There is significant variability in the immediate behavioral response displayed by inexperienced adult mice when exposed to pups for the first time. The aim of this study was to determine which brain regions were engaged (higher c-Fos-immunoreactivity, c-Fos-ir) when virgin females, that were exposed to pups for 15 or 60 min, displayed full parental behavior (FPB), partial parental behavior (PPB), or non-parental behavior (NPB), or virgin males displayed PPB or infanticidal behavior (IB). The number of c-Fos-ir neurons in the prelimbic cortex (PL) was higher in parental females than in the NPB group (after a 15-min exposure), and the group not exposed to pups (NE). C-Fos expression in the nucleus accumbens (NA) was increased in most groups of females exposed to pups compared to NE. Higher c-Fos-ir was also found in the shell subregion of the NA in infanticidal males, compared to males NE. The cortical (CoA) and medial (MA) amygdala also showed higher c-Fos-ir in parental females compared to NE animals. However, PPB and IB male groups also exhibited higher c-Fos-ir in the CoA and MA compared to the NE group. The expression of c-Fos in the different subregions of medial preoptic area and the ventromedial nucleus of the hypothalamus was not specifically associated with either parental or infanticidal behavior. No brain activation in males was specifically associated with infanticidal behavior. Our results suggest that 15 min of exposure to pups is enough to detect brain regions associated with parental behavior (PL) or pups processing (NA, MA, CoA) in mice. The PL might participate in the immediate onset of parental behavior in virgin females, coordinating and planning its rapid execution.

中文翻译：

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前额叶皮层与缺乏经验的成年小鼠（C57BL / 6）的父母行为的快速发作有关。

没有经验的成年小鼠第一次暴露于幼犬时，其即时行为反应存在显着差异。这项研究的目的是确定当暴露于幼犬15分钟或60分钟的未成年女性表现出完全的父母行为（FPB）时，哪些大脑区域被激活（较高的c-Fos-免疫反应性，c-Fos-ir），部分父母行为（PPB）或非父母行为（NPB），或未婚男性表现出PPB或杀婴行为（IB）。亲本雌性前缘皮层（PL）中c-Fos-ir神经元的数量高于NPB组（暴露15分钟后），而未暴露于幼犬（NE）组。与NE相比，大多数暴露于幼崽的雌性组伏伏核（NA）中的C-Fos表达均增加。与雄性NE相比，在杀婴性雄性不育动物的壳部分区域也发现了更高的c-Fos-ir。与NE动物相比，父母雌性的皮质（CoA）和内侧（MA）杏仁核也显示出更高的c-Fos-ir。但是，与NE组相比，PPB和IB雄性组在CoA和MA中也表现出更高的c-Fos-ir。c-Fos在内侧视前区不同区域和下丘脑腹膜内侧核的表达与父母或婴儿的行为均无特异性相关。男性没有大脑激活与婴儿行为特别相关。我们的结果表明，暴露于幼犬15分钟足以检测与小鼠的父母行为（PL）或幼犬加工（NA，MA，CoA）相关的大脑区域。