Sustained Rhythmic Brain Activity Underlies Visual Motion Perception in Zebrafish

Following moving visual stimuli (conditioning stimuli, CS), many organisms perceive, in the absence of physical stimuli, illusory motion in the opposite direction. This phenomenon is known as the motion aftereffect (MAE). Here, we use MAE as a tool to study the neuronal basis of visual motion perception in zebrafish larvae. Using zebrafish eye movements as an indicator of visual motion perception, we find that larvae perceive MAE. Blocking eye movements using optogenetics during CS presentation did not affect MAE, but tectal ablation significantly weakened it. Using two-photon calcium imaging of behaving GCaMP3 larvae, we find post-stimulation sustained rhythmic activity among direction-selective tectal neurons associated with the perception of MAE. In addition, tectal neurons tuned to the CS direction habituated, but neurons in the retina did not. Finally, a model based on competition between direction-selective neurons reproduced MAE, suggesting a neuronal circuit capable of generating perception of visual motion. [Display omitted] •Zebrafish larvae perceive the motion aftereffect (MAE)•Ablation studies demonstrate that the optic tectum is involved in MAE•Specific habituation of tectal direction-selective (DS) neurons is associated with MAE•An empirical competition model of opposite DS neuronal populations reproduces MAE Pérez-Schuster et al. use two-photon functional imaging to follow behaving GCaMP zebrafish larvae while perceiving the motion aftereffect. Analysis of the in vivo dynamics of large neuronal populations and development of empirical models shed light on the circuit processes that govern visual motion perception.