Glial-mediated synaptic remodeling in drug addiction

胶质细胞介导的毒瘾突触重塑

• 批准号: 10363436
• 负责人: Yan Dong
• 金额: $ 56.61万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10363436
• 关键词: AMPA Receptors; Address; Adult; Animal Model; Applications Grants; Astrocytes; Behavioral; Brain; Cocaine; Cocaine withdrawal; Cues; Drug Addiction; Electrophysiology (science); Ensure; Exhibits; Filopodia; Funding; Generations; Glutamates; Image; Lead; Measures; Mediating; Memory; Molecular; Monitor; Mus; Neurobiology; Neurons; Newborn Infant; Nucleus Accumbens; Outcome; Pharmaceutical Preparations; Play; Population; Prevention; Process; Property; Relapse; Retrieval; Rodent; Role; Signal Transduction; Slice; Synapses; Synaptic plasticity; Testing; Therapeutic; Thinness; Training; Up-Regulation; Vertebral column; Withdrawal; Work; addiction; base; cell type; cocaine exposure; cocaine self-administration; drug withdrawal; experience; experimental study; imaging study; in vivo; in vivo imaging; insight; memory retrieval; neural circuit; novel; recruit; response; success; synaptogenesis; targeted treatment; tool; transcriptome sequencing; two photon microscopy

Abstract This grant application proposes to understand the role of astrocytes in mediating cocaine-induced circuit alterations that drive cocaine seeking and relapse. Outcomes of the first funding period for this R01 project demonstrate that cocaine self-administration (SA) activates an astrocyte-mediated synaptogenic mechanism to generate AMPA receptor (AMPAR)-silent synapses in principal medium spiny neurons (MSNs) in nucleus accumbens shell (NAcSh). During withdrawal from cocaine SA, a subset of these cocaine-generated NAcSh synapses mature and strengthen by recruiting AMPARs. Experimentally converting and locking cocaine- generated NAcSh synapses within their silent state during drug withdrawal substantially decreases cue- induced cocaine seeking. By measuring intracellular Ca2+ activities, preliminary studies reveal that NAcSh astrocyte activities are upregulated by cocaine administration, and that this upregulation is increased after 5-d cocaine SA, indicating a ‘sensitization’ process in astrocytes. Furthermore, after cocaine SA, NAcSh astrocytes acquire the ability to respond to cocaine-associated cues by increasing their activities, and experimentally increasing astrocyte activities re-silences cocaine-generated NAcSh synapses. These and other preliminary results lead to the current hypothesis: NAcSh astrocytes gain unique properties through cocaine experience to regulate cocaine-generated synapses and formulate specific neuronal ensembles that drive cue-induced cocaine seeking after drug withdrawal. This hypothesis will be tested by three lines of experimentation. First, using astrocyte-specific molecular tools, proposed experiments will test the specific hypothesis that astrocytic levels of mGluR5 are upregulated by cocaine SA, which, in turn, mediates sensitized in vivo responses of NAcSh astrocytes to cocaine and cocaine-associated cues after cocaine withdrawal. In parallel, selective RNA- seq of NAc astrocytes will reveal novel molecular substrates for cocaine action in this cell type. Second, using in vivo two-photon microscopy combined with slice electrophysiology, proposed experiments will test the specific hypothesis that increased activities of NAcSh astrocytes is both sufficient and necessary for cue re- exposure-induced re-silencing of cocaine-generated NAcSh synapses, and thus can be used to reduce cue- induced cocaine seeking after drug withdrawal. Third, using GCaMP-mediated in vivo Ca2+ imaging, proposed experiments will test the specific hypothesis that the neuronal ensembles are formed, in part, by astrocyte- mediated synaptogenesis in response to cocaine, and then drive cue-induced cocaine seeking after drug withdrawal. These proposed experiments will characterize several novel astrocyte-associated substrates through which addiction-related memories can be manipulated for therapeutic benefits.

抽象的 该拨款申请旨在了解星形胶质细胞在介导可卡因诱导回路中的作用 导致可卡因寻求和复吸的改变。 R01 项目第一个资助期的成果 证明可卡因自我给药（SA）激活星形胶质细胞介导的突触发生机制 在细胞核中的主要中型多棘神经元 (MSN) 中产生 AMPA 受体 (AMPAR) 沉默突触 伏隔壳（NAcSh）。在戒除可卡因 SA 期间，这些可卡因生成的 NAcSh 的一个子集 突触通过招募 AMPAR 来成熟和增强。实验性地转换和锁定可卡因- 在药物戒断期间，在沉默状态下产生的 NAcSh 突触大大减少了线索 诱导寻找可卡因。通过测量细胞内 Ca2+ 活性，初步研究表明 NAcSh 给予可卡因会上调星形胶质细胞的活性，并且这种上调在 5 天后会增加 可卡因 SA，表明星形胶质细胞中存在“致敏”过程。此外，在可卡因 SA 之后，NAcSh 星形胶质细胞 通过增加活动来获得对可卡因相关线索做出反应的能力，并通过实验 星形胶质细胞活性的增加使可卡因产生的 NAcSh 突触重新沉默。这些和其他初步 结果得出当前的假设：NAcSh 星形胶质细胞通过可卡因体验获得独特的特性 调节可卡因产生的突触并形成驱动提示诱导的特定神经元整体 戒毒后寻求可卡因。该假设将通过三线实验进行检验。第一的， 使用星形胶质细胞特异性分子工具，拟议的实验将检验星形胶质细胞的具体假设 mGluR5 的水平被可卡因 SA 上调，进而介导体内致敏反应 可卡因戒断后 NAcSh 星形胶质细胞对可卡因和可卡因相关线索的影响。同时，选择性RNA- NAc 星形胶质细胞的 seq 将揭示该细胞类型中可卡因作用的新分子底物。二、使用 体内双光子显微镜与切片电生理学相结合，拟议的实验将测试 具体假设是 NAcSh 星形胶质细胞活性的增加对于提示重新来说既是充分的也是必要的 暴露引起的可卡因产生的 NAcSh 突触的重新沉默，因此可用于减少提示 戒毒后诱导可卡因寻求。第三，使用 GCaMP 介导的体内 Ca2+ 成像，提出 实验将检验神经元群部分由星形胶质细胞形成的具体假设 介导对可卡因反应的突触发生，然后驱动线索诱导的可卡因寻找药物 撤回。这些拟议的实验将表征几种新型星形胶质细胞相关底物 通过它可以操纵与成瘾相关的记忆以获得治疗效果。