STATIC AND DYNAMIC ORGANIZATION

这些实验有两个目的：第一，研究 成人运动皮质正常功能结构 第二，探索运动皮层的能力， 在周围神经损伤后重新组织的表现，或 在获得熟练的动作之后。 MI 表示模式将通过组合 皮层微刺激标测与肌电图记录 技术和使用细胞外和细胞内示踪 技术. 正常的“静态”MI组织模式：与以往的研究不同 描述了MI刺激引起的运动，我们的 研究将展示功能组的代表性 的前肢肌肉在MI通过记录肌电图活动，从每个 16块肌肉从单独的皮质部位被激活。 肌肉代表将在100-200个MI部位使用 几种不同的电流强度 这些数据将用于 确定拓扑关系、重叠范围和大小 16块肌肉的代表性。 我们的初步数据 表明某些肌肉在空间上被多重表示， 与其他几个代表性重叠的单独焦点 肌肉. 这些病灶可能代表了一种功能性 在MI中描述的分组。 细胞内 记录/染料注射和解剖路径追踪 技术将用于映射后，检查 这些个体或群体之间的联系 在MI中表示。 动态组织：这些研究的第二个目标是 确定电动机的关系 与肌肉的皮质改变（a）在正常条件下 (i.e.,是否存在对多元智能表征的持续重塑？），（B） 在神经损伤后， 前肢肌肉，（c）获得熟练的手指 动作 微刺激标测将用于研究MI 在正常动物中不同时间间隔的表征模式， 骨间前神经切断前后及 在学习了精确的手指抓握任务之后。 这些实验 将提供重要的新信息， 灵长类动物运动皮层的地形以及 MI皮质与肌肉的关系。 的结果 这些研究可能会提出新的策略， 恢复和抑制痉挛损伤后， 外周和中枢神经系统。

The proposed experiments have two goals: First, to investigate the normal functional organization of motor cortex in adult primates and second, to explore the capacity of motor cortex representations to reorganize following peripheral nerve injury or subsequent to the acquisition of a skilled movement. MI representation pattern will be evaluated by combining intracortical microstimulation mapping with EMG recording techniques and by using extracellular and intracellular tracing techniques. Normal "static" MI organization pattern: Unlike previous studies that have described the movements evoked by MI stimulation, our studies will demonstrate the representation of functional groups of forelimb muscles in MI by recording EMG activity from each of 16 muscles that are activated from individual cortical sites. Muscle representation will be mapped at 100-200 MI sites using several different current intensities. These data will be used to determine the topological relationship, extent of overlap, and size of representation of each of the 16 muscles. Our preliminary data suggest that some muscles are multiply represented in spatially separate foci that overlap the representation of several other muscles. These foci may represent a pattern of functional grouping that has been described in MI. Intracellular recording/dye injection and anatomical pathway tracing techniques will be used after mapping to examine the connectional relationship between these individual or grouped representations in MI. Dynamic organization: A second goal of these studies is to determine the extent to which the relationship of the motor cortex with the muscles is changed (a) under normal conditions (i.e., is there a continual reshaping of MI representations?), (b) following nerve injury that prevents the normal use of the distal forelimb muscles, (c) following the acquisition of skilled digit movements. Microstimulation mapping will be used to study MI representation patterns at different intervals in normal animals, before and after anterior interosseus nerve section and before and after learning of a precision finger grip task. These experiments will provide important new information concerning the efferent topography of primate motor cortex as well as the flexibility of the relationship between MI cortex and muscles. The results of these studies may suggest new strategies for enhancing functional recovery and suppressing spasticity subsequent to injury of the peripheral and central nervous system.