STRIATAL ACTIVITY IN BEHAVING PRIMATES

基底节在运动控制中的确切作用仍不清楚。 在动作的启动和执行方面都存在严重的缺陷 帕金森氏症患者和实验动物，特别是在 弹道运动以及当行为要求和结果 变幻莫测。患者和实验动物也都有缺陷 在本体感觉控制中。 目前的假说表明，基底神经节在运动中起作用。 通过“释放”丘脑皮质直接运动通路而启动 解除对大脑皮层的抑制，以便启动准备好的动作 制定了新的机动计划。这些假设还表明，间接的 通路通过抑制其他区域来抑制不想要的运动 大脑皮层与运动行为没有直接联系。促进和 在运动启动和执行过程中对皮质的抑制可能 改变皮层区域感觉神经元的反应性 向基底节提供信息输入。 单单位电生理技术将用于记录来自 表现为猴子手部运动时的纹状体神经元 导致皮层神经元反应性改变的任务。这个 拟议研究的具体目标是：1)了解 对纹状体活动的不可预测的行为要求，2) 了解纹状体神经元在控制 启动和执行正确的感觉引导动作和3) 确定纹状体神经元的激活历史是否会影响时间 刺激和运动相关活动的开始和大小。这个 建议的实验结果将与 正在进行的研究中，感觉运动性皮质神经元被记录在 同样的行为条件。此比较将确定是否 纹状体活动的变化先于皮质活动，因此 提示纹状体可能会影响大脑皮层的反应。 这项工作的长期目标是更好地理解 基底节在刺激检测和运动控制中起作用 分类、应对方案编制和选择(启动)和 响应生产(执行)。希望它将提供 更多证据支持基底节影响 调节本体感觉信息加工的运动控制 感觉运动中枢。从这些实验中获得的见解将是至关重要的 了解运动障碍的原因和程度 基底节功能障碍。

The precise role of the basal ganglia in motor control is still unclear. Profound deficits in both movement initiation and execution occur in Parkinson's disease patients and experimental animals, especially during ballistic movements and when behavioral requirements and outcome are unpredictable. Both patients and experimental animals also have deficits in proprioceptive control. Current hypotheses suggest that the basal ganglia play a role in movement initiation by "releasing" direct thalamocortical motor pathways thus "disinhibiting" cortex so that prepared movements can be initiated and new motor plans made. These hypotheses also suggest that indirect pathways suppress unwanted movements by suppressing other regions of cortex not directly associated with the motor behavior. Facilitation and suppression of the cortex during movement initiation and executive may alter the responsiveness of sensory neurons in cortical areas that provide input to the basal ganglia. Single-unit electrophysiological techniques will be used to record from striatal neurons from behaving monkeys while they perform hand movement tasks which result in changes in cortical neuronal responsiveness. The specific goals of proposed studies are 1) to understand the influence of unpredictable behavioral requirements upon striatal activity, 2) to understand the role that striatal neurons play in controlling the initiation and execution of proprioceptively guided movements and 3) to determine if a striatal neuron's activation history influences the time of onset and magnitude of stimulus and movement related activity. The results of the proposed experiments will be compared with those of ongoing studies in which sensorimotor cortical neurons are recorded under the same behavioral conditions. This comparison will determine if changes in striatal activity occur before those in cortex, thus suggesting the striatum may influence cortical responsiveness. The long-term goal of this work is to better understand the role the basal ganglia play in motor control during stimulus detection and classification, response programming and selection (initiation) and response production (execution). It is hoped that it will provide additional evidence to support the view that the basal ganglia influences motor control by regulating proprioceptive information processing in sensorimotor centers. Insights from these experiments will be crucial in understanding the cause and extent of motor deficits that accompany basal ganglia dysfunction.