title: Cajal-Retzius cells in the mouse: transcription factors, neurotransmitters, and birthdays suggest a pallial origin.
abstract: Cajal-Retzius cells are reelin-secreting neurons found in the marginal zone of the mammalian cortex during development. Recently, it has been proposed that Cajal-Retzius cells may be generated both early and late in corticogenesis, and may migrate into the cortex from proliferative zones in the subpallium (lateral ganglionic eminence and medial ganglionic eminence) or cortical hem. In the present study, we used reelin as a marker to study the properties of Cajal-Retzius cells, including their likely origins, neurotransmitters, and birthdates. In double labeling experiments, Cajal-Retzius cells (reelin(+)) expressed transcription factors characteristic of pallial neurons (Tbr1 and Emx2), contained high levels of glutamate, were usually calretinin(+), and were born early in corticogenesis, on embryonic days (E)10.5 and E11.5. Tbr1(+) cells in the marginal zone were almost always reelin(+). The first Cajal-Retzius cells (Tbr1(+)/reelin(+)) appeared in the preplate on E10.5. In contrast, interneurons expressed a subpallial transcription factor (Dlx), contained high levels of GABA, were frequently calbindin(+), and were born throughout corticogenesis (from E10.5 to E16.5). Interneurons (Dlx(+)) first appeared in the cortex on E12.5. Our results suggest that the marginal zone contains two main types of neurons: Cajal-Retzius cells derived from the pallium, and migrating interneurons derived from the subpallium.
authors.affiliation: Department of Pathology, University of Washington, Harborview Medical Center, Box 359630, 325 Ninth Ave, Seattle, WA 98104-2499, USA. rhevner@u.washington.edu
authors.forename: Robert F
authors.initials: RF
authors.lastname: Hevner
authors.forename: Tina
authors.initials: T
authors.lastname: Neogi
authors.forename: Chris
authors.initials: C
authors.lastname: Englund
authors.forename: Ray A M
authors.initials: RA
authors.lastname: Daza
authors.forename: Andy
authors.initials: A
authors.lastname: Fink
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers; D064032:Calbindin 2; D064026:Calbindins; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D019070:Cell Lineage / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005260:Female; D005333:Fetus; D018698:Glutamic Acid / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D007395:Interneurons / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009419:Nerve Tissue Proteins; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism; D011247:Pregnancy; D000091042:Reelin Protein; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D012697:Serine Endopeptidases; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D020825:T-Box Domain Proteins; D014157:Transcription Factors / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism; D000099260:Empty Spiracles Homeobox Proteins
chemical_list: D015415:Biomarkers; D064032:Calbindin 2; D064026:Calbindins; D015816:Cell Adhesion Molecules, Neuronal; D004268:DNA-Binding Proteins; D016326:Extracellular Matrix Proteins; D018698:Glutamic Acid; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents; D000091042:Reelin Protein; D064030:S100 Calcium Binding Protein G; D012697:Serine Endopeptidases; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D005680:gamma-Aminobutyric Acid; D000099260:Empty Spiracles Homeobox Proteins; C576511:Calb2 protein, mouse; C088334:Distal-less homeobox proteins; C492271:Tbr1 protein, mouse; C000717128:Reln protein, mouse