Cerebellar Codings for Control of Compensatory Eye Movements

This thesis focuses on the control of the cerebellum on motor behaviour, and more specifically on the role of the cerebellar Purkinje cells in exerting this control. As the cerebellum is an online control system, we look at both motor performance and learning, trying to identify components involved at the molecular, cellular and network level. To study the cerebellum we used the vestibulocerebellum, with visual and vestibular stimulation as input and eye movements as recorded output. The advantage of the vestibulocerebellum over other parts is that the input given is highly controllable, while the output can be reliably measured, and performance and learning can be easily studied. In addition, we conducted electrophysiological recordings from the vestibulocerebellum, in particular of Purkinje cells in the flocculus. Combining the spiking behaviour of Purkinje cells with visual input and eye movement output allowed us to study how the cerebellum functions and using genetically modified animals we could determine the role of different elements in this system. To provide some insights in the techniques used and the theory behind them, we will discuss the following topics in this introduction: compensatory eye movements, the anatomy of pathways to, within and out of the flocculus, the cellular physiology of Purkinje cells in relation to performance and the plasticity mechanisms related to motor learning.