FUNCTIONAL ORGANIZATION AND CONTROL OF MASSETERS

动物研究已经提供了对肌肉纤维的详细分析 骨性关节炎的类型、肌肉组织、神经解剖途径和机制 在咀嚼等动作中对颌肌的神经控制。数据 从这些研究中得出了目前对 神经生物学与口腔运动功能控制。然而，最近的数据 提供了更复杂的解剖和功能的证据 动物颌部肌肉的组织，但类似的系统研究 还没有在人类受试者身上进行过。随着新技术的出现 技术，现在可以非侵入性地成像肌肉 检查解剖组织的细节，并同时 获取多点记录以分析区域肌肉活动或 功能上的“隔间”。我们必须了解 正常人的解剖组织和功能控制基础 在尝试评估异常肌肉之前，受试者 涉及疼痛的情况。 因此，这项提案将审查以下基本原则 颈椎病的解剖基础、功能组织和机制 对人类咬肌的控制。一个合乎逻辑的进程将是 然后首先检查咬肌的内部解剖结构 确定其在身体中的结构分区和磁共振 人类的图像，然后研究功能性神经肌肉 通过多点肌电记录对肌肉进行分区。后者 一组实验包括(1)绘制运动单位领地图， 招募顺序和机动部队特征；(2)调查 传入神经对运动单位招募和活动的影响；以及 (3)比较不同来源皮肤传入神经的抑制作用。 口腔内运动单位活动的位置。在彻底评估了 正常人咬肌的功能组织 在没有痛苦的情况下，我们将用 实验诱导的面部疼痛并测试一个模型，试图 解释慢性疼痛患者运动活动的变化。

Animal studies have provided a detailed analysis of muscle fiber types, muscle organization, neuroanatomical pathways and mechanisms of neural control of jaw muscles during such acts as mastication. The data from these studies have helped form the current explanations of the neurobiology and control of oral-motor function. However, recent data have provided evidence of a more complex anatomical and functional organization of the jaw muscles in animals but similar systematic studies have not been performed in human subjects. With the advent of new technologies, it is now possible to non-invasively image muscles to examine the detail of the anatomical organization and to simultaneously acquire multi-site recordings to analyze regional muscle activity or functional "compartments". It is imperative to understand the fundamentals of anatomical organization and functional control of normal human subjects before attempting to evaluate the abnormal muscular conditions which involve pain. Therefore, this proposal will examine the basic fundamentals of the anatomical substrate, functional organization and mechanisms of control of the human masseter muscle. A logical progression will be followed by first examining the masseter internal anatomical architecture to identify its structural partitions in cadavers and magnetic resonance images of humans, and then studying the functional neuromuscular compartments of the muscle by multi-site EMG recordings. This latter group of experiments include (1) mapping motor unit territory, recruitment order and motor unit characteristics; (2) investigating the effects of afferents on the recruitment and activity of motor units; and (3) comparing the inhibitory effects of cutaneous afferents from several intraoral sites on motor unit activity. After a thorough evaluation of the functional organization of the masseter muscle in normal subjects without pain, we will examine the same subjects with experimentally-induced facial pain and test a model that attempts to explain the changes in motor activity described in chronic pain patients.