The visuomotor transformations underlying defensive behaviors and hunting
The visual system can process diverse stimuli and make the decision to execute appropriate behaviors, but it remains unclear where and how this transformation takes place. We imaged the zebrafish visual system while larvae responded with hunting, freezing, and escape behaviors, and systematically identified visually driven neurons and behaviorally correlated sensorimotor neurons. Our analyses indicate within the optic tectum, broadly tuned sensory neurons are functionally connected to sensorimotor neurons that respond specifically during one behavior, transforming visual information into motor output. We also identified sensorimotor neurons in four other areas downstream of the tectum, and these neurons are also specific for one behavior, indicating that once the decision to behave has been made, the segregation of the pathways continues in later areas. Our findings suggest that the tectum receives visual sensory information and is responsible for selecting a single behavioral outcome, which is then relayed to downstream areas. Significance statementHere, we developed a novel visually-evoked freezing paradigm in zebrafish, and combined this with escape and hunting behaviors to ask how visual stimuli are identified and converted into different behavioral outcomes. We found that the optic tectum contains neurons that detect all three stimuli, as well as sensorimotor neurons for the three behaviors, suggesting that it is a site of sensorimotor transformation, which was supported by our analysis of correlations between the populations. The sensorimotor neurons in the tectum are highly specific for one behavior, and this segregation is maintained in the three downstream areas where we also identified sensorimotor neurons, indicating that the tectum flexibly transforms visual information into a single behavioral output.