Mechanisms of rod-cone interaction: evidence from congenital stationary nightblindness.
The dark-adapted rod system can elevate cone-mediated thresholds for flicker detection as well as thresholds for the detection of hue. We examined these two types of rod-cone interactions in two individuals with congenital stationary nightblindness (CSNB), a retinal disorder in which rod outer segment function is intact, but in which a defect occurs in the transmission of rod signals within the retina. The two types of rod-cone interaction were differentially affected by the retinal pathology; the rod-cone flicker interaction was normal, but the rod-cone hue interaction was absent. These results provide evidence that, despite similarities in the adaptational properties of these two types of rod-cone interaction, they are mediated by different visual mechanisms.
Alexander
K R
KR
Department of Ophthalmology, University of Illinois College of Medicine, Chicago 60612.
Fishman
G A
GA
Derlacki
D J
DJ
D000293:Adolescent; D000328:Adult; D002450:Cell Communication; D003118:Color Perception / Q000502:physiology; D003623:Dark Adaptation; D004596:Electroretinography; D005425:Flicker Fusion / Q000502:physiology; D006801:Humans; D008297:Male; D009755:Night Blindness / Q000151:congenital / Q000503:physiopathology*; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000503:physiopathology*; D012684:Sensory Thresholds / Q000502:physiology