Wolf, SébastienDubreuil, Alexis M.Bertoni, TommasoBöhm, Urs LucasBormuth, VolkerCandelier, RaphaëlKarpenko, SophiaHildebrand, DavidBianco, Isaac H.Monasson, RémiDebrégeas, Georges2017-12-052017Wolf, S., A. M. Dubreuil, T. Bertoni, U. L. Böhm, V. Bormuth, R. Candelier, S. Karpenko, et al. 2017. “Sensorimotor computation underlying phototaxis in zebrafish.” Nature Communications 8 (1): 651. doi:10.1038/s41467-017-00310-3. http://dx.doi.org/10.1038/s41467-017-00310-3.http://nrs.harvard.edu/urn-3:HUL.InstRepos:34492078Animals continuously gather sensory cues to move towards favourable environments. Efficient goal-directed navigation requires sensory perception and motor commands to be intertwined in a feedback loop, yet the neural substrate underlying this sensorimotor task in the vertebrate brain remains elusive. Here, we combine virtual-reality behavioural assays, volumetric calcium imaging, optogenetic stimulation and circuit modelling to reveal the neural mechanisms through which a zebrafish performs phototaxis, i.e. actively orients towards a light source. Key to this process is a self-oscillating hindbrain population (HBO) that acts as a pacemaker for ocular saccades and controls the orientation of successive swim-bouts. It further integrates visual stimuli in a state-dependent manner, i.e. its response to visual inputs varies with the motor context, a mechanism that manifests itself in the phase-locked entrainment of the HBO by periodic stimuli. A rate model is developed that reproduces our observations and demonstrates how this sensorimotor processing eventually biases the animal trajectory towards bright regions.en-USJournal Article2017-12-0510.1038/s41467-017-00310-3