Difference of flocculus and paraflocculus in the control of vestibulo-ocular and smooth pursuit eye movements in the primate.

研究了猕猴小叶小叶及其腹侧小叶旁小叶对眼部平滑追踪的适应性，比较了浦肯野神经元在小叶小叶及其腹侧小叶旁小叶平滑追踪的适应性。当猴子追逐以3^0步进- 10 ^0/2步进模式运动的目标时，在目标运动开始后，先出现慢眼动（4^0/s），然后出现小扫视（2-3^0），随后是8^0/s等速平滑追逐。在快速扫视开始后的短时间内（100 ~ 200ms），当目标速度增加到200/s或降低到5^0/s时，平滑追踪速度出现自适应变化。同时，眼跳的幅度有所改变，眼跳的潜伏期增加。小叶浦肯野神经元对台阶-斜坡目标运动的眼动反应较弱，而腹侧副叶丛浦肯野神经元对台阶-斜坡目标运动的眼动反应较强。大部分腹侧小叶旁浦肯野神经元（14个神经元中有8个）表现出与平滑追求适应相关的神经元变化，而小叶旁浦肯野神经元（12个神经元）没有表现出与平滑追求适应相关的神经元变化。结果表明，小叶和腹侧小叶在顺追过程中起着不同的调控作用。

We examined the adaptability of macaque smooth pursuit eye movements and compared the responses of single unit activities of purkinje neurons during the adaptation of smooth pursuit between the cerebellar flocculus and its adjacent ventral paraflocculus. When the monkey pursued a target moving in 3^0step-l0^0/2rarnp mode, slow eye movement (4^0/s) first started lOOms after the onset of target movement, and later small saccade (2-3^0) occurred, which was followed by 8^0/s constant velocity smooth pursuit. Adaptive changes of the smooth pursuit velocity were seen when the target velocity was increased to 200/s or decreased to 5^0/s immediately after the onset of saccade for brief period(100-200ms). Moreover, the amplitude of saccade was modified and the latency for the saccade increased. The flocculus purkinje neurons exhibited modest responses during the eye movements to step-ramp target movements, but the ventral parafloccuhis purkinje neurons exhibited rather strong responses to the pursuit eye movements to step-ramp target movements. Neuronal changes correlated with the adaptation of the smooth pursuit was recognized in most (8 of 14 examined neurons) of ventral paraflocculus purkinje neurons, while the none of the flocculus purkinje neurons examined (12 neurons) showed responses correlated with adaptation of smooth pursuit. These results strongly suggest that the flocculus and ventral paraflocculus mediate different role in the control of smooth pursuit.