Supplemental Movies

The supplemental movies provided here are referred to throughout the text and are specifically noted at each section heading. The movies were saved in a QuickTime 6.0 format and are playable on both Mac and PC computers with freely available software (http://www.apple.com/quicktime/download/standalone/).

Files in this Data Supplement:

• Movie 1 - Step-by-step demonstration of embedding and preparation of a 5 dpf zebrafish in agarose for eye movement recordings. Steps not pertaining directly to the process have been edited for time (e.g., changing focus). Length: 4:28; size: 6.0 MB.
• Movie 2 - Step-by-step demonstration of the eye movement algorithm in operation, from initial acquisition to adjusting parameters for optimal eye tracking. Length: 0:58; size: 11.0 MB.
• Movie 3 - Comparison of OKR between small and large zebrafish with sinusoidal stimuli of 0.0625 Hz, ±10°/s. Here, the smaller animal (left) made fewer saccades and followed the stripes of the drum with a lower eye velocity than the larger animal (right). Small zebrafish gain = 0.52, 0.4° phase lead. Large zebrafish gain = 0.76; 0.1° phase lead. Superimposed on the images of the animals (top) are lines depicting the body axis (green) and eye position (blue: left eye; red: right eye). Below the animals are measurements of eye position as well as eye velocity and stimulus velocity (green). Measurement of time is along the abscissa in seconds. Eye position measurements occur in real-time; however, to generate this and the following movies, individual frames from digital video records made of each behavior were analyzed offline at 24 Hz. Eye velocity traces were smoothed using a Gaussian filter. Stimulus waveforms were recreated based on original online recording. Length: 1:13; size: 8.8 MB.
• Movie 4 - Optokinetic response in a larval goldfish at 3.0 Hz, ±10°/s. As frequency is increased, the drum position amplitude is decreased to maintain a constant amplitude for Bode frequency analysis; consequently, the eye movements are just detectible by eye. Nevertheless, in comparison to large larval medaka or zebrafish, this subject, typical of large goldfish, demonstrated an excellent OKR at this frequency (gain = 0.41) though with a noticeable phase lag (-105°). Length: 0:28; size: 5.5 MB.
• Movie 5 - Eye movements in some larval animals are not smooth. A small, young goldfish exhibits small jerks in eye position as it tries to follow an optokinetic stimulus (not shown). These ratchet like movements occurred as the eyes moved from one direction to the other. Length: 0:37; size: 8.7 MB.
• Movie 6 - Comparison of OKR between a small zebrafish and larger medaka with large amplitude sinusoidal stimuli (0.125 Hz, ±50°/s). In this extreme example, the smaller animal (left) initially made a few, weak saccades but ultimately failed to reset eye position until the stimulus changed direction (gain = 0.21; 10° lead). The larger medaka made more resets and maintained an eye velocity that approached stimulus velocity (gain = 0.71, 1.0° lag). Length: 0:44; size: 20.5 MB.
• Movie 7 - Monocular optokinetic reflex. A small, young goldfish was presented with a moving visual stimulus to the left eye (blue, 0.125 Hz, ±20°/s) and a stationary stimulus to the right eye (red). The eye viewing the stationary stimulus barely moved (g = 0.08), while the eye viewing the moving stimulus followed the drum fairly well (gain = 0.4), thereby indicating a monocular operation of the visuomotor system. Length: 0:52; size: 7.3 MB.
• Movie 8 - No angular VOR in very small larvae. A small, young zebrafish larvae (3.8 mm; 4 dpf) was rotated sinusoidally at 0.5 Hz, ±30°/s. Typical of all zebrafish, no compensatory eye movements were observed. A motion tracer within the water column suggests the angular acceleration forces the zebrafish larva is experiencing. The inset within the larval video image is the table activity during this stimulus paradigm. The table was filmed separately. Length: 0:28; size: 11 MB.
• Movie 9 - Angular VOR acceleration thresholding in a large medaka. This side-by-side comparison demonstrates the acceleration threshold observed in larval animals. Here, a large larval medaka is sinusoidally rotated (0.5 Hz) at ±30°/s (left) and ±60°/s (right). The eye velocity gain is lower (gain = 0.41, 70° lead) at the lower stimulus amplitude, and eye velocity is higher (gain = 0.80, 45° lead) at the higher stimulus amplitude. The acceleration stimulus not only evoked a VOR but also robust vestibulospinal reflexes as well. The stimulus trace (green) of table velocity has been inverted to facilitate comparison with eye velocity. Length: 0:35; size: 12.2 MB.
• Movie 10 - Angular VOR in response to velocity step stimuli. The same medaka shown in Movie 9 is stimulated using table triangles of position (0.5 Hz, ±10°, ±20°/s). With each turnaround of table motion, eye velocity quickly rises, nearly matching table velocity. However, within a very short period (< 500 ms), eye velocity quickly decays back to 0°/s, demonstrating a short cupular time constant. Length: 0:38; size: 6.5 MB.