Microanatomical Variation of the Nasal Capsular Cartilage in Newborn Primates

Abstract

The breakdown of nasal capsule cartilage precedes secondary pneumatic expansion of the paranasal sinuses. Recent work indicates the nasal capsule of monkeys undergoes different ontogenetic transformations regionally (i.e., ossification, persistence as cartilage, or resorption). This study assesses nasal capsule morphology at the perinatal age in a taxonomically broad sample of non-human primates. Using traditional histochemical methods, osteopontin immunohistochemistry and tartrateresistant acid phosphatase procedure, the cartilage of the lateral nasal wall (LNC) was studied. At birth, matrix properties differ between portions of the LNC that ultimately form elements of the ethmoid bone and regions of the LNC that have no postnatal (descendant) structure. The extent of cartilage that remains in the paranasal parts of the LNC varies among species. It is fragmented in species with the greatest extent of maxillary and/or frontal pneumatic expansion. Conversely, greater continuity of the LNC is noted in newborns of species that lack maxillary and/or frontal sinuses as adults. Chondroclasts occur adjacent to elements of the ethmoid bone, along the margin of the nasal tectum, and/or along islands of cartilage that bear no signs of ossification. Chondroclasts are prevalent along remnants of the paranasal LNC in tamarin species (Leontopithecus, Saguinus), which have extensive frontal and maxillary bone pneumatization. Taken together, the morphological observations indicate that the localized loss of cartilage might be considered a critical event at the onset of secondary pneumatization, facilitated by rapid recruitment of chondro-/osteoclasts, possibly occurring simultaneously in cartilage and bone. Anat Rec,

Tour of a Labyrinth: Exploring the Vertebrate Nose

“…In an age series of the greater false vampire bat, Megaderma lyra , the pars posterior was shown to become increasingly elaborate while the pars intermedia lags by comparison. As a result, the frontal recess is diminutive compared with the olfactory recess in this species (Smith et al, ).…”

“…Dieulafe considers the mesenchyme deep to the buds as having an “active role in the development of the turbinal” (, p 158). In theory, the most extreme cases of ethmoturbinal complexity may result from repetitive mesenchymal growth centers arising along the inferior margin of the pars posterior, although nasal ontogeny in mammals with the most complex nasal fossae (e.g., bears; some bats—Paulli, 1900c; Smith et al, ) has yet to be thoroughly studied. Conversely, the extreme simplification of the nasal fossa in some mammals, such as humans and especially cetaceans, has been attributed to merging of embryonic structures (de Beer, ; Klima, ).…”

“…Turbinals are regarded as serial homologues (Rossie, ; Macrini, ). Recent observations suggest that turbinals, including smaller projections between the larger scrolls (interturbinals) develop as mesenchymal outgrowths that appear from rostral to caudal in sequence (Smith and Rossie, ; Smith et al, ). However, the cellular (e.g., signaling) basis for turbinal complexity during embryogenesis remains unexplored.…”

“…These turbinals are the primary location for olfactory epithelium, but may also participate in respiratory air‐conditioning in some primates (Smith et al, ; DeLeon and Smith, ) and short‐snouted carnivorans (Van Valkenburgh et al, ). In addition, olfactory epithelium can be found rostrally on the nasal septum as well as lining various recesses and the lateral walls of the nasal cavity (Adams, ; Bhatnagar and Kallen, ; Smith et al, ). In many or most mammals, the nasoturbinal has a tube‐like morphology and appears to function in directing air to the posteriorly positioned olfactory region.…”

“Mucosal maps” of the canine nasal cavity: Micro‐computed tomography and histology

“…To date, mucosae have best been studied using light microscopy of stained sections (Adams, 1972; Bhatnagar & Kallen, 1975; Smith et al, 2007, 2012) or electron microscopy of whole specimens (e.g., Kumar, Kumar, & Singh, 1993; Kumar, Timoney, Southgate, & Sheoran, 2000). Such studies provide the most definitive evidence of functional traits of the mucosa, including characteristics of the epithelium (e.g., olfactory sensory neurons vs. kinocilia) and the underlying supporting tissue, or lamina propria (e.g., olfactory nerves vs. venous sinuses).…”