Wang Bo, Wang Lu, Wang Kai, Tai Fadao
College of Life Sciences, Shaanxi Normal University, Xi(')an 710062, Shaanxi, China; Genetic Engineering Laboratory, School of biological and environmental engineering, Xi'an University, Xi'an 710065, Shaanxi, China.
Genetic Engineering Laboratory, School of biological and environmental engineering, Xi'an University, Xi'an 710065, Shaanxi, China.
Physiol Behav. 2018 Sep 1;193(Pt A):35-42. doi: 10.1016/j.physbeh.2018.02.043. Epub 2018 May 2.
Mothers' brains change dramatically in response to the release of hormones related to pregnancy and labor; however, fathers' brains are also sensitive to the experience of paternal care. Thus, fathers with differing fathering experience may exhibit different behavioral responses towards pups. Using socially monogamous mandarin voles (Microtus mandarinus), effects of fathering experience on levels of paternal behavior as well as oxytocin (OT) and dopamine-2 type (D2) receptors in the nucleus accumbens (NaCC) and medial nucleus of the amygdala (MeA) were investigated. The obtained results showed that experienced fathers displayed more active paternal behaviors such as licking, retrieval, and nest building than new fathers; however, new fathers spent more time in inactive huddling than experienced fathers. Western blot analysis showed that new fathers had significantly higher levels of OTR, but lower levels of D2R compared to experienced fathers in the NaCC. Levels of OTR and D2R in the NaCC and MeA of new and experienced fathers changed with the age of pups. OTR levels in the NaCC of both new and experienced fathers significantly decreased in response to increasing age of pups. Levels of D2R in the NaCC of new fathers on postnatal day 7 (PND 7) were significantly higher than on PND1 and PND14, and levels of D2R in the NaCC of experienced fathers increased with the age of pups. OTR levels in the MeA of new fathers decreased with the age of pups. In contrast, OTR levels of experienced fathers significantly increased with the age of pups. The D2R level in the MeA of new fathers did not change significantly, while the D2R levels of experienced fathers increased with the age of pups. These data illustrate that fathering experience could increase the active components of parental care and alter the expression levels of OTR and D2R in a region- and time-dependent way.
母亲的大脑会因与怀孕和分娩相关的激素释放而发生巨大变化；然而，父亲的大脑对父性关怀的体验也很敏感。因此，具有不同育儿经历的父亲对幼崽可能会表现出不同的行为反应。利用社会一夫一妻制的棕色田鼠（Microtus mandarinus），研究了育儿经历对父性行为水平以及伏隔核（NaCC）和杏仁核内侧核（MeA）中催产素（OT）和多巴胺2型（D2）受体的影响。所得结果表明，有育儿经验的父亲比初为父亲者表现出更多积极的父性行为，如舔舐、找回和筑巢；然而，初为父亲者比有育儿经验的父亲在不活动的蜷缩上花费更多时间。蛋白质免疫印迹分析表明，与有育儿经验的父亲相比，初为父亲者在NaCC中的OTR水平显著更高，但D2R水平更低。初为父亲者和有育儿经验的父亲在NaCC和MeA中的OTR和D2R水平随幼崽年龄而变化。随着幼崽年龄增加，初为父亲者和有育儿经验的父亲在NaCC中的OTR水平均显著下降。出生后第7天（PND 7）初为父亲者在NaCC中的D2R水平显著高于PND1和PND14时，且有育儿经验的父亲在NaCC中的D2R水平随幼崽年龄增加而升高。初为父亲者在MeA中的OTR水平随幼崽年龄下降。相比之下，有育儿经验的父亲在MeA中的OTR水平随幼崽年龄显著升高。初为父亲者在MeA中的D2R水平无显著变化，而有育儿经验的父亲在MeA中的D2R水平随幼崽年龄增加而升高。这些数据表明，育儿经验可以增加亲代抚育的积极成分，并以区域和时间依赖的方式改变OTR和D2R的表达水平。
