CEREBELLAR ENCODING OF ONLINE GAIT ADJUSTMENTS

Efficient locomotion requires continuous coordination of limb movements and rapid adaptation of stepping patterns to maintain balance and meet environmental challenges. While the cerebellum has been extensively studied in the context of fine motor control and locomotion, the contribution of cerebellar cortical activity to online adjustments during locomotion remains poorly understood.
To address this, we recorded local field potentials from cerebellar cortical regions, lobule simplex and crus I, using chronic multichannel probe implants in freely moving mice. Animals walked on a complex wheel while cerebellar activity and behaviour were recorded simultaneously, allowing neural signals to be aligned to detailed kinematic measures extracted from videography.
We observed robust step-locked modulation of cerebellar cortical activity, consistent with encoding of stereotyped interlimb stepping sequences. Importantly, steps that deviated from this stereotyped sequence were associated with distinct neural signatures. During encounters with missing rungs, mice altered their stepping pattern and exhibited a transient increase in cerebellar cortical activity, indicating engagement of cerebellar processing during online gait adjustment.
Together, these findings suggest that cerebellar cortex activity in simplex and crus I reflects both regular locomotor structure and adaptive modifications of gait, supporting a role for the cerebellar cortex in online control during complex locomotion.