Figure 3. Effect of diabetes on mRNA expression of AMPA receptor subunits. qRT-PCR analysis was performed on cDNA isolated from control and STZ-induced diabetic rat retinas after 4 and 12 weeks. Expression of each gene was normalized to acidic ribosomal phosphoprotein (P0) for each rat (A), and then scaled to the 4-week control rats for each gene (B; mean ± SEM). The 12-week diabetic rats had significantly lower GRIA1 mRNA than the 4-week diabetic rats (#; p<0.05). The 12-week diabetic rats also had significantly reduced mRNA levels of GRIA4 compared to the age-matched control rats (**, p<0.01). Diabetes did not affect the mRNA levels of GRIA2 and GRIA3 flip at 4 or 12 weeks.