Replacement of receptor neurones after section of the vomeronasal nerves in the adult mouse.

Eight days after vomeronasal nerve section or removal of the accessory olfactory bulb, the majority of receptor cells of the vomeronasal neuroepithelium degenerate and disappear, leaving a regular framework consisting of supporting cells and their radial processes. The cell clusters at the boundaries of the epithelial sheet (which have been shown to be actively dividing in the normal, unoperated adult mouse) are also spared. The epithelium is subsequently repopulated by receptor cells appearing first in the basal part of the receptor cell layer and later occupying the full width of the receptor layer. These cells are anatomically fully differentiated receptor cells with normal sensory dendrites. Their axons form conspicuous intraepithelial neuromatous masses. Administration of [3H]thymidine on days 10-20 postoperatively labels some clusters of supporting cells and virtually all of the receptor cells, indicating that the repopulation of the epithelium is due to new formation of receptor cells.