Fig. 2.

Tracking changes in retinal function and visual acuity. (A) Phototransduction (a-wave) activity of moderately hypoglycemic Gcgr^−/− mice (red symbols) and euglycemic Gcgr^+/− mice (open circles; n = 6–8) as a function of age. Euthanization of older Gcgr^−/− mice for retinal histology limited sample size at 9, 10, 11, 12, and 13 months to 13, 12, 10, 7, and 4 mice, respectively. The large spread of data at 13 months results from small sample size (n = 4) and lack of ERG from one mouse. (B) Age-related changes in postphototransduction (b-wave) response (see Methods) of the same group of Gcgr^−/− and Gcgr^+/− mice plus Gcgr^+/+ mice (open squares; n = 4–6). Red line segments are least-squares fits. (C) Visual acuity of moderately hypoglycemic Gcgr^−/− mice (red symbols) and euglycemic littermate Gcgr^+/− mice (open circles; n = 3–8). Euthanization for histology limited the data at 11, 12, and 13 months to 9, 7, and 5 mice, respectively. Red curve is a polynominal fit. Median illumination at the surface of the cornea was 70 cdm⁻². Bars are SEM.