Spatial pattern of sensory cell terminals in the olfactory sac of the tiger salamander. I. A scanning electron microscope study.

The olfactory sac of adult tiger salamanders (Ambystoma tigrinum) was assessed by scanning electron microscopy and the hitherto unknown variety of the olfactory sac cells has been documented. Regional differences in respect to the composition of the apical epithelial surface border in the olfactory sac have been recorded. Transitions between the olfactory epithelium proper and epithelia with different surface structures have been described. It has been shown that both the roof and the floor of the olfactory sac are mainly covered by sensory epithelium with a surface of uniform appearance. However, the sensory area of the floor is interspaced with non-olfactory epithelial bands. Variations were also noted in regard to secretory cells, cells with conical profiles, microplicae arrangements and populations of microvilli and kinocilia. These differences have been discussed in relation to electrophysiological data which suggest a regional patterning in the response to odours.