超极化激活阳离子通道（HCN channels）参与吗啡成瘾的功能及神经环路机制研究

多巴胺奖赏神经通路参与吗啡成瘾的环路机制及关键蛋白分子有待阐明。HCN通道具有特殊电生理特性，在成瘾相关脑区高表达。研究发现，HCN通道与可卡因和甲基苯丙胺成瘾相关。我们发现，吗啡成瘾大鼠VTA脑区HCN2表达上调；脑区多巴胺神经元放电模式发生变化；HCN拮抗剂ZD7288和CsCl能部分逆转该变化；慢病毒载体敲减VTA脑区HCN2，能显著降低吗啡依赖大鼠CPP白箱停留时间。由于HCN参与吗啡成瘾的功能及环路机制仍不清楚；另外VTA神经元表达有多种阿片受体，提示HCN在吗啡成瘾中的角色不同于其它成瘾物质，亟待阐明。因此本课题在前期基础上，利用特定脑区条件敲除HCN小鼠，拟结合在体多通道电生理、脑片膜片钳和光遗传学等技术，以及条件位置偏爱、大小鼠自给药等成瘾行为实验深入研究吗啡成瘾前后奖赏通路各脑区神经元电生理特性及HCN通道参与其中的功能角色和神经环路机制，发现吗啡成瘾新机制和干预新靶点。

Mesolimbic dopamine pathway plays an important role in drug addiction. However, the key molecules involved in the formation of addiction as well as its underlying mechanisms of neural circuit still need to be further clarified. Using gene chip screening, RT-PCR validation and immunohistochemistry analysis, we found that the hyperpolarization-activated, cyclic nucleotide-gated channel (HCN channel, HCN) HCN2 subtype in ventral tegmental area (VTA) was unregulated in the process of morphine-induced addition. Multichannel electrophysiological recording showed that the properties of neural firing in VTA changed in morphine-addicted rats, which could be partly reversed by HCN channel antagonist ZD7288 and CsCl. Further research found that specific knockdown on the HCN2 gene with Lentiviral vectors injection in the VTA brain regions could significantly inhibited the acquisition of morphine-induced conditioned place preference (CPP). These results haven’t been reported up to now. Thus, in order to clarify the role and function of HCN channels during addiction and explore the novel targets on addiction intervention, we are intending to use the methods combined with optogenetics method, multichannel electrophysiological recording, patch clamp technique and LTP recording on the brain slice, as well as rat intravenous drug self-administration experiment, CPP experiment and immunohistochemical methods to study the exciting discovery mentioned above.