The miR-124 microRNA precursor is a small non-coding RNA molecule that has been identified in flies (MI0000373), nematode worms (MI0000302), mouse (MI0000150) and human (MI0000443). The mature ~21 nucleotide microRNAs are processed from hairpin precursor sequences by the Dicer enzyme, and in this case originates from the 3' arm. miR-124 has been found to be the most abundant microRNA expressed in neuronal cells. Experiments to alter expression of miR-124 in neural cells did not appear to affect differentiation. However these results are controversial since other reports have described a role for miR-124 during neuronal differentiation.
miR-124 is highly expressed in the central nervous system (CNS), including the cerebellum, plays a role in neurogenesis, and stimulates neuronal differentiation by
antagonizing the transriptional repressor element 1 silencing transcription factor (REST), which maintains embryonic stem cells' self-renewal abilities and pluripotency.