Figure 4.

ERG waveforms from a 6-month-old Cdh23^v-2J +/+ Pcdh15^av-3J double heterozygous mutant (A and B) and from an aged-matched +/Pcdh15^av-3J single heterozygote control (C and D). The amplitude and implicit time of both the rod- and cone-mediated ERG are normal. Rod-dominated responses were recorded to short-wavelength (λ_max = 470 nm; Wratten 47A filter) flashes of light over a 4.0 log unit range of intensities (0.3 log unit steps) up to the maximum allowable by the photic stimulator. Cone-dominated responses were obtained with white flashes (0.3 steps) on the rod-saturating background after 10 min of exposure to the background light to allow complete light adaptation. Signals were sample every 0.8 ms over a response window of 200 ms. For each stimulus condition, responses were computer-averaged with up to 50 records averaged for the weakest signals.