Testosterone inhibits facilitating effects of parenting experience on parental behavior and the oxytocin neural system in mice
Testosterone inhibits facilitating effects of parenting experience on parental behavior and the oxytocin neural system in mice
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DOI：
10.1016/j.physbeh.2013.05.017
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发表时间：
2013-06
影响因子：
2.9
通讯作者：
Shota Okabe;Kanako Kitano;M. Nagasawa;K. Mogi;T. Kikusui
中科院分区：
文献类型：
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作者：
Shota Okabe;Kanako Kitano;M. Nagasawa;K. Mogi;T. Kikusui
哺乳动物的亲职行为是由婴儿的感觉经验和内分泌激素促进的。然而，这些因素之间的相互作用，在非生殖成年人的父母的行为还不清楚。我们研究了性幼稚小鼠性腺激素和反复暴露于幼鼠的经验对父母行为的相互作用。我们还比较了下丘脑室旁核中催产素（OT）的表达水平与行为结果。在检索测试中观察到明显的性别差异，初始检索潜伏期女性比男性短，5次幼鼠暴露缩短检索潜伏期的女性。性腺切除既不影响初始检索潜伏期，也不影响幼鼠致敏的女性。相反，性腺切除缩短了初始检索潜伏期，并导致幼鼠致敏的男性。雌激素植入同时给予性腺切除术进一步缩短了男性的初始检索潜伏期，但幼犬致敏不受影响，并发生在两种性别。相比之下，同时睾酮植入损害两种性别的幼崽致敏。与对幼崽的反应性结果相似，仅雄性动物的性腺切除术增加了OT神经元的数量。在比较性腺切除术，OT神经元减少，同时睾酮植入，但不受雌激素在任何性别。考虑到睾酮对幼鼠致敏和OT神经元数量的平行抑制作用，我们推测，通过小鼠OT神经系统的睾酮抑制作用引起的反复幼鼠暴露促进的父母反应性的性别差异。
Parental behavior in mammals is facilitated by sensory experiences from infant, and by endocrine hormones. However, the interactions between these factors in the parental behavior of nonreproductive adults are not understood. We examined the interactive effects of gonadal hormones and the experience of repeated pup exposure on parental behavior in sexually naive mice. We also compared oxytocin (OT) expression levels in the paraventricular nucleus of the hypothalamus to behavioral outcomes. Clear sex differences were observed in retrieving tests; initial retrieving latency was shorter in females than in males, and 5-time pup exposure shortened retrieving latency in females only. Gonadectomy influenced neither initial retrieving latency nor pup sensitization in females. In contrast, gonadectomy shortened initial retrieving latency and caused pup sensitization in males. Estrogen implants given simultaneously with gonadectomy further shortened the initial retrieving latency in males, but pup sensitization was not affected and occurred in both sexes. In contrast, simultaneous testosterone implants impaired pup sensitization in both sexes. Similar to the results for responsiveness to pups, the number of OT neurons was increased by gonadectomy in males only. In comparison to gonadectomy only, OT neurons were decreased by simultaneous testosterone implants, but were not influenced by estrogen in either sex. Considering the parallel inhibitory effects of testosterone on both pup sensitization and number of OT neurons, we postulate that sex differences in parental responsiveness facilitated by repeated pup exposure were caused by an inhibitory effect of testosterone via the OT neural system in mice.