Ultrastructure (SEM, TEM) of the olfactory epithelium in the wels, Siluris glanis L. (Siluridae, Pisces).
The number of lamellae in a single olfactory rosette of the Silurus increases with age. In one-year-old specimens there are about 50 lamellae, while in the three-year-old ones their number rises to 109. The surface area of an average lamella increases from 2.5 mm2 to 8 mm2, respectively. Four continuous zones have been distinguished in the olfactory epithelium that covers the lamella: olfactory sensory, ciliary, glandular and marginal. These zones differ with respect to their cellular composition. The olfactory zone occupies 25...30% of the total surface of the epithelium. Receptor cells occur exclusively in this zone. Two types of olfactory receptor cells have been distinguished, flagellar and microvillous. Special attention is given to a third type of receptor cell (perhaps nonolfactory) the so called compound cilium receptor. Striated rootlets do not occur near the basal bodies in the flagellar olfactory receptor cells but they are found in the compound cilium ones. It is believed that the compound cilium receptor cell is sensitive to water flow between the lamellae. The formation of the sensory terminals on the olfactory receptor cells is totally completed in Silurus not earlier than between the first and second year of age. Both, sensory flagellum and compound cilium type of terminals appear earlier than the sensory microvilli. It is believed that the described types of the receptor cells are quite independent ones.
D000375:Aging; D000818:Animals; D002923:Cilia / Q000648:ultrastructure; D004848:Epithelium / Q000648:ultrastructure; D005399:Fishes / Q000033:anatomy & histology*; D005407:Flagella / Q000648:ultrastructure; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008871:Microvilli / Q000648:ultrastructure; D009831:Olfactory Mucosa / Q000648:ultrastructure*; D011984:Sensory Receptor Cells / Q000648:ultrastructure