中央杏仁核-无名质特异性神经元通路参与慢性痛调控的机制研究

Chronic pain accompanied by negative emotions and cognitive disorders has a serious impact on people’s lives. How the afferent somatosensory sensation leads to the change of emotion and cognition is always the most fundamental problem. The exploration of its potential mechanism can provide guidance for clinical practice. Substantia innominata (SI) is involved in regulating the sleep-arousal and cognitive function of the body, projecting to the somatosensory cortex that feels pain information, and receiving projections from the central nucleus of amygdala to regulate the fear memory. The high expression of FOS protein was observed in the pain model, but it was not reported whether the SI neurons receiving CeA projections were involved in the regulation of pain sensation, and the downstream nucleus of the pathway is not known. In this study, the specific neurons in SI were taken as the key targets, and the CeA-SI-ACC projection pathway was used as the main target. The following studies were carried out: activating or inhibiting the effects of the specific neurons in SI on chronic pain and related negative emotions; The chemical anatomical characteristics of CeA-SI projection pathway, its role in pain and negative emotion and its plastic changes in chronic pain, the chemical anatomical characteristics of CeA-SI-ACC projection pathway involved in pain regulation and the specific cellular and molecular mechanisms.By this study to reveal a new pathway of pain regulation and to provide a new way for elucidating the mechanism of chronic pain.

慢性痛伴发负性情绪及认知障碍等对人们生活产生严重影响。躯体感觉的传入如何引起情感和认知的改变一直是最根本问题，探讨其潜在的作用机制可对临床提供指导。SI参与调节机体的睡眠觉醒和认知功能状态，可投射至感受痛信息的躯体感觉皮层，并接受来自CeA的投射从而调节恐惧型学习记忆。在痛模型中，该部位可观察到FOS蛋白的高表达，但接受CeA投射的SI神经元是否参与了痛觉调控尚未见报道，且该通路的下游核团也尚不可知。本课题拟以SI内特异神经元为关键靶点，以CeA-SI-ACC投射通路为主要研究靶区，开展以下研究：激活或抑制SI内特异神经元对慢性痛及相关负性情绪的影响；CeA-SI投射通路的化学解剖学特点、在疼痛及负性情绪中的作用及其在慢性痛时的可塑性改变；CeA-SI-ACC投射通路参与疼痛调控的化学解剖学特征及具体细胞分子机制。通过以上研究，旨在发现新的疼痛调控通路，为阐明疼痛慢性化机制提供新思路。

因慢性痛是长期困扰人类的顽疾之一，且伴发负性情绪及认知障碍。因此探讨其潜在的作用机制一直是痛觉研究的重中之重。SI参与调节机体的睡眠觉醒和认知功能状态，可投射至感受痛信息的躯体感觉皮层，并接受来自CeA的投射从而调节恐惧型学习记忆。在痛模型中，该部位可观察到FOS蛋白的高表达，然而SI神经元如何参与痛觉调控尚未见报道。本课题以CeA-SI投射通路为主要研究靶区，以SI内各类神经元为关键靶点开展以下研究：激活或抑制SI内各类神经元对慢性痛及相关负性情绪的影响；CeA-SI投射通路的化学解剖学特点、在疼痛及负性情绪中的作用及其在慢性痛时的可塑性改变；CeA-SI投射通路参与疼痛调控的化学解剖学特征及具体细胞分子机制。. 将FG注射至SI，在CeA部位可观察到FG逆标阳性的神经元胞体，投射神经元部分染色PV阳性，提示CeA部位的PV阳性神经元可投射至SI。使用GAD67-GFP转基因小鼠，足底注射福尔马林建立急性炎性痛模型，在SI部位可观察到该部位的部分GAD67-GFP神经元表达c-Fos，提示该部位GABA 能神经元可能参与痛觉信息的传递。对SI部位进行损毁，后建立SNI模型，对KA组和saline组痛行为进行检测， KA组手术侧足机械痛阈值升高，对侧足与生理盐水组相比无明显变化。. 将光遗传病毒分别注射至SI后建立SNI模型，hM3D(Gq)组腹腔给予CNO后，机械痛阈值、旷场总运动距离及在高架十字迷宫开放臂中的时间均降低，而hM4D(Gi)则相反。电生理结果显示SNI组小鼠SI部位的GABA能神经元发生一定程度的超极化，其神经元兴奋性降低。检测该神经元的自发型突触后电流，提示SNI组小鼠SI的GABA能神经元接受的抑制性传入增强。上述结果提示SI接收CeA投射并参与痛觉信息的传递。通过以上研究，旨在发现新的疼痛调控通路，为阐明疼痛慢性化机制提供新思路。