A cell present in the developing central nervous system. It functions as both a precursor cell and as a scaffold to support neuronal migration. Some have a multipotent ability, as they can differentiate into neurons and radial glial cells by asymmetric divisions during the period of embryonic neurogenesis. They occur mainly in the ventricular layer of the tectum and decrease in number as the brain matures. [ http://purl.obolibrary.org/obo/CL_0000681 XAO:curators ]