Chris I. De Zeeuw, Dept. of Neuroscience, Erasmus MC, Rotterdam; Netherlands Institute for Neuroscience, Royal Dutch Academy of Arts & Sciences, Amsterdam

Cerebellar Modules and Learning Rules

The olivocerebellar system can be divided into modules that control a particular domain in motor and/or cognitive processing. Each module integrates the activity of Purkinje cells in the cerebellar cortex, cerebellar nuclei neurons and neurons in the inferior olive. Interestingly, the modules can be divided in at least two main types, characterized by the presence or absence of zebrin. Those that do and do not express zebrin show a low and high intrinsic average firing frequency, respectively. In this lecture I will highlight the impact of this organization on the rules that guide cerebellar learning. Whereas the zebrin-positive zones, such as those controlling adaptation of the vestibulo-ocular reflex and whisker movements, appear to engage plasticity mechanisms that increase simple spike firing frequency during learning, the zebrin-negative zones, such as those controlling Pavlovian eyeblink conditioning, seem to trigger mechanisms that suppress simple spike activity. These different cerebellar cortical mechanisms will also induce different processes downstream in the vestibular and cerebellar nuclei, including slower tonic changes and faster rebound activity, respectively. Finally, the different intrinsic activity within the olivocerebellar modules will also affect the pathogenesis of cerebellar diseases, with Purkinje cell death often occurring most prominently in zebrin-negative zones presumably reflecting enhanced cytotoxicity.

Organized by

Margret Franke