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Abstract
The teleost retina exhibits retinomotor activity in response to changing light intensity. We have shown that hypoxia interfers with normal retinomotor activity in the dark-adapted rainbow trout, so that the retina assumes an essentially light-adapted configuration with the cones contracted, the rods extended toward the pigmented epithelium, and epithelial pigment expanded. These cell movements appear to be correlated with the marked increase in ERG c-wave amplitude which we consistently observe during hypoxia in trout. Since the a-wave is not immediately affected by hypoxia, this increase in c-wave amplitude may be related to the movement of the rods toward the pigmented epithelium, which would cause a greater than normal change in extracellular [K+] near the apical membrane in response to a light stimulus, leading to an increase in c-wave amplitude.