Reconstructing a neural circuit in the spinal cord mediating nocifensivebehavior with X-ray nanotomography and electron microscopy

Animals sense painful stimuli through specialized sensory neurons on the skin and generate nocifensive behaviours to protect themselves from severe injury.
Specialized sensory neurons carry nociceptive information to the central nervous systems (CNS) locates in the spinal cord dorsal horn to trigger avoidance
behaviour. Recently, our lab identified a distinct class of sensory neurons (called Smr2+ neurons due to the unique expression of the gene Smr2) whose activation triggers nocifensive behaviour in mouse (unpublished data). We propose combining the X-ray phase contrast nanoscale tomography with electron microscopy to fully reconstruct the local neural circuitry involving Smr2+ sensory neurons in the spinal cord. Identifying the CNS neurons that process nociceptive information from Smr2+ neurons will represent a major step toward understanding how pain is sensed and processed by the nervous system.

动物通过皮肤内的特化感觉神经元感知伤害性刺激，并产生伤害防御行为以规避严重组织损伤。特化感觉神经元将伤害性信息传递至位于脊髓背角的中枢神经系统（CNS），以触发逃避行为。近期，本实验室鉴定出一类独特的感觉神经元——因特异性表达基因Smr2而被命名为Smr2+神经元，在小鼠体内其激活可诱发伤害防御行为（未发表数据）。本研究拟将X射线相位衬度纳米断层成像技术与电子显微镜相结合，以完整重建脊髓内包含Smr2+感觉神经元的局部神经环路。鉴定出负责处理来自Smr2+神经元的伤害性信息的中枢神经系统神经元，将是理解神经系统感知与处理疼痛机制的重要一步。