Prospective isolation of late development multipotent precursors whose migration is promoted by EGFR

A simple procedure to isolate neural stem cells would greatly facilitate direct studies of their properties. Here, we exploited the increase in EGF receptor (EGFR) levels, that occurs in late development stem cells or in younger precursors upon exposure to FGF-2, to isolate cells expressing high levels of EGFR (EGFRhigh) from the developing and the adult brain. Independently of age and region of isolation, EGFRhigh cells were highly enriched in multipotent precursors and displayed similar antigenic characteristics, with the exception of GFAP and Lex/SSEA-1 that were mainly expressed in adult EGFRhigh cells. EGFR levels did not correlate with neurogenic potential, indicating that the increase in EGFR expression does not directly affect differentiation. Instead, in the brain, many EGFRhigh precursors showed tangential orientation and, whether isolated from the cortex or striatum, EGFRhigh precursors displayed characteristics of cells originating from the ventral GZ such as expression Dlx and Mash-1 and the ability to generate GABAergic neurons and oligodendrocytes. Moreover, migration of EGFRhigh cells on telencephalic slices required EGFR activity. Thus, the developmentally regulated increase in EGFR levels may affect tangential migration of multipotent precursors. In addition, it can be used as a marker to effectively isolate telencephalic multipotent precursors from embryonic and adult tissue.