Description
Cortical development is a complex process involving the generation of neuronal progenitors, which proliferate and migrate to form the stratified layers of the maturing cortex. To identify microRNAs (miRNAs) and genes that may be important during early cortical development, we analyzed the expression profiles of rat neuronal progenitors obtained at embryonic day 11 (E11), E12 and E13 using microarrays. Neuronal progenitors were purified from telencephalic dissociates with a positive-selection strategy using surface labeling tetanus-toxin and cholera-toxin and fluorescence-activated cell sorting. We identified classes of miRNAs and mRNAs that were up-regulated or down-regulated in these neuronal progenitors as cortical development progressed from E11 to E13. We present data that supports a regulatory role for miRNAs during the transition from neuronal progenitors into differentiating cortical neurons.