Effect of adaptation level on maintained firing and sensitivity in receptive field center of X and Y cells.
Maintained firing rates of X cells and Y cells were compared at 6 adaptation levels (AL) between -2.71 log cd/m2 and 2.28 log cd/m2 (10 mm2 pupil size). X cell maintained firing was higher at all ALs and was statistically different at medium and high ones. Changes in AL had nearly identical effects upon X and Y cell suprathreshold sensitivity to a flashing spot in the center of their receptive fields; the Weber function had a slope of 0.744 for Y cells and 0.743 for X cells. These values are not statistically different.
D000221:Adaptation, Ocular; D000818:Animals; D002415:Cats; D008027:Light; D012160:Retina / Q000166:cytology* / Q000502:physiology; D014794:Visual Fields