title: Direct visualization of cell movement in the embryonic olfactory bulb using green fluorescent protein transgenic mice: evidence for rapid tangential migration of neural cell precursors.
abstract: We analyzed motile behavior of neuronal precursor cells in the intact olfactory bulbs (OBs) using transgenic mice expressing GFP under the control of T alpha 1 tubulin promoter. In the olfactory bulbs at the embryonic days 12.5-14.5, a large number of immature neurons expressed GFP in this transgenic line. Embryonic OBs were maintained in an organ culture system and the migratory behavior of GFP-positive cells was analyzed by time-lapse confocal microscopy. We observed rapid tangential movement of GFP-positive cells in the ventral olfactory bulb. In contrast to the typical bipolar morphology of translocating immature neurons within the developing cortex, the motile cells had neither leading nor trailing processes and changed their overall shape frequently. Comparison of the behavior of cells expressing GFP under the control of T alpha 1 tubulin or nestin promoter revealed that rapid motility was specific to cells in the neuronal lineage. The rapid movement was sensitive to an actin perturbing reagent and also dependent on the calcium influx through L-type calcium channels. These results indicate the presence of a specific form of precursor cell migration in the embryonic olfactory bulb.
authors.affiliation: Molecular Neurophysiology Group, Neuroscience Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Shigeo
authors.initials: S
authors.lastname: Okabe
mesh_terms: D000367:Age Factors; D000818:Animals; D002452:Cell Count / Q000379:methods; D002465:Cell Movement / Q000502:physiology*; D004622:Embryo, Mammalian; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D007381:Intermediate Filament Proteins / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009474:Neurons / Q000502:physiology*; D009830:Olfactory Bulb / Q000166:cytology* / Q000196:embryology*; D009924:Organ Culture Techniques; D011401:Promoter Regions, Genetic / Q000235:genetics; D013234:Stem Cells / Q000502:physiology*; D013997:Time Factors; D014404:Tubulin / Q000235:genetics; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D007381:Intermediate Filament Proteins; D008869:Microtubule-Associated Proteins; C079240:Mtap2 protein, mouse; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D014404:Tubulin; D049452:Green Fluorescent Proteins; D001616:beta-Galactosidase