Mechanisms Regulating Cocaine Memory Strength

项目摘要/摘要 成瘾障碍对个人和社会都是一个巨大的负担。不幸的是，几乎没有 有效的治疗，部分归因于与药物相关的记忆的持久性，这种记忆驱动着渴望和 旧病复发。因此，最近的研究集中在寻找方法来降低与毒品相关的强度 防止复发的记忆。可以通过以下两种方法之一来降低记忆强度： 提示和药物通过消退或通过抑制记忆在提醒事件后的重新巩固。两者都有 策略在临床前和临床模型中一直有效，但在某些情况下，记忆本应是 由于无意地加强再巩固或抑制 灭绝。为了解决这个问题，我们分析了蛋白质磷酸化的变化。 记忆经历消亡与重新整合，以识别对任一项具有选择性的信号级联 记忆过程，或者理想地以相反的方向调节这两个过程。对立面的认定 信号事件可能允许开发既增强灭绝又抑制灭绝的治疗方法 重新巩固，减少导致复发的药物相关记忆的强度。我们的初步数据 强烈提示杏仁基底外侧核(BLA)中相反的钙相关信号事件介导了 与自我注射可卡因相关的记忆的重新巩固和消失。我们将扩大我们的 在拟议研究的目标1中确定相反的信号事件，包括增加 分析了蛋白质，扩大了分析的时间进程，并将分析扩展到女性。此外， 我们将跟进我们最初研究中令人兴奋的发现，其中包括1)鉴定一部小说 钙调素依赖的蛋白激酶2α(CaMKIIα，磷酸化丝氨酸331)的磷酸化 通过在重新巩固过程中的消亡和减少而起作用，从而抑制激酶活性，以及2)一般的 消亡后蛋白质磷酸化程度的降低，暗示着磷酸酶的激活，例如 钙调神经磷酸酶。我们的数据让我们假设，除了涉及新的学习之外，灭绝训练 机制，也可以反对正常的再整合过程。我们建议这发生在相同的 通过钙离子调节的突触去增强机制的电路。消失性突触去增强 据报道，CaMKII和Calcineurin信号的差异与条件性恐惧记忆有关，但 没有接受过与可卡因相关的记忆检查。因此，在AIMS中使用多种方法的组合 2和3，我们将确定CaMKIIα是否通过S331的磷酸化而抑制，并激活钙调神经磷酸酶 磷酸酶可降低可卡因的记忆强度，通过增强来降低线索诱导的恢复 灭绝和抑制再巩固。我们还将确定这些信号通路是否直接 在相同或不同的途径中相互调节和突触强度。机制的确定 调节可卡因的记忆将导致复发预防治疗发展的新靶点。

Project Summary/Abstract Addictive disorders are a huge burden on both the individual and on society. Unfortunately, there are few effective treatments, partially due to the persistence of drug-associated memories that drive craving and relapse. Therefore, recent research has focused on finding ways to reduce the strength of drug-associated memories to prevent relapse. Memory strength can be reduced by either disrupting the association between a cue and a drug via extinction or by inhibiting the reconsolidation of the memory after a reminder event. Both strategies have been effective in preclinical and clinical models, but in some cases, a memory meant to be weakened, is instead strengthened due to unintentional enhancement of reconsolidation or inhibition of extinction. In order to address this problem, we have analyzed changes in protein phosphorylation after a memory undergoes extinction vs. reconsolidation to identify signaling cascades that are selective to either memory process, or that ideally regulate the two processes in opposite directions. Identification of opposing signaling events could allow the development of treatments that both enhance extinction and inhibit reconsolidation, reducing the strength of the drug-associated memories that drive relapse. Our preliminary data strongly suggest that opposing Ca2+-related signaling events in the basolateral amygdala (BLA) mediate the reconsolidation vs. extinction of a memory associated with self-administered cocaine. We will expand our identification of opposing signaling events in Aim 1 of the proposed studies, including increasing the number of proteins analyzed, expansion of the time course of analysis, and extending the analysis to females. Moreover, we will follow-up on the exciting findings from our initial study, which include 1) identification of a novel phosphorylation event on Ca2+ -calmodulin-dependent kinase 2 alpha (CaMKIIα, phospho-serine 331) induced by extinction and reduced during reconsolidation that functions to inhibit kinase activity, and 2) a general decrease in protein phosphorylation after extinction, implicating activation of a phosphatase, such as calcineurin. Our data led us to hypothesize that extinction training, in addition to involving new learning mechanisms, can also oppose normal reconsolidation processes. We propose that this occurs within the same circuits via Ca2+-regulated synaptic depotentiation mechanisms. Extinction-induced synaptic depotentiation and differences in CaMKII and calcineurin signaling have been reported for conditioned fear memories, but have not been examined for cocaine-associated memories. Thus, using a combination of approaches in Aims 2 & 3, we will determine if CaMKIIα inhibition via S331 phosphorylation, and activation of calcineurin phosphatase, can reduce cocaine memory strength to decrease cue-induced reinstatement via enhancement of extinction AND inhibition of reconsolidation. We will also determine if these signaling pathways directly regulate each other and synaptic strength in the same or different pathways. Determination of the mechanisms regulating cocaine memories will lead to novel targets for relapse prevention treatment development.