THE ROLE OF GLIAL MONOAMINE TRANSPORTERS IN COCAINE-INDUCED SENSITIZATION

胶质单胺转运蛋白在可卡因引起的致敏中的作用

• 批准号: 8573334
• 负责人: MIKHAIL INYUSHIN
• 金额: $ 13.09万
• 依托单位: UNIVERSIDAD CENTRAL DEL CARIBE
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8573334
• 关键词: Affect; Affinity; Animals; Astrocytes; Behavioral; Bilateral; Binding; Biomedical Research; Brain; Brain region; Cells; Cocaine; Cocaine Abuse; Cocaine Dependence; Corpus striatum structure; Data; Development; Dopamine; Drug Addiction; Elements; Excision; Extracellular Space; Family; Homeostasis; Human; Image; Infusion procedures; Injection of therapeutic agent; Instruction; Iodides; Lead; Measures; Mediating; Metabolism; Modeling; Motor Activity; Neuroglia; Neurons; Norepinephrine; Nucleus Accumbens; Organic Cation Transporter; Pharmaceutical Preparations; Prefrontal Cortex; Process; Proteins; Rattus; Reporting; Rewards; Rodent; Role; Serotonin; Slice; Synapses; System; Testing; Time; Toxin; United States; Ventricular; Western Blotting; addiction; analog; base; behavioral sensitization; behavioral tolerance; cyanine; extracellular; fluorocitrate; inhibitor/antagonist; monoamine; neurotransmitter release; noradrenaline transporter; novel; patch clamp; research study; response; reuptake; uptake

The Role of Glial Monoamine Transporters in Cocaine-Induced Sensitization and Tolerance In the United States, there are 1.5 million people classified as dependent on or abusing cocaine. Cocaine inhibits dopamine reuptake by binding to high-affinity monoamine transporters thereby impairing removal of dopamine from the synapse. These increased dopamine levels have been associated with the rewarding effect reported by cocaine abusers. In the brain, glial cells surround neuronal processes and synapses and have multiple types of monoamine transporters, including the organic cation transporters (OCT) that are not blocked by cocaine. The general hypothesis of the present proposal is that activation of astrocytes by repeated administration of cocaine enhances their OCT- mediated monoamine uptake thus decreasing dopamine levels in response to a drug challenge and leading to the development of tolerance to cocaine. This hypothesis will be tested in the following two specific aims: Specific Aim 1: To determine the role of astrocytes in the development of behavioral sensitization and tolerance to cocaine. Our preliminary data suggest that inhibition of glial metabolism by the selective glial toxin fluorocitrate reduces tolerance to cocaine. We will determine if this effect is due to inhibition of monoamine uptake by the electrogenic transporters in astrocytes. Specific Aim 2: To determine the effect of repeated cocaine and monoamine administration on transporter currents and the protein levels of OCT transporters in cultured astrocytes and rat brain. We will determine if elevated levels of monoamines, particularly dopamine, up-regulate expression of the OCT transporters on astrocytes resulting in apparent behavioral tolerance to cocaine. In the present electrophysiological and western blot experiments, we will assess the effects of monoamines on OCT electrogenic currents and protein levels in both cultured astrocytes (i.e., a direct effect) and in brain slices after rats have become sensitized or tolerant to cocaine. Specific Aim 3: To determine the effects of repeated administration of cocaine on the accumulation in astrocytes of the fluorescent monoamine analog 4-(4-(dimethylaminp)-styryl)-Nmethylpyridinium; (ASP+). Using fluorescent imaging to study the accumulation of ASP+, a fluorescent substrate for DAT, NET and OCT in acutely separated astrocytes, we will measure the accumulation of ASP+ in acutely isolated astrocytes from control and cocaine treated animals.

神经胶质单胺转运蛋白在可卡因引起的致敏和耐受中的作用 在美国，有 150 万人被归类为可卡因依赖或滥用者。可卡因通过与高亲和力单胺转运蛋白结合来抑制多巴胺再摄取，从而削弱多巴胺从突触的去除。这些增加的多巴胺水平与可卡因滥用者报告的奖励效应有关。在大脑中，神经胶质细胞围绕神经元突起和突触，并具有多种类型的单胺转运蛋白，包括不被可卡因阻断的有机阳离子转运蛋白（OCT）。本提议的一般假设是，通过重复施用可卡因激活星形胶质细胞增强其 OCT 介导的单胺摄取，从而降低响应药物挑战的多巴胺水平并导致对可卡因的耐受性的发展。该假设将在以下两个具体目标中得到检验： 具体目标 1：确定星形胶质细胞在行为敏感性和可卡因耐受性发展中的作用。我们的初步数据表明，选择性神经胶质毒素氟柠檬酸盐抑制神经胶质代谢会降低对可卡因的耐受性。我们将确定这种效应是否是由于星形胶质细胞中的生电转运蛋白抑制单胺摄取所致。具体目标 2：确定重复施用可卡因和单胺对培养的星形胶质细胞和大鼠脑中转运蛋白电流和 OCT 转运蛋白水平的影响。我们将确定单胺（尤其是多巴胺）水平升高是否会上调星形胶质细胞上 OCT 转运蛋白的表达，从而导致对可卡因的明显行为耐受。在目前的电生理学和蛋白质印迹实验中，我们将评估单胺对培养的星形胶质细胞（即直接影响）和大鼠对可卡因敏感或耐受后脑切片中 OCT 生电电流和蛋白质水平的影响。具体目标 3：确定重复施用可卡因对星形胶质细胞中荧光单胺类似物 4-(4-(二甲氨基)-苯乙烯基)-N 甲基吡啶鎓积累的影响； （ASP+）。使用荧光成像研究急性分离的星形胶质细胞中 ASP+（DAT、NET 和 OCT 的荧光底物）的积累，我们将测量来自对照和可卡因治疗动物的急性分离的星形胶质细胞中 ASP+ 的积累。