Neural Immune mechanisms of heroin withdrawal and stress

项目摘要/摘要 阿片类药物戒断和创伤后应激障碍(PTSD)经常同时出现在临床环境中。 临床数据还表明，阿片类药物滥用是创伤后应激障碍的潜在危险因素。对机制的理解 对于阿片类药物使用者的共生症状和创伤后应激障碍的易感性，将提供关于 阿片类药物滥用，并为制定减轻海洛因戒断症状的干预措施提供信息， 已知的复发风险因素，以及海洛因对应激障碍的长期影响。我们实验室已经鉴定出 应激增强恐惧学习(SEFL)动物发展所需的海马区机制 创伤后应激障碍的模型。我们证实，SEFL范式中的严重应激源诱导背侧海马区(DH)。 IL-1受体拮抗剂(IL-1β，IL-1β)可直接阻断DH IL-1信号转导。 1ra)在严重的压力之后，阻止了随后增强的恐惧学习。我们已经开发了一种临床前模型 探讨海洛因戒断对增强恐惧学习的影响。我们发现撤军不会升级 在SEFL范式中，海洛因管理替代了严重的应激源，海洛因戒断也同样如此 增加DHIL-1β和胶质纤维酸性蛋白的表达，这是星形胶质细胞激活的标志。因此，计划是测试 创新的独特假说认为海洛因戒断也通过海马区IL-1β和 导致恐惧学习增强的星形胶质细胞。特别目标1将检验海洛因戒断的假设- 诱导的恐惧学习增强是由白介素1β(IL-1 DNA)介导的。具体来说，我们将确定(A)是否 戒断诱导的增强恐惧学习与IL-1β信号的增强有关 星形胶质细胞，(B)在戒断过程中用IL-1RA阻断DHIL-1受体是否会保护 海洛因戒断后增强恐惧学习的发展；(C)DH输注外源性IL- 1β将取代压力和/或戒断的影响，以诱导增强的恐惧学习，以及(D)是否 在海洛因戒断过程中，药物阻断DHIL-1受体将防止戒断症状。 预测结果是，海洛因戒断将增加IL-1β水平，主要是在星形胶质细胞中，并且这种影响 海洛因戒断对增强恐惧学习的影响将被IL-1RA阻断，并通过注射IL-1β来模拟 卫生署。此外，使用IL-1RA可减轻或阻断戒断症状。 总而言之，这些结果阐明了DHIL-1信号在海洛因戒断和增强恐惧中的关键作用 学习。特殊目标2将使用先进的单个细胞的3-D重建来进行形态测量分析 结合突触标志物(突触后密度95和突触素1)的评估来测试创新 星形胶质细胞形态计量学特性改变和/或星形胶质细胞/神经元改变的假说 交互作用与海洛因戒断和SEFL使用的严重应激源的影响有关， 并视IL-1信号而定。这些研究测试了关于心力衰竭潜在机制的独特假说 减少海洛因戒断的影响，并为减轻海洛因滥用的长期影响提供新的目标。

Project Summary/Abstract Opiate withdrawal and post-traumatic stress disorder (PTSD) frequently present together in clinical settings. Clinical data also suggests that opiate abuse is a potential risk factor for PTSD. Understanding the mechanism for co-occurrence and vulnerability to PTSD in opiate users will provide information about the consequences of opiate abuse and inform the development of interventions that mitigate both the symptoms of heroin withdrawal, a known risk factor for relapse, and heroin’s long-term effects on stress disorders. Our laboratory has identified the hippocampal mechanisms required for development of stress enhanced fear learning (SEFL), an animal model of PTSD. We established that the severe stressor in the SEFL paradigm induces dorsal hippocampal (DH) interleukin-1β (IL-1β) in astrocytes, and that directly blocking DH IL-1 signaling with IL-1 receptor antagonist (IL- 1RA) after severe stress prevents subsequent enhanced fear learning. We have developed a pre-clinical model to investigate the effect of heroin withdrawal on enhanced fear learning. We found that withdrawal from escalating heroin administration substitutes for a severe stressor in the SEFL paradigm and that heroin withdrawal similarly increases DH IL-1β and GFAP expression, a marker of astrocyte activation. Accordingly, the plan is to test the innovative unique hypothesis that heroin withdrawal also acts through hippocampal IL-1β and alterations in astrocytes that result in enhanced fear learning. Specific Aim 1 will test the hypothesis that heroin withdrawal- induced enhancement of fear learning is mediated by IL-1β in the DH. Specifically, we will determine (A) whether withdrawal-induced enhanced fear learning is associated with potentiation of IL-1β signaling specifically in astrocytes, (B) whether blockade of DH IL-1 receptors with IL-1RA during withdrawal will protect against the development of enhanced fear learning following heroin withdrawal, (C) whether DH infusion of exogenous IL- 1β will substitute for the effects of stress and/or withdrawal to induce enhanced fear learning, and (D) whether pharmacological blockade of DH IL-1 receptors during heroin withdrawal will prevent withdrawal symptoms. Predicted results are that heroin withdrawal will increase IL-1β levels, primarily in astrocytes, and that the effect of heroin withdrawal on enhanced fear learning will be blocked by IL-1RA and mimicked by infusion of IL-1β in the DH. Also, the symptoms of withdrawal will be attenuated or blocked by the administration of IL-1RA. Collectively, the results elucidate the critical role of DH IL-1 signaling in heroin withdrawal and enhanced fear learning. Specific Aim 2 will use advanced 3-D reconstruction of individual cells to conduct morphometric analysis in combination with assessment of synaptic markers (postsynaptic density 95 and Synapsin 1) to test innovative hypotheses that changes in the morphometric properties of astrocytes, and/or alterations of astrocyte/neuron interactions are associated with the effects of both the heroin withdrawal and the severe stressor used in SEFL, and contingent on IL-1 signaling. These studies test unique hypotheses regarding the underlying mechanism of the effects of heroin withdrawal, and provide new targets for mitigating the long-term effects of heroin abuse.