Schizophrenia and Endocannabinoid Effects on Inhibitory Circuitry

精神分裂症和内源性大麻素对抑制回路的影响

• 批准号: 7798063
• 负责人: DAVID W VOLK
• 金额: $ 17.15万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7798063
• 关键词: 2-arachidonylglycerol; Adolescent; Affect; Animal Model; Autopsy; Axon; Binding; Biological; Brain; Brain region; CNR1 gene; Cannabis; Cognitive; Cognitive deficits; Development; Disease; Disinhibition; Down-Regulation; Effectiveness; Endocannabinoids; Enzymes; Etiology; Experimental Models; Fluorescence; GAD67 enzyme; Genetic Transcription; Genetic Translation; Goals; Housekeeping; Housekeeping Gene; Human; Impaired cognition; Impairment; In Situ Hybridization; Individual; Injection of therapeutic agent; Investigation; Knock-out; Knowledge; Lasers; Lead; Lentivirus Vector; Ligand Binding; Ligands; Link; Measures; Medial; Mediating; Messenger RNA; Metabolism; Microdissection; Molecular; Monoacylglycerol Lipases; Neurons; Outcome; Pathogenesis; Prefrontal Cortex; Presynaptic Terminals; Process; Protein Analysis; Protein Isoforms; Proteins; Public Health; RNA; RNA Interference; Rattus; Recording of previous events; Regulation; Relative (related person); Reporting; Research; Research Personnel; Risk; Rodent; Schizophrenia; Signal Transduction; Small Interfering RNA; Specificity; System; Techniques; Testing; Time; Tissue Sample; Training; Transcript; Viral Vector; Western Blotting; base; brain tissue; cell type; cohort; endogenous cannabinoid system; experience; gamma-Aminobutyric Acid; genetic manipulation; hippocampal pyramidal neuron; immunocytochemistry; in vivo; insight; lipoprotein lipase; mRNA Expression; neural circuit; neurotransmission; protein degradation; public health relevance; receptor internalization; response; skills; vector-induced

DESCRIPTION (provided by applicant): Cannabis use by individuals with, or at risk for, schizophrenia is increasingly recognized as a major public health concern. For example, cannabis use is linked to an increased risk for developing schizophrenia and poorer long-term outcomes in individuals who already have schizophrenia. Cannabis use also induces prefrontal cortex (PFC)-related cognitive impairments similar to those seen in schizophrenia. Interestingly, deficits in RFC GABA neurons may lead to cognitive problems in schizophrenia, and cannabis reduces GABA signaling by activating the CB1 receptor. Thus, one potential link between cannabis use and cognitive impairments in schizophrenia may involve an interaction of deficits in the RFC GABA system. Direct investigations of the eCB system in schizophrenia may help further clarify the biological basis for the negative consequences of cannabis use in schizophrenia. For example, determining whether the recently reported finding of lower RFC CB1 receptor levels in schizophrenia reflects a deficiency in eCB signaling, or, conversely, a downregulation of CB1 receptor levels in response to excessive eCB signaling requires knowledge of the eCB ligand (2-AG) that binds to the CB1 receptor. Furthermore, why is the eCB system altered in schizophrenia in the first place? One possibility is that alterations in eCB signaling in schizophrenia are pathogenetically downstream to impairments in GABA synthesis.Therefore, the first two aims will determine whether (and how) the mRNA and protein levels for the synthesizing and metabolizing enzymes (diacylglycerol lipase and monoglyceride lipase) for 2-AG are changed in the RFC in schizophrenia using quantitative PCR, in situ hybridization, Western blots, and immunocytochemistry. The third aim will use in vivo injections of lentiviral vectors expressing siRNA against the GABA synthesizing enzyme, GAD67, and determine the effects on markers of eCB signaling. The training goal of this application is to obtain the necessary research skills to become an independent investigator who tests pathogenetic hypotheses involving cortical circuitry abnormalities in schizophrenia by combining postmortem human brain tissue studies with cell-type specific genetic manipulations in animal models. PUBLIC HEALTH RELEVANCE: These studies will provide insight into potential abnormalities in the brain's own cannabis system in schizophrenia and may help identify new treatment possibilities for the disease.

描述（由申请人提供）：患有精神分裂症或有患精神分裂症风险的人使用大麻越来越被认为是一个主要的公共卫生问题。例如，使用大麻与患精神分裂症的风险增加以及已经患有精神分裂症的人的长期结果较差有关。吸食大麻还会引起前额皮质（PFC）相关的认知障碍，类似于精神分裂症。有趣的是，RFC GABA 神经元的缺陷可能会导致精神分裂症的认知问题，而大麻通过激活 CB1 受体来减少 GABA 信号传导。因此，大麻使用与精神分裂症认知障碍之间的一个潜在联系可能涉及 RFC GABA 系统缺陷的相互作用。对精神分裂症中的 eCB 系统的直接研究可能有助于进一步阐明大麻对精神分裂症的负面影响的生物学基础。例如，要确定最近报道的精神分裂症中 RFC CB1 受体水平较低是否反映了 eCB 信号传导的缺陷，或者相反，CB1 受体水平因过度的 eCB 信号传导而下调，需要了解与 CB1 受体结合的 eCB 配体 (2-AG)。 Furthermore, why is the eCB system altered in schizophrenia in the first place?一种可能性是，精神分裂症中 eCB 信号传导的改变在病理上是 GABA 合成受​​损的下游。因此，前两个目标将使用定量方法确定精神分裂症 RFC 中 2-AG 的合成和代谢酶（二酰甘油脂肪酶和单甘油酯脂肪酶）的 mRNA 和蛋白质水平是否（以及如何）发生变化。 PCR、原位杂交、蛋白质印迹和免疫细胞化学。第三个目标是体内注射表达针对 GABA 合成酶 GAD67 的 siRNA 的慢病毒载体，并确定对 eCB 信号转导标记的影响。该应用程序的培训目标是获得必要的研究技能，成为一名独立研究者，通过将死后人类脑组织研究与动物模型中细胞类型特异性遗传操作相结合，测试涉及精神分裂症皮质回路异常的发病假设。公共卫生相关性：这些研究将深入了解精神分裂症患者大脑自身大麻系统的潜在异常，并可能有助于确定该疾病的新治疗可能性。