CEREBELLAR CONTROL OF MULTIJOINT LIMB MOVEMENT

描述(摘自申请者的摘要)：实验内容如下 旨在首先，表征被插入者的贡献和 小脑齿状核在运动学和动力学控制中的作用 伸手可及。猫被训练成执行多关节任务，伸手进入 为了获得食物而固定在不同高度的小管子。这是 一种快速的、特征鲜明的动作，动作高度 一只完好无损的猫的准确性。在拟议的研究中，肢体的测量 将进行轨迹、肌电活动和关节扭矩测试 猫中间核或齿状核的特异性失活 随着伸展运动的进行。将通过以下方式产生停用 微量注射GABA激动剂麝香酚。 据预测，原子核的失活将导致 由于弹道中的特定错误而产生的不准确。 这些实验将检验这样的假设，即这些错误可能是 归因于未能补偿相互作用的扭矩 发展是因为多个肢体节段被用来产生运动。 间位和齿状突起对适应的特殊贡献 肢体轨迹的控制将使用一系列五个 挑战动物能力的基本到达任务的变化 使用躯体感觉或视觉信息触发矫正 在运动过程中的反应或计划随后的运动。两项任务， 负荷和障碍任务，主要取决于躯体麻醉剂的使用 信息。在解剖学和生理学基础上，表现 这些任务应该被代位物的失活所损害。这个 背副橄榄向间位核投射 中间小脑主要由本体感觉刺激驱动。 然而，外侧小脑和齿状回接受非躯体定位 橄榄核的输入和通过桥核的主要视觉输入。因此， 预测是，涉及非同伦信息的任务 (即障碍、移动目标和计时任务)将受到 齿状突起失活。 在第二系列实验中， 红核的小细胞和大细胞分裂为 多关节轨迹控制和适应性将使用 相同的行为模式。据推测，行为的一部分 间位核失活的作用将通过以下途径来实现 大细胞红核和红核脊髓系统 大细胞红核的输入是间位。其影响 小细胞红核失活的比例预计会更高 很复杂。这个核团接受来自两个齿状核的密集投射 核团和运动皮质，是复杂的小脑前脑的一部分 循环，并可能通过多条下行通路发挥作用。

DESCRIPTION (Adapted from applicant's abstract): The experiments are designed to first, characterize the contributions of the interposed and dentate nuclei of the cerebellum in the kinematic and dynamic control of reaching. Cats are trained to perform a multijoint task, reaching into a small tube held at varying heights in order to obtain food. This is a rapid, well-characterized movement performed with a high degree of accuracy in an intact cat. In the proposed studies, measures of limb trajectory, electromyographic activity, and joint torques will be made during specific inactivation of the interposed or dentate nuclei in cats as reaching movements are made. Inactivation will be produced with microinjections of the GABA agonist muscimol. The prediction is that inactivation of the nuclei will result in inaccuracies that are the consequence of specific errors in trajectory. The experiments will test the hypothesis that these errors can be attributed to a failure to compensate for interaction torques that develop because multiple limb segments are used to produce the movement. The specific contributions of the interpositus and dentate to adaptive control of limb trajectories will be investigated using a series of five variations of the basic reaching task to challenge the animal's capacity to use either somesthetic or visual information to trigger corrective responses during a movement or to plan subsequent movements. Two tasks, the load and obstacle tasks, depend primarily on the use of somesthetic information. On anatomical and physiological grounds, performance of these tasks should be impaired by inactivation of the interpositus. The dorsal accessory olive projection to the nucleus interpositus and intermediate cerebellum is driven primarily by proprioceptive stimuli. The lateral cerebellum and dentate, however, receive a non-somatotopic olivary input and a major visual input through the pontine nuclei. Thus, the prediction is that tasks that involve non-homotopic information (i.e., the barrier, moving target, and timing tasks) will be impaired by dentate inactivation. In the second series of experiments, the contributions of the parvicellular and magnocellular divisions of the red nucleus to multijoint trajectory control and adaptation will be examined using the same behavioral paradigms. It is hypothesized that part of the behavioral effect of inactivation of the nucleus interpositus will be mediated by the magnocellular red nucleus and the rubrospinal system, since the major input to the magnocellular red nucleus is the interpositus. The effects of parvicellular red nucleus inactivation are expected to be more complex. This nucleus receives dense projections from both the dentate nucleus and the motor cortex and is part of a complex precerebellar circuit and may exert its effects through multiple descending pathways.