Role of Class IIa HDAC Target Genes in Opioid and Cocaine Addiction

具体目标 与药物使用环境相关的外部和内部线索往往发展成为持久的， 是重新吸毒的有力诱因许多研究表明，表观遗传酶，如组蛋白 脱乙酰酶（HDAC），改变染色质结构和影响基因表达发挥重要作用， 成瘾相关行为的动物模型。在上一个资助期，我们证明了IIa类 HDACs，HDAC 5，在多种可卡因诱导行为的调节中起重要作用， 相关的学习和记忆。HDAC 5靶基因Npas 4是一种重要的新型转录因子， 可卡因条件性位置偏爱和操作性药物辨别在成人NAc中所需的因子 在小鼠静脉内自我给药的学习。我们的初步研究结果表明，NPAS 4是诱导的， 在DARPP-32阳性的中棘神经元（MSNs）和小白蛋白阳性的快速尖峰中间神经元（PV-32）中， FSI），但NPAS 4调节药物行为的相关人群仍不清楚。 我们的长期目标是了解NPAS 4在发展和/或 与药物成瘾相关的行为。我们的中心假设是，NPAS 4诱导在一个或多个细胞内， 更多的活化NAc神经元亚群促进了突触可塑性事件， 持久的药物背景/线索学习和记忆。我们将采用一系列多学科的假设， 测试实验和尖端的分子遗传学方法，将询问体内细胞类型- NPAS 4和NPAS 4表达细胞在NAc中对药物成瘾相关的特定作用和调节 学习和记忆。我们将测试和完善我们的中心假设，具体目标如下： 具体目标1：确定NPAS 4在获得和消退过程中的细胞类型特异性作用 药物自我管理。在这个目标中，我们将采取细胞类型特异性功能丧失和获得的方法， 研究NPAS 4在小鼠药物自身操作性辨别和消退学习中的作用。 给药试验 具体目标2：确定NPAS 4阳性NAc神经元是否定义了功能性“印迹” 将外部线索与药物奖励和寻求联系起来的人群。使用我们新开发的Npas 4 增强子驱动的，依赖他莫昔芬的cre病毒，我们将使用化学遗传学方法来操纵 NPAS 4阳性群体的活性，并测试其在杜尔格服用和寻求行为中的作用。 具体目的3：确定药物SA期间NAc中NPAS 4的细胞功能。我们会用手机- 类型特异性功能丧失和获得策略来评估NPAS 4对兴奋性AD抑制性的作用 自我注射可卡因或海洛因的小鼠的突触可塑性。

SPECIFIC AIMS External and internal cues associated with the drug use environment often develop into persistent and powerful triggers for relapse to drug seeking. Many studies have reported that epigenetic enzymes, like histone deacetylases (HDACs), that alter chromatin structure and influence gene expression play an important role in addiction-relevant behaviors in animal models. In the previous grant period, we showed that the class IIa HDACs, HDAC5, plays important roles in the regulation of multiple cocaine-induced behaviors, including drug related learning and memory. The HDAC5 target gene, Npas4, emerged as an important, novel transcription factor required in the adult NAc for cocaine conditioned place preference and operant drug discrimination learning in the mouse intravenous self-administration. Our preliminary findings indicate that NPAS4 is induced in DARPP-32-positive medium spiny neurons (MSNs) and parvalbumin-positive fast spiking interneurons (PV- FSIs), but the relevant population(s) in which NPAS4 regulates drug behaviors remains unknown. Our long-term goal is to understand the role and regulation of NPAS4 in the development and/or persistence of drug addiction-related behaviors. Our central hypothesis is that NPAS4 induction within one or more subpopulations of activated NAc neurons promotes glutamatergic synaptic plasticity events that underlie long-lasting drug context/cue learning and memory. We will employ a series of multi-disciplinary, hypothesis testing experiments and cutting-edge molecular genetic approaches that will interrogate the in vivo cell type- specific role and regulation of NPAS4 and NPAS4-expressing cells in the NAc for drug addiction-related learning and memory. We will test and refine our central hypothesis with the following specific aims: Specific Aim 1: Determine the cell-type specific roles for NPAS4 during acquisition and extinction of drug self-administration. In this aim, we will take a cell-type specific loss- and gain-of-function approaches to study the function of NPAS4 during operant discrimination and extinction learning in the mouse drug self- administration assay. Specific Aim 2: Determine whether NPAS4-positive NAc neurons define a functional “engram” population linking external cues to drug reward and seeking. Using our newly developed Npas4 enhancer-driven, tamoxifen-dependent cre virus, we will use a chemogenetic approach to manipulate the activity of the NPAS4-positive population and test its role in durg taking and seeking behaviors. Specific Aim 3: Determine the cellular function of NPAS4 in the NAc during drug SA. We will use cell- type specific loss- and gain-of-function strategies to evaluate the effects of NPAS4 on excitatory ad inhibitory synapse plasticity in mice self-administering cocaine or heroin.