Figure 4.
Eye velocity (ve) traces of wt and the spontaneous oscillations (SO) displayed by some bel rev. The ve traces were obtained from either a single wt or a single bel rev larva. A, Eye velocity of wt during moving and still grating. B, Behavior of bel rev under identical conditions. Eye movements are observed without motion stimulus. C, Eye velocity of wt when moving grating, still grating, and darkness were alternated. D, bel rev under the same conditions. Oscillations are visual input dependent. E, Eye velocity of bel rev in response to moving grating, still grating, and light exposure without grating. Sampling rate of the eye position recording were 5 samples/s (A–D) and 12 samples/s (E). Eye velocity traces were smoothened around the spikes caused by saccades when the eye velocity exceeded 18°/s. The traces were further smoothened with a three-frame running average. All gratings had a contrast of 100% and a spatial frequency of 0.055 c/deg. Gray arrows indicate a moving grating at a stimulus velocity of 8°/s with alternating direction every 3 s. When a still grating was presented, no special mark was put. Black rectangles signify complete darkness, whereas white rectangles indicate mere light exposure without a grating.