Functional Analysis of SV2 by Targeted Gene Disruption

描述（由申请人提供）：确定产生和调节神经递质释放的分子事件是分子神经生物学的中心目标之一。定义这些事件，以及它们如何随着经验和疾病而改变，将提供对学习等正常过程的理解，并作为开发精神疾病，神经系统疾病和成瘾新疗法的生物学基础。 这里提出的工作解决了突触囊泡蛋白2（SV 2）的功能，所有神经递质（突触）囊泡的糖蛋白成分。在上一个资助期间，我们证明了突触囊泡蛋白2（SV 2）是神经传递的重要调节剂。SV 2A的缺失减少了海马和皮质神经元的神经传递，并减少了嗜铬细胞中易于释放的囊泡池的大小。减少神经传递不是由于形态学的变化或减少在形态学上“对接”突触囊泡。总之，这些结果表明，SV 2是一个积极的调制器的囊泡启动后，在质膜上的囊泡附着的行为。我们建议使用SV 2基因敲除小鼠来确定SV 2在快速神经传递中的分子功能，并解决亚型功能的差异。我们的具体目标是： 1.确定SV 2科斯培养的海马神经元中神经传递如何改变。 2.利用海马神经元中外源性蛋白的表达来验证SV 2功能的假设。 3.验证SV 2B在带状突触维持和/或功能中起关键作用的假设。

DESCRIPTION (provided by applicant): Determining the molecular events that produce and regulate the release of neurotransmitters is one of the central goals of molecular neurobiology. Defining these events, and how they are altered with experience and in disease, will provide an understanding of normal processes such as learning and serve as the biological basis for developing new therapies for mental illness, neurological disorders and addiction. The work proposed here addresses the function of Synaptic Vesicle Protein 2 (SV2), a glycoprotein constituent of all neurotransmitter-containing (synaptic) vesicles. In the last funding period we demonstrated that Synaptic Vesicle Protein 2 (SV2) is an essential modulator of neurotransmission. Loss of SV2A reduces neurotransmission in hippocampal and cortical neurons, and reduces the size of the readily releasable pool of vesicles in chromaffin cells. Reduced neurotransmission is not due to morphological changes or to a decrease in morphologically "docked" synaptic vesicles. Together these results suggest that SV2 is a positive modulator of vesicle priming that acts after vesicle attachment at the plasma membrane. We propose to use SV2 knockout mice to determine SV2's molecular function in fast neurotransmission and to resolve differences in isoform functioning. Our specific aims are: 1. To determine how neurotransmission is altered in cultured hippocampal neurons from SV2 KOs. 2. To use exogeneous protein expression in hippocampal neurons to test hypotheses of SV2 function. 3. To test the hypothesis that SV2B plays a crucial role in ribbon synapse maintenance and/or functioning.