Synaptic changes in the medial prefrontal cortex in the development of compulsive alcohol drinking

抑制饮酒的能力对于恢复酗酒者来说是一个重大挑战，特别是在酒精存在的情况下。 相关线索反复的酒精暴露会诱导神经适应，这种适应在急性戒断后仍会持续， 增加酒精的激励显着性，导致酒精摄入量和厌恶性酒精寻求的升级。醇 使用也会导致与内侧前额叶皮层（mPFC）相关的认知功能缺陷，这进一步加剧了 强迫性饮酒和复发在啮齿动物中，酒精寻求激活了腹侧（边缘下， IL）和mPFC的前边缘（PL）区域，它们在控制复发行为中起着很大程度上相反的作用。而 PL的激活驱动恢复，IL中的神经元促进消退学习并通过以下方式抑制药物寻求： 它们向伏隔核壳以及基底外侧杏仁核（BLA）的投射。然而，有一个关键的 在认知过程中，这些回路中驱动适应不良可塑性的突触机制的知识存在缺口。 从控制性酗酒到强迫性酗酒在家长补助金申请的实验将提供一个更好的 了解慢性酒精暴露和戒断影响执行的网络特定机制 mPFC的认知功能，并减少对目标导向行为的抑制控制。当前的目标 该提案是为了响应“促进健康相关领域多样性的研究补充”的机会而提交的 研究（PA-21 - 071）"，是：首先，通过培训Skylar Mendez女士，博士，促进健康相关研究的多样性 来自生物医学科学背景的学生，第二，加强基础科学方面的研究， 通过检验中心假设，即mPFC和BLA中的戒断激活神经元 也是长时间饮酒和戒酒后出现的负面情绪状态的原因。目标1将 有助于训练候选人的负面影响的行为措施（特别是高架加迷宫，大理石 掩埋任务和新奇抑制喂养任务），并在长期暴露于EtOH和 退缩的老鼠在目标2中，我们将使用Fos 2AiCreER小鼠在活跃群体中的靶向扩增（TRAP 2）， 分别在IL和PL的戒断激活神经元中选择性表达盐视紫红质。神经元被困其中 然后，在测试期间，将抑制长期接触酒精或在后依赖条件下的行为 负面影响（如目标1所述），以确定这些神经元对戒断诱导的负面影响的贡献。 情感状态在目标3中，我们将类似地在BLA中的TRAPed神经元中表达盐视紫红质，以测试光遗传学效应是否在BLA中的TRAPed神经元中表达。 从BLA到mPFC的戒断激活传入的沉默可以逆转酒精诱导的负性测量。 影响。总之，这些研究将提供有关酒精诱导的网络变化的重要新信息。 mPFC和BLA，有助于负面影响和线索诱导的恢复。该项目将促进多样性 在健康相关的研究，提供多层次的研究培训和职业生涯优秀的培训机会 发展计划，它将通过确定是否特定的退出激活，以提高家长补助金 mPFC和BLA网络的负面影响，有助于复发。

The ability to inhibit drinking is a significant challenge for recovering alcoholics, especially in the presence of alcohol‐ associated cues. Repeated alcohol exposure induces neuroadaptations that persist beyond acute withdrawal, and which increase alcohol's incentive salience, leading to escalation of alcohol intake and aversion‐resistant alcohol seeking. Alcohol use also causes deficits in cognitive functions associated with the medial prefrontal cortex (mPFC), which further fuel compulsive drinking and relapse. In rodents, alcohol seeking activates specialized networks within the ventral (infralimbic, IL) and prelimbic (PL) regions of the mPFC, which play largely opposite roles in the control of relapse behavior. While activation of the PL drives reinstatement, neurons in the IL facilitate extinction learning and inhibit drug‐seeking through their projections to the Nucleus Accumbens shell, as well as the basolateral amygdala (BLA). However, there is a critical gap in the knowledge about the synaptic mechanisms that drive maladaptive plasticity in these circuits during the transition from controlled to compulsive alcohol‐seeking. Experiments in the parent grant application will provide a better understanding of network‐specific mechanisms through which chronic alcohol exposure and withdrawal affect executive cognitive functions of the mPFC and diminish inhibitory control over goal‐directed behavior. The objectives of this current proposal, which is submitted in response to opportunity “Research Supplement to Promote Diversity in Health‐Related Research (PA‐21‐071)”, are: First, to promote diversity in health‐related research by training Ms. Skylar Mendez, a PhD student from a background underrepresented in bio‐medical sciences, and second, to enhance a basic science aspect of the parent application by testing the central hypothesis that withdrawal‐activated neurons in the mPFC and the BLA are also responsible for negative affective states that emerge after prolonged alcohol exposure and withdrawal. Aim 1 will serve to train the candidate in behavioral measures of negative affect (specifically the Elevated Plus Maze, the Marble Burying Task, and the Novelty Suppressed Feeding Task) and to validate these measures in chronically EtOH‐exposed and withdrawn mice. In Aim 2 we will use Targeted Recombination in Active Populations (TRAP2) with Fos2AiCreER mice to express halorhodopsin selectively in withdrawal‐activated neurons in the IL and PL, respectively. Neurons TRAPed in this manner following either extended access to alcohol or under post‐dependent conditions will then be inhibited during tests of negative affect (as described in Aim 1) to determine the contribution of these neurons to withdrawal‐induced negative affective states. In Aim 3 we will similarly express halorhodopsin in TRAPed neurons in the BLA to test whether optogenetic silencing of withdrawal‐activated afferents from the BLA to the mPFC can reverse alcohol‐induced measures of negative affect. Taken together, these studies will provide important novel information about alcohol‐induced changes in networks of the mPFC and BLA that contribute to negative affect and cue‐induced reinstatement. This project will promote diversity in health‐related research, provide outstanding training opportunities in a multi‐level research training and career development program, and it will enhance the parent grant by determining whether specific withdrawal‐activated networks in the mPFC and BLA negative affect that contributes to relapse.