Time and tide in cerebellar memory formation.

The notion that the olivocerebellar system is crucial for motor learning is well established. In recent years, it has become evident that there can be many forms of both synaptic and non-synaptic plasticity within this system and that each might have a different role in developing and maintaining motor learning across a wide range of tasks. There are several possible molecular and cellular mechanisms that could underlie adaptation of the vestibulo-ocular reflex and eyeblink conditioning. Although causal relationships between particular cellular processes and individual components of a learned behaviour have not been demonstrated unequivocally, an overall picture is emerging that the different types and sites of cellular plasticity relate importantly to the stage of learning and/or its temporal specifics.