Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA; Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA, USA.
Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA; Department of Biological Sciences, Columbia University, New York, NY, USA.
Cell. 2023 Feb 2;186(3):577-590.e16. doi: 10.1016/j.cell.2022.12.034. Epub 2023 Jan 23.
Pleasurable touch is paramount during social behavior, including sexual encounters. However, the identity and precise role of sensory neurons that transduce sexual touch remain unknown. A population of sensory neurons labeled by developmental expression of the G protein-coupled receptor Mrgprb4 detects mechanical stimulation in mice. Here, we study the social relevance of Mrgprb4-lineage neurons and reveal that these neurons are required for sexual receptivity and sufficient to induce dopamine release in the brain. Even in social isolation, optogenetic stimulation of Mrgprb4-lineage neurons through the back skin is sufficient to induce a conditioned place preference and a striking dorsiflexion resembling the lordotic copulatory posture. In the absence of Mrgprb4-lineage neurons, female mice no longer find male mounts rewarding: sexual receptivity is supplanted by aggression and a coincident decline in dopamine release in the nucleus accumbens. Together, these findings establish that Mrgprb4-lineage neurons initiate a skin-to-brain circuit encoding the rewarding quality of social touch.
愉悦的触摸在社交行为中至关重要，包括性接触。然而，将性触觉转化为感觉神经元的身份和确切作用仍不清楚。一群通过 G 蛋白偶联受体 Mrgprb4 的发育表达标记的感觉神经元可以检测到小鼠的机械刺激。在这里，我们研究了 Mrgprb4 谱系神经元的社交相关性，并揭示这些神经元是性接受所必需的，足以在大脑中诱导多巴胺释放。即使在社交隔离中，通过背部皮肤对 Mrgprb4 谱系神经元进行光遗传学刺激也足以诱导条件性位置偏好和类似于交配时的背屈的显著背屈。在没有 Mrgprb4 谱系神经元的情况下，雌性小鼠不再发现雄性交配有奖励：性接受被攻击性取代，同时伴随着伏隔核中多巴胺释放的下降。总之，这些发现确立了 Mrgprb4 谱系神经元启动了一种皮肤到大脑的回路，该回路编码了社交触摸的奖励质量。
