Role of NMDAR Regulation in Phencyclidine-Induced Neurotoxicity

描述（由申请方提供）：由于术后幻觉和定向障碍行为的报告，放弃了苯环利定（PCP）（一种强效分离性麻醉剂）的临床使用。由于其致幻作用，五氯苯酚在20世纪60年代中期出现在被称为“天使尘”的滥用药物的舞台上，但由于其拟精神病特性，其非法使用已大大减少。五氯苯酚在人体中的中毒表现出类似精神分裂症的阳性和阴性症状，并加剧精神分裂症患者的精神病。PCP的主要作用是作为非竞争性NMDAR拮抗剂，离子型谷氨酸受体家族的成员。在未成年大鼠中施用五氯苯酚已被证明会导致...神经毒性和发育后期的异常行为。初步实验表明，受体运输和蛋白质合成的两种不同机制可能涉及围产期急性和亚慢性五氯苯酚给药之间存在的NMDAR上调差异，这可能是五氯苯酚诱导神经毒性机制的区域和剂量依赖性差异的基础。本研究的目的是确定PCP诱导的NMDAR调节与围产期大鼠额叶皮层和纹状体神经毒性相关的机制和功能后果。该项目的具体目标将侧重于描述NMDAR的调节机制，特别是通过使用合成和运输途径的选择性抑制剂并通过蛋白质印迹进行分析，在急性和亚慢性施用五氯苯酚后，该受体的合成和运输的作用。此外，我们计划使用3 H-MK-801结合来研究DA和5-HT受体的间接激活对NMDAR的作用。最后，为了将NMDAR的调节和功能与NMDA介导的细胞死亡联系起来，我们计划将NR 1和NR 2A/B亚基以及已知的神经毒性标志物裂解的半胱天冬酶-3的双标记免疫组织化学结合起来。概述：五氯苯酚又称“天使尘”，是一种强效精神活性物质，主要在美国几个大城市的城区滥用。它通过阻断负责记忆、情感和高级思维过程的大脑区域中的NMDA受体来发挥作用。本项目旨在进一步阐明PCP对NMDA受体的作用，以深入了解其致幻、拟精神病和神经毒性特性的机制。

DESCRIPTION (provided by applicant): Clinical use of phencyclidine (PCP), a potent dissociative anesthetic, was abandoned because of reports of post-operative hallucinations and disoriented behavior. Due to its hallucinogenic effects, PCP appeared on the drug of abuse scene in the mid-1960's known as "angel dust" but its illicit use has substantially diminished because of its psychotomimetic properties. PCP intoxication in humans has also been shown to mimic both the positive and negative symptoms of schizophrenia as well as exacerbate psychoses in schizophrenics. PCP elicits its major actions as a noncompetitive NMDAR antagonist, a member of the ionotropic glutamate family of receptors. PCP administration in immature rats has been shown to cause.. neurotoxicity and later in development, aberrant behaviors. Preliminary experiments have shown that two distinct mechanisms of receptor trafficking and protein synthesis are likely involved in the differences in NMDAR up-regulation that exist between perinatal acute and sub-chronic PCP administration and that this may underlie regional- and dosage-dependent differences in the mechanism of PCP-induced neurotoxicity. The purpose of this study is to determine the mechanism and functional consequences of PCP-induced regulation of the NMDAR in association with neurotoxicity in the frontal cortex and striatum in perinatal rats. The specific aims of this project will focus on delineating the mechanisms of regulation of the NMDAR, specifically the role of synthesis and trafficking of the receptor following acute and sub-chronic PCP administration through the use of selective inhibitors of synthesis and trafficking pathways and analysis via Western blot. In addition, we plan to investigate the role of indirect activation of DA and 5-HT receptors on the NMDAR using 3H-MK-801 binding. Finally, in order to relate regulation and function of the NMDAR to NMDA-mediated cell death, we plan to incorporate double-labeled immunohistochemistry of the NR1 and NR2A/B subunits and a known marker of neurotoxicity, cleaved caspase-3. Lay Summary: PCP, also known as "angel dust", is a powerful psychoactive substance that is mainly abused in urban regions of several large cities in the United States. It elicits its actions through blockade of the NMDA receptor in brain regions responsible for memory, emotions, and higher thought processes. This project aims to further clarify the actions of PCP at the NMDA receptor in order to gain insight into the mechanisms underlying its hallucinogenic, psychotomimetic, and neurotoxic properties.