Electroretinograms (ERGs) and Visually-Evoked Responses (VERs) in the California Sea Lion (Zalophus californianus).
NAVAL ELECTRONICS LAB CENTER SAN DIEGO CALIF
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Biopotentials generated by visual stimulation have been successfully recorded from sea mammals in a project undertaken by NELC in cooperation with Naval Undersea Center. Reliable and highly replicable electroretinograms ERGs have been obtained from California sea lions with noninvasive techniques and amplifying circuits designed and developed at NELC. Visually-evoked responses VERs to stimulation with flashes of light have been successfully recorded. The feasibility and utility of these techniques for the electrophysiological study of sea mammals have been proved. Preliminary results indicate that the ERG of sea lions is most responsive to stimulation with wavelengths from the blue, green, and orange portions of the humans visible spectrum. Changes in the ERG of the sea lion which occur with changes in intensity of the stimulus, changes in adaptation level of the subject, and changes in the level of ambient illumination parallel changes found in humans. The VER obtained from the sea lion is not simply a remote recording of the ERG. Preliminary work with colors and patterns suggests that the VER recorded at the scalp is differentially sensitive to variations in several factors. Modiified author abstract
- Anatomy and Physiology