Functional consequences of cocaine self-administration on astrocytes

可卡因自我给药对星形胶质细胞的功能影响

• 批准号: 10682221
• 负责人: Kathryn Joanna Reissner
• 金额: $ 34.3万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2028-02-29
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10682221
• 关键词: Abstinence; Acute; Adenosine; Adenosine A1 Receptor; Affect; Animal Behavior; Area; Astrocytes; Atrophic; Automobile Driving; Behavior; Behavioral; Biosensor; Brain; Calcium Signaling; Cell model; Cell physiology; Cells; Chronic; Cocaine; Communication; Coupled; Data; Dopamine; Dopamine D1 Receptor; Dopamine D2 Receptor; Drug Targeting; Drug abuse; Electrophysiology (science); Exhibits; Functional disorder; G-Protein-Coupled Receptors; GTP-Binding Proteins; Glutamates; Goals; Homeostasis; Image; Impairment; In Situ; Incubated; Intervention; Intravenous; Knowledge; Label; Ligands; Measures; Mediating; Neuroglia; Neurons; Neurophysiology - biologic function; Nucleus Accumbens; Pathologic; Pathology; Pharmaceutical Preparations; Phenotype; Physiological; Physiology; Public Health; Pump; Rat Transgene; Rattus; Regulation; Role; Saline; Self Administration; Signal Transduction; Slice; Structure; Substance Use Disorder; Surface; Synapses; Synaptic Transmission; Testing; Time; antagonist; cocaine craving; cocaine exposure; cocaine seeking; cocaine self-administration; cocaine use; craving; designer receptors exclusively activated by designer drugs; drug seeking behavior; experimental study; fluorescence imaging; high resolution imaging; in vivo; inhibitor; male; multimodality; neural; neural circuit; neuroadaptation; novel; patch clamp; pharmacologic; presynaptic; prolonged abstinence; receptor; response; reward circuitry; stimulant use disorder; synaptic depression; synaptic inhibition; treatment strategy

Project Summary/Abstract Accumulating evidence has identified nucleus accumbens astrocytes as salient targets of drug abuse. For example, numerous studies indicate that rat self-administration of multiple drug classes results in impaired glutamate homeostasis, as well as decreased structural features and synaptic colocalization of nucleus accumbens astrocytes. Preliminary data for this proposal reveal that male rat accumbens astrocytes exhibit striking (~40%) reductions in surface area, volume, and synaptic colocalization 45 days after 10 days of long- access (6h/d) cocaine self-administration. These findings suggest loss of physiological function of astrocytes as regulators of neural circuits. However, the mechanism(s) driving these observations are unknown, as are the consequences to neural function. We hypothesize that astrocyte pathology underscores the neural adaptations and increased measures of craving observed across prolonged abstinence (also known as incubation). Accordingly, the goal of this proposal is to define the relationship between cocaine self- administration and the onset of astrocyte dysfunction in the nucleus accumbens, as well as the relationship between astrocyte dysfunction, synaptic transmission, and behavior. Aim 1 will assess the effects of operant cocaine self-administration on evoked Ca2+ responses in accumbens astrocytes as a function of both self- administration and abstinence, and will determine the functional significance of astrocyte Ca2+ to cocaine seeking behaviors. Aim 2 will examine how cocaine self-administration affects the ability of astrocytes to negatively regulate excitatory synaptic transmission in D1 and D2 receptor-positive medium spiny neurons. Lastly, Aim 3 will establish the role of dopamine and G protein-mediated astrocyte signaling in the pathological effects of cocaine on accumbens astrocyte structure. For each aim, we will evaluate endpoints as a function of time across abstinence. These objectives will collectively be accomplished by leveraging a multimodal approach that spans cellular physiology to circuit analysis and animal behavior, combining rat cocaine self- administration with high-resolution imaging of fluorescently-labeled astrocytes, acute slice imaging of Ca2+- labeled astrocytes using a photoconvertible Ca2+ indicator (astro-CaMPARI2), astrocyte DREADD stimulation, astrocyte Ca2+ depletion using an astrocyte-expressed PMCA2 Ca2+ pump, whole cell patch-clamp electrophysiology, neuronal subtype-specific analyses using Drd1a-Cre and Drd2-Cre transgenic rats, and fluorescent imaging of an adenosine biosensor GRABAdo. Collectively, these studies will define the relationship between astrocyte dysfunction across abstinence from cocaine self-administration with neural physiology and behavior.

项目摘要/摘要 越来越多的证据表明，伏隔核星形胶质细胞是药物滥用的主要目标。为 例如，大量研究表明，大鼠自我给药多种药物类别会导致损害 谷氨酸稳态，以及核内结构特征和突触共定位减少 伏隔星形胶质细胞。这一提议的初步数据显示，雄性大鼠伏隔核星形胶质细胞显示 在长时间的10天后，45天的表面积、体积和突触共定位显著减少(~40%) 获得(6小时/天)可卡因自我给药。这些发现提示星形胶质细胞的生理功能丧失。 作为神经回路的调节器。然而，推动这些观察的机制(S)是未知的，也是如此 对神经功能的影响。我们假设星形胶质细胞病理强调了神经细胞 在长期禁欲(也称为 孵化)。因此，这项提案的目标是界定可卡因自身与 给药与伏隔核星形胶质细胞功能障碍的发生及其关系 星形胶质细胞功能障碍、突触传递和行为之间的关系。目标1将评估操作剂的效果 可卡因自身给药对伏隔核星形胶质细胞诱发的钙反应的影响 给药和戒断，并将决定星形胶质细胞钙离子对可卡因的功能意义 寻找行为。目标2将研究可卡因自身给药如何影响星形胶质细胞 负向调节D1和D2受体阳性中棘神经元的兴奋性突触传递。 最后，目标3将确定多巴胺和G蛋白介导的星形胶质细胞信号在病理中的作用。 可卡因对伏隔核星形胶质细胞结构的影响。对于每个目标，我们将评估端点作为以下各项的函数 跨越禁欲的时间。这些目标将通过利用多式联运共同实现 一种跨越细胞生理学、电路分析和动物行为的方法，结合大鼠可卡因自身 应用高分辨率荧光标记星形胶质细胞成像，急性切片钙离子成像 用光可转换钙指示剂标记星形胶质细胞(Astro-CaMPARI2)，星形胶质细胞DREADD刺激， 星形胶质细胞表达的PMCA2钙泵全细胞膜片钳对星形胶质细胞的钙耗竭作用 电生理学，使用Drd1a-Cre和Drd2-Cre转基因大鼠的神经元亚型特异性分析，以及 腺苷生物传感器的荧光成像。总而言之，这些研究将定义这种关系 可卡因戒断后星形胶质细胞功能障碍与神经生理学的关系 行为。