Optical imaging of dopamine kinetics in prefrontal cortex of normal and schizophrenia model mice

项目摘要 精神分裂症是一种使人衰弱的终身精神疾病，全球患病率为1%。它的特点 根据阳性症状（妄想、幻觉、思维混乱），阴性症状（扁平化的情感， 快感缺乏、言语缺乏）和认知症状（执行功能、注意力和工作能力的缺陷 内存（WM））。虽然积极的症状可以有效地管理与抗精神病药物，没有 治疗消极和认知症状。 最近的PET成像精神分裂症患者已证实，有一个皮质多巴胺（DA）的缺陷， 在用DA释放药物安非他明（AMPH）挑战之后。皮质DA的这种缺陷长期以来一直是 被认为在精神分裂症的阴性和认知症状的病理学中起关键作用，包括 WM的缺陷。由于缺乏研究单突触分辨率神经传递的工具， 体内，这种缺陷的性质尚未确定。 为了研究单突触分辨的体内DA神经传递，我们优化了一种新的工具， 用于小鼠的体内多光子成像。荧光假神经递质（FFN）是荧光底物 DA转运蛋白（DAT）、去甲肾上腺素转运蛋白（NET）和囊泡单胺转运蛋白 （VMAT），其被摄取到轴突的突触前终扣中，在那里它们随后被加载到 突触前囊泡FFN以前曾用于急性脑切片实验， 然而，它们在体内的应用是一个未公开的应用。我们使用FFN 来成像体内皮质中的儿茶酚胺神经传递。在这个项目中，我们将利用多光子 FFNs和GCaMP6f的体内成像，以记录DA从突触前皮质中终末的释放。 WT和精神分裂症模型小鼠在AMPH诱导的电诱发过程中， 和自发性释放的能力。 该建议实施了一种新的方法来检查WT和两种小鼠模型中体内DA的释放。 精神分裂症，以提供在AMPH诱导的释放和 WM的任务。阐明精神分裂症小鼠模型中DA缺陷的潜在机制可能提供 关键翻译信息的变化发生在精神分裂症患者，并可能揭示新的目标， 有助于未来的治疗策略。

PROJECT SUMMARY Schizophrenia is a debilitating lifelong psychiatric disorder with a worldwide prevalence of 1%. It is characterized by positive symptoms (delusions, hallucinations, disorganized thinking), negative symptoms (flattened affect, anhedonia, paucity of speech) and cognitive symptoms (defects in executive function, attention, and working memory (WM)). While the positive symptoms can be effectively managed with antipsychotic drugs, there are no treatments for the negative and cognitive symptoms. Recent PET imaging of schizophrenic patients has confirmed that there is a cortical dopamine (DA) deficit following a challenge with the DA releasing drug amphetamine (AMPH). This deficit in cortical DA has long been thought to play a critical role in the pathology of the negative and cognitive symptoms of schizophrenia, including the deficit in WM. Due to a lack of tools with which to study neurotransmission with single synapse resolution in vivo, the nature of this deficit has yet to be determined. In order to study DA neurotransmission in vivo with single synapse resolution, we have optimized a novel tool for in vivo multiphoton imaging of mice. Fluorescent false neurotransmitters (FFNs) are fluorescent substrates for the DA transporter (DAT), the norepinephrine transporter (NET), and the vesicular monoamine transporter (VMAT), that are taken up into the presynaptic boutons of axons where they are subsequently loaded into presynaptic vesicles. FFNs have previously been used in acute brain slice experiments to allow determination of the kinetics of synaptic release, however, their use in vivo is an unpublished application. We have used FFNs to image catecholamine neurotransmission in the cortex in vivo. For this project, we will utilize multiphoton imaging in vivo of FFNs and GCaMP6f, to record DA release from presynaptic mesocortical terminals in the medial prefrontal cortex of WT and schizophrenia model mice both during AMPH induced electrically evoked, and spontaneous release and during a task of WM. This proposal implements a novel method to examine DA release in vivo in WT and two mouse models of schizophrenia to provide the first measurement of in vivo kinetics of DA during both AMPH induced release and a task of WM. Elucidating the mechanism underlying DA deficits in schizophrenia mouse models may provide key translational information for the changes that occur in schizophrenic patients and may reveal new targets to aid future therapeutic strategies.