Nasal Fossa of Mouse and Dwarf Lemurs (Primates, Cheirogaleidae)

Abstract

Dimensions of the external midface in mammals are sometimes related to olfactory abilities (e.g., ''olfactory snouts'' of strepsirrhine primates). This association hinges on the largely unexplored relationship between the protruding midface and internal topography of the nasal fossae. Herein, serially sectioned heads of embryonic to adult cheirogaleid primates (mouse and dwarf lemurs) and a comparative sample were studied. To assess the anteroposterior distribution of olfactory epithelium (OE) within the nasal fossa, the surface area of OE and non-OE was measured in two mouse lemurs (one adult, one infant). Prenatally, ethmoturbinal projections appear in an anteroposterior sequence. Fetal mouse lemurs, tenrecs, voles, and flying lemurs have four ethmoturbinals that project toward the nasal septum. Major distinctions among these mammals include the number of turbinals in recesses and the extent of the olfactory recess. Surface area measurements in the adult mouse lemur reveal that 31% of the entire nasal fossa is lined with OE. The majority is sequestered in a posterior recess (70% OE). Anterior to this space, only 28% of the nasal fossa is lined with OE. Ethmoturbinal I is lined with relatively less OE (35%) compared with more posterior ethmoturbinals (46-57%). Age comparisons support the idea that OE increases less than non-OE between ages. Regionally, results suggest that most growth in surface area occurs in turbinals. But in all ethmoturbinals, surface area of non-OE differs between ages more than that of OE. This study shows that the anterior part of the nasal fossa is mostly nonolfactory in Microcebus murinus. Anat Rec,

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“…Ontogeny is a thematic thread within this special issue that underpins one concept in nasal terminology—the “tripartite nasal capsule.” Initially the nasal capsule has three chondrification centers that go on to form the internal nasal skeleton (Fig. ), as well as unossified external elements (de Beer, ; Moore, ; Maier, ; Smith and Rossie, ; Maier and Ruf, ). All amniotes appear to develop an intermediate chondrification center, the bilateral paranasal cartilages, which form distinctive associations with other chondrification centers on rostral and caudal ends (de Beer, ).…”

Functional promiscuity in a mammalian chemosensory system: extensive expression of vomeronasal receptors in the main olfactory epithelium of mouse lemurs

“…We also tested one female infant and removed tissue from the maxilloturbinals of one adult as a negative control. Maxilloturbinal tissue is non-sensory (no olfactory mucosa) but nasal tissue in close proximity to the vomeronasal organ (Smith and Rossie, 2008). If maxilloturbinal tissue was not contaminated with VNO cells during its removal, we assume that MOE tissue was also not contaminated with VNO cells and potential expression patterns of VRs in MOE tissue shown in this study relate to actual expression in the MOE.…”

The Anatomical Record Uncovers Nature's Extreme Species and How They Have Survived in a Novel Two‐Volume Special Issue

“…Just ask anyone in the field (except Tim, who is as modest as they come and will squint, blush, and squirm in his chair when he reads this essay.) Indeed, our journal has reaped the bounty of his science, publishing work by Tim and his many colleagues stemming back over 20 years (e.g., Smith et al, , , , , , , , , Smith and Bhatnager, ; Smith and Rossie, ; Bhatnagar and Smith, ; Burrows and Smith, ; DeLeon and Smith, ; Roslinski et al, ; Eiting et al, ; Dennis et al, , .) Indeed, Tim has also co‐Guest Edited three of our most successful Special Issues on: special senses of primates (Dominy et al, ; Laitman, ); primate functional morphology and biomechanics (Laitman, ; Laitman and Albertine, ; Organ et al, ); and on the vertebrate nose (Van Valkenburgh et al, ; Laitman, ; Laitman and Albertine, .)…”