Figure 5

Histological sections of the capybara VNO showing its main components. (A,B) Transverse sections of the nasal septum exposing the nature of the vomeronasal capsule. (A) corresponds to the central level, where the cartilage is replaced ventrally by the dorsal projection of the maxillary bone (white arrow). (B) corresponds to a caudal level where the bone capsule fully encapsulates both VNOs. (C) Cross section of the VNO showing the main components in the parenchyma: Vomeronasal duct (VND) lined medially by sensory epithelium (SE) and laterally by respiratory epithelium (RE), vomeronasal glands (VNG), vomeronasal nerves (VNN), vomeronasal cartilage (VNC) and veins (Vv). Both epithelia, RE and SE, insets are magnified in figures (E) and (G) respectively. In the SE, the three cellular strata can be seen: SC, sustentacular cells; NC, neuroreceptor cells; and BC, basal cells. The microvilli (asterisk) contact with the lumen of the vomeronasal duct. (D) Enlargement of the dorsolateral area of the VNO showing the serous and AB + nature of the vomeronasal glands. (F) Study of the VNO irrigation by confocal microscopy showing veins along the lateral part of parenchyma. Elastin autofluorescence of a transversal section. Nuclear counterstaining with TO-PRO-3. Aa: Artery; Mx: Maxillary bone; MR: Respiratory mucosa of the nasal cavity: Vm: Vomer bone; l: lateral; m: medial. Stainings: (A) Hematoxylin–Eosin; (B,C,E,G) Gallego’s trichrome; (D) Alcian blue. Scale bars: (A–D) 500 µm; (E–G) 100 µm.