Cerebellar circuit mechanisms for coordinated locomotion in mice

Smooth and efficient walking requires the coordination of movement across the body and depends critically on an intact cerebellum. We aim to understand how neural circuit mechanisms within the cerebellum contribute to specific aspects of coordinated locomotion. To this end, we have developed an automated, markerless 3D tracking system (LocoMouse) and used it to establish a quantitative framework for locomotor coordination in freely walking mice. In this talk I will describe our work combining these high resolution behavioral measurements with perturbations of the underlying neural circuits in order to probe the neural basis for locomotor coordination. Analyzing the behavior of mice with cerebellar defects has revealed specific features of locomotor coordination that suggest that cerebellar ataxia results from an inability to predict the consequences of movements across the body. In current experiments we are testing this idea by investigating neural circuit mechanisms of locomotor learning, in which mice learn to adapt their locomotor patterns to achieve a more symmetrical gait while walking on a split-belt treadmill. This approach is providing insight into how the highly stereotyped cellular architecture of the cerebellum supports a wide variety of behaviors, from relatively simple forms of learning to complex feats of coordination.