We report that the amplitude of VEPs recorded in response to stimulation of the occluded eye in IGF-1+MD rats (VEP amplitude 0.35 ± 0.05) was significantly lower (t-test; P = 0.047, n = 5) with respect to that obtained in saline-treated animals (VEP amplitude = 0.68 ± 0.12) after MD (Figure 1(a), Insert). This evidence concerns the gene IGF1 and Menkes disease.