonsocial than prosocial. We also examined nonapeptide neural activity in response to a novel conspecific in brain regions important for promoting sociality and aggression using the immediate early gene cFos. Assessment of developmental changes in neural activity showed that vasopressin neurons in the medial bed nucleus of the stria terminalis exhibit functional plasticity, providing a potential functional mechanism that contributes to this change in sociality as prairie voles mature. This behavioral shift corresponds to the transition from a period of allopatric cohabitation with siblings to a period of time when voles disperse and presumably attempt to establish and defend territories. Taken together our data provide a putative mechanism by which brain and behavior prepare for the opportunity to pairbond (characterized by selective affiliation with a partner and aggression toward unfamiliar conspecifics) by undergoing changes away from general affiliation and toward selective aggression, accounting for this important life history event.
虽然草原田鼠（Microtus ochrogaster）的社会行为在成年期已经得到很好的描述，但令人惊讶的是，关于草原田鼠社会行为的发展过程却知之甚少。此外，绝大多数关于草原田鼠的研究都是在生殖背景下考察其社会行为。在这里，我们研究了从属行为和攻击行为的发育可塑性及其潜在的神经相关性。我们使用性不成熟的雄性，在四个不同的年龄组中，研究了与一个年龄匹配的、新颖的、同性同窝的同种动物的互动，这些年龄组跨越了从断奶前到成年期。我们发现，随着雄性的成熟，亲社会行为减少，攻击性增加。此外，断奶前的雄性比非社会性的雄性更亲社会，而断奶后的雄性则比亲社会的雄性更非社会性。我们还使用即时早期基因 cFos 研究了神经肽在大脑中促进社交和攻击的重要区域对新奇同种动物的反应，以研究神经活动的发育变化。评估神经活动的发育变化表明，终纹床核内侧的加压素神经元表现出功能可塑性，这为草原田鼠成熟时社会行为的这种变化提供了一个潜在的功能机制。这种行为转变与从与兄弟姐妹的隔离共生过渡到草原田鼠分散并试图建立和保护领地的时期相对应。总之，我们的数据提供了一种可能的机制，即大脑和行为通过远离一般的从属关系并转向有选择性的攻击来为配对结合的机会做准备（其特征是与伴侣的选择性从属关系和对陌生同种动物的攻击性），从而解释了这一重要的生活史事件。
