Neuropilin-2 mediates axonal fasciculation, zonal segregation, but not axonal convergence, of primary accessory olfactory neurons.
The mechanisms that underlie axonal pathfinding of vomeronasal neurons from the vomeronasal organ (VNO) in the periphery to select glomeruli in the accessory olfactory bulb (AOB) are not well understood. Neuropilin-2, a receptor for secreted semaphorins, is expressed in V1R- and V3R-expressing, but not V2R-expressing, postnatal vomeronasal neurons. Analysis of the vomeronasal nerve in neuropilin-2 (npn-2) mutant mice reveals pathfinding defects at multiple choice points. Vomeronasal sensory axons are severely defasciculated and a subset innervates the main olfactory bulb (MOB). While most axons of V1R-expressing neurons reach the AOB and converge into distinct glomeruli in stereotypic locations, they are no longer restricted to their normal anterior AOB target zone. Thus, Npn-2 and candidate pheromone receptors play distinct and complementary roles in promoting the wiring and patterning of sensory neurons in the accessory olfactory system.
Cloutier
Jean François
JF
Department of Neuroscience, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
Giger
Roman J
RJ
Koentges
Georgy
G
Dulac
Catherine
C
Kolodkin
Alex L
AL
Ginty
David D
DD
D000818:Animals; D001369:Axons / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000033:anatomy & histology / Q000502:physiology; D017403:In Situ Hybridization; D008024:Ligands; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009414:Nerve Growth Factors / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D039942:Neuropilin-1; D009830:Olfactory Bulb / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D019147:Vomeronasal Organ / Q000166:cytology / Q000378:metabolism*
D008024:Ligands; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D039942:Neuropilin-1