1
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Enck JR, Olson EC. Calcium Signaling during Cortical Apical Dendrite Initiation: A Role for Cajal-Retzius Neurons. Int J Mol Sci 2023; 24:12965. [PMID: 37629145 PMCID: PMC10455361 DOI: 10.3390/ijms241612965] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
The apical dendrite of a cortical projection neuron (CPN) is generated from the leading process of the migrating neuron as the neuron completes migration. This transformation occurs in the cortical marginal zone (MZ), a layer that contains the Cajal-Retzius neurons and their axonal projections. Cajal-Retzius neurons (CRNs) are well known for their critical role in secreting Reelin, a glycoprotein that controls dendritogenesis and cell positioning in many regions of the developing brain. In this study, we examine the possibility that CRNs in the MZ may provide additional signals to arriving CPNs, that may promote the maturation of CPNs and thus shape the development of the cortex. We use whole embryonic hemisphere explants and multiphoton microscopy to confirm that CRNs display intracellular calcium transients of <1-min duration and high amplitude during early corticogenesis. In contrast, developing CPNs do not show high-amplitude calcium transients, but instead show a steady increase in intracellular calcium that begins at the time of dendritic initiation, when the leading process of the migrating CPN is encountering the MZ. The possible existence of CRN to CPN communication was revealed by the application of veratridine, a sodium channel activator, which has been shown to preferentially stimulate more mature cells in the MZ at an early developmental time. Surprisingly, veratridine application also triggers large calcium transients in CPNs, which can be partially blocked by a cocktail of antagonists that block glutamate and glycine receptor activation. These findings outline a model in which CRN spontaneous activity triggers the release of glutamate and glycine, neurotransmitters that can trigger intracellular calcium elevations in CPNs. These elevations begin as CPNs initiate dendritogenesis and continue as waves in the post-migratory cells. Moreover, we show that the pharmacological blockade of glutamatergic signaling disrupts migration, while forced expression of a bacterial voltage-gated calcium channel (CavMr) in the migrating neurons promotes dendritic growth and migration arrest. The identification of CRN to CPN signaling during early development provides insight into the observation that many autism-linked genes encode synaptic proteins that, paradoxically, are expressed in the developing cortex well before the appearance of synapses and the establishment of functional circuits.
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Affiliation(s)
| | - Eric C. Olson
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, 505 Irving Ave., Syracuse, NY 13210, USA;
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2
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Causeret F, Moreau MX, Pierani A, Blanquie O. The multiple facets of Cajal-Retzius neurons. Development 2021; 148:268379. [PMID: 34047341 DOI: 10.1242/dev.199409] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cajal-Retzius neurons (CRs) are among the first-born neurons in the developing cortex of reptiles, birds and mammals, including humans. The peculiarity of CRs lies in the fact they are initially embedded into the immature neuronal network before being almost completely eliminated by cell death at the end of cortical development. CRs are best known for controlling the migration of glutamatergic neurons and the formation of cortical layers through the secretion of the glycoprotein reelin. However, they have been shown to play numerous additional key roles at many steps of cortical development, spanning from patterning and sizing functional areas to synaptogenesis. The use of genetic lineage tracing has allowed the discovery of their multiple ontogenetic origins, migratory routes, expression of molecular markers and death dynamics. Nowadays, single-cell technologies enable us to appreciate the molecular heterogeneity of CRs with an unprecedented resolution. In this Review, we discuss the morphological, electrophysiological, molecular and genetic criteria allowing the identification of CRs. We further expose the various sources, migration trajectories, developmental functions and death dynamics of CRs. Finally, we demonstrate how the analysis of public transcriptomic datasets allows extraction of the molecular signature of CRs throughout their transient life and consider their heterogeneity within and across species.
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Affiliation(s)
- Frédéric Causeret
- Université de Paris, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, F-75015 Paris, France.,Université de Paris, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, F-75014 Paris, France
| | - Matthieu X Moreau
- Université de Paris, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, F-75015 Paris, France.,Université de Paris, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, F-75014 Paris, France
| | - Alessandra Pierani
- Université de Paris, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, F-75015 Paris, France.,Université de Paris, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, F-75014 Paris, France.,Groupe Hospitalier Universitaire Paris Psychiatrie et Neurosciences, F-75014 Paris, France
| | - Oriane Blanquie
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, D-55128 Mainz, Germany
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3
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Genescu I, Garel S. Being superficial: a developmental viewpoint on cortical layer 1 wiring. Curr Opin Neurobiol 2020; 66:125-134. [PMID: 33186879 DOI: 10.1016/j.conb.2020.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/03/2020] [Accepted: 10/04/2020] [Indexed: 01/01/2023]
Abstract
Functioning of the neocortex relies on a complex architecture of circuits, as illustrated by the causal link between neocortical excitation/inhibition imbalance and the etiology of several neurodevelopmental disorders. An important entry point to cortical circuits is located in the superficial layer 1 (L1), which contains mostly local and long-range inputs and sparse inhibitory interneurons that collectively regulate cerebral functions. While increasing evidence indicates that L1 has important physiological roles, our understanding of how it wires up during development remains limited. Here, we provide an integrated overview of L1 anatomy, function and development, with a focus on transient early born Cajal-Retzius neurons, and highlight open questions key for progressing our understanding of this essential yet understudied layer of the cerebral cortex.
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Affiliation(s)
- Ioana Genescu
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Sonia Garel
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France; Collège de France, Paris, France.
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4
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Riva M, Genescu I, Habermacher C, Orduz D, Ledonne F, Rijli FM, López-Bendito G, Coppola E, Garel S, Angulo MC, Pierani A. Activity-dependent death of transient Cajal-Retzius neurons is required for functional cortical wiring. eLife 2019; 8:50503. [PMID: 31891351 PMCID: PMC6938399 DOI: 10.7554/elife.50503] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/06/2019] [Indexed: 12/19/2022] Open
Abstract
Programmed cell death and early activity contribute to the emergence of functional cortical circuits. While most neuronal populations are scaled-down by death, some subpopulations are entirely eliminated, raising the question of the importance of such demise for cortical wiring. Here, we addressed this issue by focusing on Cajal-Retzius neurons (CRs), key players in cortical development that are eliminated in postnatal mice in part via Bax-dependent apoptosis. Using Bax-conditional mutants and CR hyperpolarization, we show that the survival of electrically active subsets of CRs triggers an increase in both dendrite complexity and spine density of upper layer pyramidal neurons, leading to an excitation/inhibition imbalance. The survival of these CRs is induced by hyperpolarization, highlighting an interplay between early activity and neuronal elimination. Taken together, our study reveals a novel activity-dependent programmed cell death process required for the removal of transient immature neurons and the proper wiring of functional cortical circuits.
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Affiliation(s)
- Martina Riva
- Institut Imagine, Université de Paris, Paris, France.,Institut Jacques Monod, CNRS UMR 7592, Université de Paris, Paris, France.,Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Université de Paris, Paris, France
| | - Ioana Genescu
- Institut de Biologie de l'École Normale Supérieure (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Chloé Habermacher
- Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Université de Paris, Paris, France.,INSERM U1128, Paris, France
| | | | - Fanny Ledonne
- Institut Jacques Monod, CNRS UMR 7592, Université de Paris, Paris, France
| | - Filippo M Rijli
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | | | - Eva Coppola
- Institut Imagine, Université de Paris, Paris, France.,Institut Jacques Monod, CNRS UMR 7592, Université de Paris, Paris, France.,Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Université de Paris, Paris, France
| | - Sonia Garel
- Institut de Biologie de l'École Normale Supérieure (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Maria Cecilia Angulo
- Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Université de Paris, Paris, France.,INSERM U1128, Paris, France
| | - Alessandra Pierani
- Institut Imagine, Université de Paris, Paris, France.,Institut Jacques Monod, CNRS UMR 7592, Université de Paris, Paris, France.,Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Université de Paris, Paris, France
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5
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Shikanai H, Oshima N, Kawashima H, Kimura SI, Hiraide S, Togashi H, Iizuka K, Ohkura K, Izumi T. N-methyl-d-aspartate receptor dysfunction in the prefrontal cortex of stroke-prone spontaneously hypertensive rat/Ezo as a rat model of attention deficit/hyperactivity disorder. Neuropsychopharmacol Rep 2018; 38:61-66. [PMID: 30106260 PMCID: PMC7292284 DOI: 10.1002/npr2.12007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/10/2018] [Accepted: 01/11/2018] [Indexed: 11/07/2022] Open
Abstract
AIM We previously reported that stroke-prone spontaneously hypertensive rat/Ezo (SHRSP/Ezo) has high validity as an attention deficit/hyperactivity disorder (AD/HD) animal model, based on its behavioral phenotypes, such as inattention, hyperactivity, and impulsivity. Fronto-cortical dysfunction is implicated in the pathogenesis of AD/HD. In this study, we investigated prefrontal cortex (PFC) function in SHRSP/Ezo rats by electrophysiological methods and radioreceptor assay. METHODS We recorded excitatory postsynaptic potential in layer V pyramidal neurons in the PFC by intracellular recording method to assess synaptic plasticity in the form of long-term potentiation (LTP). We also performed N-methyl-d-aspartate acid (NMDA) receptor binding assay in the PFC and hippocampus using radiolabeled NMDA receptor antagonist [3 H]MK-801. RESULTS Theta-burst stimulation induced LTP in the PFC of genetic control, WKY/Ezo, whereas failed to induce LTP in that of SHRSP/Ezo. The Kd value of [3 H]MK-801 binding for NMDA receptors in the PFC of SHRSP/Ezo was higher than in the WKY/Ezo. Neither the Bmax nor Kd of [3 H]MK-801 binding in the SHRSP/Ezo hippocampus was significantly different to WKY/Ezo. CONCLUSION These results suggest that the AD/HD animal model SHRSP/Ezo has NMDA receptor dysfunction in the PFC.
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Affiliation(s)
- Hiroki Shikanai
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
| | - Nobuhiro Oshima
- Department of Biophysical Sciences, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
| | - Hidekazu Kawashima
- Department of Biophysical Sciences, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
| | - Shin-Ichi Kimura
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
| | - Sachiko Hiraide
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
| | - Hiroko Togashi
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
| | - Kenji Iizuka
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
| | - Kazue Ohkura
- Department of Biophysical Sciences, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
| | - Takeshi Izumi
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Kanazawa, Ishikari-Tobetsu, Japan
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6
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Anstötz M, Quattrocolo G, Maccaferri G. Cajal-Retzius cells and GABAergic interneurons of the developing hippocampus: Close electrophysiological encounters of the third kind. Brain Res 2018; 1697:124-133. [PMID: 30071194 DOI: 10.1016/j.brainres.2018.07.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/17/2018] [Accepted: 07/28/2018] [Indexed: 01/24/2023]
Abstract
In contrast to the large number of studies investigating the electrophysiological properties and synaptic connectivity of hippocampal pyramidal neurons, granule cells, and GABAergic interneurons, much less is known about Cajal-Retzius cells. In this review article, we discuss the possible reasons underlying this difference, and review experimental work performed on this cell type in the hippocampus, comparing it with results obtained in the neocortex. Our main emphasis is on data obtained with in vitro electrophysiology. In particular, we address the bidirectional connectivity between Cajal-Retzius cells and GABAergic interneurons, examine their synaptic properties and propose specific functions of Cajal-Retzius cell/GABAergic interneuron microcircuits. Lastly, we discuss the potential involvement of these microcircuits in critical physiological hippocampal functions such as postnatal neurogenesis or pathological scenarios such as temporal lobe epilepsy.
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Affiliation(s)
- Max Anstötz
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
| | - Giulia Quattrocolo
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
| | - Gianmaria Maccaferri
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
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7
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Mining Big Neuron Morphological Data. COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2018; 2018:8234734. [PMID: 30034462 PMCID: PMC6035829 DOI: 10.1155/2018/8234734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 05/09/2018] [Accepted: 05/24/2018] [Indexed: 11/26/2022]
Abstract
The advent of automatic tracing and reconstruction technology has led to a surge in the number of neurons 3D reconstruction data and consequently the neuromorphology research. However, the lack of machine-driven annotation schema to automatically detect the types of the neurons based on their morphology still hinders the development of this branch of science. Neuromorphology is important because of the interplay between the shape and functionality of neurons and the far-reaching impact on the diagnostics and therapeutics in neurological disorders. This survey paper provides a comprehensive research in the field of automatic neurons classification and presents the existing challenges, methods, tools, and future directions for automatic neuromorphology analytics. We summarize the major automatic techniques applicable in the field and propose a systematic data processing pipeline for automatic neuron classification, covering data capturing, preprocessing, analyzing, classification, and retrieval. Various techniques and algorithms in machine learning are illustrated and compared to the same dataset to facilitate ongoing research in the field.
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8
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Adnani L, Han S, Li S, Mattar P, Schuurmans C. Mechanisms of Cortical Differentiation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 336:223-320. [DOI: 10.1016/bs.ircmb.2017.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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9
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Ruiz-Reig N, Studer M. Rostro-Caudal and Caudo-Rostral Migrations in the Telencephalon: Going Forward or Backward? Front Neurosci 2017; 11:692. [PMID: 29311773 PMCID: PMC5742585 DOI: 10.3389/fnins.2017.00692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/23/2017] [Indexed: 11/13/2022] Open
Abstract
The generation and differentiation of an appropriate number of neurons, as well as its distribution in different parts of the brain, is crucial for the proper establishment, maintenance and plasticity of neural circuitries. Newborn neurons travel along the brain in a process known as neuronal migration, to finalize their correct position in the nervous system. Defects in neuronal migration produce abnormalities in the brain that can generate neurodevelopmental pathologies, such as autism, schizophrenia and intellectual disability. In this review, we present an overview of the developmental origin of the different telencephalic subdivisions and a description of migratory pathways taken by distinct neural populations traveling long distances before reaching their target position in the brain. In addition, we discuss some of the molecules implicated in the guidance of these migratory paths and transcription factors that contribute to the correct migration and integration of these neurons.
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10
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Ledonne F, Orduz D, Mercier J, Vigier L, Grove EA, Tissir F, Angulo MC, Pierani A, Coppola E. Targeted Inactivation of Bax Reveals a Subtype-Specific Mechanism of Cajal-Retzius Neuron Death in the Postnatal Cerebral Cortex. Cell Rep 2017; 17:3133-3141. [PMID: 28009284 DOI: 10.1016/j.celrep.2016.11.074] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 09/26/2016] [Accepted: 11/23/2016] [Indexed: 12/31/2022] Open
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.
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Affiliation(s)
- Fanny Ledonne
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France
| | - David Orduz
- INSERM U1128, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
| | - Judith Mercier
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France
| | - Lisa Vigier
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France
| | | | - Fadel Tissir
- Université Catholique de Louvain, Institute of Neuroscience, 1200 Brussels, Belgium
| | - Maria Cecilia Angulo
- INSERM U1128, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
| | - Alessandra Pierani
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France.
| | - Eva Coppola
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France.
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11
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12
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de Frutos C, Bouvier G, Arai Y, Thion M, Lokmane L, Keita M, Garcia-Dominguez M, Charnay P, Hirata T, Riethmacher D, Grove E, Tissir F, Casado M, Pierani A, Garel S. Reallocation of Olfactory Cajal-Retzius Cells Shapes Neocortex Architecture. Neuron 2016; 92:435-448. [DOI: 10.1016/j.neuron.2016.09.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 07/13/2016] [Accepted: 09/06/2016] [Indexed: 11/25/2022]
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13
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Hadzic M, Jack A, Wahle P. Ionotropic glutamate receptors: Which ones, when, and where in the mammalian neocortex. J Comp Neurol 2016; 525:976-1033. [PMID: 27560295 DOI: 10.1002/cne.24103] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/09/2016] [Accepted: 08/15/2016] [Indexed: 12/14/2022]
Abstract
A multitude of 18 iGluR receptor subunits, many of which are diversified by splicing and RNA editing, localize to >20 excitatory and inhibitory neocortical neuron types defined by physiology, morphology, and transcriptome in addition to various types of glial, endothelial, and blood cells. Here we have compiled the published expression of iGluR subunits in the areas and cell types of developing and adult cortex of rat, mouse, carnivore, bovine, monkey, and human as determined with antibody- and mRNA-based techniques. iGluRs are differentially expressed in the cortical areas and in the species, and all have a unique developmental pattern. Differences are quantitative rather than a mere absence/presence of expression. iGluR are too ubiquitously expressed and of limited use as markers for areas or layers. A focus has been the iGluR profile of cortical interneuron types. For instance, GluK1 and GluN3A are enriched in, but not specific for, interneurons; moreover, the interneurons expressing these subunits belong to different types. Adressing the types is still a major hurdle because type-specific markers are lacking, and the frequently used neuropeptide/CaBP signatures are subject to regulation by age and activity and vary as well between species and areas. RNA-seq reveals almost all subunits in the two morphofunctionally characterized interneuron types of adult cortical layer I, suggesting a fairly broad expression at the RNA level. It remains to be determined whether all proteins are synthesized, to which pre- or postsynaptic subdomains in a given neuron type they localize, and whether all are involved in synaptic transmission. J. Comp. Neurol. 525:976-1033, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Minela Hadzic
- Developmental Neurobiology, Faculty for Biology and Biotechnology ND 6/72, Ruhr University Bochum, 44801, Bochum, Germany
| | - Alexander Jack
- Developmental Neurobiology, Faculty for Biology and Biotechnology ND 6/72, Ruhr University Bochum, 44801, Bochum, Germany
| | - Petra Wahle
- Developmental Neurobiology, Faculty for Biology and Biotechnology ND 6/72, Ruhr University Bochum, 44801, Bochum, Germany
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14
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Anstötz M, Huang H, Marchionni I, Haumann I, Maccaferri G, Lübke JHR. Developmental Profile, Morphology, and Synaptic Connectivity of Cajal-Retzius Cells in the Postnatal Mouse Hippocampus. Cereb Cortex 2015; 26:855-72. [PMID: 26582498 PMCID: PMC4712808 DOI: 10.1093/cercor/bhv271] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cajal–Retzius (CR) cells are early generated neurons, involved in the assembly of developing neocortical and hippocampal circuits. However, their roles in networks of the postnatal brain remain poorly understood. In order to get insights into these latter functions, we have studied their morphological and synaptic properties in the postnatal hippocampus of the CXCR4-EGFP mouse, where CR cells are easily identifiable. Our data indicate that CR cells are nonuniformly distributed along different subfields of the hippocampal formation, and that their postnatal decline is regulated in a region-specific manner. In fact, CR cells persist in distinct areas of fully mature animals. Subclasses of CR cells project and target either local (molecular layers) or distant regions [subicular complex and entorhinal cortex (EC)] of the hippocampal formation, but have similar firing patterns. Lastly, CR cells are biased toward targeting dendritic shafts compared with spines, and produce large-amplitude glutamatergic unitary postsynaptic potentials on γ-aminobutyric acid (GABA) containing interneurons. Taken together, our results suggest that CR cells are involved in a novel excitatory loop of the postnatal hippocampal formation, which potentially contributes to shaping the flow of information between the hippocampus, parahippocampal regions and entorhinal cortex, and to the low seizure threshold of these brain areas.
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Affiliation(s)
- Max Anstötz
- Institute of Neuroscience and Medicine INM-2, Research Centre Jülich GmbH, Jülich 52425, Germany Institute for Neuroanatomy, University/University Hospital Hamburg, Hamburg 20246, Germany
| | - Hao Huang
- Department of Physiology, Northwestern University, Feinberg School of Medicine, IL 60611-3008, USA
| | - Ivan Marchionni
- Department of Physiology, Northwestern University, Feinberg School of Medicine, IL 60611-3008, USA Current address: Instituto Italiano di Tecnologia, Neuroscience and Brain Technologies, Genova 16163, Italy
| | - Iris Haumann
- Institute for Neuroanatomy, University/University Hospital Hamburg, Hamburg 20246, Germany
| | - Gianmaria Maccaferri
- Department of Physiology, Northwestern University, Feinberg School of Medicine, IL 60611-3008, USA
| | - Joachim H R Lübke
- Institute of Neuroscience and Medicine INM-2, Research Centre Jülich GmbH, Jülich 52425, Germany Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH/University Hospital Aachen, Aachen 52074, Germany JARA Translational Medicine, Jülich/Aachen, Germany
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15
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Migration Speed of Cajal-Retzius Cells Modulated by Vesicular Trafficking Controls the Size of Higher-Order Cortical Areas. Curr Biol 2015; 25:2466-78. [DOI: 10.1016/j.cub.2015.08.028] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 07/01/2015] [Accepted: 08/13/2015] [Indexed: 11/19/2022]
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16
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Martínez-Cerdeño V, Noctor SC. Cajal, Retzius, and Cajal-Retzius cells. Front Neuroanat 2014; 8:48. [PMID: 24987337 PMCID: PMC4060955 DOI: 10.3389/fnana.2014.00048] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 05/29/2014] [Indexed: 01/06/2023] Open
Abstract
The marginal zone (MZ) of the prenatal cerebral cortex plays a crucial role in cellular migration and laminar patterning in the developing neocortex and its equivalent in the adult brain – layer I, participates in cortical circuitry integration within the adult neocortex. The MZ/layer I, which has also been called the plexiform layer and cell-poor zone of Meynert, among others, is home to several cell populations including glia, neurons, and Cajal–Retzius (CR) cells. Cajal once said that the MZ is one of the oldest formations in the phylogenetic series, and that the characteristics of layer I in human are similar in all vertebrates except fish (Ramon y Cajal, 1899). Despite the presence of CR cells in the MZ/layer I of all developing and adult vertebrate brains, and more than one hundred years of research, the phenotype and function of layer I cells have still not been clearly defined. Recent technological advances have yielded significant progress in functional and developmental studies, but much remains to be understood about neurons in MZ/layer I. Since the time of Retzius and Cajal, and continuing with modern era research from the likes of Marín-Padilla, the study of CR cells has been based on their morphological characteristics in Golgi staining. However, since Cajal’s initial description, the term “CR cell” has been applied differently and now is often used to indicate reelin (Reln)-positive cells in MZ/layer I. Here we review the history of work by Cajal, Retzius, and others pertaining to CR cells. We will establish a link between original descriptions of CR cell morphology by Cajal, Retzius, and others, and current understandings of the cell populations that reside in MZ/layer I based on the use of cellular markers. We propose to use the term “CR cell” for the class of neurons that express Reln in the MZ/layer I in both prenatal, developing and adult cerebral cortex.
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Affiliation(s)
- Verónica Martínez-Cerdeño
- Institute for Pediatric Regenerative Medicine, University of California at Davis Sacramento, CA, USA ; Medical Pathology and Laboratory Medicine, University of California at Davis Sacramento, CA, USA ; MIND Institute, University of California at Davis Sacramento, CA, USA
| | - Stephen C Noctor
- MIND Institute, University of California at Davis Sacramento, CA, USA ; Department of Psychiatry and Behavioral Sciences, University of California at Davis Sacramento, CA, USA
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Kirischuk S, Luhmann HJ, Kilb W. Cajal-Retzius cells: update on structural and functional properties of these mystic neurons that bridged the 20th century. Neuroscience 2014; 275:33-46. [PMID: 24931764 DOI: 10.1016/j.neuroscience.2014.06.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/03/2014] [Accepted: 06/03/2014] [Indexed: 02/02/2023]
Abstract
Cajal-Retzius cells (CRc) represent a mostly transient neuronal cell type localized in the uppermost layer of the developing neocortex. The observation that CRc are a major source of the extracellular matrix protein reelin, which is essential for the laminar development of the cerebral cortex, attracted the interest in this unique cell type. In this review we will (i) describe the morphological and molecular properties of neocortical CRc, with a special emphasize on the question which markers can be used to identify CRc, (ii) summarize reports that identified the different developmental origins of CRc, (iii) discuss the fate of CRc, including recent evidence for apoptotic cell death and a possible persistence of some CRc, (iv) provide a detailed description of the electrical membrane properties and transmitter receptors of CRc, and (v) address the role of CRc in early neuronal circuits and cortical development. Finally, we speculate whether CRc may provide a link between early network activity and the structural maturation of neocortical circuits.
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Affiliation(s)
- S Kirischuk
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
| | - H J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
| | - W Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
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18
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Gutzmann A, Ergül N, Grossmann R, Schultz C, Wahle P, Engelhardt M. A period of structural plasticity at the axon initial segment in developing visual cortex. Front Neuroanat 2014; 8:11. [PMID: 24653680 PMCID: PMC3949221 DOI: 10.3389/fnana.2014.00011] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 02/20/2014] [Indexed: 01/09/2023] Open
Abstract
Cortical networks are shaped by sensory experience and are most susceptible to modifications during critical periods characterized by enhanced plasticity at the structural and functional level. A system particularly well-studied in this context is the mammalian visual system. Plasticity has been documented for the somatodendritic compartment of neurons in detail. A neuronal microdomain not yet studied in this context is the axon initial segment (AIS) located at the proximal axon segment. It is a specific electrogenic axonal domain and the site of action potential (AP) generation. Recent studies showed that structure and function of the AIS can be dynamically regulated. Here we hypothesize that the AIS shows a dynamic regulation during maturation of the visual cortex. We therefore analyzed AIS length development from embryonic day (E) 12.5 to adulthood in mice. A tri-phasic time course of AIS length remodeling during development was observed. AIS first appeared at E14.5 and increased in length throughout the postnatal period to a peak between postnatal day (P) 10 to P15 (eyes open P13–14). Then, AIS length was reduced significantly around the beginning of the critical period for ocular dominance plasticity (CP, P21). Shortest AIS were observed at the peak of the CP (P28), followed by a moderate elongation toward the end of the CP (P35). To test if the dynamic maturation of the AIS is influenced by eye opening (onset of activity), animals were deprived of visual input before and during the CP. Deprivation for 1 week prior to eye opening did not affect AIS length development. However, deprivation from P0 to 28 and P14 to 28 resulted in AIS length distribution similar to the peak at P15. In other words, deprivation from birth prevents the transient shortening of the AIS and maintains an immature AIS length. These results are the first to suggest a dynamic maturation of the AIS in cortical neurons and point to novel mechanisms in the development of neuronal excitability.
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Affiliation(s)
- Annika Gutzmann
- CBTM, Medical Faculty Mannheim, Institute of Neuroanatomy, Heidelberg University Heidelberg, Germany
| | - Nursah Ergül
- CBTM, Medical Faculty Mannheim, Institute of Neuroanatomy, Heidelberg University Heidelberg, Germany
| | - Rebecca Grossmann
- CBTM, Medical Faculty Mannheim, Institute of Neuroanatomy, Heidelberg University Heidelberg, Germany
| | - Christian Schultz
- CBTM, Medical Faculty Mannheim, Institute of Neuroanatomy, Heidelberg University Heidelberg, Germany
| | - Petra Wahle
- AG Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Germany
| | - Maren Engelhardt
- CBTM, Medical Faculty Mannheim, Institute of Neuroanatomy, Heidelberg University Heidelberg, Germany
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Qian T, Chen R, Nakamura M, Furukawa T, Kumada T, Akita T, Kilb W, Luhmann HJ, Nakahara D, Fukuda A. Activity-dependent endogenous taurine release facilitates excitatory neurotransmission in the neocortical marginal zone of neonatal rats. Front Cell Neurosci 2014; 8:33. [PMID: 24574969 PMCID: PMC3918584 DOI: 10.3389/fncel.2014.00033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 01/22/2014] [Indexed: 12/27/2022] Open
Abstract
In the developing cerebral cortex, the marginal zone (MZ), consisting of early-generated neurons such as Cajal-Retzius cells, plays an important role in cell migration and lamination. There is accumulating evidence of widespread excitatory neurotransmission mediated by γ-aminobutyric acid (GABA) in the MZ. Cajal-Retzius cells express not only GABAA receptors but also α2/β subunits of glycine receptors, and exhibit glycine receptor-mediated depolarization due to high [Cl−]i. However, the physiological roles of glycine receptors and their endogenous agonists during neurotransmission in the MZ are yet to be elucidated. To address this question, we performed optical imaging from the MZ using the voltage-sensitive dye JPW1114 on tangential neocortical slices of neonatal rats. A single electrical stimulus evoked an action-potential-dependent optical signal that spread radially over the MZ. The amplitude of the signal was not affected by glutamate receptor blockers, but was suppressed by either GABAA or glycine receptor antagonists. Combined application of both antagonists nearly abolished the signal. Inhibition of Na+, K+-2Cl− cotransporter by 20 µM bumetanide reduced the signal, indicating that this transporter contributes to excitation. Analysis of the interstitial fluid obtained by microdialysis from tangential neocortical slices with high-performance liquid chromatography revealed that GABA and taurine, but not glycine or glutamate, were released in the MZ in response to the electrical stimulation. The ambient release of taurine was reduced by the addition of a voltage-sensitive Na+ channel blocker. Immunohistochemistry and immunoelectron microscopy indicated that taurine was stored both in Cajal-Retzius and non-Cajal-Retzius cells in the MZ, but was not localized in presynaptic structures. Our results suggest that activity-dependent non-synaptic release of endogenous taurine facilitates excitatory neurotransmission through activation of glycine receptors in the MZ.
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Affiliation(s)
- Taizhe Qian
- Department of Neurophysiology, Hamamatsu University School of Medicine Hamamatsu, Japan
| | - Rongqing Chen
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University Mainz, Germany
| | - Masato Nakamura
- Department of Psychology and Behavioral Neuroscience, Hamamatsu University School of Medicine Hamamatsu, Japan
| | - Tomonori Furukawa
- Department of Neurophysiology, Hamamatsu University School of Medicine Hamamatsu, Japan
| | - Tatsuro Kumada
- Department of Neurophysiology, Hamamatsu University School of Medicine Hamamatsu, Japan ; Department of Occupational Therapy, Tokoha University Hamamatsu, Japan
| | - Tenpei Akita
- Department of Neurophysiology, Hamamatsu University School of Medicine Hamamatsu, Japan
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University Mainz, Germany
| | - Daiichiro Nakahara
- Department of Psychology and Behavioral Neuroscience, Hamamatsu University School of Medicine Hamamatsu, Japan
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine Hamamatsu, Japan
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Luhmann HJ, Kirischuk S, Sinning A, Kilb W. Early GABAergic circuitry in the cerebral cortex. Curr Opin Neurobiol 2014; 26:72-8. [PMID: 24434608 DOI: 10.1016/j.conb.2013.12.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 11/25/2013] [Accepted: 12/19/2013] [Indexed: 10/25/2022]
Abstract
In the cerebral cortex GABAergic signaling plays an important role in regulating early developmental processes, for example, neurogenesis, migration and differentiation. Transient cell populations, namely Cajal-Retzius in the marginal zone and thalamic input receiving subplate neurons, are integrated as active elements in transitory GABAergic circuits. Although immature pyramidal neurons receive GABAergic synaptic inputs already at fetal stages, they are integrated into functional GABAergic circuits only several days later. In consequence, GABAergic synaptic transmission has only a minor influence on spontaneous network activity during early corticogenesis. Concurrent with the gradual developmental shift of GABA action from excitatory to inhibitory and the maturation of cortical synaptic connections, GABA becomes more important in synchronizing neuronal network activity.
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Affiliation(s)
- Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Sergei Kirischuk
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
| | - Anne Sinning
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
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21
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Sun H, An S, Luhmann HJ, Kilb W. Resonance properties of GABAergic interneurons in immature GAD67-GFP mouse neocortex. Brain Res 2014; 1548:1-11. [PMID: 24389032 DOI: 10.1016/j.brainres.2013.12.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 12/19/2013] [Accepted: 12/24/2013] [Indexed: 12/22/2022]
Abstract
Subthreshold resonance is a characteristic membrane property of different neuronal classes, is critically involved in the generation of network oscillations, and tunes the integration of synaptic inputs to particular frequency ranges. In order to investigate whether neocortical GABAergic interneurons show resonant behavior already during early postnatal development, we performed whole-cell patch-clamp recordings from visually identified interneurons in supragranular layers of parietal regions in coronal neocortical slices from postnatal day (P) P6-P13 GAD67-GFP knock-in mice. Subthreshold resonance was analyzed by injection of sinusoidal current with varying frequency. About 50% of the investigated GABAergic interneurons showed subthreshold resonance with an average frequency of 2.0±0.2 Hz (n=38). Membrane hyperpolarization to -86 mV attenuated the frequency and strength of subthreshold resonance. In the presence of 1 mM Ni(2+) subthreshold resonance was virtually abolished, suggesting that T-type Ca(2+) currents are critically involved in the generation of resonance. In contrast, subthreshold resonance was not affected by ZD7288, a blocker of HCN channels. Application of TTX suppressed subthreshold resonance at depolarized, but not hyperpolarized membrane potential, suggesting that persistent Na(+) current contribute to the amplification of membrane resonance. In summary, these results demonstrate that GABAergic interneurons express subthreshold resonance at low frequencies, with T-type Ca(2+) and persistent Na(+) currents underlying the generation of membrane resonance. The membrane resonance of immature interneurons may contribute to the generation of slow oscillatory activity pattern in the immature neocortex and enhance the temporal precision of synaptic integration in developing cortical neurons.
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Affiliation(s)
- Haiyan Sun
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany
| | - Shuming An
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany.
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22
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Novel GABAergic circuits mediating excitation/inhibition of Cajal-Retzius cells in the developing hippocampus. J Neurosci 2013; 33:5486-98. [PMID: 23536064 DOI: 10.1523/jneurosci.5680-12.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cajal-Retzius cells are a class of neurons believed to play critical roles during cortical development. However, their network computational functions remain poorly understood. Although work in the neocortex and hippocampus has shown that Cajal-Retzius cells receive predominantly, if not exclusively, spontaneous GABA(A) receptor-mediated input, the cellular sources originating these events remain unclear. However, a precise definition of the presynaptic GABAergic interneurons contacting Cajal-Retzius cells is important to understand the microcircuits and network patterns controlling their activation. Here, we have taken advantage of electrophysiological and anatomical techniques applied to mouse hippocampal slices in vitro to directly address this question. Our paired recording experiments indicate that Cajal-Retzius cells receive small-amplitude, kinetically slow synaptic input from stratum lacunosum-moleculare interneurons, anatomically identified as neurogliaform cells. In addition, a convergence of optogenetic, electrophysiological, and pharmacological experiments shows that Cajal-Retzius cells receive GABAergic input from oriens lacunosum-moleculare cells and that this input has different physiological properties (i.e., larger amplitude and faster kinetics) from the one provided by neurogliaform cells. Last, we show that GABAergic evoked synaptic input onto Cajal-Retzius cells may either increase their excitability and trigger action potentials or inhibit spontaneous firing by depolarization block. We propose that the specific type of response depends on both the membrane potential of Cajal-Retzius cells and the kinetics of the received GABAergic input. In conclusion, we have unraveled a novel hippocampal microcircuit with complex GABAergic synaptic signaling, which we suggest may play a role in the refinement of the hippocampal network and connections during development.
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23
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Hansen MB, Jespersen SN, Leigland LA, Kroenke CD. Using diffusion anisotropy to characterize neuronal morphology in gray matter: the orientation distribution of axons and dendrites in the NeuroMorpho.org database. Front Integr Neurosci 2013; 7:31. [PMID: 23675327 PMCID: PMC3653140 DOI: 10.3389/fnint.2013.00031] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 04/16/2013] [Indexed: 01/07/2023] Open
Abstract
Accurate mathematical modeling is integral to the ability to interpret diffusion magnetic resonance (MR) imaging data in terms of cellular structure in brain gray matter (GM). In previous work, we derived expressions to facilitate the determination of the orientation distribution of axonal and dendritic processes from diffusion MR data. Here we utilize neuron reconstructions available in the NeuroMorpho database (www.neuromorpho.org) to assess the validity of the model we proposed by comparing morphological properties of the neurons to predictions based on diffusion MR simulations using the reconstructed neuron models. Initially, the method for directly determining neurite orientation distributions is shown to not depend on the line length used to quantify cylindrical elements. Further variability in neuron morphology is characterized relative to neuron type, species, and laboratory of origin. Subsequently, diffusion MR signals are simulated based on human neocortical neuron reconstructions. This reveals a bias in which diffusion MR data predict neuron orientation distributions to have artificially low anisotropy. This bias is shown to arise from shortcomings (already at relatively low diffusion weighting) in the Gaussian approximation of diffusion, in the presence of restrictive barriers, and data analysis methods involving higher moments of the cumulant expansion are shown to be capable of reducing the magnitude of the observed bias.
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Affiliation(s)
- Mikkel B Hansen
- Center for Functionally Integrative Neuroscience and MINDLab, NeuroCampus Aarhus, Aarhus University Aarhus, Denmark
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24
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Sun H, Luhmann HJ, Kilb W. Resonance properties of different neuronal populations in the immature mouse neocortex. Eur J Neurosci 2012; 36:2753-62. [PMID: 22748148 DOI: 10.1111/j.1460-9568.2012.08196.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In vivo recordings in the immature neocortex revealed spontaneous and sensory-driven oscillatory activity from delta (0.5-4 Hz) to gamma (30-100 Hz) frequencies. In order to investigate whether the resonance properties of distinct neuronal populations in the immature neocortex contribute to these network oscillations, we performed whole-cell patch-clamp recordings from visually identified neurons in tangential and coronal neocortical slices from postnatal day (P)0-P7 C57Bl/6 mice. Subthreshold resonance was analysed by sinusoidal current injection of varying frequency. All Cajal-Retzius cells showed subthreshold resonance, with an average frequency of 2.6 ± 0.1 Hz (n = 60), which was massively reduced by ZD7288, a blocker of hyperpolarization-activated cation currents. Approximately 65.6% (n = 61) of the supragranular pyramidal neurons showed subthreshold resonance, with an average frequency of 1.4 ± 0.1 Hz (n = 40). Application of Ni(2+) suppressed subthreshold resonance, suggesting that low-threshold calcium currents contribute to resonance in these neurons. Approximately 63.6% (n = 77) of the layer V pyramidal neurons showed subthreshold resonance, with an average frequency of 1.4 ± 0.2 Hz (n = 49), which was abolished by ZD7288. Only 44.1% (n = 59) of the subplate neurons showed subthreshold resonance, with an average frequency of 1.3 ± 0.2 Hz (n = 26) and a small resonance strength. In summary, these results demonstrate that neurons in all investigated layers show resonance behavior, with either hyperpolarization-activated cation or low-threshold calcium currents contributing to the subthreshold resonance. The observed resonance frequencies are in the range of slow activity patterns observed in the immature neocortex, suggesting that subthreshold resonance may support the generation of this activity.
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Affiliation(s)
- Haiyan Sun
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
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Kolbaev SN, Luhmann HJ, Kilb W. Activity-dependent scaling of GABAergic excitation by dynamic Cl- changes in Cajal-Retzius cells. Pflugers Arch 2011; 461:557-65. [PMID: 21336585 DOI: 10.1007/s00424-011-0935-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 02/04/2011] [Accepted: 02/04/2011] [Indexed: 11/29/2022]
Abstract
To unravel the functional implications of activity-dependent Cl- changes during early stages of neuronal development, we determined which changes in the GABA reversal potential (E (GABA)) and GABAergic rheobase shifts were induced by episodes of GABA(A) receptor activation using gramicidin-perforated patch-clamp recordings from Cajal-Retzius cells in tangential cortical slices of newborn mice. Under this condition, focal application of the GABA(A) agonist muscimol (10 μM) depolarized the membrane by 15 ± 0.8 mV (n = 35). Such subthreshold GABAergic depolarizations considerably reduced the rheobase, corresponding to an excitatory action. After repetitive focal muscimol applications (50 pulses at 0.5 Hz) a significant reduction of E (GABA) and an attenuation of the excitatory GABAergic rheobase shift were observed, while the GABAergic membrane conductance and the absolute value of the rheobase were unaltered after the muscimol pulses. Bath application of 100 μM carbachol induced bursts of spontaneous GABAergic postsynaptic potentials. Both, E (GABA) and the excitatory GABAergic rheobase shift was significantly reduced after such barrage of carbachol-induced GABAergic postsynaptic potentials, while neither the GABAergic membrane conductance nor the absolute value of the rheobase was affected under this condition. Both results indicate that GABAergic activity itself can limit the excitatory effects of GABA(A) receptor activation, which supports the hypothesis that the low capacity of the Cl- homeostasis in immature neurons could be a substrate for synaptic scaling and homeostatic plasticity.
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Affiliation(s)
- Sergey N Kolbaev
- Institute of Physiology and Pathophysiology, University Medical Center Mainz, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
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