The imprinted DLK1-DIO3 and SNURF-SNRPN (PWS) chromosomal domains are characterized by large arrays of box C/D small nucleolar RNA and microRNA genes that display preferential expression in the brain. Here, we provide an overview of their multifaceted roles in brain function and behaviour focusing particularly on the miR-379/miR-410, SNORD115 and SNORD116 gene clusters.