Background adaptation in RCS rats.

The stimulus/response (S/R) relations of scotopic b-waves from dark-adapted RCS-p+ rats and those adapted to steady background lights were investigated in animals ages 14 to 50 days. The shapes of the S/R curves were normal at all ages and in all adaptation conditions. However, dark-adapted sensitivity, amplitude, and latency were abnormal in the second postnatal month. As the disease progressed, background lights varied amplitude and decreased sensitivity less than normal. Thus, the effects of the RCS degeneration on b-wave adaptation were different than previously found in the PCD mouse retinal degeneration studied in a similar fashion. A suggestion is made that investigations of b-wave background adaptation may contribute to elucidation of underlying retinal dysfunction in the human retinal degenerations.