Further detection of related genes by RT-PCR showed that the expressions of PSD-95 (Fig. 4E), fragile X-related 1 (FXR1, Fig. 4F), FXR2 (Fig. 4G), GluN2B (Fig. 4I) and GluA2 (Fig. 4J) in the brain tissue of mice in T2DM and Pg groups were significantly decreased (P < 0.05), and Pg + T2DM further decreased the expression of these genes in the brain tissue of mice in the T2DM/Pg group (P < 0.05). This evidence concerns the gene FXR2 and type 2 diabetes mellitus.