Investigation of spatial distribution of excitation in cerebellar cortical slices

The aim of this project is to describe the spatial distribution of excitation in the cerebellar cortex, in particular in the granular layer, following mossy fiber electrical stimulation. The granular layer of the cerebellar cortex is composed by densely packed granule cells and fewer Golgi cells. The excitatory input to this layer is provided by glutamatergic mossy fibers, which contact both granule and Golgi cells in peculiar structures called cerebellar glomeruli. While granule cells are excitatory neurons and project to the molecular and Purkinje cell layers of the cerebellar cortex, Golgi cells are inhibitory interneurons that inhibit granule cells and make contact with other Golgi cells (through synapses or gap-junctions). Since granular cell axons excites Golgi cell dendrites, the inhibition of granule cells is obtained through a feed-forward and a feed-back loops. This organization provides specific temporal and spatial properties to granular layer spread of excitation, once the mossy fiber input is active. For a comprehensive review on this subject see D’Angelo et al. (2013) and Mapelli et al. (2014). In this project, voltage sensitive dyes recordings are used to characterize the spread of excitation in the granular layer following single-pulse electrical activation of mossy fibers, in acute slices of the cerebellar vermis (as in Soda et al., 2019).