Activity of interpositus neurons during a visually guided reach
Activity of interpositus neurons during a visually guided reach
复制标题
DOI：
10.1139/cjpp-74-4-499
复制
发表时间：
1996-04-01
影响因子：
2.1
通讯作者：
VanKan, PLE
中科院分区：
文献类型：
--
作者：
Gibson, AR;Horn, KM;VanKan, PLE
当猴子伸手去抓一个物体时，小脑间位核的神经元会大大增加它们的放电频率。然而，当猴子被要求通过移动操纵器来跟踪屏幕上的目标时，放电率的增加相对较小或不存在。将手直接移动到目标是视觉任务，其可能与远程跟踪任务有根本不同。我们假设，间位核是专门为肢体的直接视觉指导，或者，间位是专门为控制手的动作，需要抓住一个对象。一只猴子被训练拿着一个传感器，并将它直接移动到一个视觉目标上，以获得水的奖励。在两个目标旁边安装了小抽屉;在一些试验中，抽屉会打开，猴子可以伸手去拿放在抽屉里的葡萄干，在猴子伸手去抓葡萄干的过程中，间位神经元强烈放电，但当猴子将传感器放在目标上时，就没有了。对于单个细胞，放电模式和幅度在很大程度上是独立的大小和方向的达成把握，这表明，interpositus不控制方向或幅度的达成。结果是一致的假设，即在前肢区域的interpositus神经元参与控制的手的动作用于抓，但他们不符合的假设，interpositus神经元参与直接视觉指导的肢体。
Neurons in the cerebellar interpositus nucleus greatly increase their discharge rates when a monkey reaches out to grasp an object. However, when the monkey is required to track a target on a screen by moving a manipulandum, the increase in discharge rate is relatively small or nonexistent. Moving the hand directly to a target is a visuomotor task that may be fundamentally different from a remote tracking task. We hypothesize that the interpositus nucleus is specialized for direct visual guidance of the limb or, alternatively, interpositus is specialized for controlling hand movements required to grasp an object. A monkey was trained to hold a sensor and move it directly over a visual target to obtain water reward. Small drawers were mounted next to two of the targets; on some trials a drawer would open so that the monkey would reach out and retrieve a raisin that had been placed in it. Interpositus neurons discharged strongly during reach to grasp the raisin but not when the monkey was positioning the sensor over the target. For individual cells, discharge pattern and amplitude were largely independent of the size and direction of the reach to grasp, suggesting that interpositus does not control direction or amplitude of the reach. The results are consistent with the hypothesis that neurons in forelimb regions of interpositus participate in the control of hand movements used in grasping, but they are not consistent with the hypothesis that interpositus neurons participate in direct visual guidance of the limb.