SIGNALING PATHWAY FOR BENZODIAZEPINE INDUCED BEHAVIORS

描述：(申请人摘要) 苯二氮卓类药物是世界上最常用的处方药之一。 世界上，虽然苯并氮卓类药物在临床上既有效又安全，但 尽管如此，还是担心是否不适当或过度开出 这些药物助长了滥用和依赖。场地(S)和机制 苯二氮卓类药物在中枢神经系统中的行为作用 仍然不确定。这项拟议的研究旨在测试一种 苯二氮卓类药物引发行为的假说 氨基丁酸A(GABAA)受体复合体由一氧化氮介导 (NO)/环GMP(CGMP)/蛋白激酶G(PKG)信号通路，即， 刺激苯二氮/GABAA受体复合体激活NO 合成酶(NOS)产生NO，从而激活可溶性鸟苷酸环化酶 (GC-S)产生cGMP，cGMP进而激活循环GMP依赖 蛋白激酶，导致行为效应。这将是 通过比较苯二氮类药物的行为效果来完成 GABAA激动剂氯氮卓酮 4，5，6，7-tetrahydro-isoxazolo[5，4-c]pyridin-3-ol(THIP)和一氧化二氮， 另一种滥用药物，似乎至少部分通过 苯二氮卓类/GABAA受体在小鼠体内的药理作用 中枢神经系统中一氧化氮合酶、一氧化氮、鸟苷酸环化酶、环鸟苷和蛋白激酶G的调控。 药物预处理可通过抑制脑组织NO的表达而降低脑组织中的NO含量 一氧化氮合酶、一氧化氮合酶抑制脑内一氧化氮的恢复、一氧化氮合酶抑制一氧化氮的作用 NO清除剂，通过抑制GC-S降低脑内cGMP含量，增加脑内cGMP含量 脑内cGMP通过抑制cGMP降解而选择性抑制 蛋白激酶G(PKG)。其他毒品挑战将包括没有捐赠者， 二丁酰基cGMP和PKG激活剂。本研究拟采用的方法 包括对小鼠的行为测试(高架正迷宫和明/暗 探查)，中央微量注射前处理药物，以及检测 测定cGMP和NOS或PKG酶活性。建议的目的是 研究的目的是找出介导 苯二氮类药物诱导的行为并提供逐步更完整的 在分子水平上理解药理学和 急性苯二氮类药物诱发行为的神经化学机制。

DESCRIPTION: (Applicant's Abstract) Benzodiazepines are among the most widely prescribed medications in the world, While benzodazepines are both clinically efficacious and safe, there are nonetheless concerns about whether inappropriate or over prescription of these drugs contributes to abuse and dependence. The site(s) and mechanism of behavioral actions of benzodiazepines in the central nervous system (CNS) remain uncertain. The proposed research is designed to test a working hypothesis that behaviors initiated by drug action at the benzodiazepine/y aminobutyric acidA (GABAA) receptor complex are mediated by a nitric oxide (NO)/cyclic GMP (cGMP)/protein kinase G (PKG) signaling pathway, i.e., stimulation of the benzodiazepine/GABAA receptor complex activates NO synthase (NOS) to produce NO, which activates soluble guanylyl cyclase (GC-S) to produce cGMP, which, in turn, activates a cyclic GMP-dependent protein kinase, leading to the behavioral effects. This will be accomplished by comparing the behavioral effects of the benzodiazepine chlordiazepoxide, the GABAA agonist 4,5,6,7-tetrahydro-isoxazolo[5,4-c]pyridin-3-ol (THIP) and nitrous oxide, another drug of abuse that appears to work at least in part through benzodiazepine/GABAA receptors, in mice following pharmacological manipulation of NOS, NO, guanylyl cyclase, cyclic GMP, and PKG in the CNS. Drug pretreatments will result in reduction in brain NO by inhibition of NOS, restoration of NO in NOS-inhibited brain, inhibition of NO action by an NO scavenger, reduction in brain cGMP by inhibition of GC-S, increase in brain cGMP by inhibition of cGMP degradation, and selective inhibition of protein kinase G (PKG). Other drug challenges will include NO-donors, dibutyryl cGMP and PKG-activators. Methods to be used in this research include behavioral testing in mice (elevated plus-maze and light/dark exploration), central microinjection of pretreatment drugs, and assays to measure cGMP and NOS or PKG enzyme activities. The purpose of the proposed studies is to identify the signaling pathway that mediates benzodiazepine-induced behaviors and provide a progressively more complete understanding, at the molecular level, of the pharmacological and neurochemical mechanisms underlying acute benzodiazepine-induced behaviors.