FGF2 promotes neuronal differentiation in explant cultures of adult and embryonic mouse olfactory epithelium

Neurogenesis in the adult olfactory epithelium is highly regulated in vivo. Little is known of the molecular signals which control this process, although contact with the olfactory bulb or with astrocytes has been implicated. Explants of mouse olfactory epithelium were grown in the presence or absence of several peptide growth factors. Basic fibroblast growth factor (FGF2) stimulated differentiation of sensory neurons in adult and embryonic olfactory epithelium. Other growth factors tested were ineffective. FGF2‐stimulated neurons were born in vitro and expressed neurofilament, neural cell adhesion molecule, and β‐tubulin. The cells also expressed olfactory marker protein, a marker for mature olfactory sensory neurons in vivo. These bipolar neurons did not express glial fibrillary acidic protein or low‐affinity nerve growth factor receptor. These results indicate that neither astrocytes nor olfactory bulb are necessary for differentiation of olfactory sensory neurons in vitro. © 1996 Wiley‐Liss, Inc.