m4 & m5 muscarinic acetylcholine receptor subtypes in ethanol-induced locomotion

描述（由申请人提供）：我们的长期目标是确定影响乙醇对急性运动刺激敏感性的基因，乙醇是一种假定的酒精中毒内表型（行为刺激）小鼠模型。本提案的总体目标是确定m4和/或m5毒蕈碱乙酰胆碱受体（mAChR）亚型基因是否在急性乙醇运动刺激中起作用。小鼠2号染色体上的基因影响对乙醇刺激的敏感性在Chr 2的相关区域内存在m4和m5 mAChR亚型基因。提出的研究旨在阐明m4和/或m5基因表达的差异是否与乙醇诱导刺激的易感性相关，以及它们是否直接参与这种行为。小鼠的FAST和SLOW系对乙醇运动刺激作用的高敏感性和低敏感性进行了选择性繁殖，因此是研究这些差异的敏感遗传动物模型。该建议的具体目的是：1)确定m4和/或m5 mAChR亚型基因是否在特定的大脑区域中有差异表达

DESCRIPTION (provided by applicant): Our long-term goal is to identify genes that influence sensitivity to acute locomotor stimulation to ethanol, a putative mouse model of an endophenotype (behavioral stimulation) for alcoholism. The overall goal of this proposal is to determine if the m4 and/or m5 muscarinic acetylcholine receptor (mAChR) subtype genes have a role in acute locomotor stimulation to ethanol. Genes on mouse chromosome 2 (Chr 2) influence sensitivity to ethanol-induced stimulation; within the relevant region on Chr 2 reside the m4 and m5 mAChR subtype genes. The proposed studies are intended to elucidate if differences in m4 and/or m5 gene expression are associated with predisposition to ethanol-induced stimulation, and if they are directly involved in this behavior. The FAST and SLOW lines of mice were selectively bred for high and low sensitivity to the locomotor stimulant effects of ethanol, and are therefore a sensitive genetic animal model in which to study these differences. The specific aims of this proposal are to 1.) determine whether there are specific brain regions in which the m4 and/or m5 mAChR subtype genes are differentially expressed in FAST and SLOW mice, and 2.) determine whether selective gene silencing of the m4 and/or m5 mAChR subtype genes affects acute locomotor stimulation to ethanol. Gene expression will be assessed in lasercapture-dissected brain regions using qRT-PCR and Western blot analysis. Silencing of the m4 and m5 receptor subtype genes will be accomplished by microinjecting selective RNA interference (RNAi) transcripts into the nucleus accumbens (NAc) and ventral tegmental area (VTA), respectively. It is hypothesized that FAST mice will display decreased expression of the m4 gene in the NAc and enhanced expression of the m5 gene in the VTA as compared to SLOW mice. It is also hypothesized that microinjection of m4-selective RNAi into the NAc of SLOW mice will enhance the acute locomotor stimulant response to ethanol, while microinjection of m5-selective RNAi into the VTA of FAST mice will block ethanol-induced stimulation. It is important to understand the pharmacogenetic underpinnings of acute sensitivity to ethanol because it has some value for the prediction of future alcohol use/abuse. Findings from this proposal may inform future pharmacotherapies for development in the treatment of alcoholism.