Epigenetic Brainscape Epigenetic modifications and their potential changes during development are of high interest, but few studies have characterized such differences. Lister et al. ( 1237905 , published online 4 July; see the Perspective by Gabel and Greenberg ) report whole-genome base-resolution analysis of DNA cytosine modifications and transcriptome analysis in the frontal cortex of human and mouse brains at multiple developmental stages. The high-resolution mapping of DNA cytosine methylation (5mC) and one of its oxidation derivatives (5hmC) at key developmental stages provides a comprehensive resource covering the temporal dynamics of these epigenetic modifications in neurons compared to glia. The data suggest that methylation marks are dynamic during brain development in both humans and mice.