Role of lateral habenula in methamphetamine TAAR1-mediated synaptic plasticity and aversion

项目总结 相当多的研究集中在药物使用障碍作为动机障碍，涉及固有的或药物- 诱导奖赏通路功能。然而，此应用程序的重点是对抗 甲基苯丙胺(MA)可能会限制其使用，这方面的研究很少。理查兹夫妇(菲利普斯) 实验室发现痕量胺相关受体1(TAAR1)是影响MA诱导的关键靶点 厌恶。TAAR1是一种定位于细胞内的G蛋白偶联受体。MA只有在以下情况下才能访问TAAR1 被输送到细胞内。这是通过细胞外膜转运蛋白，如多巴胺和 5-羟色胺转运体，分别为DAT和SERT。我们认为MA在多巴胺中激活TAAR1 5-羟色胺神经元负责MA诱导的厌恶，单胺能回路与 外侧缰核(LHb)尤为重要。本报告中提出的研究的总体目标 应用是理解单胺能神经元-LHb相互作用对MA-LHb经验的影响 通过TAAR1诱导厌恶，可能会降低MA使用的风险。我们的初步数据显示MA激活了 外侧缰核(LHb)神经元，尤其是具有功能TAAR1的小鼠。目标1中的研究将使用SLICE 电生理学研究MA对腹侧被盖区多巴胺和多巴胺的TAAR1依赖效应 中缝背侧5-羟色胺神经元，比较野生型和CRISPRD敲入小鼠的切片，小鼠有 功能性和非功能性TAAR1。AIM 1的研究还将使用光遗传刺激来 观察MA对LHb谷氨酸能突触的影响。根据我们已发表的研究结果， 这一目的的功能行为学研究将检验谷氨酸受体亚单位GluN2B在MA上的作用 厌恶和摄取。Aim 2将进行以LHb为重点的行为研究，这已被证明 中介其他类型的厌恶，还没有关于MA厌恶的研究。我们将消融小鼠的LHb 并研究无功能性TAAR1对MA厌恶和摄入量的影响。最后，Aim 3研究将使用 一种逆行示踪剂，用于识别投射到腹侧被盖或中缝背侧的LHb神经元。 电生理学研究将确定多巴胺或5-羟色胺是否调节LHb的MA激活 腹侧被盖区突触前终末神经元及MA对TAAR1的激活作用 多巴胺神经元或中缝背侧5-羟色胺神经元调节MA的作用 并且没有功能TAAR1。因此，这项提议利用了遗传工具，通过电生理学进行电路分析 以及行为分析，以确定MA如何以TAAR1依赖的方式与LHb神经元接触，无论是 LHB通路对于MA诱导的厌恶行为是必要的，以及它们是否抑制MA的摄入。这 该策略也可用于研究MA对其他地区TAAR1信号的影响。机构学研究 对MA诱导的厌恶的潜在敏感性可能导致一类新的治疗方法的确定。

PROJECT SUMMARY Considerable research has focused on drug use disorders as motivational disorders involving inherent or drug- induced reward pathway function. However, the focus of this application is on opposing aversive effects of methamphetamine (MA) that may curb its use, which have been little studied. The Richards (Phillips) laboratory identified the trace amine associated receptor 1 (TAAR1) as a critical target impacting MA-induced aversion. TAAR1 is an intracellularly located G protein-coupled receptor. MA gains access to TAAR1 only if it is transported into the cell. This occurs via extracellular membrane transporters, such as dopamine and serotonin transporters, DAT and SERT, respectively. We propose that TAAR1 activation by MA in dopamine and serotonin neurons is responsible for MA-induced aversion and that monoaminergic circuit interactions with the lateral habenula (LHb) are of particular importance. The overarching goal of the studies proposed in this application is to understand the monoaminergic neuron-LHb interactions responsible for the experience of MA- induced aversion via TAAR1 that may reduce risk for MA use. Our preliminary data show that MA activates lateral habenula (LHb) neurons, specifically in mice with functional TAAR1. The studies in Aim 1 will use slice electrophysiology to examine the TAAR1-dependent effects of MA in ventral tegmental area dopamine and dorsal raphe serotonin neurons, comparing slices from wildtype and CRISPRed knock-in mice, mice that have functional vs. nonfunctional TAAR1, respectively. Aim 1 studies will also use optogenetic stimulation to examine the effects of MA on glutamatergic synapses from the LHb. Based on our published findings, functional behavioral studies in this aim will examine the role of a glutamate receptor subunit, GluN2B, on MA aversion and intake. Aim 2 will perform behavioral studies focused on the LHb, which has been shown to mediate other types of aversion, has not been studied for MA aversion. We will ablate the LHb in mice with and without functional TAAR1 and study the impact on MA aversion and intake. Finally, Aim 3 studies will use a retrograde tracer to identify the LHb neurons that project to either the ventral tegmentum or dorsal raphe. Electrophysiological studies will determine whether dopamine or serotonin modulate MA activation of LHb neurons and determine whether MA activation of TAAR1 in presynaptic terminals of ventral tegmental area dopamine neurons or dorsal raphe serotonin neurons regulate the effects of MA using slices from mice with and without functional TAAR1. Thus, this proposal utilizes genetic tools, circuit analysis via electrophysiology and behavioral analysis to identify how MA engages LHb neurons in a TAAR1-dependent manner, whether LHb circuits are necessary for MA-induced aversion behaviors, and whether they inhibit MA intake. This strategy could be used to study effects of MA on TAAR1 signaling in other regions. The study of mechanisms underlying sensitivity to MA-induced aversion could lead to the identification of a new class of therapeutics.