Retinoic acid signaling and incubation of cocaine craving

视黄酸信号传导和可卡因渴望的孵化

• 批准号: 10335114
• 负责人: Amanda Marilyn Wunsch
• 金额: $ 7.05万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-18 至 2022-02-17
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10335114
• 关键词: AMPA Receptors; Abstinence; Brain; Brain region; Calcium; Cell surface; Cells; Cocaine; Cocaine Users; Coculture Techniques; Cues; Drug abuse; Drug usage; Electrophysiology (science); Excitatory Synapse; Exhibits; Exposure to; Female; Fiber; Glutamates; Goals; Hippocampus (Brain); Incubated; Link; Maintenance; Measures; Mediating; Methods; Mission; Modeling; Monitor; Neurons; Nucleus Accumbens; Permeability; Pharmaceutical Preparations; Pharmacology; Photometry; Protein Biosynthesis; Proteins; Rattus; Regulation; Relapse; Reporter; Research; Rodent; Role; Saline; Self Administration; Signal Pathway; Signal Transduction; Slice; Substance Use Disorder; Synapses; Synaptic Transmission; Synaptic plasticity; System; Testing; Therapeutic Intervention; Time; Training; Translations; Tretinoin; United States National Institutes of Health; Withdrawal; Work; base; blood flow measurement; cocaine self-administration; cocaine use; craving; disorder later incidence prevention; ineffective therapies; male; neural correlate; neuropsychiatric disorder; new therapeutic target; novel; patch clamp; postnatal; postsynaptic; prevent; response; scale up; skills; substance use; transmission process

Project Summary A major problem in treating drug abuse is persistent vulnerability to relapse, even after long periods of abstinence. In the incubation of cocaine craving model of relapse, rats undergo extended access to cocaine self- administration. During withdrawal, rats exhibit a progressive intensification (incubation) of cue-induced cocaine craving. We have shown that calcium (Ca2+)-permeable AMPA receptors (CP-AMPAR), comprised exclusively of the GluA1 subunit, accumulate in the nucleus accumbens (NAc) during late withdrawal and thereafter are required for the expression of incubated cue-induced craving. Therefore, understanding mechanisms regulating CP-AMPAR accumulation and maintenance may yield novel therapeutic targets for reducing craving and prolonging abstinence. Work from our lab and others have shown that cocaine withdrawal is associated with multiple adaptations that predict reduced Ca2+ levels in NAc medium spiny neurons (MSN). However, little is known about mechanisms that may link this reduced activity during withdrawal to the subsequent insertion of CP-AMPARs. One promising candidate involves the retinoic acid (RA) signaling cascade. Studies in hippocampal neurons have demonstrated that Ca2+ levels associated with basal synaptic transmission are sufficient to suppress RA synthesis. However, following a period of inactivity, RA synthesis is disinhibited, leading to increased translation of GluA1 and synaptic insertion of homomeric GluA1 CP-AMPARs. CP-AMPAR accumulation in the NAc during incubation may likewise involve reduced activity and has been demonstrated in our unpublished studies to be associated with increased translation of GluA1. Based on these similarities to RA- induced synaptic scaling, my central hypothesis is that cocaine incubation leads to a decrease in activity in NAc neurons at baseline, increased RA synthesis, and scaling up of CP-AMPARs. Aim 1 will determine if Ca2+ levels are altered in the NAc core during incubation of cocaine craving. I will use fiber photometry to measure changes in intracellular Ca2+, a correlate of neural activity, in early and late withdrawal from extended access to cocaine (or saline) self-administration. I will measure Ca2+ at baseline and during exposure to a cocaine-associated cue. Aim 2 will determine whether RA contributes to CP-AMPAR accumulation in NAc core MSN of cocaine incubated rats. Whole-cell patch clamp recordings in brain slices from cocaine incubated or saline rats will be used to determine if pharmacological manipulation of RA signaling alters AMPAR-mediated synaptic transmission in NAc medium spiny neurons. Aim 3 will determine if RA mediates synaptic scaling in cultured NAc MSN. I will use a RA reporter system to confirm that RA expression in MSN is activity- dependent, and pharmacological methods to determine whether RA-dependent scaling of CP-AMPAR occurs in NAc neurons. While these studies are underway, I will participate in a multi-faceted training plan to develop the non-bench skills needed to reach my goal of becoming a PI in an academic setting.

项目摘要 治疗药物滥用的一个主要问题是，即使在长期吸毒之后， 禁欲在可卡因渴求模型的孵化复发，大鼠经历了延长获得可卡因自我， 局在戒断过程中，大鼠表现出线索诱导的可卡因的进行性强化（潜伏期 渴望我们已经表明，钙（Ca 2+）渗透性AMPA受体（CP-AMPAR），只包括 GluA 1亚单位的，积累在神经核（NAc）在晚期撤退，此后， 表达潜伏的线索诱导的渴望所必需的。因此，了解调节机制 CP-AMPAR的积累和维持可能产生新的治疗靶点，用于减少渴望， 延长禁欲期我们实验室和其他实验室的工作表明，可卡因戒断与 预测NAc中棘神经元（MSN）中Ca 2+水平降低的多种适应。然而， 已知的机制可能将撤回期间的活动减少与随后的插入联系起来， CP-AMPAR。一个有前途的候选人涉及视黄酸（RA）信号级联。研究 海马神经元已经证明，与基础突触传递相关的Ca 2+水平， 足以抑制RA合成。然而，经过一段时间的不活动，RA合成被解除抑制，导致 增加GluA 1的翻译和同型GluA 1 CP-AMPAR的突触插入。CP-AMPAR 在孵育期间NAc中的积累同样可能涉及活性降低，并且已经在 我们未发表的研究与GluA 1翻译增加有关。基于这些与RA的相似性- 诱导的突触缩放，我的中心假设是可卡因孵育导致NAc活性降低 神经元在基线时，增加RA合成，并按比例增加CP-AMPAR。目标1将确定Ca 2 + 在可卡因渴求的潜伏期内，NAc核心中的水平发生了变化。我会用光纤测光 测量细胞内Ca 2+的变化，神经活动的相关性，在早期和晚期退出延长 可卡因（或生理盐水）自我给药。我将在基线和暴露于 可卡因相关线索目的2将确定RA是否有助于NAc中CP-AMPAR的积累 可卡因孵育大鼠的核心MSN。可卡因孵育脑片的全细胞膜片钳记录 或盐水大鼠将用于确定RA信号传导的药理学操作是否改变AMPAR介导的 NAc中棘神经元突触传递。目标3将确定RA是否介导突触缩放 在培养的NAc MSN中。我将使用RA报告系统来确认MSN中的RA表达是活性的- 依赖性和药理学方法，以确定是否发生RA依赖性缩放的CP-AMPAR中， NAc神经元。在这些研究正在进行的同时，我将参加一个多方面的培训计划来制定 非板凳技能需要达到我的目标，成为一个PI在学术环境。