Ultrastructural and electrophysiological changes in the olfactory epithelium following exposure to organic solvents

The present study describes some effects on frog olfactory mucosa following acute exposure to styrene and toluene, two organic solvents. The olfactory summed receptor potential (EOG) was recorded in order to monitor the functional effect. The olfactory epithelium was examined with transmission electron microscopy, using both thin section and freeze-fracture technique. The ultrastructural changes in the olfactory epithelium following exposure to the solvents were mainly of two types: (1) an increased secretion from the sustentacular cells, (2) membrane fusion of the cilia, sometimes with a loosening of the ciliary membrane. The tight junctional complex between the receptor and sustentacular cells at the epithelial surface remained intact. The EOG amplitude generally showed some degree of reduction following exposure, with a gradual recovery towards pre-exposure values.