Transmission at Synapsin-deficient Synapses

描述(由申请人提供)： 化学突触释放神经递质是大脑内信息传输和存储的核心过程。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，突触蛋白是一种被认为对神经递质释放至关重要的蛋白质家族。缺乏这三种哺乳动物突触素基因的小鼠将通过定向基因破坏而产生，预期突触蛋白的移除将损害依赖这些蛋白质的任何突触功能。突触传递将通过对这些突触素缺陷小鼠的神经元进行电学和光学测量来评估。然后，通过将这三个突触素基因分别导入突触素缺失的神经元，然后比较每个突触素修复在突变神经元中观察到的突触缺陷的能力，来评估这三个突触素的功能。使用类似的技术方法，将通过将阻止磷酸化的突变或模拟永久磷酸化的突变导入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，突触素与突触小泡的可逆结合的作用将通过在活的神经元中成像这一过程，并通过确定突触蛋白与小泡结合的改变如何改变神经递质释放特性来解决。这些实验应该会澄清大脑中交流的分子基础的重要方面，并最终将深入了解由突触传递缺陷引起的神经和精神障碍。

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.