title: Synaptogenesis in the mouse olfactory bulb during glomerulus development.
abstract: Synaptogenesis is essential for the development of neuronal networks in the brain. In the olfactory bulb (OB) glomeruli, numerous synapses must form between sensory olfactory neurons and the dendrites of mitral/tufted and periglomerular cells. Glomeruli develop from E13 to E16 in the mouse, coincident with an increment of the neuropil in the border between the external plexiform (EPL) and olfactory nerve layers (ONL), coupled to an extensive labelling of phalloidin and GAP-43 from the ONL to EPL. We have tracked synaptogenesis in the OB during this period by electron microscopy (EM) and immunolabelling of the transmembrane synaptic vesicle glycoprotein SV-2. No SV-2 labelling or synapses were detected at E13, although electrodense junctions lacking synaptic vesicles could be observed by EM. At E14, sparse SV-2 labelling appears in the most ventral and medial part of the incipient OB, which displays a ventro-dorsal gradient by E15 but covers the entire OB by E16. These data establish a spatio-temporal pattern of synaptogenesis, which perfectly matches with the glomeruli formation in developing OB.
authors.affiliation: Department of Cellular, Molecular and Developmental Neurobiology, Instituto Cajal, CSIC, Madrid, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Blanchart
authors.forename: Miriam
authors.initials: M
authors.lastname: Romaguera
authors.forename: Jose M
authors.initials: JM
authors.lastname: García-Verdugo
authors.forename: Juan A
authors.initials: JA
authors.lastname: de Carlos
authors.forename: Laura
authors.initials: L
authors.lastname: López-Mascaraque
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D019922:GAP-43 Protein / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D009419:Nerve Tissue Proteins / Q000378:metabolism; D019581:Neuropil / Q000378:metabolism / Q000648:ultrastructure*; D009830:Olfactory Bulb / Q000196:embryology* / Q000378:metabolism / Q000648:ultrastructure*; D009831:Olfactory Mucosa / Q000196:embryology / Q000378:metabolism / Q000648:ultrastructure; D018034:Olfactory Receptor Neurons / Q000196:embryology / Q000378:metabolism / Q000648:ultrastructure; D010590:Phalloidine / Q000378:metabolism; D013569:Synapses / Q000378:metabolism / Q000648:ultrastructure*; D013570:Synaptic Membranes / Q000378:metabolism / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology; D013572:Synaptic Vesicles / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors
chemical_list: D015415:Biomarkers; D019922:GAP-43 Protein; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; C489614:Sv2a protein, mouse; D010590:Phalloidine