Rod photoresponses in 6-week and 4-month-old human infants.
Rod-only electroretinograms (ERGs) were recorded from 6-week and 4-month-old normal human infants. The leading edge of the rod a-wave was fitted with a model of the activation phase of phototransduction to provide estimates of S (a sensitivity parameter) and RmP3 (the maximum saturated photoreceptor response) at each of the investigated ages. Both S and RmP3 increased over the first postnatal months but followed different developmental time courses with S approaching adult-like values sooner than RmP3. The changes in S and RmP3 can be interpreted within the context of a model incorporating the combined effects of increased levels of rhodopsin and the changing structure of the rod outer segment during development.
Nusinowitz
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Jules Stein Eye Institute, Los Angeles, CA 90024, USA. nusinowitz@jsei.ucla.edu
Birch
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Birch
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D000375:Aging; D003623:Dark Adaptation; D004596:Electroretinography; D006801:Humans; D007223:Infant; D008027:Light; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D013997:Time Factors