Spatial and Temporal Locomotor Learning in Mouse Cerebellum

Area of Science:

• Neuroscience
• Motor Control
• Locomotion

Background:

• Locomotion requires precise coordination of limbs and body.
• Learned motor adaptations, like interlimb coordination changes, can be induced by altered sensory feedback, such as on split-belt treadmills.

Purpose of the Study:

• To investigate locomotor learning and adaptation in mice using a split-belt treadmill.
• To determine the neural substrates and circuit-level mechanisms underlying mouse locomotor adaptation.
• To explore the conserved nature of locomotor adaptation across species.

Main Methods:

• Split-belt treadmill training in mice.
• Quantitative behavioral analysis of locomotion.
• Lesion studies targeting the cerebellum and cerebral cortex.
• Cell-type-specific chemogenetics.

Main Results:

• Mice exhibit robust locomotor adaptation on a split-belt treadmill, specific to interlimb coordination.
• Adaptation involves distinct spatial and temporal components that change at different rates.
• Locomotor adaptation in mice is dependent on the intermediate cerebellum but not the cerebral cortex.
• Spatial and temporal components of adaptation are dissociable at the circuit level.

Conclusions:

• Mouse locomotor adaptation shares key features with human adaptation, suggesting a conserved mechanism across vertebrates.
• The intermediate cerebellum is critical for split-belt adaptation, while the cerebral cortex is not essential.
• Neural circuits underlying spatial and temporal aspects of motor learning are distinct and can be manipulated independently.