Xiong Tingbi, Tsuchida Lena, Inutsuka Ayumu, Onaka Tatsushi, Yamada Kazuo, Orikasa Chitose
Laboratory for Psychology and Behavioral Neuroscience, University of Tsukuba, Tsukuba, Japan.
Department of Physiology, Jichi Medical University, Shimotsuke, Japan.
Front Behav Neurosci. 2024 Sep 23;18:1459957. doi: 10.3389/fnbeh.2024.1459957. eCollection 2024.
Parental behavior comprises a set of crucial actions essential for offspring survival. In this study, a double transgenic mouse model engineered to specifically express channelrhodopsin-2 (ChR2) in paraventricular hypothalamic nucleus (PVN)-oxytocin neurons and ablate lateral hypothalamic area (LHA)-melanin-concentrating hormone (MCH) neurons was used to determine the relationship between PVN-oxytocin neurons and LHA-MCH neurons associated with parental behavior. Optogenetic stimulation of ChR2-expressing PVN-oxytocin neurons induces typical parental behavior with intact LHA-MCH neurons. However, after the partial ablation of LHA-MCH neurons, even optogenetic stimulation of PVN-oxytocin neurons failed to induce parental behavior in virgin male mice, resulting in neglect rather than parental behavior. Furthermore, approximately half of the subjects exhibited burying behavior toward pups, suggesting that pups became aversive stimuli, and male mice actively performed burying behavior to avoid these aversive stimuli. This study emphasizes the novel aspect of oxytocin neurons that could result in neglect in the absence of LHA-MCH neurons regulation.
亲本行为包括一系列对后代生存至关重要的关键行为。在本研究中，一种双转基因小鼠模型被用于确定室旁下丘脑核（PVN）-催产素神经元与外侧下丘脑区域（LHA）-促黑素细胞激素（MCH）神经元之间与亲本行为相关的关系，该模型经基因工程改造，能在室旁下丘脑核-催产素神经元中特异性表达通道视紫红质-2（ChR2），并消融外侧下丘脑区域-促黑素细胞激素神经元。对表达ChR2的室旁下丘脑核-催产素神经元进行光遗传学刺激，在外侧下丘脑区域-促黑素细胞激素神经元完整的情况下可诱发典型的亲本行为。然而，在部分消融外侧下丘脑区域-促黑素细胞激素神经元后，即使对室旁下丘脑核-催产素神经元进行光遗传学刺激，也无法在未交配的雄性小鼠中诱发亲本行为，反而导致忽视而非亲本行为。此外，约一半的实验对象对幼崽表现出掩埋行为，这表明幼崽变成了厌恶刺激，雄性小鼠主动进行掩埋行为以避免这些厌恶刺激。本研究强调了催产素神经元的新特性，即在缺乏外侧下丘脑区域-促黑素细胞激素神经元调节的情况下可能导致忽视行为。
