The contribution of cone responses to rat electroretinograms.
The contribution of rods and cones to the scotopic electroretinogram (ERG) of small animals is unclear, with a recent report suggesting that the mouse has no cone a-wave. The present study considered the contribution of cones to the ERG of the rat. Dark-adapted Long Evans rats (n = 4) had ERG signals collected following a single flash, which stimulated rods and cones (mixed response), or a twin-fash paradigm (short interstimulus interval, 1 s), which isolated cone responses. Rod signals were derived by digital subtraction of the cone signal from the mixed rod/cone ERG. The rat a-wave was found to be dominated by rod responses but cone responses contributed substantially (45%) to post-receptoral waveforms (b-wave) at higher light levels.
Nixon
P J
PJ
Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia.
Bui
B V
BV
Armitage
J A
JA
Vingrys
A J
AJ
D000818:Animals; D003623:Dark Adaptation; D004596:Electroretinography; D008297:Male; D010775:Photic Stimulation; D051381:Rats; D020318:Rats, Long-Evans; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology