Role of cerebellar dorsal vermis in generation of pursuit eye movements in three dimensional space

前眼灵长类动物使用前平行平面的平滑追踪和深度追踪来跟踪在三维（3D）空间中缓慢移动的物体。3D追踪信号表示在额眼场（FEF）中。研究表明，小脑背侧蚓部参与平滑追踪和旋转前庭眼反射（VOR）的控制。为了了解它如何参与3D追踪信号和翻译VOR的处理，我们在猴子中进行了两系列研究。在第一年，我们描述了追踪信号。在40%的蠕虫追踪P细胞中，观察到3D追踪信号。然而，大多数（60%）的蠕虫追求的P-细胞放电的边缘追求或额叶追求。此外，大多数的聚散追求P-细胞放电的会聚和放电的眼运动开始之前。蝇蕈醇输注到背蚓部导致峰值会聚眼速度和初始会聚眼速度的降低， ...更多信息 眼加速这些结果表明，参与的背蚓部分解的3D追求信号到额叶和深度组件。在第二年，我们测试了放电的蠕虫P-细胞在右/左平移被动移动整个身体，而目标是在不同的观看距离。目标要么随着整个身体移动，要么在虚拟空间中保持静止。与FEF追踪神经元中获得的结果进行了比较。大多数的vermal追求P-细胞，激活的右/左平移水平的首选方向。相比之下，大多数追求的P-细胞，在垂直方向或追求的首选方向很少响应右/左平移。在目标静止在空间中的平移过程中，放电调制与所得的水平眼速度。这些结果表明，FEF追求神经元在整个身体的翻译过程中进行的信号被发送到背蚓部进一步处理的追求信号在翻译过程中。少

Frontal-eyed primates use both smooth-pursuit in fronto-parallel planes and pursuit-in-depth to track objects moving slowly in three-dimensional (3D) space. 3D-pursuit signals are represented in frontal eye fields (FEF). Previous studies have shown that the cerebellar dorsal vermis is involved in smooth-pursuit and the control of rotational vestibulo-ocular reflex (VOR). To understand how it is involved in processing of 3D-pursuit signals and translational VOR, we performed two series of studies in monkeys. In the first year, we characterized pursuit signals. In 40% of vermal pursuit P-cells, 3D-pursuit signals were observed. However, the majority of vermal pursuit P-cells (60%) discharged either for vergence-pursuit or frontal-pursuit. Furthermore, the majority of vergence pursuit P-cells discharged for convergence and discharged before the onset of eye movements. Muscimol infusion into the dorsal vermis resulted in a reduction of peak convergent eye velocity and of initial convergent … More eye acceleration. These results suggest involvement of the dorsal vermis in decomposition of 3D-pursuit signals into frontal and depth components. In the second year, we tested discharge of vermal P-cells during right/left translation by passively moving the whole body while a target was presented at different viewing distances. The target was moved either with the whole body or stayed stationary in virtual space. Results were compared with those obtained in FEF pursuit neurons. The majority of vermal pursuit P-cells that were activated by right/left translation had horizontal preferred directions. In contrast, the majority of pursuit P-cells that had preferred directions in vertical directions or pursuit-in-depth rarely responded to right/left translation. During target stationary in space during translation, discharge modulation was correlated with resultant horizontal eye velocity. These results suggest that signals carried by FEF pursuit neurons during whole body translation are sent to the dorsal vermis for further processing of pursuit signals during translation. Less