KCC2介导的初级传入去极化在脊髓后索电刺激镇痛中的作用机制研究

Spinal Cord Stimulation (SCS) is one of clinical applications in analgesia, which commonly used in the treatment of refractory pain.Recent studies indicate that SCS works by regulating in neural network of spinal cord, but its mechanism is not clear yet. Prmiary afferent depolarization (PAD) is a prolonged decrease in membrane potential at the presynaptic terminals of afferent fibers.Euron-specific K-Cl co-transporter (KCC2) and gamma-aminobutyric acid (GABA) A receptors co-regulate Cl- outflow, and that induces PAD. Our preliminary experiment results show that GABA enhanced postsynaptic field potentials, which is induced by spinal dorsal funiculus stimulation.It is hypothesized that this positive feedback is damaged in pain status, and SCS may effect by recovering this positive feedback in analgesia. This experiment is designed as follows: (1) to use multi-electrode array as a new method to study neural network in spinal dorsal horn; (2) To demostrate that SCS regulates GABA-ergic interneurons in deep layers of dorsal horn in analgesia; (3) To prove that PAD positive feedback mediated by KCC2 is a key mechanism in SCS analgesia.The aim of this study is to elucidate the molecular mechanism of SCS analgesia in the view of neural netmork.

脊髓电刺激（SCS）镇痛在临床上常用于治疗难治性疼痛，近期研究证实其镇痛作用在于脊髓背角节段神经网络的调控，但具体机制不明。初级传入去极化（PAD）是突触前持续的跨膜电位减少导致去极化，进而导致突触后的神经元兴奋性增加的效应，目前认为PAD为GABAA受体和突触前钾氯共转运体（KCC2）的引起突触前Cl-外流有关。前期预实验观察到GABA可增强脊髓后索电刺激的突触后电位，所以我们推测，正常状态下后索电刺激引发PAD，是正反馈调节，而疼痛时此调节被破坏，SCS镇痛可能是通过恢复PAD的正反馈调节实现。本课题应用平面微电极阵列技术建立研究脊髓背角节段神经网络研究模型，结合膜片钳等方法验证SCS镇痛机制是通过恢复KCC2调节的背角深层神经元PAD效应，实现对浅层神经元调节。从神经网络角度阐明SCS镇痛的分子机制

脊髓电刺激（SCS）镇痛在临床上常用于治疗神经病理性疼痛，现有研究证实其镇痛作用在于脊髓背角节段神经网络的调控，但具体机制不明。初级传入去极化（PAD）是突触前持续的跨膜电位减少导致去极化，进而导致突触后的神经元兴奋性增加的效应，目前认为PAD为GABAA受体和突触前钾氯共转运体（KCC2）的引起突触前Cl-外流有关。主要研究内容：正常状态下后索电刺激引发PAD，是正反馈调节，而疼痛时此调节被破坏，SCS镇痛通过恢复KCC2的表达使PAD的正反馈调节实现镇痛。重要结果：1、应用平面微电极阵列技术建立研究脊髓背角节段神经网络研究模型；2、结合多种实验方法验证SCS镇痛机制是通过恢复KCC2调节的背角深层神经元PAD效应，实现对浅层神经元调节；3、从神经网络角度阐明SCS镇痛的分子机制。关键数据见正文及成果附件。科学意义：明确了SCS镇痛通过脊髓背角节段神经环路即可调节；且这种调节可通过KCC2进行。为进一步研发镇痛药物及军事应用提供了新的思路。