An anterior part of the cerebral cortex of C57BL/6J mice submitted to a 6-h SD was sampled, and DNA was extracted using a DNeasy Blood & Tissue Kit (Qiagen). The remaining cerebral cortex was used for RNA extraction to perform qPCR validations (see above). Six pools of DNA (that is, three SD and three control) each including the DNA of three SD or three control mice (total nine mice per condition) were fragmented using a bioruptor (Diagenode, Denville, NJ, USA) and used for both methylation (5mC) and hydroxymethylation (5hmC) enrichments. 5 mC enrichment was performed as previously described.29 (link) 5hmC enrichment was performed using the Hydroxymethyl collector kit (ActiveMotif, Carlsbad, CA, USA). The DNA input and bound fractions were purified, amplified and labeled using Whole Genome Amplification (Sigma-Aldrich) and CGH Enzymatic Labeling (Agilent Technologies) kits.