ACTION CURRENTS & SKELETAL MUSCLE ELECTROPHYSIOLOGY

拟议研究的目标是研究生物磁信号IF 正常人骨骼肌单纤维和多细胞活性的研究 动物、肌肉可塑性的动物模型、正常人类受试者以及 患有某些肌肉疾病的患者。在过去三年中，我们 已经用我们的室温生物磁流探头进行了 独一无二的蜂窝磁场测量系列 肌肉的动作电流(AC)。与此同时，我们已经开发出 将生物磁场与细胞AC联系起来的数学模型， 根据磁记录技术提供的主要结论， 在我们现在详细了解的范围内，更好的量化 关于活跃的肌肉细胞的电生理学的信息可以 用常规的细胞外电记录获得。一个 细胞内ACs的定量测定及其跨膜作用 这些电流产生的电势甚至可以通过磁性获得 而不需要用微吸管穿透细胞。或者，也可以使用 磁记录交流结合微电极测量 电势可以提供细胞内的电导率和细胞膜 电容。我们已经从整体上测量了电磁信号 肌肉，单一运动单位，以及哺乳动物肌肉的单一纤维， 使我们能够通过我们的数学模型建立一家公司 磁-磁相互作用关系的理论描述 记录AC和电记录的细胞内和细胞外 动作电位，并确定有效电导率 用于肌肉纤维束。我们还展示了ACS与 收缩力。虽然必须继续增加这样的 基础知识，我们现在有足够的信息来确保生产 我们的研究扩展到检查正常肌肉膜的变化 生理学。技术的进步使我们能够获得一种独特的、 高分辨率超导量子干涉器件(SQUID) 在非侵入性记录能力方面无与伦比的磁力计 磁肌图(MMG)。通过应用我们所有的新磁记录 研究实验诱导的肌肉变化的技术，我们 应该能够获得关于肌肉可塑性的新信息，表现出来 在废用萎缩、工作引起的肥大和 神经丧失。通过应用这些新技术来检查 肌肉疾病的患者，我们应该能够开始澄清 肌肉疾病过程的潜在机制。

The objective of the proposed research is to study biomagnetic signals if single fiber and multicellular activity in skeletal muscle of normal animals, animal models of muscular plasticity, normal human subjects, and patients with certain muscular disorders. For the past three years, we have used our room-temperature, Biomagnetic-Current Probe to conduct a unique series of measurements of magnetic fields produced by cellular action currents (ACs) in muscle. In parallel, we have developed mathematical models that relate the biomagnetic field to cellular ACs, with the major conclusion that magnetic recording techniques provide, within limits that we now understand in detail, better quantitative information about the electrophysiology of active muscle cells that can be obtained with conventional extracellular electric recording. A quantitative measure of the intracellular ACs and the transmembrane action potential generated by these currents can even be obtained magnetically without penetrating the cell with micropipette. Alternatively, the magnetically-recorded AC combined with a microelectrode measurement of potential can provide the intracellular conductivity and membrane capacitance. We have measured electric and magnetic signals from whole muscles, single motor units, and single fibers from, mammalian muscles, enabling us to establish, by means of our mathematical models, a firm theoretical description of the relationship between the magnetically- recorded AC and the electrically-recorded intracellular and extracellular action potentials, and to determine effective electrical conductivities for muscle fiber bundles. We have also shown the relationship of ACs to contractile force. While it is imperative to continue adding to such basic knowledge, we now have sufficient information to assure a productive extension of our research to examine alterations of normal muscle membrane physiology. Technological advances have enabled us to obtained a unique, high-resolution Superconducting Quantum Interference Device (SQUID) magnetometer that is unsurpassed in its ability to noninvasively record the magnetomyogram (MMG). By applying all of our new magnetic recording techniques to study experimentally-induced alterations of muscle, we should be able to obtain new information on muscle plasticity, manifest under such conditions as disuse atrophy, work-induced hypertrophy, and denervation. By applying these new techniques to examine tissues of patients with muscular disorders, we should be able to begin elucidating mechanisms underlying muscle disease processes.