Saccadic Suppression Enhances Saliency of Prey-Like Stimuli in the Optic Tectum

Saccadic suppression, a reduction in visual sensitivity around the time of a rapid eye movement, is a robust perceptual phenomenon, extensively studied in primate psychophysics. However, the mechanisms and purpose of saccadic suppression are still debated in the field. Here, we demonstrate saccadic suppression in zebrafish, and trace its origins not only in retinal circuits, but also in downstream visual and motor-related neurons of the optic tectum. Using electrophysiology, we first established that retinal ganglion cells jumpstart saccadic suppression, in a spatial frequency dependent manner. Calcium imaging of the optic tectum, combined with 360° visual stimulation and behavioral tracking, revealed that motor signals enhance peri-saccadic suppression strength up to 0.5 s after the saccade. Notably, vision-mediated saccadic suppression lasts more than 3 s. Suppression strength depends on saccade size. Interestingly, we found much weaker saccadic suppression in the optic tectum for stimuli related to hunting behavior than for behaviorally less relevant global flashes, suggesting a selectivity of saccadic suppression aimed at increasing the salience of particular types of visual stimuli after saccades. These findings demonstrate that saccadic suppression in zebrafish integrates visual and motor signals to optimize sensory processing within neural constraints, providing insights into evolutionarily conserved visual strategies.