Association between 5hmC and gene transcription. Local (A) 5hmC and (B) 5mC enrichment at promoter regions of genes associated with neurodevelopment. (C) Transcriptional level of nine genes in mouse brain. (D) The significant difference P<0.05 between 5mC or 5hmC enrichment and mRNA level are listed. All data are presented as the mean ± standard deviation of the mean of individual experiments (control for five; POCD for six duplications). *P<0.05 vs. control group. 5hmC, 5′hydroxymethylcytosine; 5mC, 5′methylcytosine; ACSS2, acyl-CoA synthetase short chain family member 2; BDNF, brain derived neurotrophic factor; CCL2, C-C motif chemokine ligand 2; FAS, fas cell surface death receptor; GCR, glucocorticoid receptor; GDNF, glial cell-derived neurotrophic factor; GluR2, glutamate receptor 2 precursor; HMGB1, high mobility group protein B1; MMP9, matrixmetallopeptidase-9.