CEREBELLAR CONTROL OF MULTIJOINT LIMB MOVEMENT

描述（改编自申请人的摘要）：实验是 设计的目的是，首先，表征的贡献， 小脑齿状核的运动学和动力学控制 到达。 猫被训练来执行一项多关节任务， 为了获取食物而被固定在不同高度的小管。 这是 一种快速的、特征鲜明的动作， 在一个完整的猫的准确性。在拟议的研究中，肢体的措施， 轨迹，肌电活动和关节扭矩将被制成 在猫的插入核或齿状核的特异性失活过程中 当进行到达运动时。 灭活将产生， 微量注射GABA激动剂蝇蕈醇。 预测是细胞核的失活将导致 不精确性是轨迹中的特定误差的结果。 这些实验将检验这样一个假设： 由于未能补偿相互作用扭矩， 因为多个肢体段用于产生运动。 间位肌和齿状肌对适应性的特殊贡献 肢体轨迹的控制将使用一系列的五个 挑战动物能力的基本伸展任务的变化 使用躯体感觉或视觉信息来触发纠正 在运动过程中的反应或计划后续运动。 两项任务， 负荷和障碍任务，主要取决于使用躯体感觉 信息. 从解剖学和生理学的角度来看， 这些任务应该会因间质的失活而受损。的 背侧副橄榄投射至间位核， 中间小脑主要由本体感受刺激驱动。 然而，外侧小脑和齿状核接受非躯体定位的 橄榄输入和通过脑桥核的主要视觉输入。 因此，在本发明中， 预测是涉及非同伦信息的任务 (i.e.,障碍物、移动目标和计时任务）将受到以下因素的影响： 齿状失活 在第二系列实验中， 红核的小细胞和大细胞分裂， 多关节轨迹控制和适应将使用 相同的行为模式。据推测，部分行为 间位核失活的作用将由 大细胞红核和红核脊髓系统，因为主要 输入到大细胞红核的是中间体。 的影响 的小细胞红核失活，预计将更多 复杂.这个核接受来自齿状核和齿状核的密集投射 它是复杂的小脑前核和运动皮层的一部分， 可能通过多个下行通路发挥其作用。

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.