The pseudostratified olfactory epithelium consists of three major cell types: Olfactory receptor neurons, glial supporting cells and proliferative basal cells. Supporting cell bodies line the nasal cavity that extends into thin cytoplasmic appendages spanning the whole width of the epithelium. Nucleotides act as extracellular signaling molecules and we have shown that supporting and basal cells of the olfactory epithelium of larval Xenopus laevis express purinergic receptors that can be activated by nucleotides. In contrast to higher vertebrates, olfactory receptor neurons of larval Xenopus laevis do not express purinergic receptors. UTP, ATP and ATPgS activate supporting cells and evoke characteristic wave-like patterns of increases in intracellular calcium concentration. These intracellular calcium waves always start apically and progress towards the basal lamina. Thereby, the calcium signals propagated with a mean velocity of 17.10 ± 1.02 mm/s and cover a distance of about 80–100 mm. A pharmacological characterization showed that metabotropic P2Y₂/P2Y₄-like purinergic receptor subtypes mediate these intraepithelial calcium signals. The calcium wave eventually advances into the basal cell layer containing the olfactory stem/progenitor cells of the olfactory epithelium. Basal cells themselves can be activated by a broader range of nucleotides than supporting cells, including dinucleotides, and seem to express different/additional types of purinergic receptors. Blocking the purinergic receptors of basal cells with suramin led to a reduction of BrdU labeled basal cells, implying a reduction of proliferation rate. Supporting cells may convey information from the apical layers of the olfactory epithelium, e.g. about damaged cells, to the basal cell layer via release of nucleotides.