Mapping the developmental structure of stereotyped and individual-unique behavioral spaces inC. elegans

Developmental patterns of behavior are variably organized in time and among different individuals. However, long-term behavioral diversity was previously studied using pre-defined behavioral parameters, representing a limited fraction of the full individuality structure. Here, we continuously extracted ∼1.2 billion body postures of ∼2,200 single C. elegans individuals throughout their full development time, to create a complete developmental atlas of stereotyped and individual-unique behavioral spaces. Unsupervised inference of low-dimensional movement modes of each single individual revealed a dynamic developmental trajectory of stereotyped behavioral spaces and exposed unique behavioral trajectories of individuals that deviate from the stereotyped patterns. Moreover, classification of behavioral spaces within tens of neuromodulatory- and environmentally-perturbed populations efficiently uncovered plasticity in the temporal structures of stereotyped behavior and individuality. These results present a comprehensive atlas of continuous behavioral dynamics across development time and a general framework for unsupervised dissection of shared and unique developmental signatures of behavior.