While our study is the first to show that miR-34a inhibits neuronal differentiation of human neurons, previous studies in animal models have described the effects of miR-34a on neural stem cells59, and neuronal progenitors60, as well as on dendritic outgrowth and synaptic structure of neurons in culture26. Taken together with our results these studies suggest that although miR-34a inhibits neuronal maturation and synaptogenesis after the onset of neurogenesis, it is also capable of pushing neural stem cells to exit the cell cycle and become neuronal progenitors. Similar cell- and developmental stage- specific roles of miRNAs have before been described for other brain enriched miRNAs such as in the case of miR-13461.
