Modular organization of murine locomotor pattern in the presence and absence of sensory feedback from muscle spindles

Abstract

Locomotion on land and in water requires the coordination of a great number of muscle activations and joint movements. Constant feedback about the position of own body parts in relation to the surrounding environment and the body itself (proprioception) is required to maintain stability and avoid failure. The central nervous system may follow a modular type of organization by controlling muscles in orchestrated groups (muscle synergies) rather than individually. We used this concept on genetically modified mice lacking muscle spindles, one of the two main classes of proprioceptors. We provide evidence that proprioceptive feedback is required by the central nervous system to accurately tune the modular organization of locomotion.