The electroretinogram (ERG) and single-unit ganglion cell activity were recorded from the eyecup of the skate (Raja erinacea and R. oscellata), and the adaptation properties of both types of response compared with in situ rhodopsin measurements obtained by fundus reflectometry. Under all conditions tested, the b-wave of the ERG and the ganglion cell discharge showed identical adaptation properties. For example, after flash adaptation that bleached 80% of the rhodopsin, neither ganglion cell nor b-wave activity could be elicited for 10–15 min. Following this unresponsive period, thresholds fell rapidly; by 20 min after the flash, sensitivity was within 3 log units of the dark-adapted level. Further recovery of threshold was slow, requiring an additional 70–90 min to reach absolute threshold. Measurements of rhodopsin levels showed a close correlation with the slow recovery of threshold that occurred between 20 and 120 min of dark adaptation; there is a linear relation between rhodopsin concentration and log threshold. Other experiments dealt with the initial unresponsive period induced by light adaptation. The duration of this unresponsive period depended on the brightness of the adapting field; with bright backgrounds, suppression of retinal activity lasted 20–25 min, but sensitivity subsequently returned and thresholds fell to a steady-state value. At all background levels tested, increment thresholds were linearly related to background luminance.
Article|
October 01 1970
Visual Adaptation in the Retina of the Skate
John E. Dowling,
John E. Dowling
From the Marine Biological Laboratory, Woods Hole, Massachusetts 02543, the Wilmer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, and the Department of Ophthalmology, New York University School of Medicine, New York 10016
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Harris Ripps
Harris Ripps
From the Marine Biological Laboratory, Woods Hole, Massachusetts 02543, the Wilmer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, and the Department of Ophthalmology, New York University School of Medicine, New York 10016
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John E. Dowling
From the Marine Biological Laboratory, Woods Hole, Massachusetts 02543, the Wilmer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, and the Department of Ophthalmology, New York University School of Medicine, New York 10016
Harris Ripps
From the Marine Biological Laboratory, Woods Hole, Massachusetts 02543, the Wilmer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, and the Department of Ophthalmology, New York University School of Medicine, New York 10016
Received:
April 08 1970
Online Issn: 1540-7748
Print Issn: 0022-1295
Copyright © 1970 by The Rockefeller University Press
1970
J Gen Physiol (1970) 56 (4): 491–520.
Article history
Received:
April 08 1970
Citation
John E. Dowling, Harris Ripps; Visual Adaptation in the Retina of the Skate . J Gen Physiol 1 October 1970; 56 (4): 491–520. doi: https://doi.org/10.1085/jgp.56.4.491
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