Septal

Mice homozygous for an ETA receptor gene disruption show craniofacial malformations, such as cleft palate, micrognathia, microtia and microglossia. ETA (—/—) mice die shortly after birth due to respiratory failure. Mice with an ET-l-null mutation show the same cranciofacial malformations and, in addition, cardiovascular disorders (e.g. septal defects, abnormal cardial outflow tract, aortic arch and subclavian arteries). 

Tikkanen J, Heinonen OP. 1991. Risk factors for ventricular septal defect in Finland. Public Health 105 99-112. 

Cingulate cortex Septal nuclei Occipital cortex Parietal cortex... 

Berridge, CW (1998) Modulation of forebrain electroencephalographic action and behavioral state by locus coeruleus-noradrenergic system involvement of the medial septal area. Adv. in... 

A possible alternative is the microvillous part of the chemosensory epithelium in the Organ of Rodolfo-Masera (Septal Organ), which is VN-like (Taniguchi etal., 1993). This mixed receptor population requires much further study since it could prove to have intermediate odourant sensitivities (Giannetti et al., 1995). Its distribution and function(s) are still incompletely known however it is sufficiently widespread, from Opossums to Rodents, to warrant an intensive survey (Rodolfo-Masera, 1943 Kratzing, 1978 Giannetti et al., 1992 and 1995). 

The higher vertebrates retained the basic Nervus termitialis, a VN-associated chemoreceptive neurai network (Fig. 2.9) with some cognate functions (Chap. 5 and Murphy, 1998). In mammals, an apparently unique and enigmatic OR cell cluster with a separable MOB input occurs. This minor structure (Fig. 2.10), the Septal Organ (of Masera), is possibly adaptive, has no peripheral connection to the VNO, and its capacity for central modulation of MOS and or AOS input is unknown (Naguro, 1984 Marshall, 1986). 

Fig. 2.4 Displacement of the N-P duct caudally and intra-nasai transfer nasal aperture of the organ (VNd) on the rostral septum in (a) rodents, (b) lagomorphs, and (c) interconnection of VNd i— to N-Pd by sub-septal gutter in rat (from Wysocki and Meredith, 1991 Wohrmann-Repenning, 1981a and b).

Fig. 2.5 Dissection of horse nasal cavity, with septal opening of VN duct atrophy of incisive canal (= absence of N-P duct) (from Lindsay and Burton, 1984).

Fig. 2.10 Nasal chemoreceptive systems (Rodent) — chemosensory and autonomic fibres Masera s organ (= Septal Organ) and NT, and vasomotor (NP and Ethmoidal) in adult hamster (from Meredith, 1983).

Fig. 2.11 (a) Dissection of VNC — Mouse Lemur (Microcebus murinus). Cl-C3 = Para-septal cartilage bars LV = ventral vein NC = arterioles/capillary network SV = dorsal vein and VNw = ventral wall (from Schilling, 1970). Vomeronasal complex in murine Rodents. Comparison of LS with TS in Rat (b) LS (horizontal). VV = vascular sinus arrow = venous diverticulum = VN lumen and NE = neuroepithelium (from Larriva-Sahd, 1994). (c) TS (coronal). G = glands RFE = non-sensory epithelium (from Mendoza, 1993). 

Fig. 2.12 Vomeronasal complex Reptiles, TS Snake, (a) Drawing of Amphibolurus muricatus. skeletal elements in yellow (from Broom, 1895). (b) Generalised diagram of epithelial types L = lateral and M= medial (from Rehorek, 1998). (c) VNC, Primitive mammal junction of vomeronasal duct (VNd), with naso-palatine (Stenson s) duct (N-Pd) in Spiny Anteater (Short-nosed Echidna) brown = skeletal elements — septal and para-septal cartilages (from Broom, 1895).

Fig. 2.19 Central pathways and nuclei, (a) Frog AOS Pl/Pm = lateral and medial pallium EP = post, olfactory eminence and nSm = medial Septal nucleus (from Kratskin, 1995). Reptiles and mammals-—afferent pathways from AOB to amygdala nuclei (Cortical C3 and Medial M), with tertiary connections to other central nuclei in hypothalamus (MPOA, VMH and PMN) (from Johnston, 2000). (b) Snake AOS Second-order projection of accessory fibres nAOT - nucleus of AOT AM = anterior amygdala and nSph = nucleus Sphericus. (c) Mammal AOS Projection sites of vomeronasal fibres in cortex and hypothalamus (from Johnston, 1998).

Fig. 4.4(b) N. terminalisNomeronasal septal innervation in human embryo (45 mm), silver impregnation x 13 (from Pearson, 1941). 

The vasculature is established by the 18th day of gestation in rats, and comes from the arterial supply as the anterior cerebral vessel, eventually entering the basal lamina via septal tributaries of the olfactory artery (Szabo, 1988). Unlike the MOE, the organ s capillaries penetrate in loops into the neuroepithelium. Blood from the vomeronasal complex arrives for collection in the vomeronasal vein, as described earlier [Fig. 2.11(a)]. The establishment of the highly vascular columnar complexes seen in the ophidian organ has not been correlated with functional development (c.f. Wang and Halpem, 1980 Holtzman and Halpem, 1990). 

Fig. 5.7(b) Vascular Swell Bodies (SB) basal septal region in cat with bilateral cavernous tissue ([), enclosure of VN capsule ()) may allow alternation of pressure and modulation of VN lumen contents (see text) (after Negus, 1958). 

Adams D.R. (1992). Fine structure of the vomeronasal and septal olfactory epithelia, and of glandular structures. Micro Res Techrt 23, 86-97. 

Giannetti N., Saucier D. and Astic L. (1992). Organization of the septal organ projection to the main olfactory bulb in adult and newborn rats. J Comp Neurol 323, 288-298. 

Giannetti N., Pellier V., Oestreicher A.B. and Astic L. (1995). Immunocytochemical study of the differentiation process of the Septal Organ of Masera in developing rats. Dev Brain Res 84, 287-293. 

Kemble E.D. and Nagel J.A. (1975). Decreased sniffing behavior in rats following septal lesions. Psychonom Sci 5, 309-310. 

Taniguchi K., Arai T. and Ogawa K. (1993). Fine-structure of the septal olfactory Organ of Masera, and its associated gland in the Golden Hamster. J Vet Med Sci 5, 107-116. 

Excess fluid administration may increase right-ventricular (RV) wall stress, RV ischemia, tricuspid regurgitation, and cause a septal shift that may impair left-ventricular (LV) compliance and filling. Administer with caution in patients with documented severe RV dysfunction or when measured pressures are high... 

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