title: Multimodal tangential migration of neocortical GABAergic neurons independent of GPI-anchored proteins.
abstract: Neuronal migration is crucial for the construction of neuronal architecture such as layers and nuclei. Most inhibitory interneurons in the neocortex derive from the basal forebrain and migrate tangentially; however, little is known about the mode of migration of these neurons in the cortex. We used glutamate decarboxylase (Gad)67-green fluorescent protein (GFP) knock-in embryonic mice with expression of GFP in gamma-aminobutyric acid (GABA)-ergic neurons and performed time-lapse analysis. In coronal slices, many GFP-positive neurons in the lower intermediate zone (IZ) and subventricular zone (SVZ) showed robust tangential migration from lateral to medial cortex, while others showed radial and non-radial migration mostly towards the pial surface. In flat-mount preparations, GFP-positive neurons of the marginal zone (MZ) showed multidirectional tangential migration. Some of these neurons descended toward the cortical plate (CP). Intracortical migration of these neurons was largely unaffected by a treatment that cleaves glycosylphosphatidylinositol (GPI) anchors. These findings suggest that tangential migration of cortical interneurons from lateral to medial cortex predominantly occurs in the IZ/SVZ and raise the possibility that a part of the pial surface-directed neurons in the IZ/SVZ reach the MZ, whereby they spread into the whole area of the cortex. At least a part of these neurons may descend toward the CP. Our results also suggest that intracortical migration of GABAergic neurons occurs independent of GPI-anchored proteins.
authors.affiliation: Graduate School of Frontier Biosciences, Osaka University, Machikaneyama 1-3, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tanaka
authors.forename: Yohei
authors.initials: Y
authors.lastname: Nakaya
authors.forename: Yuchio
authors.initials: Y
authors.lastname: Yanagawa
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Obata
authors.forename: Fujio
authors.initials: F
authors.lastname: Murakami
mesh_terms: D000818:Animals; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology* / Q000378:metabolism; D058969:Contactin 2; D004622:Embryo, Mammalian / Q000033:anatomy & histology / Q000502:physiology; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D010738:Type C Phospholipases / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; C548675:Cntn2 protein, mouse; D058969:Contactin 2; D017261:Glycosylphosphatidylinositols; D007527:Isoenzymes; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D005680:gamma-Aminobutyric Acid; D010738:Type C Phospholipases; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1