DETERMINANTS OF SYNAPTIC STRENGTH IN MUSCLE

肌肉突触强度的决定因素

• 批准号: 3476837
• 负责人: ROBERT S WILKINSON
• 金额: $ 8.41万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-04-01 至 1992-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3476837
• 关键词: axon; electrical potential; electrophysiology; freeze etching; gene expression; image processing; innervation; motor neurons; myofibrils; nerve endings; neural information processing; neuroanatomy; neuromuscular junction; neurotransmitters; snakes; synapses

The project uses a thin snake muscle to study the determinants of synaptic strength, or efficacy, at the neuromuscular junction. The project's focus is to examine the structure and function of synapses within individual motor units which have been identified in a living preparation. The first goal is to determine the quantal release parameters of individual boutons which comprise nerve terminals in snake muscles. Quantal content will be compared to bouton size and ultrastructure to determine if the terminal bouton serves an an anatomical correlate of synaptic strength. Second, synaptic strength will be compared to indicators of target cell requirements, such as input resistance, at all synapses supplied by one motor axon. This will permit the influence of target cell properties on synaptic strength to be independently assessed. Finally, synaptic strength will be systematically compared among all motor units within the muscle. This will permit the influence of motor neuron size and type to be independently determined for synapses whose target-related properties are precisely known. These measurements will determine the extent to which synaptic efficacy is an intrinsic motor neuron property, and how efficacy relates to other neuron properties. Knowledge of these relationships is essential in understanding how the size and strength of synapses are regulated, and why such regulation fails in diseases which attack pre- or postsynaptic cells.

该项目使用细蛇肌肉来研究突触的决定因素 神经肌肉接头处的强度或功效。 项目重点 是检查个体内突触的结构和功能 已在活体制剂中确定的运动单位。 第一个 目标是确定各个按钮的量子释放参数 其中包括蛇肌肉中的神经末梢。 量子含量将是 与按钮大小和超微结构进行比较，以确定终端是否 bouton 与突触强度具有解剖学相关性。 第二， 突触强度将与靶细胞指标进行比较 要求，例如输入电阻，由一个提供的所有突触 运动轴突。 这将允许靶细胞特性的影响 突触强度进行独立评估。 最后，突触强度 将系统地比较肌肉内的所有运动单位。 这将允许运动神经元大小和类型的影响 独立确定其目标相关属性的突触 准确地知道。 这些测量结果将决定 突触功效是运动神经元的一种内在特性，而功效如何 与其他神经元特性有关。 对这些关系的了解是 对于理解突触的大小和强度至关重要 监管，以及为什么这种监管在攻击前或前的疾病中失败 突触后细胞。