Figure 4.
Flash response families of dark-adapted control cones (A) and GCAPs−/− cones (B) from transretinal recordings. Cone responses were evoked by a series of 500 nm test flashes (10 ms in duration) with intensities (photons μm−2) 36, 1.2 × 102, 3.9 × 102, 1.1 × 103, and 3.6 × 103. The largest response in each case was triggered by unattenuated white flash. C, Fractional single-photon responses of control (black) and GCAPs−/− (gray) cones. Error bars show SEM. The cone collecting area was estimated to be 0.12 μm2 (for details, see Eq. 6 and Materials and Methods). D, Intensity–response relations of cone transretinal responses to estimate sensitivity in control (filled circles) and GCAPs−/− (open circles) retinas. The solid curves represent the corresponding intensity–response functions (Eq. 1) with Io of 2180 and 918 photons μm−2, respectively. Error bars show SEM.