The role L-type calcium channels (LTCCs) in regulating dopaminergic activity during cocaine abstinence

这项提案的总体目标是研究内源性大麻素（ECB）信号在 调节不同的皮层抑制性突触。大脑的生理发育和功能是 依赖于突触兴奋和抑制的微调平衡。因此，抑制的失调 与多种神经发育障碍有关细胞目标和后果 成年动物中的GABA能信号传导是很好理解的，然而， 对欧洲央行信号的研究仍然很少。皮层抑制由多种GABA能神经递质介导。 中间神经元（IN），包括共表达钙结合蛋白小清蛋白（PV）、肽 递质生长抑素（SOM）或5-羟色胺5 HT 3a受体。皮层神经元的突触靶点不同， PV-IN在靶锥体神经元的体周和近端树突区域上形成突触 和连接到树枝状乔木上的自组织神经元。一个5 HT 3a-IN的子集，其表达 血管活性肠肽（VIP），支配锥体神经元和其他中间神经元的树突。这 亚细胞定位允许PV-IN调节PN尖峰输出的幅度和定时， 调节树突棘和轴钙内流沿着与突触可塑性。虽然出生和 GABA能神经元的迁移已经被很好地理解，但我们对GABA能神经元迁移的分子和 影响抑制信号的细胞机制。ECBs影响突触发生和长时程可塑性 兴奋性和抑制性连接的联系。尽管数据显示大麻素1型的共表达 (CB1)受体与SOM或VIP，CB 1受体在各种中间神经元内的共定位， 我们已经研究过了，并将在本提案中加以讨论。皮层释放ECB调节突触前GABA 释放，并可以驱动短期和长期的抑制传递抑郁症，然而， 对ECB活动敏感的突触前IN没有很好的特征。此外，CB 1的后果 不同中间神经元的受体损失是未知的。在这份提案中，我们试图确定欧洲央行如何发出信号， 调节由不同IN群体介导的GABA能信号传导。我们假设欧洲央行发出的信号 调节皮质活动，在影响树突靶向介导的可塑性方面发挥关键作用 中间神经元我们提出了一种新的工具组合，包括电生理学，双光子激光扫描， 显微镜（2 PLSM）和小鼠初级视觉中遗传靶向IN的光遗传学刺激。 皮层我们的实验将为GABA能的发展提供前所未有的洞察力。 大脑皮层的回路

The overall goal of this proposal is to investigate the role of endocannabinoid (ECB) signaling in regulating distinct cortical inhibitory synapses. Physiological brain development and function are dependent on a fine-tuned balance of synaptic excitation and inhibition. As such, dysregulation of inhibition has been implicated in a variety of neurodevelopmental disorders. The cellular targets and consequences of GABAergic signaling in adult animals is well understood, however the specific interneurons modulated by ECB signaling remains poorly studied. Cortical inhibition is mediated by a diverse group of GABAergic interneurons (INs), including cells co-expressing the calcium binding protein parvalbumin (PV), the peptide transmitter somatostatin (SOM), or the serotonin 5HT3a receptor. Cortical INs differ in their synaptic targets, with PV-INs making synapses onto the perisomatic and proximal dendritic regions of target pyramidal neurons and SOM-INs making connections onto the dendritic arbors. A subset of 5HT3a-INs which express the vasoactive intestinal peptide (VIP), innervate dendrites of pyramidal neurons and other interneurons. This subcellular localization allows PV-INs to regulate the magnitude and timing of PN spike output and SOM-INs to regulate dendritic spine and shaft calcium influx along with glutamatergic synaptic plasticity. While the birth and migration of GABAergic INs is well understood, there remain gaps in our knowledge of the molecular and cellular mechanisms that influence inhibitory signaling. ECBs influence synaptogenesis and long-term plasticity of both excitatory and inhibitory connections. Although data has shown coexpression of the cannabinoid type-1 (CB1) receptor with SOM or VIP, colocalization of the CB1 receptor within the various interneurons has not been studied and will be addressed in this proposal. ECB release in the cortex modulates presynaptic GABA release and can drive both short- and long-term depression of inhibitory transmission, however the identity of the presynaptic INs sensitive to ECB activity is not well-characterized. Moreover, the consequences of CB1 receptor loss from distinct interneurons is unknown. In this proposal, we seek to determine how ECB signaling modulates GABAergic signaling mediated by distinct IN populations. We hypothesize that ECB signaling modulates cortical activity, with a key role in influencing plasticity mediated by dendritic targeting interneurons. We propose a novel combination of tools including electrophysiology, 2-photon laser-scanning microscopy (2PLSM), and optogenetic stimulation of genetically-targeted INs in the mouse primary visual cortex. Our experiments will provide an unprecedented level of insight into the development of GABAergic circuits in the neocortex.