Figure 1. Effect of a single systemic dose of valproic acid (VPA) on neurotrophic factor gene expression and rod-specific gene expression in the immature retina of wild-type mice. A: Expression of the Gdnf, Bdnf, and Cntf genes in the neural retinas of wild-type mice (C57BL/6) was examined at two postnatal ages, P12 (n = 2/group) and P15 (n = 3/group), 18 h after one systemic VPA dose. Littermates at each age received a high dose (415 mg/kg), low dose (250 mg/kg), or PBS. The graph shows the average of these experiments (mean±standard deviation [SD]). Gene expression was normalized to endogenous Actb expression and is plotted relative to control PBS-injected littermates (t test, * p<0.01, ** p<0.001, relative to PBS). B: Retinal Nrl gene expression at two postnatal ages, P12 (n = 2/group) and P15 (n = 3/group), 18 h after a single systemic injection (IP) of VPA. Littermates within each age received a high dose (VPA 415 mg/kg), low dose (VPA 250 mg/kg), or PBS only (control). The graph shows the average of the two experiments (mean±SD; t test, *p<0.05 relative to PBS). C: Rod-specific Mef2c gene expression at age P15, 18 h after treatment with a high dose (VPA 415 mg/kg), low dose (VPA 250 mg/kg), or control (PBS) (t test, *p<0.05 relative to PBS, n = 3/group). D: Rhodopsin gene (Rho) expression in the P12 neural retina, 18 h after injection (IP) with a high or low dose of VPA compared to PBS only (mean±SD; n = 2/group).