Figure 3.

Effects of tricaine and gradual cooling on the optokinetic response. (A) Illustration of the visual stimulus (top) and the experimental protocol (bottom). A 3 min looping stimulus was presented to animals using an LED arena (Supplementary Figure 1). It consisted of a moving bar rotating at a constant velocity (18°/s) for 60 s counter-clockwise, followed by 60 s clockwise, and finally alternating between counter-clockwise and clockwise in 4 s intervals for a total of 60 s. (B) Sample traces of the eye movements evoked by the stimulus protocol during experiments carried out in the presence of the vehicle control (1% v/v 1,2-propanediol), during gradual cooling (11°C) and in the presence of tricaine at a concentration of 168 mg/L. (C,D) The dynamic range of the evoked eye movements and the number of saccades occurring during each 3 min stimulus period were analyzed and significance was determined via two-way repeated measures ANOVA with Tukey's HSD test. Horizontal colored bars indicate which time points were significantly different from respective controls, for clarity only one significance level is shown (p < 0.05). Vertical white lines indicate the 1 min stationary grating period shown in (A), as no visual stimulus was present during this time. (E) Comparison of the recovery timepoints of saccade rate and dynamic range for the different treatments. N = 4–18.