Chemosensory modulation of eye-body coordination in larval zebrafish

Coordinated eye-body movements are essential for adaptive behavior, yet little is known about how multisensory input, particularly chemosensory cues, shapes this coordination. Using our enhanced Fish-On-Chips optofluidic platform, we uncovered complex dynamics in how larval zebrafish coordinate saccadic eye movements with tail flips. Under baseline conditions, spontaneous tail flips dynamically align with saccades in frequency and direction for coordinated turns. Chemosensory valence further modulates this coordination: death-associated cues intensify both the strength and frequency of coupled saccade-tail flips during turns, whereas food-related cues promote forward gliding without altering saccade coupling. Concurrent brain-wide neuronal imaging reveals that the zebrafish pallium represents the transformation of aversive valence into enhanced saccade-tail coordination, with stronger coupling associated with higher pallium activation. These findings uncover the neural basis by which chemosensory inputs of different valences distinctly regulate eye-body coordination to drive adaptive locomotion in a developing vertebrate, offering insights into principles of sensory-motor integration.