Methylation of NMDA receptor NR2B gene as a function of age in the mouse brain.

We have previously reported that there is an up-regulation of the NR2B gene expression in the adult cortex and cultured fetal cortical neurons of mice following chronic ethanol treatment due to demethylation of cytosine residues in the NR2B gene CpG island. In the present study, we investigated the methylation pattern of the NR2B CpG island as a function of the mouse age by digesting the cortex genomic DNA with HpaII enzyme, amplifying the interested regions by performing PCR and detecting the methylated regions by Southern hybridization so as to determine whether age affects the methylation process. We observed demethylation of various regions of NR2B gene (5227-5567), (5647-6003), (6091-6445), (6424-7024) of adult mouse cortex. Our results indicate that methylation of NR2B gene in the mouse brain is age-dependent phenomenon.