title: Involvement of cajal-retzius neurons in spontaneous correlated activity of embryonic and postnatal layer 1 from wild-type and reeler mice.
abstract: Cajal-Retzius (CR) cells are a transient population of neurons in developing cortical layer 1 that secrete reelin, a protein necessary for cortical lamination. Combining calcium imaging of cortical hemispheres and cross-correlation analysis, we previously found spontaneous correlated activity among non-CR neurons in postnatal rat layer 1. This correlated activity was blocked by GABAergic and glutamatergic antagonists, and we postulated that it was controlled by CR cells. We now investigate the correlated activity of embryonic and postnatal layer 1 in wild-type and reeler mice, mutant in the production of reelin. We find that mouse layer 1 also sustains patterned spontaneous activity and that CR cells participate in correlated networks. These networks are present in embryonic marginal zone and are blocked by GABAergic and glutamatergic antagonists. Surprisingly, network activity in reeler mice displays similar characteristics and pharmacological profile as in wild-type mice, although small differences are detected. Our results demonstrate that the embryonic marginal zone has correlated spontaneous activity that could serve as the scaffold for the development of intracortical connections. Our data also suggest that reelin does not have a major impact in the development of specific synaptic circuits in layer 1.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
authors.forename: A
authors.initials: A
authors.lastname: Aguiló
authors.forename: T H
authors.initials: TH
authors.lastname: Schwartz
authors.forename: V S
authors.initials: VS
authors.lastname: Kumar
authors.forename: Z A
authors.initials: ZA
authors.lastname: Peterlin
authors.forename: A
authors.initials: A
authors.lastname: Tsiola
authors.forename: E
authors.initials: E
authors.lastname: Soriano
authors.forename: R
authors.initials: R
authors.lastname: Yuste
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology* / Q000502:physiology*; D004622:Embryo, Mammalian / Q000166:cytology / Q000502:physiology; D018691:Excitatory Amino Acid Antagonists; D005456:Fluorescent Dyes; D016257:Fura-2 / Q000031:analogs & derivatives; D018756:GABA Antagonists / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008818:Mice, Neurologic Mutants; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D000091042:Reelin Protein; D012016:Reference Values
chemical_list: D018691:Excitatory Amino Acid Antagonists; D005456:Fluorescent Dyes; D018756:GABA Antagonists; D000091042:Reelin Protein; C000717129:Reln protein, rat; C049925:fura-2-am; C000717128:Reln protein, mouse; D016257:Fura-2