Action-based organization of a cerebellar module specialized for predictive control of multiple body parts

Highlights

• Mice learn a defensive movement requiring coordination of multiple body parts

• Cerebellar rostral anterior interpositus nucleus (rAIN) drives the entire movement

• A population of rAIN neurons with specialized receptive fields encode the movement

• Some modules of the cerebellum are organized based on an action map

Summary

The role of the cerebellum in predictive motor control and coordination has been thoroughly studied during movements of a single body part. In the real world, however, actions are often more complex. Here, we show that a small area in the rostral anterior interpositus nucleus (rAIN) of the mouse cerebellum is responsible for generating a predictive motor synergy that serves to protect the eye by precisely coordinating muscles of the eyelid, neck, and forelimb. Within the rAIN region, we discovered a new functional category of neurons with unique properties specialized for control of motor synergies. These neurons integrated inhibitory cutaneous inputs from multiple parts of the body, and their activity was correlated with the vigor of the defensive motor synergy on a trial-by-trial basis. We propose that some regions of the cerebellum are organized in poly-somatotopic “action maps” to reduce dimensionality and simplify motor control during ethologically relevant behaviors.