Fine structure of the olfactory epithelium in some primates
Loo, S.K.
Journal of Anatomy 123(Pt 1): 135-145
1977
ISSN/ISBN: 0021-8782 PMID: 838619 Document Number: 122316
The olfactory epithelium of 4 spp. of primates, the tree shrew (Tupaia glis), slow loris (Nycticebus coucang), macaque (Macaca fascicularis) and gibbon (Hylobates agilis) was investigated by EM, to see whether overall reduction in the size of the olfactory apparatus in the higher primates would be accompanied by any changes in the fine structure of the olfactory epithelium. The olfactory epithelium was very similar in all the species studied and was comparable to that in ordinary mammals. It was a pseudostratified columnar epithelium consisting of receptor cells, supporting cells and basal cells. Receptor cells were always ciliated except in the tree shrew, where some non-ciliated receptors bearing microvilli were seen. Of the 3 cell types, supporting cells were the only ones which differed between the 4 spp. There was progressive increase in numbers and length of microvilli from tree shrew to slow loris to macaque to gibbon. This may imply a more discriminatory surface in the higher primates in view of the fact that microvilli of supporting cells form a close network over the olfactory knobs and their cilia, and could affect olfactory sensitivity.