PROBABILITY OF QUANTAL SECRETION AT NEUROMUSCULAR SYNAPSES

神经肌肉突触量子分泌的概率

• 批准号: nhmrc : 107211
• 负责人: Prof Maxwell Bennett
• 金额: $ 22.29万
• 依托单位国家: 澳大利亚
• 项目类别: NHMRC Project Grants
• 财政年份: 2000
• 资助国家: 澳大利亚
• 起止时间: 2000-01-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://researchdata.edu.au/probability-quantal-secretion-neuromuscular-synapses/76283
• 关键词: PROBABILITY; QUANTAL; SECRETION; NEUROMUSCULAR; SYNAPSES

The classical preparation for the study of synaptic transmission is the amphibian neuromuscular junction, for which there is the largest body of experimental data. This synapse was instrumental in the discovery that transmitters are released in packets or quanta, that this occurs at specialized release sites in the nerve terminal, and that receptor molecules on the muscles cells are strategically placed to receive the transmitter. Our work on this synapse has shown that each of these release sites have different probabilities for the secretion of a quantum and that this probability is correlated with the width of the release site. More recently we have shown that, whilst the size of a quantum does not vary between adjacent release sites, the area over which the quantum is released does vary between sites. The probability of quantal secretion is proportional to this area, as is the number of vesicles present at the release site. In this project we intend to relate this probability of secretion to the proteins that regulate the release of a quantum and in particular how these proteins interact to determine the time course of increase in probability at a release site after the passage of an impulse. The affects of trains of impulses on this probability are also to be delineated, in particular how the calcium which enters the terminal during these trains determines a long-term enhancement in probability after the train has ceased. This research will provide a molecular description of secretion from motor-nerve terminals.

研究突触传递的经典准备是两栖动物的神经肌肉接点，它有最大的实验数据体。这个突触有助于发现递质以包或量子的形式释放，这种释放发生在神经末梢的特定释放位点，肌肉细胞上的受体分子被战略性地放置在接收递质的位置。我们对这个突触的研究表明，每个释放位点都有不同的量子分泌概率，这种概率与释放位点的宽度有关。最近，我们已经证明，虽然量子的大小在相邻的释放点之间没有变化，但量子释放的面积在不同的位置之间确实不同。定量分泌的概率与这个区域成正比，释放部位的囊泡数量也是如此。在这个项目中，我们打算将这种分泌概率与调节量子释放的蛋白质联系起来，特别是这些蛋白质如何相互作用，以确定脉冲通过后释放位点概率增加的时间过程。脉冲序列对这一概率的影响也将加以描述，特别是在脉冲序列期间进入终端的钙如何决定脉冲序列停止后概率的长期增强。这项研究将提供运动神经末梢分泌的分子描述。