NCAM and Thy-1 in special sense organs of the developing mouse

Abstract

The distribution of the neural cell adhesion molecule (NCAM) and Thy-1 in the olfactory mucosa and olfactory bulb, the eye and the inner ear was examined with immunocytochemistry in mouse embryos from embryonic day 12 (E 12) to embryonic day 19 (E 19). In general, neurons are completely outlined with NCAM, whereas Thy-1 outlines only dendrites and axons. A variable cytoplasmic staining for Thy-1 is present in the perikarya. Neurons directly associated with special sense organs express NCAM and Thy-1 already from the earliest stage and throughout the period investigated, apart from the olfactory neurons in which Thy-1 disappears at E 19. The mitral cells in the olfactory bulb show Thy-1 but no NCAM reactivity. In the eye, lens fibers express Thy-1 and the pigmented layer expresses NCAM; neither of the two molecules can be detected at E 19. In the inner ear, hair cells express NCAM at E 19. Based on the distribution during the developmental period studied and on the cellular localisation of reaction products, it is suggested that the NCAM adhesion function could be of a more general nature by keeping appropriate cell membranes in close contact and thereby allowing more specific molecular interactions to take place. Thy-1, which is located on dendrites and axons, could be such a specific factor and function as recognition molecule in the developing nervous system.

Maturational gradients in the retina of the ferret

“…Rather, the inner plexiform layer may form only after a critical number of dendritic arbors has differentiated at any particular retinal locus, a process that is dependent on the steady addition of newborn ganglion cells after the initial wave of neurogenesis has spread across the retina (Walsh and Polley, 1985;Sengelaub et al, 1986;Harman and Beazley, 1989;Allodi et al, 1992;Harman et al, 1992;Reese and Colello, 1992;Reese et al, 199413). The delayed maturation around the optic nerve head may relate to the thickening of retinal nerve fiber layer that is present in these very central regions, where the neuroepithelium is correspondingly thinner (see, e.g., Terkelsen et al, 1989;FitzGibbon and Reese, 1992, 19961, although exactly how these processes relate is unclear. Cells of uncertain destiny in this region of the embryonic retina express the Pax2 protein (Nornes et al, 1990;Piischel et al, 1992;Hitchcock et al, 19951, which is associated otherwise with compartmental boundaries in the CNS, and the delayed maturation here may relate to such cells.…”

Glomerular formation in the developing rat olfactory bulb

“…During early olfactory pathway formation in the rat, CSPGs have been localized to developing telencephalon (presumptive olfactory bulb), and it has been proposed that these molecules act to prevent axons from growing more deeply into the bulb (Treloar et al, 1996). Finally, many cell surface molecules have been localized to the developing olfactory system, including O-CAM (Yoshihara et al, 1997), N-CAM (Miragall et al, 1989;Terkelsen et al, 1989;Miragall and Dermietzel, 1992;Aoki et al, 1995), PSA-N-CAM (Miragall and Dermietzel, 1992), L1 (Miragall et al, 1989;Miragall and Dermietzel, 1992), and a variety of lectins (for review see Plendl and Sinowatz, 1998). The expression of these molecules may be spatially and temporally regulated during development in the olfactory nerve as well as the olfactory bulb to guide (attract and/or repulse) growing axons to their appropriate targets.…”

Zinc-finger geneFezin the olfactory sensory neurons regulates development of the olfactory bulb non-cell-autonomously

“…In wild-type mice, OSNs extended their axons, which stain with anti-NCAM and anti-GAP43 antibodies (Terkelsen et al, 1989;Verhaagen et al, 1989), through the lamina cribrosa, and innervated 1435 RESEARCH ARTICLE Fez in olfactory system development , and coronal sections of the olfactory epithelium (I-K) and the olfactory bulb (K). Fez transcripts were detected in the olfactory epithelium (black arrowheads; E,I,J,K), septum (black arrow, E), roof of the telencephalon (F), hypothalamus (asterisks; G,H), prethalamus (black arrowhead, G) and amygdala (black arrows; G,H), but not in the olfactory bulb (black arrows in K).…”