Cocaine, Parvalbumin, and Perineuronal Nets

项目总结/摘要 可卡因使用障碍仍然是一个普遍的问题，没有FDA批准的治疗和深刻的社会影响。 后果可卡因相关的记忆很强，不易被修改，但却是 在许多人中复发。我们的长期目标是减少可卡因相关的记忆， 毒瘾复发啮齿类动物的自我给药模型最好地再现了强烈的可卡因相关记忆。 我们发现，去除大鼠内侧前额叶皮层（mPFC）的神经元束膜网（PNNs）， 通过干扰这些记忆的重新巩固来破坏可卡因自我给药记忆。PNNs 主要在含有小白蛋白（PV）的快速尖峰中间神经元周围形成，这些中间神经元有力地调节mPFC 众所周知，mPFC输出控制动物和人类的药物寻求行为。PV 神经元维持皮质兴奋性：抑制性平衡，并有助于θ和γ振荡， 尽管mPFC PV神经元在大脑区域之间的交流，但几乎没有人知道mPFC PV神经元如何促进大脑区域之间的交流。 可卡因记忆重新巩固。我们的初步数据表明，在mPFC中PNN的去除：（1）减少 PV神经元放电，并增加药物初治大鼠锥体细胞的兴奋性;（2）深刻地破坏 自我给药可卡因记忆的再巩固，包括线索诱导的恢复和进行性恢复。 比率响应;以及（3）破坏mPFC内θ和γ振荡的同步性， mPFC和海马体之间对可卡因线索的反应。这些发现意义重大，因为 他们有望对大脑振荡模式提供新的见解， 以及如何改变这些持久的药物相关记忆。我们假设PNN允许PV 神经元来稳定和维持可卡因记忆，如果没有PNN，这些记忆可以被 不稳定和深刻的破坏。我们将使用PV-Cre基因敲入大鼠与tdTomato基因敲入大鼠杂交， 大鼠自始至终确定目标1中PNN去除如何改变mPFC PV神经元功能，以及目标2中如何改变 PNN去除改变可卡因记忆再巩固过程中的mPFC电路功能。在目标3中，我们将评估 两种机制的途径，其中PNN去除块再巩固，包括铬依赖，具体 用Gi-DREADD抑制PNN和PV神经元活性的Cr依赖性抑制。我们将使用两者 切片和体内电生理学、转录组学、束示踪、免疫组织化学、分子和 化学遗传学方法鉴定PV神经元介导的可卡因寻求行为控制中的关键因素 可卡因记忆再巩固的过程中我们的研究有望在以下方面取得重大进展： 了解如何消除驱动可卡因寻求行为的强大记忆。

PROJECT SUMMARY/ABSTRACT Cocaine use disorder remains a prevalent problem with no FDA-approved treatment and profound societal consequences. Cocaine-associated memories are strong and resistant to modification but are the basis of relapse in many individuals. Our long-term goal is to diminish cocaine-associated memories to reduce drug relapse. The self-administration model in rodents best reproduces strong cocaine-associated memory. We have found that the removal of perineuronal nets (PNNs) in the rat medial prefrontal cortex (mPFC) disrupts cocaine self-administration memories by interfering with reconsolidation of these memories. PNNs form mainly around parvalbumin (PV)-containing, fast spiking interneurons that powerfully regulate mPFC output, and mPFC output is well known to control drug-seeking behavior in both animals and humans. PV neurons maintain cortical excitatory:inhibitory balance and contribute to theta and gamma oscillations vital for communication across brain regions, yet almost nothing is known about how mPFC PV neurons contribute to cocaine memory reconsolidation. Our Preliminary Data show that PNN removal in the mPFC: (1) decreases PV neuron firing and increases excitability of pyramidal cells in drug-naïve rats; (2) profoundly disrupts the reconsolidation of a self-administration cocaine memory, including cue-induced reinstatement and progressive ratio responding; and (3) disrupts the synchrony of theta and gamma oscillations within the mPFC and between the mPFC and hippocampus in response to a cocaine cue. These findings are significant because they are expected to give novel insights into brain oscillatory patterns that may signify disrupted cocaine memory and how to modify these persistent drug-associated memories. We hypothesize that PNNs allow PV neurons to stabilize and maintain cocaine memories and that, without PNNs, these memories can be destabilized and profoundly disrupted. We will use PV-Cre knock-in rats crossed with tdTomato knock-in rats throughout to determine in Aim 1 how PNN removal alters mPFC PV neuron function and in Aim 2 how PNN removal alters mPFC circuit function during cocaine memory reconsolidation. In Aim 3, we will assess two mechanistic pathways by which PNN removal blocks reconsolidation, including Cre-dependent, specific suppression of PNNs and Cre-dependent inhibition of PV neuron activity with Gi-DREADDs. We will use both slice and in vivo electrophysiology, transcriptomics, tract tracing, immunohistochemistry, molecular, and chemogenetic approaches to identify key factors in PV neuron-mediated control of cocaine-seeking behavior during cocaine memory reconsolidation. Our studies are expected to generate significant advances in understanding how to diminish powerful memories that drive cocaine-seeking behavior.