Transmission at Synapsin-deficient Synapses

描述（由申请人提供）： 神经递质在化学突触处的释放是大脑内信息传输和存储的中心过程。在这个项目中，分子遗传学方法将被用来定义突触蛋白的功能，突触蛋白是一个被认为对神经递质释放很重要的蛋白质家族。三种哺乳动物突触蛋白基因缺陷的小鼠将通过靶向基因破坏产生，预期突触蛋白的去除将损害依赖于这些蛋白质的任何突触功能。将通过对这些突触蛋白缺陷小鼠的神经元进行电学和光学测量来评估突触传递。然后，通过将三种突触蛋白基因单独转染到突触蛋白缺陷神经元中，然后比较每种突触蛋白拯救突变神经元中观察到的突触缺陷的能力，来评估这三种突触蛋白基因的功能。使用类似的技术方法，将通过用阻止磷酸化的突变或用模拟永久磷酸化的突变检测突触蛋白来评估磷酸化在调节突触蛋白功能中的作用。同样，突触蛋白与突触囊泡的可逆关联的作用将通过在活神经元中成像这一过程以及通过确定突触蛋白与囊泡的关联的改变如何改变神经递质释放特性来解决。这些实验应该澄清大脑中通信的分子基础的重要方面，并最终将深入了解突触传递缺陷导致的神经和精神疾病。

DESCRIPTION (provided by applicant): The release of neurotransmitters at chemical synapses is a process that is central to information transmission and storage within the brain. In this project, molecular genetic approaches will be used to define the functions of synapsins, a family of proteins thought to be important for neurotransmitter release. Mice deficient in the three mammalian synapsin genes will be generated by targeted gene disruption, with the expectation that removal of synapsins will impair any synaptic functions that rely upon these proteins. Synaptic transmission will be assessed by performing electrical and optical measurements on neurons from these synapsin-deficient mice. The functions of the three synapsin genes will then be assessed by transfecting them individually into synapsin-deficient neurons and then comparing the ability of each synapsin to rescue the synaptic defects observed in the mutant neurons. Using a similar technical approach, the roles of phosphorylation in regulating the function of synapsins will be assessed by transfecting synapsins with mutations that prevent phosphorylation or with mutations that mimic permanent phosphorylation. Likewise, the role of the reversible association of synapsins with the synaptic vesicle will be addressed by imaging this process in living neurons and by determining how alterations in the association of synapsins with vesicles alters neurotransmitter release properties. These experiments should clarify important aspects of the molecular basis of communication in the brain and, ultimately, will field insights into neurological and psychiatric disorders that result from defects in synaptic transmission.