In vitro neurogenesis by progenitor cells isolated from the adult human hippocampus

Neurogenesis persists in the adult mammalian hippocampus. To identify and i solate neuronal progenitor cells of the adult human hippocampus, we transfe cted ventricular zone-free dissociates of surgically-excised dentate gyrus with DNA encoding humanized green fluorescent protein (hGFP), placed under the control of either the nestin enhancer (E/nestin) or the T alpha 1 tubul in promoter (P/T alpha 1), two regulatory regions that direct transcription in neural progenitor cells. The resultant P/T alpha 1:hGFP(+) and E/nestin :enhanced (E)GFP(+) cells expressed beta III-tubulin or microtubule-associa ted protein-2; many incorporated bromodeoxyuridine, indicating their genesi s in vitro. Using fluorescence-activated cell sorting, the E/nestin:EGFP(+) and P/T alpha 1:hGFP(+) cells were isolated to near purity, and matured an tigenically and physiologically as neurons. Thus, the adult human hippocamp us contains mitotically competent neuronal progenitors that can be selectiv ely extracted. The isolation of these cells may provide a cellular substrat e for re-populating the damaged or degenerated adult hippocampus.