Ito M
Frontier Research Program, Saitama, Japan.
Can J Neurol Sci. 1993 May;20 Suppl 3:S70-4.
Synaptic plasticity plays a role in the learning capability of brain tissues. Long-term depression (LTD) of parallel fiber synapses in cerebellar Purkinje cells occurs when these synapses are activated in conjunction with climbing fiber synapses. Signal transduction mechanisms underlying LTD have recently been investigated extensively. It has also become apparent that climbing fiber signals encode errors in the motor performance of an animal. It is therefore hypothesized that learning proceeds in cerebellar tissues in such a way that error signals of climbing fibers act to depress by LTD those parallel fiber synapses responsible for the errors. The cerebellum contains a large number of corticonuclear microcomplexes. Each microcomplex is connected to an extracerebellar system and is presumed to endow the system with learning capability. The hypothesis accounts for the adaptation of the vestibuloocular reflex and probably also for other forms of motor and cognitive learning.
突触可塑性在脑组织的学习能力中发挥作用。当小脑浦肯野细胞中的平行纤维突触与攀缘纤维突触同时被激活时，会发生平行纤维突触的长时程抑制（LTD）。最近对LTD潜在的信号转导机制进行了广泛研究。同样明显的是，攀缘纤维信号编码动物运动表现中的误差。因此推测，小脑组织中的学习过程是这样进行的，即攀缘纤维的误差信号通过LTD作用于抑制那些对误差负责的平行纤维突触。小脑包含大量皮质核微复合体。每个微复合体都与一个小脑外系统相连，并被认为赋予该系统学习能力。这一假说解释了前庭眼反射的适应性，可能也解释了其他形式的运动和认知学习。
