Cerebellar connectivity maps embody individual adaptive behavior

Abstract

From planification to execution, cerebellar microcircuits encode different features of skilled movements. However, it is unknown whether cerebellar synaptic connectivity maps encode movement features in a motor context specific manner. Here we investigated the spatial organization of excitatory synaptic connectivity in mice cerebellar cortex in different locomotor contexts: during development and in normal, trained or altered locomotor conditions. We combined optical, electrophysiological and graph modelling approaches to describe synaptic connectivity between granule cells (GCs) and Purkinje cells (PCs). Synaptic map maturation during development revealed a critical period in juvenile animals before the establishment of a stereotyped functional organization in adults. However, different locomotor conditions lead to specific GC-PC connectivity maps in PCs. Ultimately, we demonstrated that the variability in connectivity maps directly accounts for individual specific behavioral features of mice locomotion, suggesting that GC-PC networks encode a general motor context as well as individual specific internal models underlying motor adaptation.

A stable proportion of Purkinje cell inputs from parallel fibers are silent during cerebellar maturation

“…Our finding that nearly half of PFs lose their functionality in acute slices (a close to 0.5) suggests that the probability of recording a pair of connected cells (based on anatomical data, respective cell location, and geometrical considerations) has been overestimated (30). Second, for any given PC, GCs connecting it with a talkative synapse appear not randomly distributed in the granular layer but rather in microzones (56). Therefore, the experimenter must ensure that paired recordings are obtained from samples large enough to encompass different microzones.…”