First, I will explain the relation of the brain to the outside world, the components of the brain and the role the cerebellum plays in movement control. Then, in part two of this introduction, I will introduce the cell types of the cerebellar cortex and how they are connected to each other. In part three, the cerebellar nuclei are discussed. Subsequently, I will explain and discuss the techniques used in this thesis. This can be found in section four. Finally, in part five, I will identify some issues and questions related to cerebellar function that have not been sufficiently investigated and that form the basis for my thesis