Uncovering principles of long timescale sensory evoked navigation in larval zebrafish*

Animals navigate their environments by chaining short timescale bouts into long strategies, reflecting the complex interplay between sensory cues and internal states. We study the principles driving these strategies in larval zebrafish by quantifying behavior across timescales. By concatenating the fish’s tail pose across bouts over time, we constructed maximally predictive sequences and investigated the time evolution of behavior through a high-fidelity Markovian model. The eigenspectrum of the inferred transition matrix revealed a hierarchy of timescales with three main modes - the first involving Cruising and Wandering strategies with steady or rapid changes in orientation, the second encoding overall speed, and the third encoding preference for direction (left vs. right).

This approach allowed us to study of how sensory conditions impact navigation along these modes. Aversive stimuli such as expanding spots trigger fast wandering strategies, while chasing dots only reduce speeds. When hunting prey, eye convergence events elicit a switch to slow cruising, whereas inter-hunt behavior is dominated by wandering strategies. Our ensemble model also revealed individual preferences for strategies at the timescale of the experiment, suggesting the influence of long lasting latent states on the behavior overruling the environmental sensory cues. Altogether, our approach illuminates the modulation of behavior by sensory stimuli and individual preferences across a hierarchy of timescales.