Arias Del Razo Rocío, Bales Karen L
Department of Psychology, University of California, Davis, CA, USA.
Department of Psychology, University of California, Davis, CA, USA.
Behav Processes. 2016 Nov;132:66-75. doi: 10.1016/j.beproc.2016.10.002. Epub 2016 Oct 5.
Socially monogamous prairie voles (Microtus ochrogaster) display remarkable individual variation in social behaviors, which has been associated with differences in early life experience and neuropeptide receptor densities. These differences are also seen in the wild, where approximately 70% of young voles remain in their natal group as non-breeding alloparents, while the other 30% disperse. We investigated whether natural variation in early parental care could contribute to offspring's willingness to "disperse" (willingness to explore) in a laboratory context. Behavioral differences between dispersers and residents could also provide a way to interpret individual variation in other behaviors commonly observed under laboratory conditions. Breeder pairs ranked as high, medium or low-contact, according to the amount of early parental care they provided to offspring, were used to produce and rear experimental subjects. Effects of early parental care on the offspring's willingness to disperse were seen at post-natal day 21, with high-contact offspring spending more time in the start cage and low-contact offspring spending more time exploring. Variations in parental care were also associated with differences in juvenile and adult behaviors that could potentially encourage philopatry or dispersal behavior in the wild. High-contact offspring displayed less anxiety-like behavior compared to low-contact animals. Low-contact offspring displayed the lowest amount of alloparental care. High-contact offspring spent more time in side-by-side contact with a potential partner compared to medium and low-contact offspring. These results suggest that variations in early parental care can impact weanlings' exploratory behavior, but that philopatry is not driven by high anxiety.
社会性一夫一妻制的草原田鼠（Microtus ochrogaster）在社会行为上表现出显著的个体差异，这与早期生活经历和神经肽受体密度的差异有关。在野外也能观察到这些差异，大约70%的幼年田鼠作为非繁殖性异亲留在出生群体中，而另外30%则会扩散。我们研究了早期亲代抚育的自然差异是否会影响后代在实验室环境中“扩散”（探索意愿）的意愿。扩散者和留居者之间的行为差异也可以为解释在实验室条件下常见的其他行为的个体差异提供一种方法。根据亲代对后代提供的早期亲代抚育量，将繁殖对分为高接触、中接触或低接触组，用于繁殖和饲养实验对象。在出生后第21天观察到早期亲代抚育对后代扩散意愿的影响，高接触组后代在起始笼中停留的时间更长，而低接触组后代探索的时间更长。亲代抚育的差异还与幼年和成年行为的差异有关，这些差异可能会在野外促进留居或扩散行为。与低接触组动物相比，高接触组后代表现出较少的焦虑样行为。低接触组后代表现出的异亲抚育量最少。与中接触组和低接触组后代相比，高接触组后代与潜在伴侣并排接触的时间更长。这些结果表明，早期亲代抚育的差异会影响断奶幼崽的探索行为，但留居行为并非由高度焦虑驱动。
