title: Targeted Inactivation of Bax Reveals a Subtype-Specific Mechanism of Cajal-Retzius Neuron Death in the Postnatal Cerebral Cortex.
abstract: Cajal-Retzius cells (CRs), the first-born neurons in the developing cerebral cortex, coordinate crucial steps in the construction of functional circuits. CRs are thought to be transient, as they disappear during early postnatal life in both mice and humans, where their abnormal persistence is associated with pathological conditions. Embryonic CRs comprise at least three molecularly and functionally distinct subtypes: septum, ventral pallium/pallial-subpallial boundary (PSB), and hem. However, whether subtype-specific features exist postnatally and through which mechanisms they disappear remain unknown. We report that CR subtypes display unique distributions and dynamics of death in the postnatal mouse cortex. Surprisingly, although all CR subtypes undergo cell death, septum, but not hem, CRs die in a Bax-dependent manner. Bax-inactivated rescued septum-CRs maintain immature electrophysiological properties. These results underlie the existence of an exquisitely refined control of developmental cell death and provide a model to test the effect of maintaining immature circuits in the adult neocortex.
authors.affiliation: Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Ledonne
authors.affiliation: INSERM U1128, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France.
authors.forename: David
authors.initials: D
authors.lastname: Orduz
authors.affiliation: Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France.
authors.forename: Judith
authors.initials: J
authors.lastname: Mercier
authors.affiliation: Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France.
authors.forename: Lisa
authors.initials: L
authors.lastname: Vigier
authors.affiliation: Department of Neurobiology, University of Chicago, IL 60637, USA.
authors.forename: Elisabeth A
authors.initials: EA
authors.lastname: Grove
authors.affiliation: Université Catholique de Louvain, Institute of Neuroscience, 1200 Brussels, Belgium.
authors.forename: Fadel
authors.initials: F
authors.lastname: Tissir
authors.affiliation: INSERM U1128, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France.
authors.forename: Maria Cecilia
authors.initials: MC
authors.lastname: Angulo
authors.affiliation: Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France. Electronic address: alessandra.pierani@ijm.fr.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Pierani
authors.affiliation: Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France. Electronic address: eva.coppola@ijm.fr.
authors.forename: Eva
authors.initials: E
authors.lastname: Coppola
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D016923:Cell Death / Q000235:genetics*; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics; D002540:Cerebral Cortex / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D004622:Embryo, Mammalian; D006801:Humans; D051379:Mice; D009474:Neurons / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D051028:bcl-2-Associated X Protein
keywords: Bax; Cajal-Retzius cells; death; distribution; immature circuits; postnatal cerebral cortex; transient neurons