Dopamine transporter regulation of short-term plasticity in dopamine release

多巴胺（DA）在哺乳动物大脑纹状体内的传递对于包括奖励信息和行动选择在内的广泛过程至关重要，并且在成瘾和帕金森病（PD）等疾病中失调。纹状体内DA释放传递受多个局部过程控制，包括神经调节输入和控制轴突兴奋性和神经递质释放概率的内在轴突机制。纹状体内DA的释放概率不是静态的，而是表现出从促进到抑制的短期可塑性。最近的研究表明，除了在控制DA摄取方面的典型作用外，DA转运体（DAT）还调节DA的释放及其动态可塑性。多巴胺抑制剂如可卡因增加潜在的多巴胺释放，并通过改变轴突钙进入而强烈改变多巴胺释放的短期可塑性，这被认为是由于轴突兴奋性的改变。因此，DAT可以很好地通过几种机制来调节DA功能。然而，目前尚不清楚DAT的一些特性如何影响DA的传输及其短期可塑性。在本项目中，我们将使用快速扫描循环伏安法（FSCV）在小鼠大脑离体纹状体切片中实时检测DA，以更充分地探索DA功能的DAT调控。我们将评估数据构象状态、翻译后修饰和运输对纹状体数据释放及其短期可塑性的影响。我们还将使用最先进的基因编码电压传感器直接测试dat调节轴突活动的假设，并在健康和帕金森小鼠模型中定义与轴突活动的其他关键修饰因子的相互作用，包括强直性GABA抑制。该项目将为DA轴突上的dat如何形成和控制与健康和疾病相关的多巴胺功能提供基本的新见解。

Dopamine (DA) transmission within the striatum of the mammalian brain is critical for a wide range of processes, including reward information and action selection, and is dysregulated in disorders such as addiction and Parkinson's disease (PD). Striatal DA release transmission within the striatum is governed by multiple local processes including neuromodulatory inputs and intrinsic axonal mechanisms governing axonal excitability and neurotransmitter release probability. DA release probability within the striatum is not static but rather, it exhibits short-term plasticity which ranges from facilitation to depression. It has recently been shown that in addition to its canonical role in gating DA uptake, the DA transporter (DAT) regulates DA release and its dynamic plasticity. DAT inhibitors such as cocaine increase underlying DA release, and strongly modify short-term plasticity in DA release, by changing axonal calcium entry proposed to be due to changes to axon excitability. The DAT is therefore well placed to modulate DA function through several mechanisms. However, It is currently unclear how several properties of the DAT affect DA transmission and its short-term plasticity. In the proposed project, we will use fast scan cyclic voltammetry (FSCV) to detect DA in real-time in ex vivo striatal slices from mouse brain to explore DAT regulation of DA function more fully. We will assess the impact of DAT conformational state, post-translational modifications and trafficking, on striatal DA release and its short-term plasticity. We will also test directly the hypotheses that DATs modulate axonal activity, using state-of-the-art genetically encoded voltage sensors, and define interactions with other key modifiers of axonal activity including tonic GABA inhibition, in health and in a mouse model of Parkinson's. This project will provide fundamental new insights into how DATs on DA axons shape and govern dopamine function relevant to health and disease.