A guide to in vivo optogenetic applications for cerebellar studies

Abstract

The mammalian cerebellum consists of a superficial cortex and centrally located output nuclei, which together with brainstem nuclei are organized in a modular fashion. Regardless of the function, these cerebellar modules consist of the same cell types, and their connectivity has been unraveled to some detail using electrical stimulation experiments. To unravel the highest level of detail, cell-specific stimulation experiments are warranted, which cannot be accomplished using electrical stimulation. To reach this unprecedented level of specificity, optogenetic applications are now being implemented in cerebellar studies. Due to the extensive knowledge about cell-specific markers in both the cerebellar cortex and the cerebellar nuclei, optogenetics can be applied cell specifically. Ideally the anatomical and electrophysiological characteristics of the cerebellum can be utilized for designing future optogenetic studies. In this chapter we review the opportunities and pitfalls for optogenetic studies in the cerebellum. We provide insights into the technical issues at hand and which solutions are currently available.