Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Université de la Réunion, DéTROI, UMR 1188 INSERM, Sainte Clotilde, La Réunion 97490, France.
Neuron. 2021 Jan 6;109(1):91-104.e5. doi: 10.1016/j.neuron.2020.10.003. Epub 2020 Nov 11.
Cutaneous somatosensory modalities play pivotal roles in generating a wide range of sensorimotor behaviors, including protective and corrective reflexes that dynamically adapt ongoing movement and posture. How interneurons (INs) in the dorsal horn encode these modalities and transform them into stimulus-appropriate motor behaviors is not known. Here, we use an intersectional genetic approach to functionally assess the contribution that eight classes of dorsal excitatory INs make to sensorimotor reflex responses. We demonstrate that the dorsal horn is organized into spatially restricted excitatory modules composed of molecularly heterogeneous cell types. Laminae I/II INs drive chemical itch-induced scratching, laminae II/III INs generate paw withdrawal movements, and laminae III/IV INs modulate dynamic corrective reflexes. These data reveal a key principle in spinal somatosensory processing, namely, sensorimotor reflexes are driven by the differential spatial recruitment of excitatory neurons.
皮肤躯体感觉模态在产生广泛的感觉运动行为中起着关键作用，包括保护性和矫正性反射，这些反射可以动态适应正在进行的运动和姿势。尚不清楚背角中的中间神经元（IN）如何对这些模态进行编码，并将其转化为刺激适当的运动行为。在这里，我们使用交叉遗传方法来功能评估八种背侧兴奋性 IN 对感觉运动反射反应的贡献。我们证明背角组织成由分子异质细胞类型组成的空间受限的兴奋性模块。I/II 层 IN 驱动化学性瘙痒诱导的搔抓，II/III 层 IN 产生爪缩回运动，而 III/IV 层 IN 调节动态矫正反射。这些数据揭示了脊髓躯体感觉处理中的一个关键原则，即感觉运动反射是由兴奋性神经元的差异空间募集驱动的。
