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Contributions of Nitrergic Interneurons and NO Signaling in Cocaine Relapse

氮能中间神经元和 NO 信号在可卡因复发中的作用

基本信息

批准号：
9757725
负责人：
Michael David Scofield
金额：
$ 24.9万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2021-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9757725
关键词：
Animals Behavior Brain Caliber Ceramics Chemosensitization Cleaved cell Cocaine Cocaine Dependence Coupled Cues Data Dendritic Spines Designer Drugs Development Dorsal Drug Addiction Drug Receptors Drug Targeting Electrochemistry Enterobacteria phage P1 Cre recombinase Enzymes Exposure to Extinction (Psychology)Extracellular Matrix Glutamates Head Interneurons Knock-in Mouse Learning Link Matrix Metalloproteinases Measures Mediating Mentors Microelectrodes Mus N-Methylaspartate National Institute of Drug Abuse Neurobiology Neuronal Plasticity Neurons Nitric Oxide Nitric Oxide Synthase Type I Nucleus Accumbens Pharmacology Phase Play Population Procedures Production Rabies virus Rattus Relapse Research Role Saline Self Administration Signal Transduction Synapses Synaptic plasticity System Techniques Technology Time Training Transgenic Mice Ventral Tegmental Area awake cell type cocaine exposure cocaine relapse design designer receptors exclusively activated by designer drugs direct application drug abstinence experience experimental study in vivo insight neurobiological mechanism novel novel therapeutics potential biomarker public health relevance receptor

项目摘要

DESCRIPTION (provided by applicant): Cocaine addiction produces long-lasting alterations in neuroplasticity within the nucleus accumbens core (NAcore) linked to an enduring vulnerability to relapse. Following extinction of cocaine self-administration, cocaine-conditioned cues produce a transient synaptic potentiation (t-SP) of NAcore medium spiny neurons (MSNs), characterized by increased dendritic spine head diameter and AMPA:NMDA ratios. This t-SP also extends to the extracellular matrix, where exposure to cocaine-conditioned cues causes a rapid enhancement of matrix metalloproteinase (MMP) activity, which is required for dendritic spine head enlargement. To date, the mechanism of MMP activation following exposure to cocaine-conditioned cues has yet to be elucidated. MMPs are secreted as an inactive pro-form which must be cleaved or modified prior to activation, and one mechanism for this activation is S-nitrosylation of the MMP pro-domain by nitric oxide (NO). The gaseous transmitter NO is produced by a small population of interneurons that express the enzyme neuronal nitric oxide synthase (nNOS), deemed nitrergic interneurons. Preliminary data presented here demonstrates that cocaine exposure enhanced NAcore nNOS and MMP activity and that inhibition of nNOS activity in the NAcore inhibited reinstated cocaine seeking and the cue-induced induction of MMP activity. I also show that selective activation of Gq signaling in NAcore nitrergic interneurons (with Gq-coupled designer receptors exclusively activated by designer drugs (DREADD)) enhanced MMP activity in-vivo and that nitrergic interneurons receive input from the prelimbic cortex (PL) dorsal raphe (DRN) and the ventral tegmental area (VTA). In the K99 aims, I propose to characterize glutamate and DREADD-evoked NO release in the NAcore following cocaine experience using anesthetized NO electrochemical recordings in rats and transgenic mice, which I have gained experience with during my NIDA T32. I will also selectively modulate the activity NAcore nitrergic interneurons with the DREADD receptor technology in order to determine the impact of activation/deactivation of these neurons on cued cocaine reinstatement. To do this, I will learn mouse self-administration techniques. In the R00 aims, I will perform electrochemical recordings in behaving rats to observe NO dynamics during self-administration, extinction and reinstatement. Training for these experiments will be completed in year 2 of the K99 phase. Finally, I will use NOS1cre knock-in mice and a cre-dependent AAV helper / rabies virus system to express Gq- DREADD in the monosynaptic afferents of NAcore nitrergic interneurons. Following DREADD-mediated activation of neurons in the PL, DRN or VTA I will measure NAcore NO levels in vivo. These experiments have the potential to reveal undiscovered neurobiological mechanisms of cocaine addiction, and could contribute to the development of novel therapeutic options aimed at reversing cocaine-induced neurobiological alterations.

描述（由申请人提供）：可卡因成瘾在与持久的复发脆弱性相关的丘脑核核心（NAcore）内产生持久的神经可塑性改变。可卡因自我管理灭绝后，可卡因条件的线索产生短暂的突触增强（t-SP）的NAcore中型多刺神经元（MSN），其特征在于增加树突棘头直径和AMPA：NMDA的比例。这种t-SP也延伸到细胞外基质，暴露于可卡因条件的线索导致基质金属蛋白酶（MMP）活性的快速增强，这是树突棘头部扩大所需的。迄今为止，暴露于可卡因条件线索后MMP激活的机制尚未阐明。MMP作为无活性的前体形式分泌，其必须在活化之前被切割或修饰，并且这种活化的一种机制是MMP前体结构域被一氧化氮（NO）的S-亚硝基化。气态递质NO由一小群表达神经元型一氧化氮合酶（nNOS）的中间神经元（被认为是氮能中间神经元）产生。这里提出的初步数据表明，可卡因暴露增强NAcore nNOS和MMP活性，抑制NAcore中的nNOS活性抑制恢复可卡因寻求和线索诱导的MMP活性诱导。我还表明，选择性激活的Gq信号在NAcore氮能中间神经元（与Gq耦合的设计师受体专门激活的设计师药物（DREADD））增强MMP的活性在体内和氮能中间神经元接收输入的前边缘皮层（PL）中缝背核（DRN）和腹侧被盖区（VTA）。在K99目标中，我建议在大鼠和转基因小鼠中使用麻醉NO电化学记录来表征可卡因经历后NAcore中谷氨酸和DREADD诱发的NO释放，我在NIDA T32期间获得了经验。我还将选择性地调节活动NAcore氮能中间神经元的DREADD受体技术，以确定这些神经元的激活/失活对提示可卡因恢复的影响。为了做到这一点，我将学习老鼠自我管理技术。在R 00目标中，我将在行为大鼠中进行电化学记录，以观察自我给药、消退和恢复过程中的NO动态。这些实验的培训将在K99阶段的第2年完成。最后，我将使用NOS 1cre基因敲入小鼠和依赖cre的AAV辅助/狂犬病病毒系统在NAcore氮能中间神经元的单突触传入中表达Gq- DREADD。在PL、DRN或VTA中的神经元的DREADD介导的活化之后，I将测量体内的NAcore NO水平。这些实验有可能揭示可卡因成瘾的未发现的神经生物学机制，并可能有助于开发旨在逆转可卡因诱导的神经生物学改变的新治疗方案。