INIA: Chimeric Analysis of Alcohol & Stress Interactions

描述（由申请人提供）： 酒精中毒和酒精相关的表型有很强的遗传成分。 许多候选基因已经被假设为决定 这些表型包括NMDA、5-羟色胺和GABA系统。通常 证明这些候选分子中的哪一个实际上是负责的方法， 是通过使用基因敲除小鼠。在某些情况下， 解决这个问题的能力是复杂的事实，即突变是 胚胎或新生儿致死，使得无法确定 基因在大多数行为表型，特别是乙醇相关的行为。 消除问题的一种方法是通过使用嵌合小鼠。 嵌合小鼠是通过混合突变体和野生型小鼠来制备的。 野生型细胞的存在能够消除致死性， 动物的分析。假设NMDA受体介导 多种酒精相关影响，包括饮酒量增加， 戒断反应的严重程度。此外，NMDA受体已被证明 对压力的反应很重要。NMDA受体复合物由以下组成： 目前还不清楚哪些亚基对 这些影响。有两个亚单位被认为是重要的， NRI和NR 2B亚基。这两个亚基的敲除都是胚胎性的 因此，每个受体的作用的最终解决方案是 未知为了确定这些受体的作用，两种不同的嵌合体 将进行组合：NRI-/-<->野生型和NR 2B-/-<->野生型 嵌合小鼠成年嵌合小鼠将在两瓶选择中进行测试 乙醇消耗试验和使用足部电击的应激反应试验 在高架十字迷宫中评估。随后，每一个嵌合体的大脑 将对小鼠进行组织学分析以确定1）是否存在基因 剂量效应，即如果行为在具有 较高百分比的突变细胞，和2）如果存在更大的重要性， 在某些脑区敲除细胞而不是其他脑区。这些数据将提供 深入了解NR 1和NR 2B基因在这些表型中的作用。

DESCRIPTION (provided by applicant): Alcoholism and alcohol-related phenotypes have a strong genetic component. Numerous candidate genes have been hypothesized to be critical in determining these phenotypes including NMDA, serotonin and GABA systems. Typically, the way to demonstrate which of these candidate molecules are in fact responsible for the phenotype is through the use of knock-out mice. In some instances, the ability to address this issue is complicated by the fact that the mutation is embryonic or neonatal lethal making it impossible to ascertain the role of the gene in most behavioral phenotypes, particularly ethanol-related behaviors. One method of eliminating problem is through the use of chimeric mice. Chimeric mice are made by mixing mutant and wild-tax e many instances, the presence of wild-type cells is able to eliminate the lethality allowing for the analysis of animals. NMDA receptors have been hypothesized to mediate multiple alcohol-related effects including increased alcohol consumption and severity of withdrawal effects. Additionally, NMDA receptors have been shown to be important in responses to stress. The NMDA receptor complex is made up of multiple subunits and it is unclear which of the subunits are critical for these effects. Two subunits that have been hypothesized to be important are the NRI and NR2B subunits. Knock-outs of both of these subunits are embryonic lethal and thus, the definitive resolution of the role of each receptor is unknown. To determine the role of these receptors, two different chimeric combinations will be make: NRI-/-<-> wild-type and NR2B-/-<-> wild-type chimeric mice. Adult chimeric mice will be tested on both a two-bottle choice test of ethanol consumption and in a response to stress test using foot shock evaluated in an elevated plus maze. Subsequently, the brains of each chimeric mouse will be analyzed histologically to determine 1) if there is a gene dosage effect i.e. if the behavior is more abnormal in chimeric mice with a higher percentage of mutant cells, and 2) if there is a greater importance of knock-out cells in some brain regions versus others. This data will provide insights into the role of the NR1 and NR2B genes in these phenotypes.