Rate-dependent inhibition of pattern-evoked retinal responses in the pigeon.

Robust signals of corneal derivation were recorded from the pigeon (a foveate model) in response to alternating gratings. When a rotating windmill-like display was superimposed upon the visual field, there was rate-dependent inhibition of the response to the gratings. Inhibition diminished linearly with grating contrasts (11-40%) and nonlinearly above 50%. The responses to diffuse-light stimuli showed no rate dependence but a predictable, steady reduction at all windmill rates. Rate-dependent inhibition has been reported only in the inner-retinal cells of other animals where intracellular recordings have been made.