Transcriptional regulation of neuronal differentiation: the epigenetic layer of complexity

The transcriptional programs of neural progenitor cells change dynamically during neurogenesis, a process regulated by both intrinsic and extrinsic factors. Although many of the transcription factors required for neuronal differentiation have long been identified, we are only at the brink of understanding how epigenetic mechanisms influence transcriptional activity and the accessibility of transcription factors to bind consensus cis-elements. Herein, we delineate the chief epigenetic modifications and the machinery responsible for these alterations. Further, we review the epigenetic modifications presently known to participate in the maintenance of the neural progenitor cell state and in the regulation of neuronal differentiation.