Title: DEGENERATION AND REGENERATION OF THE OLFACTORY EPITHELIUM AFTER OLFACTORY BULB ABLATION IN THE PIG: A MORPHOLOGICAL AND ELECTROPHYSIOLOGICAL STUDY
Abstract: The olfactory bulbs were removed surgically from Large White male and female pigs, 10–12 weeks of age. At intervals of 3, 7, 14, 42 and 84 d after bulbectomy, the pigs were sacrificed and portions of olfactory mucosa were removed from the ethmoturbinate and septum regions of the nasal cavity; olfactory mucosa was also removed from unoperated pigs. A piece of each tissue sample was processed for light microscopy. The remaining tissue was placed in Ringer‐Locke solution, saturated with O 2 /CO 2 at room temperture, and the electrical activity of the olfactory epithelium was investigated in vitro by passing a stimulus of butyl acetate vapour over the epithelium. Slow negative potential changes (electro‐olfactogram, e.o.g.) induced by butyl acetate were recorded. During the first two weeks after bulbectomy there was a rapid decrease in the height of the olfactory epithelium associated with the disappearance of the e.o.g. response. However by 42 and 84 d after bulbectomy, partial recovery of the height and some electrical activity of the olfactory mucosa had occurred. In some pigs, the insertion of a stainless steel lining over the cribriform plate to prevent any association of regenerating axons with forebrain tissue had no effect on the regenerative characteristics studied.