CREB, Alcohol Reward and Consumption in ENT1 Null Mice

乙醇抑制培养细胞中的1型平衡核苷转运体(ENT1)。初步研究 ENT1缺失的小鼠表明ENT1也是体内乙醇的靶点，因为ENT1缺失的小鼠更少 对酒精的急性影响有反应。ENT1基因缺失的小鼠也比野生型小鼠消耗更多的乙醇 一窝产仔。初步研究表明，谷氨酸驱动的CREB活性在 ENT1基因缺失小鼠的纹状体。这似乎是由于纹状体突触前突触激活减弱所致 通过电生理学研究发现腺苷A1受体由于腺苷张力降低所致。 由于纹状体CREB的激活与药物奖赏的减少有关，ENT1中过量饮酒 空白鼠可能与对乙醇奖励的耐受性有关。与这一假设一致的是， 条件性位置偏爱研究表明，ENT1缺失的小鼠更喜欢乙醇配对的一侧(2.0 G/kg)显著低于野生型小鼠。这项建议将在初步研究和审查的基础上进行扩展 CREB信号在调节ENT1基因缺失小鼠酒精行为反应中的作用第一，首字母 敏感度、急性和慢性耐受性、可操作性自我给药和局部条件反射分析将是 用于检测酒精耐受性，以及乙醇的奖励和增强作用。第二，增加了 CREB活性将通过使用Cre-LacZ报告鼠并通过检测表达来鉴定特定细胞中的CREB活性 在ENT1基因缺失的小鼠纹状体中发现了两个由CRE驱动的基因脑啡肽和强啡肽。第三，pCREB 免疫反应性将用于测量纹状体脑片中CREB的活性，以确定信号通路 这有助于ENT1基因缺失小鼠基础CREB活性的增加。最后，我们将确定是否 导致纹状体pCREB增加的信号通路的改变有助于耐受 在ENT1基因缺失的小鼠中，乙醇的奖赏效应和乙醇消耗量的增加。这样做的目的是 该项目旨在了解ENT1基因缺失小鼠饮酒行为增强背后的信号通路 并确定酒精中毒的新治疗靶点。

Ethanol inhibits the type 1 equilibrative nucleoside transporter (ENT1) in cultured cells. Preliminary studies with ENT1 null mice indicate that ENT1 is also a target for ethanol in vivo since ENT1 null mice are less responsive to acute effects of ethanol. ENT1 null mice also consume more ethanol than wild type littermates. Preliminary studies demonstrate that glutamate-driven CREB activation was increased in the striatum of ENT1 null mice. This appears to result from diminished activation of striatal presynaptic adenosine A1 receptors due to reduced adenosine tone as measured by electrophysiological studies. Since striatal CREB activation is associated with reduced drug reward, excessive ethanol drinking in ENT1 null mice may be causally related to tolerance to ethanol reward. Consistent with this hypothesis, a conditioned place preference study demonstrated that ENT1 null mice prefer the ethanol-paired side(2.0 g/kg) significantly less than wild type mice. This proposal will expand upon preliminary studies and examine the role of CREB signaling in regulating behavioral responses to alcohol in ENT1 null mice. First, initial sensitivity, acute and chronic tolerance, operant self-administration, and place conditioning assays will be used to examine ethanol tolerance, and rewarding and reinforcing effects of ethanol. Second, increases in CREB activity will be identified in specific cells using CRE-lacZ reporter mice and by examining expression of two CRE-driven genes, enkephalin and dynorphin, in the striatum of ENT1 null mice. Third, pCREB immunoreactivity will be used to measure CREB activity in striatal brain slices to identify signaling pathways that contribute to increased basal CREB activity in ENT1 null mice. Finally, we will determine whether alterations in signaling pathways that account for increased striatal pCREB contribute to tolerance to rewarding effects of ethanol and increased ethanol consumption in ENT1 null mice. The goal of this project is to understand signaling pathways underlying enhanced alcohol drinking behavior in ENT1 null mice and to identify novel therapeutic targets for alcoholism.