OLFACTORY NEURONS IN-VITRO SHOW PHENOTYPIC ORIENTATION IN EPITHELIAL SPHERES

PRODUCTION and differentiation of olfactory neurons occur in spherical , multi-neuronal aggregates that form in cultures where dissociated ne wborn rat nasal cells are plated on to CNS glial cells. We show here t hat neuronal cell bodies were primarily located in the peripheral laye rs of the spheres, and almost every neuronal sphere contained one or s everal non-cellular central cavities. The dendrite-like processes of t he olfactory neurons, immunostained for neuron-specific tubulin or the olfactory marker protein, were aligned and directed towards the centr al cavities. Olfactory neurons in the intact animal show a similar rel ationship with the nasal lumen. Non-neuronal cells formed multiple lay ers centrally, bordering the cavities. This degree of phenotypic re-cr eation is unusual in a dissociated monolayer culture system.