Investigating How Alcohol Withdrawal Dysregulates 'Reward' and 'Aversion' Neurons in the Basolateral Amygdala

基底外侧杏仁核（BLA）在酒精使用障碍（AUD）的发展中至关重要。其独特 在奖励和厌恶相关回路中的位置允许它调节酒精摄入和戒断诱导 焦虑谷氨酸能锥体神经元驱动这些行为反应， 兴奋性促进焦虑和寻求奖励。锥体神经元接受来自中线的神经元能输入 通过终纹（ST）的内侧前额叶皮层和更多的外侧皮层区域发送 通过外囊（EC）的神经递质输入。GABA能外侧囊旁细胞（LPC）和 “局部”中间神经元调节锥体神经元。我的项目的目标是研究慢性间歇性 乙醇和戒断（CIE/WD）使投射到奖赏和厌恶相关区域的BLA神经元失调 来了解增加酒精摄入量的机制。脑桥核（NAC）参与 奖励寻求，而终纹床核（BNST）调节焦虑。因此，我的项目 将使用BLA-NAC神经元作为“奖励”神经元，BLA-BNST神经元作为“厌恶”神经元。本实验室 已经表明WD通过ST输入的突触前和突触后机制增加突触能功能 和EC-BLA突触。我的初步数据显示，WD增加ST的谷氨酸释放 输入到BLA-BNST神经元，而WD介导的突触后功能增加， 在EC-BLA突触是投射和性别依赖。我的初步数据还表明WD改变了 GABA能传递阻断时BLA-NAC和BLA-BNST神经元的兴奋性。在BLA-NAC中 在CIE/WD后，雌性神经元具有更高的基础兴奋性，只有雄性神经元兴奋性增加。在BLA- BNST神经元，WD增加兴奋性，无论性别。阻断谷氨酸能和GABA能 传输取消了兴奋性的增加，强调了在WD- 介导的过度兴奋。这项建议将继续调查WD如何影响“奖励”和“厌恶” BLA神经元。具体目标1将采用电生理学和逆行标记来检查GABA能 在与BLA-NAC和BLA-BNST神经元的突触中起作用。实验室数据表明，WD抑制LPC GABA释放和突触后GABA能功能在“局部”中间神经元突触。此外，降低了LPC GABA的释放是男性独有的。具体目标1还将检查GABA能突触的结构可塑性 BLA-NAC和BLA-BNST神经元，使用免疫组织化学、共聚焦显微镜和逆行 标签。特定目标2将联合收割机结合行为方法和化学遗传学来抑制特定的BLA回路 并评估其在CIE后酒精摄入中的作用。这些实验将证明“奖赏”和“厌恶” BLA神经元经历不同的神经生理和结构变化，导致酒精摄入量增加 在CIE/WD之后。确定驱动酒精摄入增加的机制可以改善AUD的治疗。

The basolateral amygdala (BLA) is critical to the development of alcohol use disorder (AUD). Its unique position within reward- and aversion-related circuitry allows it to regulate alcohol intake and withdrawal-induced anxiety. Glutamatergic pyramidal neurons drive these behavioral responses such that higher pyramidal neuron excitability facilitates anxiety and reward-seeking. Pyramidal neurons receive glutamatergic inputs from midline structures like the medial prefrontal cortex through the stria terminalis (ST) and more lateral cortical areas send glutamatergic inputs through the external capsule (EC). GABAergic lateral paracapsular cells (LPCs) and ‘local’ interneurons regulate pyramidal neurons. The goal of my project is to examine how chronic intermittent ethanol and withdrawal (CIE/WD) dysregulates BLA neurons projecting to reward and aversion-related regions to understand the mechanisms driving increased alcohol intake. The nucleus accumbens (NAC) is involved in reward-seeking while the bed nucleus of the stria terminalis (BNST) regulates anxiety. Therefore, my project will use BLA-NAC neurons as ‘reward’ neurons and BLA-BNST neurons as ‘aversion’ neurons. Our laboratory has shown that WD increases glutamatergic function through pre- and postsynaptic mechanisms at ST inputs and EC-BLA synapses, respectively. My preliminary data reveal that WD increases glutamate release from ST inputs onto BLA-BNST neurons regardless of sex, whereas the WD-mediated increase in postsynaptic function at EC-BLA synapses is both projection- and sex-dependent. My preliminary data also indicate that WD alters the excitability of BLA-NAC and BLA-BNST neurons when GABAergic transmission is blocked. In BLA-NAC neurons, females have higher basal excitability and only males increase excitability after CIE/WD. In BLA- BNST neurons, WD increases excitability, regardless of sex. Blocking glutamatergic and GABAergic transmission abolished the increase in excitability, emphasizing the role of glutamatergic transmission in WD- mediated hyperexcitability. This proposal will continue to investigate how WD impacts ‘reward’ and ‘aversion’ BLA neurons. Specific Aim 1 will employ electrophysiology and retrograde labeling to examine GABAergic function in synapses with BLA-NAC and BLA-BNST neurons. Laboratory data reveal that WD suppresses LPC GABA release and postsynaptic GABAergic function in ‘local’ interneuron synapses. Moreover, reduced LPC GABA release is unique to males. Specific Aim 1 will also examine structural plasticity in GABAergic synapses with BLA-NAC and BLA-BNST neurons using immunohistochemistry, confocal microscopy, and retrograde labeling. Specific Aim 2 will combine behavioral approaches and chemogenetics to inhibit specific BLA circuits and evaluate their role in post-CIE alcohol intake. These experiments will establish that ‘reward’ and ‘aversion’ BLA neurons undergo distinct neurophysiological and structural changes, leading to increased alcohol intake after CIE/WD. Identifying the mechanisms driving increased alcohol intake could improve treatments for AUD.