Neurobiological mechanisms of prescription opioid withdrawal

项目摘要 本R01提案是针对PA-16-233“处方药滥用”而编写的。处方类阿片滥用 对男性和女性来说都是一个主要的公共卫生问题。尽管阿片成瘾在历史上表现出 在男性患病率大幅上升的情况下，性别差距正在缩小，这突显了进行研究的必要性 男性和女性都有。阿片类药物戒断综合征，特征是急性躯体综合征和长期- 持久的情感综合症，包括快感缺乏、焦虑和对药物的渴望，是导致病情升级的主要因素。 阿片类药物的使用和复发。我们实验室和其他实验室的累积工作表明，阿片类药物的戒断 增加谷氨酸介导的伏隔核外壳(NASH)的激活，这有助于 戒断综合症。例如，我们已经证明，吗啡依赖与增加 NASH中AMPA谷氨酸受体(AMPAR)GluA1亚单位的神经元表面表达 戒断诱导的抑郁样状态需要Nash GluA1 AMPAR激活。它还表明， 丘脑室旁核(PVT)向NASH的谷氨酸能投射激活 表达吗啡戒断症状所必需的。然而，这项先前的研究已经进行了 主要是在实验者注射阿片类药物后经历戒断的雄性啮齿动物。这项规定 Nash谷氨酸能信号在男性和女性戒断自身给药阿片类药物中的作用 不知道。这项提案的目标是在这些调查结果的基础上，研究如何针对具体的预测 (PVT到NASH)AMPAR介导的信号转导有助于戒断引发的负面情绪状态 雄性和雌性大鼠的羟考酮自我给药(SA)。我们的中心假设是羟考酮SA 在NASH中触发AMPAR介导的信号的投影特异性增加，这是表达 消极的情感状态和复发。我们将在四个目标中解决这一假设，在这些目标中，雄性和雌性老鼠 将暴露于长期接触(LGA)羟考酮SA 2周，然后戒断2周。在AIMS 1中 我们将研究停用LGA羟考酮对细胞外谷氨酸水平和突触的影响 微透析在NASH中的传播(目标1)和切片电生理学与光遗传学配对 激活PVT至NASH投影(目标2)。在目标3和4中，我们将确定谷氨酸释放和 NASH中AMPAR的激活对于羟考酮戒断诱导的负面情绪状态是必要的， 用颅内自我刺激的方法进行测量。我们将利用PVT对NASH的化学遗传调控 调节谷氨酸释放的投影(AIM 3)和病毒载体介导的GluA1ct表达，它具有 已被证明可以阻止GluA1亚基的活性依赖的运输，以调节AMPAR在 纳什(目标4)。来自这些研究的数据将在特定的投影之间建立机械联系 NASH和羟考酮戒断诱导的两种男性负性情感状态中的谷氨酸能信号转导 和女性，这最终可能使开发针对性别的阿片成瘾治疗成为可能。

Project Summary This R01 proposal was written in response to PA-16-233 “Prescription Drug Abuse”. Prescription opioid abuse is a major public health concern for both men and women. Although opioid addiction has historically exhibited a substantially higher prevalence in men, the gender gap is closing, underscoring the need to conduct research in both sexes. The opioid withdrawal syndrome, characterized by an acute physical syndrome and a long- lasting affective syndrome that includes anhedonia, anxiety, and drug cravings, is a major factor in escalation of opioid use and relapse. Cumulative work from our laboratory and others suggests that opioid withdrawal increases glutamate-mediated activation of the nucleus accumbens shell (NASh), which contributes to the withdrawal syndrome. For example, we have shown that morphine dependence is associated with increased neuronal surface expression of the AMPA glutamate receptor (AMPAR) GluA1 subunit in the NASh, and withdrawal-induced depressive-like states require NASh GluA1 AMPAR activation. It has also been shown that activation of glutamatergic projections from the paraventricular nucleus of the thalamus (PVT) to the NASh is required for expression of morphine withdrawal signs. However, this prior research has been conducted primarily in male rodents that experience withdrawal after experimenter-administered opioids. The regulation and role of NASh glutamatergic signaling in withdrawal from self-administered opioids in males and females is not known. The objective of this proposal is to build on these findings and examine how projection-specific (PVT to NASh) AMPAR-mediated signaling contributes to negative affective states triggered by withdrawal from oxycodone self-administration (SA) in male and female rats. Our central hypothesis is that oxycodone SA triggers projection-specific increases in AMPAR-mediated signaling in the NASh necessary for expression of negative affective states and relapse. We will address this hypothesis in 4 aims in which male and female rats will be exposed to long-access (LgA) oxycodone SA for 2 weeks followed by 2 weeks of abstinence. In Aims 1 and 2 we will examine how withdrawal from LgA oxycodone affects extracellular glutamate levels and synaptic transmission in the NASh using microdialysis (Aim 1) and slice electrophysiology paired with optogenetic activation of PVT to NASh projections (Aim 2). In Aims 3 and 4 we will determine if glutamate release and activation of AMPARs in the NASh is necessary for oxycodone withdrawal-induced negative affective states, as measured with intracranial self-stimulation. We will use chemogenetic modulation of PVT to NASh projections to regulate glutamate release (Aim 3) and viral vector-mediated expression of GluA1ct, which has been shown to block activity-dependent trafficking of GluA1 subunits, to regulate AMPAR transmission in the NASh (Aim 4). Data from these studies will establish a mechanistic link between projection-specific glutamatergic signaling in the NASh and oxycodone withdrawal-induced negative affective states in both males and females, which may ultimately enable development of gender-optimized opioid addiction treatments.