Abstract: Objective To study the effects of 5-Aza-2′-deoxycytidine (5-Aza-CdR) on learning and memory capacity of mice by step-down test and tyrosine phosphorylation of NR2B 1472 site (p-Y1472 NR2B) in hippocampus. Methods Mice were randomly divided into control group (control) and 5-Aza-CdR treatment group (5-Aza-CdR). In the test, 5-Aza-CdR (10 μmol/L) was administered to treatment group mice via intracerebroventricular injection. The ability of learning and memory in mice was evaluated by step-down test. The mRNA level of NR2B in hippocampal tissues of mice was measured by real-time PCR. NR2B and p-Y1472 NR2B in hippocampal tissues of mice were measured by Western blot and immunofluorescence. Results In the 5-Aza-CdR treatment group, the latency period was increased, the error records were decreased, the behavioral memory was significantly improved in step-down test(P＜0.05). While the expression of NR2B mRNA and protein in the hippocampus of mice was not significantly changed, the phosphorylation of p-Y1472 NR2B was increased(P＜0.05), and CDK5 activity was decreased(P＜0.05). There was no difference in NR2B fluorescence intensity between CA1 region and CA3 region, while p-Y1472 NR2B in CA1 region was significantly increased (P＜0.05). Conclusions The effects of 5-Aza-CdR on behavioral memory ability may be related to the p-Y1472 NR2B in the hippocampus of mice.

Key words: 5-Aza-CdR, NR2B, p-Y1472 NR2B, learning and memory