title: Layer acquisition by cortical GABAergic interneurons is independent of Reelin signaling.
abstract: Functioning of the cerebral cortex requires the coordinated assembly of circuits involving glutamatergic projection neurons and GABAergic interneurons. Despite their segregated origin in different regions of the telencephalon, projection neurons and interneurons born synchronically end up adopting the same cortical layer, suggesting that layer acquisition is highly coordinated for both neuronal types. The radial migration and laminar arrangement of projection neurons depends on Reelin, a secreted glycoprotein expressed near the pial surface during embryogenesis. In contrast, the mechanisms controlling layer acquisition by cortical interneurons remain essentially unknown. Here, we have used an ultrasound-guided transplantation approach to analyze the mechanisms underlying the acquisition of laminar locations by cortical interneurons. We found that layer acquisition by cortical GABAergic interneurons does not directly depend on Reelin signaling. Moreover, interneurons invade their target layers well after synchronically generated projection neurons reach their final destination. These results suggest a model in which cues provided by projection neurons guide cortical interneurons to their appropriate layer, and reveal that, at least for some neuronal types, long-range radial migration does not directly require Reelin.
authors.affiliation: Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Pla
authors.forename: Víctor
authors.initials: V
authors.lastname: Borrell
authors.forename: Nuria
authors.initials: N
authors.lastname: Flames
authors.forename: Oscar
authors.initials: O
authors.lastname: Marín
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology* / Q000378:metabolism* / Q000502:physiology; D004622:Embryo, Mammalian; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000378:metabolism*; D009474:Neurons / Q000502:physiology / Q000637:transplantation; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; C103773:Dab1 protein, mouse; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D000091042:Reelin Protein; D005680:gamma-Aminobutyric Acid; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases