Neurophysiological and anatomical investigation-The paraflocculus-cerebellar nuclear control mechanisms of the primate smooth pursuit eye movement system

作为小脑运动控制的实验模型，研究了前庭眼反射（VOR）短期适应的神经机制。我在兔和猴实验中的损伤、单单位记录和电路分析研究的结果一致地支持以下假设：小叶通过对小叶内浦肯野细胞突触传递效能的长期抑制（LTD）来自适应地控制VOR的增益。对于这种小叶假说，有人提出了小叶在猴VOR中的不同作用，即VOR的适应是由小叶及其脑干中的靶神经元的合作诱导的（Lisberger和Sejnowski 1993）。然而，对于这个建议，我的神经解剖学研究使用逆行和/或顺行轴突流的方法和单位记录实验的研究表明，猴绒球的尾侧一半的VOR控制的特性，但它的吻侧一半的特性，控制顺利的追求。因此，我认为，猴绒球的嘴侧一半属于腹侧副绒球。Lisberger小组报告的实验观察似乎包括腹侧旁小叶中获得的观察结果。因此，我认为，在灵长类动物中，绒球和腹侧副绒球分别控制前庭眼和平滑追踪眼的运动。我的行为研究使用的灵长类动物VOR的适应和那些为适应平稳追求眼球运动也支持这两个缓慢的眼球运动是独立控制的小脑中的不同的神经元组的观点。

The neural mechanisms for the short-term adaptation of the vestibulo-ocular reflex (VOR) has been investigated as an experimental model of the cerebellar motor control. My results of lesion, single unit recording and circuitry analysis studies in the rabbit and monkey experiments consistently support the hypothesis that the flocculus adaptively controls the gain of the VOR through the long-term depression (LTD) of transmission efficacy of the synapses on the Purkinje cells within the flocculus. To this flocculus hypothesis, a different role of the flocculus is proposed in the monkey VOR that the adaptation of the VOR is induced by the cooperation of the flocculus and its target neurons in the brain stem (Lisberger and Sejnowski 1993). To this proposal, however, my neuroanatomical study using retrograde and/or anterograde axonal flow methods and study of unit recording experiments reveal that the caudal half of the monkey flocculus has the characteristics for the control of the VOR,but the rostral half of it has the characteristics for the control of smooth pursuit. So I suggest that the rostral half of the monkey flocculus belongs to the ventral paraflocculus. The experimental observations reported by the Lisberger's group seem to include thoses obtained in the ventral paraflocculus. Therefore, I suggest that the flocculus and ventral paraflocculus respectively controls the vestibulo-ocular and smooth pursuit eye movements in the primate. My behavioral study using the adaptation of the primate VOR and those for the adaptation smooth pursuit eye movements also support the view that these two slow eye movements are independently controlled by the different groups of neurons in the cerebellum.