When newborn rat olfactory mucosal cells were dissaggregated and plated as single cells onto astrocyte bed layers, abundant generation and maturation of olfactory receptor neurons was observed. Both immature and mature neurons were found in large multicellular spheres after 15 days in culture,. In sections of the spheres, almost all had central cavities, and the neurons were located almost exclusively in the external 1-2 cell layers. We show here that the spheres also contain olfactory sustentacular cells, neuronal supporting cells similar to retinal Muller cells. Sustentacular cell presence was shown by immunostaining cultured cells with a monoclonal antibody, SUS, which has previously been shown to recognize only sustentacular cells and a subset of the Bowman's gland cells. Fig. 1 shows that cultured cellular spheres contained numerous SUSpositive, roughly bipolar cells. These cells appear to be located internally rather than on the external surface. Sustentacular cell presence was further confirmed by immunostaining with a monoclonal antibody, 1F4, developed in this laboratory.
