Predicting natural behavior from whole-brain neural dynamics

We record calcium activity from the majority of head neurons in freely moving C. elegans to reveal where and how natural behavior is encoded in a compact brain. We find that a sparse subset of neurons distributed throughout the head encode locomotion. A linear combination of these neurons9 activity predicts the animal9s velocity and body curvature and is sufficient to infer its posture. This sparse linear model outperforms single neuron or PCA models at predicting behavior. Among neurons important for the prediction are well-known locomotory neurons, such as AVA, as well as neurons not traditionally associated with locomotion. We compare neural activity of the same animal during unrestrained movement and during immobilization and find large differences between brain-wide neural dynamics during real and fictive locomotion.