PERSISTENT COCAINE INDUCED CHANGES IN DOPAMINE CLEARANCE

描述：(申请人摘要) 本申请书是一份申请，要求继续资助独立的 科学家奖(ISA；K02)，支持卫生部的Nancy Zahniser博士 科罗拉多大学医学院药理学教授。它的重要性 对Zahniser博士的职业生涯和职业成长的影响是它将 继续(1)减少她的行政和教学责任， (2)加强对药物滥用研究的关注；(3)让她致力于 为新的研究方向所做的最大努力 支持期限和(4)提供更多机会，以进一步延长 她的研究范围。在过去的四年里。扎尼瑟博士的实验室 开发并表征了一种在体电化学测量方法 外源性多巴胺(DA)清除，一种衡量DA转运体(DAT)的指标 麻醉大鼠不同脑区的活动。使用这个 方法，他们证明，与行为敏感化一致， 可卡因抑制DA清除的能力在 伏隔核，但不包括尾壳核。 反复吸食可卡因。对中提出的实验至关重要 本申请，她和她的合作者最近扩展了 此方法可以测量行为和DAT活动 同时存在于自由活动的老鼠体内。在启动的协作项目中 在Zahniser博士的休假期间，在非洲爪哇卵母细胞中表达的人DAT 被证明是电生的，具有一些类似离子通道的属性，并 依赖于电压。这里提出的实验将探索后者 在卵母细胞表达系统和脑片中的进一步发现 大鼠和D2DA受体基因敲除小鼠。具体地说，建议的 实验将检验以下假设：(I) 外源性DA从细胞外间隙清除的速率与 内源性DA清除，(2)DAT活性的持续变化 特定脑区参与可卡因诱导的基因表达 行为敏感化和(3)D2DA自身受体引起的脑内神经元的变化 膜电位瞬时调节DAT活性。这些研究的结果 研究不仅将加强对大脑持续变化的理解 达 有助于行为敏感化的系统，也有助于机制敏感化 它对DAT活性进行瞬时调节。

DESCRIPTION: (Applicant's Abstract) This application is a request for continued funding of an Independent Scientist Award (ISA; K02) to support Dr. Nancy Zahniser in the Department of Pharmacology, University of Colorado School of Medicine. The importance of this ISA to Dr. Zahniser's career and professional growth is that it will continue to (1) minimize her administrative and teaching responsibilities, (2) enhance her focus on drug abuse research, (3) allow her to devote maximal effort toward new research directions initiated during the previous support period and (4) provide increased opportunities to further extend the scope of her research. During the past four years. Dr. Zahniser's lab developed and characterized an in vivo electrochemical method to measure exogenous dopamine (DA) clearance, a measure of DA transporter (DAT) activity, in discrete brain regions of anesthetized rats. Using this approach, they demonstrated that, consistent with behavioral sensitization, the ability of cocaine to inhibit DA clearance is persistently enhanced in nucleus accumbens, but not caudate-putamen, following withdrawal from repeated cocaine administration. Critical to the experiments proposed in the present application, she and her collaborators have recently extended this methodology so that behavior and DAT activity can be measured concurrently in freely-moving rats. In a collaborative project initiated during Dr. Zahniser's sabbatical, human DAT expressed in Xenopus oocytes was shown to be electrogenic, to possess some ion channel-like properties and to be voltage-dependent. Experiments proposed here will explore the latter finding further in the oocyte expression system and in brain slices from rats and D2 DA receptor knockout mice. Specifically, the proposed experiments will test the following hypotheses: (I) that the rate at which exogenous DA is cleared from the extracellular space parallels the rate of endogenous DA clearance, (2) that persistent changes in DAT activity in specific brain regions contribute to the expression of cocaine-induced behavioral sensitization and (3) that D2 DA autoreceptor-induced changes in membrane potential transiently regulate DAT activity. The results of these studies will enhance understanding not only of persistent changes in brain DA systems that contribute to behavioral sensitization but also of mechanisms by which DAT activity is transiently regulated.