Figure 2. Effect of a single systemic dose of valproic acid (VPA) on retinal neurotrophic factor gene expression in the Pde6b^rd1/rd1 mouse strain. A single dose of VPA (350 mg/kg) was administered by intraperitoneal injection, and neural retinas were collected 18 h after the injection at age P15. Gene expression relative to PBS-injected littermates was measured using real-time PCR for the gene of interest (Gdnf, Bdnf, Cntf, Fgf2) and was normalized to Actb expression (mean±standard deviation; n = 3/group, t test, *p<0.08, **p<0.005, ***p<0.001, relative to PBS).