Electrical Response and Growth of Olfactory Cilia of the Olfactory Epithelium of the Newt in Water and on Land

A correlation between the length of the olfactory cilia and the electrical activity of the olfactory epithelium was studied in newts living in water and on land. The olfactory cilia grew when newts were transferred onto land. The cilia in the olfactory bud became longest in 108 hours after the transfer and then became shorter, while those in the interstitium only gradually elongated. Slow potentials were evoked in the epithelium by the application of odorous fluids but not by odorous vapors for 20 hours after the transfer. Thereafter, the slow potential began to appear in response to odorous vapors and reached maximal magnitude between 60 and 70 hours after the transfer, while it was not evoked by odorous fluids in this period. In the later stage, the slow potential to odorous vapors decreased in magnitude and disappeared 120 hours after the transfer, while it began to reappear in response to odorous fluids. When these changes in the slow potential were compared with those in the cilium, a discrepancy was found between the period of maximal potential magnitude and that of maximal cilium length.