Cerebellar Plasticity and the Ocular Following Response

Abstract

We constructed a realistic simulation model to elucidate whether the characteristics of the cerebellar synaptic plasticity reported in vitro guide the acquisition and adaptation of the ocular following response (OFR). The model reconstructed the firing frequency of the inputs of granule cell axons (GCA), inhibitory cells (IC), and climbing fibers (CF) to cerebellar Purkinje cells for the OFR, to simulate the reported cerebellar plasticity, including long-term depression, long-term potentiation, and rebound potentiation. When the model used the same visual inputs as reported for monkeys, it successfully simulated the real characteristics of simple spikes in Purkinje cells of adult monkeys and adaptation of gain and direction. The success of our simulation relied on the temporal relationship of the synaptic weight changes when CF inputs preceded GCA and IC inputs, corresponding to the relationship reported by Chen and Thompson and reanalysis of the data of Karachot et al. The success of our simulation strongly suggests that acquisition and adaptation of the OFR arise from cerebellar plasticity.