The ability to care for the young is innate and readily displayed by postpartum females after delivery to ensure offspring survival. Upon pup exposure, rodent virgin (nulliparous) females also develop parental behavior that over time becomes displayed at levels equivalent to parenting mothers. Although maternal behavior in postpartum females and the associated neurocircuits are well characterized, the neural mechanisms underlying the acquisition of maternal behavior without prior experience remain poorly understood. Here, we show that the development of maternal care behavior in response to first-time pup exposure in virgin females is initiated by the activation of the anterior cingulate cortex (ACC). ACC activity is dependent on feedback excitation by Vglut2⁺/Galanin⁺ neurons of the centrolateral nucleus of the thalamus (CL), with their activity sufficient to display parenting behaviors. Accordingly, acute bidirectional chemogenetic manipulation of neuronal activity in the ACC facilitates or impairs the attainment of maternal behavior, exclusively in virgin females. These results reveal an ACC-CL neurocircuit as an accessory loop in virgin females for the initiation of maternal care upon first-time exposure to pups.

中文翻译：

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辅助前额叶皮层-丘脑回路塑造处女雌性小鼠的母性行为

照顾幼崽的能力是与生俱来的，产后女性在分娩后很容易表现出来，以确保后代存活。在幼崽接触后，处女（未生育）雌性啮齿动物也会发展出父母行为，随着时间的推移，这种行为会表现出与养育母亲相当的水平。尽管产后女性的母性行为和相关的神经回路已得到很好的表征，但在没有先验经验的情况下获得母性行为的神经机制仍然知之甚少。在这里，我们表明，处女雌性首次接触幼犬时母性护理行为的发展是由前扣带皮层 (ACC) 的激活引发的。ACC 活动取决于 Vglut2 ⁺ /Galanin ^{+的反馈激发}丘脑中央外侧核 (CL) 的神经元，其活动足以显示育儿行为。因此，ACC 中神经元活动的急性双向化学遗传学操纵促进或损害了母性行为的实现，仅在处女女性中。这些结果揭示了 ACC-CL 神经回路作为处女雌性的辅助回路，用于在首次接触幼崽时启动母性护理。