151
|
Kessaris N, Magno L, Rubin AN, Oliveira MG. Genetic programs controlling cortical interneuron fate. Curr Opin Neurobiol 2014; 26:79-87. [PMID: 24440413 PMCID: PMC4082532 DOI: 10.1016/j.conb.2013.12.012] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/17/2013] [Accepted: 12/19/2013] [Indexed: 11/04/2022]
Abstract
Cortical interneurons originate in the embryonic subcortical telencephalon. Spatial and temporal control of progenitor differentiation generates diversity. Genetic pathways of interneuron cell fate specification. Intrinsic pathways and extrinsic cues interplay in interneuron specification.
The origins of cortical interneurons in rodents have been localized to the embryonic subcortical telencephalon where distinct neuroepithelial precursors generate defined interneuron subsets. A swathe of research activity aimed at identifying molecular determinants of subtype identity has uncovered a number of transcription factors that function at different stages of interneuron development. Pathways that lead to the acquisition of mature interneuron traits are therefore beginning to emerge. As genetic programs are influenced by external factors the search continues not only into genetic determinants but also extrinsic influences and the interplay between the two in cell fate specification.
Collapse
Affiliation(s)
- Nicoletta Kessaris
- Wolfson Institute for Biomedical Research and Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Lorenza Magno
- Wolfson Institute for Biomedical Research and Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Anna Noren Rubin
- Wolfson Institute for Biomedical Research and Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Marcio Guiomar Oliveira
- Wolfson Institute for Biomedical Research and Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK
| |
Collapse
|
152
|
Decision making during interneuron migration in the developing cerebral cortex. Trends Cell Biol 2014; 24:342-51. [PMID: 24388877 DOI: 10.1016/j.tcb.2013.12.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 12/02/2013] [Accepted: 12/03/2013] [Indexed: 01/06/2023]
Abstract
Appropriate interneuron migration and distribution is essential for the construction of functional neuronal circuitry and the maintenance of excitatory/inhibitory balance in the brain. Gamma-aminobutyric acid (GABA)ergic interneurons originating from the ventral telencephalon choreograph a complex pattern of migration to reach their target destinations within the developing brain. This review examines the cellular and molecular underpinnings of the major decision-making steps involved in this process of oriental navigation of cortical interneurons.
Collapse
|
153
|
Rakić S, Kanatani S, Hunt D, Faux C, Cariboni A, Chiara F, Khan S, Wansbury O, Howard B, Nakajima K, Nikolić M, Parnavelas JG. Cdk5 phosphorylation of ErbB4 is required for tangential migration of cortical interneurons. ACTA ACUST UNITED AC 2013; 25:991-1003. [PMID: 24142862 PMCID: PMC4380000 DOI: 10.1093/cercor/bht290] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Interneuron dysfunction in humans is often associated with neurological and psychiatric disorders, such as epilepsy, schizophrenia, and autism. Some of these disorders are believed to emerge during brain formation, at the time of interneuron specification, migration, and synapse formation. Here, using a mouse model and a host of histological and molecular biological techniques, we report that the signaling molecule cyclin-dependent kinase 5 (Cdk5), and its activator p35, control the tangential migration of interneurons toward and within the cerebral cortex by modulating the critical neurodevelopmental signaling pathway, ErbB4/phosphatidylinositol 3-kinase, that has been repeatedly linked to schizophrenia. This finding identifies Cdk5 as a crucial signaling factor in cortical interneuron development in mammals.
Collapse
Affiliation(s)
- Sonja Rakić
- Department of Cell and Developmental Biology, University College London, London WC1 6BT, UK
| | - Shigeaki Kanatani
- Department of Anatomy, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - David Hunt
- Department of Cell and Developmental Biology, University College London, London WC1 6BT, UK
| | - Clare Faux
- Department of Cell and Developmental Biology, University College London, London WC1 6BT, UK
| | - Anna Cariboni
- Department of Cell and Developmental Biology, University College London, London WC1 6BT, UK
| | - Francesca Chiara
- Department of Cell and Developmental Biology, University College London, London WC1 6BT, UK
| | - Shabana Khan
- Department of Cell and Developmental Biology, University College London, London WC1 6BT, UK
| | - Olivia Wansbury
- Breakthrough Breast Cancer Research Centre, Institute of Cancer Research, London SW3 6JB, UK
| | - Beatrice Howard
- Breakthrough Breast Cancer Research Centre, Institute of Cancer Research, London SW3 6JB, UK
| | - Kazunori Nakajima
- Department of Anatomy, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Margareta Nikolić
- Department of Cellular and Molecular Neuroscience, Imperial College School of Medicine, London W12 0NN, UK
| | - John G Parnavelas
- Department of Cell and Developmental Biology, University College London, London WC1 6BT, UK
| |
Collapse
|
154
|
PROX1: a lineage tracer for cortical interneurons originating in the lateral/caudal ganglionic eminence and preoptic area. PLoS One 2013; 8:e77339. [PMID: 24155945 PMCID: PMC3796451 DOI: 10.1371/journal.pone.0077339] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 08/31/2013] [Indexed: 11/19/2022] Open
Abstract
The homeobox-encoding gene Prox1 and its Drosophila homologue prospero are key regulators of cell fate-specification. In the developing rodent cortex a sparse population of cells thought to correspond to late-generated cortical pyramidal neuron precursors expresses PROX1. Using a series of transgenic mice that mark cell lineages in the subcortical telencephalon and, more specifically, different populations of cortical interneurons, we demonstrate that neurons expressing PROX1 do not represent pyramidal neurons or their precursors but are instead subsets of cortical interneurons. These correspond to interneurons originating in the lateral/caudal ganglionic eminence (LGE/CGE) and a small number of preoptic area (POA)-derived neurons. Expression within the cortex can be detected from late embryonic stages onwards when cortical interneurons are still migrating. There is persistent expression in postmitotic cells in the mature brain mainly in the outer cortical layers. PROX1(+ve) interneurons express neurochemical markers such as calretinin, neuropeptide Y, reelin and vasoactive intestinal peptide, all of which are enriched in LGE/CGE- and some POA-derived cells. Unlike in the cortex, in the striatum PROX1 marks nearly all interneurons regardless of their origin. Weak expression of PROX1 can also be detected in oligodendrocyte lineage cells throughout the forebrain. Our data show that PROX1 can be used as a genetic lineage tracer of nearly all LGE/CGE- and subsets POA-derived cortical interneurons at all developmental and postnatal stages in vivo.
Collapse
|
155
|
Greig LC, Woodworth MB, Galazo MJ, Padmanabhan H, Macklis JD. Molecular logic of neocortical projection neuron specification, development and diversity. Nat Rev Neurosci 2013; 14:755-69. [PMID: 24105342 DOI: 10.1038/nrn3586] [Citation(s) in RCA: 583] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The sophisticated circuitry of the neocortex is assembled from a diverse repertoire of neuronal subtypes generated during development under precise molecular regulation. In recent years, several key controls over the specification and differentiation of neocortical projection neurons have been identified. This work provides substantial insight into the 'molecular logic' underlying cortical development and increasingly supports a model in which individual progenitor-stage and postmitotic regulators are embedded within highly interconnected networks that gate sequential developmental decisions. Here, we provide an integrative account of the molecular controls that direct the progressive development and delineation of subtype and area identity of neocortical projection neurons.
Collapse
|
156
|
Dual origins of functionally distinct O-LM interneurons revealed by differential 5-HT(3A)R expression. Nat Neurosci 2013; 16:1598-607. [PMID: 24097043 PMCID: PMC3839306 DOI: 10.1038/nn.3538] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/11/2013] [Indexed: 12/31/2022]
Abstract
Forebrain circuits rely upon a relatively small but remarkably diverse population of GABAergic interneurons to bind and entrain large principal cell assemblies for network synchronization and rhythmogenesis. Despite the high degree of heterogeneity across cortical interneurons, members of a given subtype typically exhibit homogeneous developmental origins, neuromodulatory response profiles, morphological characteristics, neurochemical signatures, and electrical features. Here we report a surprising divergence amongst hippocampal oriens-lacunosum moleculare (O-LM) projecting interneurons that have hitherto been considered a homogeneous cell population. Combined immunocytochemical, anatomical, and electrophysiological interrogation of Htr3a-GFP and Nkx2-1-cre:RCE mice revealed that O-LM cells parse into caudal ganglionic eminence-derived 5-HT3AR-expressing, and medial ganglionic eminence- derived 5-HT3AR-lacking subpopulations. These two cohorts differentially participate in network oscillations with 5-HT3AR-containing O-LM cell recruitment dictated by serotonergic tone. Thus, members of a seemingly uniform interneuron population can exhibit unique circuit functions and neuromodulatory properties dictated by disparate developmental origins.
Collapse
|
157
|
Lin LC, Sibille E. Reduced brain somatostatin in mood disorders: a common pathophysiological substrate and drug target? Front Pharmacol 2013; 4:110. [PMID: 24058344 PMCID: PMC3766825 DOI: 10.3389/fphar.2013.00110] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Accepted: 08/13/2013] [Indexed: 12/23/2022] Open
Abstract
Our knowledge of the pathophysiology of affect dysregulation has progressively increased, but the pharmacological treatments remain inadequate. Here, we summarize the current literature on deficits in somatostatin, an inhibitory modulatory neuropeptide, in major depression and other neurological disorders that also include mood disturbances. We focus on direct evidence in the human postmortem brain, and review rodent genetic and pharmacological studies probing the role of the somatostatin system in relation to mood. We also briefly go over pharmacological developments targeting the somatostatin system in peripheral organs and discuss the challenges of targeting the brain somatostatin system. Finally, the fact that somatostatin deficits are frequently observed across neurological disorders suggests a selective cellular vulnerability of somatostatin-expressing neurons. Potential cell intrinsic factors mediating those changes are discussed, including nitric oxide induced oxidative stress, mitochondrial dysfunction, high inflammatory response, high demand for neurotrophic environment, and overall aging processes. Together, based on the co-localization of somatostatin with gamma-aminobutyric acid (GABA), its presence in dendritic-targeting GABA neuron subtypes, and its temporal-specific function, we discuss the possibility that deficits in somatostatin play a central role in cortical local inhibitory circuit deficits leading to abnormal corticolimbic network activity and clinical mood symptoms across neurological disorders.
Collapse
Affiliation(s)
- Li-Chun Lin
- Department of Psychiatry, Center for Neuroscience, University of Pittsburgh Pittsburgh, PA, USA
| | | |
Collapse
|
158
|
Bartolini G, Ciceri G, Marín O. Integration of GABAergic Interneurons into Cortical Cell Assemblies: Lessons from Embryos and Adults. Neuron 2013; 79:849-64. [DOI: 10.1016/j.neuron.2013.08.014] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2013] [Indexed: 01/31/2023]
|
159
|
Directed differentiation of forebrain GABA interneurons from human pluripotent stem cells. Nat Protoc 2013; 8:1670-9. [PMID: 23928500 DOI: 10.1038/nprot.2013.106] [Citation(s) in RCA: 205] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Forebrain γ-aminobutyric acid (GABA) interneurons have crucial roles in high-order brain function via modulating network activities and plasticity, and they are implicated in many psychiatric disorders. Availability of enriched functional human forebrain GABA interneurons, especially those from people affected by GABA interneuron deficit disease, will be instrumental to the investigation of disease pathogenesis and development of therapeutics. We describe a protocol for directed differentiation of forebrain GABA interneurons from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) in a chemically defined system. In this protocol, human PSCs are first induced to primitive neuroepithelial cells over 10 d, and then patterned to NKX2.1-expressing medial ganglionic eminence progenitors by simple treatment with sonic hedgehog or its agonist purmorphamine over the next 2 weeks. These progenitors generate a nearly pure population of forebrain GABA interneurons by the sixth week. This simple and efficient protocol does not require transgenic modification or cell sorting, and it has been replicated with multiple human ESC and iPSC lines.
Collapse
|
160
|
Chiu CQ, Lur G, Morse TM, Carnevale NT, Ellis-Davies GCR, Higley MJ. Compartmentalization of GABAergic inhibition by dendritic spines. Science 2013; 340:759-62. [PMID: 23661763 DOI: 10.1126/science.1234274] [Citation(s) in RCA: 218] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
γ-aminobutyric acid-mediated (GABAergic) inhibition plays a critical role in shaping neuronal activity in the neocortex. Numerous experimental investigations have examined perisomatic inhibitory synapses, which control action potential output from pyramidal neurons. However, most inhibitory synapses in the neocortex are formed onto pyramidal cell dendrites, where theoretical studies suggest they may focally regulate cellular activity. The precision of GABAergic control over dendritic electrical and biochemical signaling is unknown. By using cell type-specific optical stimulation in combination with two-photon calcium (Ca(2+)) imaging, we show that somatostatin-expressing interneurons exert compartmentalized control over postsynaptic Ca(2+) signals within individual dendritic spines. This highly focal inhibitory action is mediated by a subset of GABAergic synapses that directly target spine heads. GABAergic inhibition thus participates in localized control of dendritic electrical and biochemical signaling.
Collapse
Affiliation(s)
- Chiayu Q Chiu
- Department of Neurobiology, Yale School of Medicine, New Haven, CT 06510, USA
| | | | | | | | | | | |
Collapse
|
161
|
Germain ND, Banda EC, Becker S, Naegele JR, Grabel LB. Derivation and isolation of NKX2.1-positive basal forebrain progenitors from human embryonic stem cells. Stem Cells Dev 2013; 22:1477-89. [PMID: 23351095 PMCID: PMC4854221 DOI: 10.1089/scd.2012.0264] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 01/22/2013] [Indexed: 10/27/2022] Open
Abstract
Gamma aminobutyric acid (GABA)-expressing interneurons are the major inhibitory cells of the cerebral cortex and hippocampus. These interneurons originate in the medial ganglionic eminence (MGE) and lateral ganglionic eminence of the ventral forebrain during embryonic development and show reduced survival and function in a variety of neurological disorders, including temporal lobe epilepsy. We and others have proposed that embryonic stem cell (ESC)-derived ventral forebrain progenitors might provide a source of new GABAergic interneurons for cell-based therapies. While human ESCs (hESCs) are readily differentiated in vitro into dorsal telencephalic neural progenitors, standard protocols for generating ventral subtypes of telencephalic progenitors are less effective. We now report efficient derivation of GABAergic progenitors using an established hESC reporter line that expresses green fluorescent protein (GFP) under the control of an endogenous NKX2.1 promoter. GABAergic progenitors were derived from this hESC line by a modified monolayer neural differentiation protocol. Consistent with sonic hedgehog (SHH)-dependent specification of NKX2.1-positive progenitors in the embryonic MGE, we show a dose-dependent increase in the generation of NKX2.1:GFP-positive progenitors after SHH treatment in vitro. Characterization of NKX2.1:GFP-positive cells confirms their identity as MGE-like neural progenitors, based on gene expression profiles and their ability to differentiate into GABAergic interneurons. We are also able to generate highly enriched populations of NKX2.1:GFP-positive progenitors, including cells with telencephalic identity, by fluorescence-activated cell sorting. These hESC-derived ventral forebrain progenitors are suitable candidates for cell-based therapies that aim at replacing dysfunctional or damaged cortical or hippocampal GABAergic interneurons.
Collapse
Affiliation(s)
| | - Erin C. Banda
- Department of Biology, Wesleyan University, Middletown, Connecticut
| | - Sandy Becker
- Department of Biology, Wesleyan University, Middletown, Connecticut
| | - Janice R. Naegele
- Department of Biology, Wesleyan University, Middletown, Connecticut
- Program in Neuroscience and Behavior, Wesleyan University, Middletown, Connecticut
| | - Laura B. Grabel
- Department of Biology, Wesleyan University, Middletown, Connecticut
| |
Collapse
|
162
|
Marín O. Cellular and molecular mechanisms controlling the migration of neocortical interneurons. Eur J Neurosci 2013; 38:2019-29. [DOI: 10.1111/ejn.12225] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/18/2013] [Accepted: 03/21/2013] [Indexed: 12/16/2022]
Affiliation(s)
- Oscar Marín
- Instituto de Neurociencias; Consejo Superior de Investigaciones Científicas; Universidad Miguel Hernández; Sant Joan d'Alacant; Spain
| |
Collapse
|
163
|
Neurons and circuits for odor processing in the piriform cortex. Trends Neurosci 2013; 36:429-38. [PMID: 23648377 DOI: 10.1016/j.tins.2013.04.005] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/04/2013] [Accepted: 04/04/2013] [Indexed: 01/13/2023]
Abstract
Increased understanding of the early stages of olfaction has lead to a renewed interest in the higher brain regions responsible for forming unified 'odor images' from the chemical components detected by the nose. The piriform cortex, which is one of the first cortical destinations of olfactory information in mammals, is a primitive paleocortex that is critical for the synthetic perception of odors. Here we review recent work that examines the cellular neurophysiology of the piriform cortex. Exciting new findings have revealed how the neurons and circuits of the piriform cortex process odor information, demonstrating that, despite its superficial simplicity, the piriform cortex is a remarkably subtle and intricate neural circuit.
Collapse
|
164
|
Wang B, Long JE, Flandin P, Pla R, Waclaw RR, Campbell K, Rubenstein JLR. Loss of Gsx1 and Gsx2 function rescues distinct phenotypes in Dlx1/2 mutants. J Comp Neurol 2013; 521:1561-84. [PMID: 23042297 PMCID: PMC3615175 DOI: 10.1002/cne.23242] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 07/31/2012] [Accepted: 10/02/2012] [Indexed: 11/14/2022]
Abstract
Mice lacking the Dlx1 and Dlx2 homeobox genes (Dlx1/2 mutants) have severe deficits in subpallial differentiation, including overexpression of the Gsx1 and Gsx2 homeobox genes. To investigate whether Gsx overexpression contributes to the Dlx1/2 mutant phenotypes, we made compound loss-of-function mutants. Eliminating Gsx2 function from the Dlx1/2 mutants rescued the increased expression of Ascl1 and Hes5 (Notch signaling mediators) and Olig2 (oligodendrogenesis mediator). In addition, Dlx1/2;Gsx2 mutants, like Dlx1/2;Ascl1 mutants, exacerbated the Gsx2 and Dlx1/2 patterning and differentiation phenotypes, particularly in the lateral ganglionic eminence (LGE) caudal ganglionic eminence (CGE), and septum, including loss of GAD1 expression. On the other hand, eliminating Gsx1 function from the Dlx1/2 mutants (Dlx1/2;Gsx1 mutants) did not severely exacerbate their phenotype; on the contrary, it resulted in a partial rescue of medial ganglionic eminence (MGE) properties, including interneuron migration to the cortex. Thus, despite their redundant properties, Gsx1 and -2 have distinct interactions with Dlx1 and -2. Gsx2 interaction is strongest in the LGE, CGE, and septum, whereas the Gsx1 interaction is strongest in the MGE. From these studies, and earlier studies, we present a model of the transcriptional network that regulates early steps of subcortical development.
Collapse
Affiliation(s)
- Bei Wang
- Department of Psychiatry and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San FranciscoSan Francisco, California 94158-2324
| | - Jason E Long
- Department of Psychiatry and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San FranciscoSan Francisco, California 94158-2324
| | - Pierre Flandin
- Department of Psychiatry and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San FranciscoSan Francisco, California 94158-2324
| | - Ramon Pla
- Department of Psychiatry and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San FranciscoSan Francisco, California 94158-2324
| | - Ronald R Waclaw
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of MedicineCincinnati, Ohio 45229
| | - Kenneth Campbell
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of MedicineCincinnati, Ohio 45229
| | - John LR Rubenstein
- Department of Psychiatry and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San FranciscoSan Francisco, California 94158-2324
| |
Collapse
|
165
|
Le Magueresse C, Monyer H. GABAergic interneurons shape the functional maturation of the cortex. Neuron 2013; 77:388-405. [PMID: 23395369 DOI: 10.1016/j.neuron.2013.01.011] [Citation(s) in RCA: 308] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2013] [Indexed: 10/27/2022]
Abstract
From early embryonic development to adulthood, GABA release participates in the construction of the mammalian cerebral cortex. The maturation of GABAergic neurotransmission is a protracted process which takes place in discrete steps and results from the dynamic interaction between developmentally directed gene expression and brain activity. During the course of development, GABAergic interneurons contribute to key aspects of the functional maturation of the cortex in different ways, from exerting a trophic role to pacing immature neural networks. In this review, we provide an overview of the maturation of GABAergic neurotransmission and discuss the role of GABAergic interneurons in cortical wiring, plasticity, and network activity during pre- and postnatal development. We also discuss psychiatric diseases that may be considered at least in part developmental disorders of the GABAergic system.
Collapse
Affiliation(s)
- Corentin Le Magueresse
- Department of Clinical Neurobiology, Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | | |
Collapse
|
166
|
Lahti L, Achim K, Partanen J. Molecular regulation of GABAergic neuron differentiation and diversity in the developing midbrain. Acta Physiol (Oxf) 2013; 207:616-27. [PMID: 23297792 DOI: 10.1111/apha.12062] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 12/10/2012] [Accepted: 12/26/2012] [Indexed: 12/23/2022]
Abstract
The midbrain GABAergic neurones control several aspects of behaviour, play important roles in psychiatric disease and are targets of medical treatments as well as drugs of abuse. However, their molecular diversity and regulation of development are only beginning to be understood. In this review, we briefly introduce distinct subpopulations of the midbrain GABAergic neurones and discuss knowledge on their development, including the developmental origins of midbrain GABAergic neurones as well as transcriptional regulatory mechanisms guiding their differentiation and identity. Important GABAergic neuron subpopulations are found within the dopaminergic (DA) nuclei in the ventral midbrain. GABAergic substantia nigra pars reticulata is the main output pathway of the basal ganglia system regulating voluntary movements. Recent studies have also highlighted importance of the GABAergic neurones associated with the ventral tegmental area for the control of DA neuron activity and motivated behaviours. Interestingly, the development of the GABAergic neurones associated with the DA nuclei is very different from the rest of the midbrain. Knowledge on developmental regulation can lead to insights into the molecular, structural and functional diversity of the midbrain GABAergic neurones and their subpopulations, cell groups of great physiological and medical interest.
Collapse
Affiliation(s)
- L. Lahti
- Department of Biosciences; Viikki Biocenter; University of Helsinki; Helsinki; Finland
| | - K. Achim
- European Molecular Biology Laboratory; Heidelberg; Germany
| | - J. Partanen
- Department of Biosciences; Viikki Biocenter; University of Helsinki; Helsinki; Finland
| |
Collapse
|
167
|
Neocortical somatostatin-expressing GABAergic interneurons disinhibit the thalamorecipient layer 4. Neuron 2013; 77:155-67. [PMID: 23312523 DOI: 10.1016/j.neuron.2012.11.004] [Citation(s) in RCA: 257] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2012] [Indexed: 12/25/2022]
Abstract
Subtypes of GABAergic interneurons (INs) are crucial for cortical function, yet their specific roles are largely unknown. In contrast to supra- and infragranular layers, where most somatostatin-expressing (SOM) INs are layer 1-targeting Martinotti cells, the axons of SOM INs in layer 4 of somatosensory cortex largely remain within layer 4. Moreover, we found that whereas layers 2/3 SOM INs target mainly pyramidal cells (PCs), layer 4 SOM INs target mainly fast-spiking (FS) INs. Accordingly, optogenetic inhibition of SOM INs in an active cortical network increases the firing of layers 2/3 PCs whereas it decreases the firing of layer 4 principal neurons (PNs). This unexpected effect of SOM INs on layer 4 PNs occurs via their inhibition of local FS INs. These results reveal a disinhibitory microcircuit in the thalamorecipient layer through interactions among subtypes of INs and suggest that the SOM IN-mediated disinhibition represents an important circuit mechanism for cortical information processing.
Collapse
|
168
|
Cxcr4 regulation of interneuron migration is disrupted in 22q11.2 deletion syndrome. Proc Natl Acad Sci U S A 2012; 109:18601-6. [PMID: 23091025 DOI: 10.1073/pnas.1211507109] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Interneurons are thought to be a primary pathogenic target for several behavioral disorders that arise during development, including schizophrenia and autism. It is not known, however, whether genetic lesions associated with these diseases disrupt established molecular mechanisms of interneuron development. We found that diminished 22q11.2 gene dosage-the primary genetic lesion in 22q11.2 deletion syndrome (22q11.2 DS)-specifically compromises the distribution of early-generated parvalbumin-expressing interneurons in the Large Deletion (LgDel) 22q11.2DS mouse model. This change reflects cell-autonomous disruption of interneuron migration caused by altered expression of the cytokine C-X-C chemokine receptor type 4 (Cxcr4), an established regulator of this process. Cxcr4 is specifically reduced in LgDel migrating interneurons, and genetic analysis confirms that diminished Cxcr4 alters interneuron migration in LgDel mice. Thus, diminished 22q11.2 gene dosage disrupts cortical circuit development by modifying a critical molecular signaling pathway via Cxcr4 that regulates cortical interneuron migration and placement.
Collapse
|
169
|
Abstract
Switches between different behavioral states of the animal are associated with prominent changes in global brain activity, between sleep and wakefulness or from inattentive to vigilant states. What mechanisms control brain states, and what are the functions of the different states? Here we summarize current understanding of the key neural circuits involved in regulating brain states, with a particular emphasis on the subcortical neuromodulatory systems. At the functional level, arousal and attention can greatly enhance sensory processing, whereas sleep and quiet wakefulness may facilitate learning and memory. Several new techniques developed over the past decade promise great advances in our understanding of the neural control and function of different brain states.
Collapse
Affiliation(s)
- Seung-Hee Lee
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, California 94720
| | - Yang Dan
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, California 94720
| |
Collapse
|
170
|
Jaglin XH, Hjerling-Leffler J, Fishell G, Batista-Brito R. The origin of neocortical nitric oxide synthase-expressing inhibitory neurons. Front Neural Circuits 2012; 6:44. [PMID: 22787442 PMCID: PMC3391688 DOI: 10.3389/fncir.2012.00044] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 06/20/2012] [Indexed: 01/08/2023] Open
Abstract
Inhibitory neurons are critical for regulating effective transfer of sensory information and network stability. The precision of inhibitory function likely derives from the existence of a variety of interneuron subtypes. Their specification is largely dependent on the locale of origin of interneuron progenitors. Neocortical and hippocampal inhibitory neurons originate the subpallium, namely in the medial and caudal ganglionic eminences (MGE and CGE), and in the preoptic area (POA). In the hippocampus, neuronal nitric oxide synthase (nNOS)-expressing cells constitute a numerically large GABAergic interneuron population. On the contrary, nNOS-expressing inhibitory neurons constitute the smallest of the known neocortical GABAergic neuronal subtypes. The origins of most neocortical GABAergic neuron subtypes have been thoroughly investigated, however, very little is known about the origin of, or the genetic programs underlying the development of nNOS neurons. Here, we show that the vast majority of neocortical nNOS-expressing neurons arise from the MGE rather than the CGE. Regarding their molecular signature, virtually all neocortical nNOS neurons co-express the neuropeptides somatostatin (SST) and neuropeptide Y (NPY), and about half of them express the calcium-binding protein calretinin (CR). nNOS neurons thus constitute a small cohort of the MGE-derived SST-expressing population of cortical inhibitory neurons. Finally, we show that conditional removal of the transcription factor Sox6 in MGE-derived GABAergic cortical neurons results in an absence of SST and CR expression, as well as reduced expression of nNOS in neocortical nNOS neurons. Based on their respective abundance, origin and molecular signature, our results suggest that neocortical and hippocampal nNOS GABAergic neurons likely subserve different functions and have very different physiological relevance in these two cortical structures.
Collapse
Affiliation(s)
- Xavier H Jaglin
- NYU Neuroscience Institute, New York University Langone Medical Center New York, NY, USA
| | | | | | | |
Collapse
|
171
|
Dynamic changes in interneuron morphophysiological properties mark the maturation of hippocampal network activity. J Neurosci 2012; 32:6688-98. [PMID: 22573691 DOI: 10.1523/jneurosci.0081-12.2012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
During early postnatal development, neuronal networks successively produce various forms of spontaneous patterned activity that provide key signals for circuit maturation. Initially, in both rodent hippocampus and neocortex, coordinated activity emerges in the form of synchronous plateau assemblies (SPAs) that are initiated by sparse groups of gap-junction-coupled oscillating neurons. Subsequently, SPAs are replaced by synapse-driven giant depolarizing potentials (GDPs). Whether these sequential changes in mechanistically distinct network activities correlate with modifications in single-cell properties is unknown. To determine this, we studied the morphophysiological fate of single SPA cells as a function of development. We focused on CA3 GABAergic interneurons, which are centrally involved in generating GDPs in the hippocampus. As the network matures, GABAergic neurons are engaged more in GDPs and less in SPAs. Using inducible genetic fate mapping, we show that the individual involvement of GABAergic neurons in SPAs is correlated to their temporal origin. In addition, we demonstrate that the SPA-to-GDP transition is paralleled by a remarkable maturation in the morphophysiological properties of GABAergic neurons. Compared with those involved in GDPs, interneurons participating in SPAs possess immature intrinsic properties, receive synaptic inputs spanning a wide amplitude range, and display large somata as well as membrane protrusions. Thus, a developmental switch in the morphophysiological properties of GABAergic interneurons as they progress from SPAs to GDPs marks the emergence of synapse-driven network oscillations.
Collapse
|
172
|
Arber S. Motor Circuits in Action: Specification, Connectivity, and Function. Neuron 2012; 74:975-89. [DOI: 10.1016/j.neuron.2012.05.011] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2012] [Indexed: 10/28/2022]
|
173
|
Apicella AJ, Wickersham IR, Seung HS, Shepherd GMG. Laminarly orthogonal excitation of fast-spiking and low-threshold-spiking interneurons in mouse motor cortex. J Neurosci 2012; 32:7021-33. [PMID: 22593070 PMCID: PMC3377057 DOI: 10.1523/jneurosci.0011-12.2012] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Revised: 03/27/2012] [Accepted: 04/04/2012] [Indexed: 11/21/2022] Open
Abstract
In motor cortex, long-range output to subcortical motor circuits depends on excitatory and inhibitory inputs converging on projection neurons in layers 5A/B. How interneurons interconnect with these projection neurons, and whether these microcircuits are interneuron and/or projection specific, is unclear. We found that fast-spiking interneurons received strong intralaminar (horizontal) excitation from pyramidal neurons in layers 5A/B including corticostriatal and corticospinal neurons, implicating them in mediating disynaptic recurrent, feedforward, and feedback inhibition within and across the two projection classes. Low-threshold-spiking (LTS) interneurons were instead strongly excited by descending interlaminar (vertical) input from layer 2/3 pyramidal neurons, implicating them in mediating disynaptic feedforward inhibition to both projection classes. Furthermore, in a novel pattern, lower layer 2/3 preferentially excited interneurons in one layer (5A/LTS) and excitatory neurons in another (5B/corticospinal). Thus, these inhibitory microcircuits in mouse motor cortex follow an orderly arrangement that is laminarly orthogonalized by interneuron-specific, projection-nonspecific connectivity.
Collapse
Affiliation(s)
- Alfonso J. Apicella
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, and
| | - Ian R. Wickersham
- Howard Hughes Medical Institute and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - H. Sebastian Seung
- Howard Hughes Medical Institute and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Gordon M. G. Shepherd
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, and
| |
Collapse
|
174
|
Faux C, Rakic S, Andrews W, Britto JM. Neurons on the move: migration and lamination of cortical interneurons. Neurosignals 2012; 20:168-89. [PMID: 22572780 DOI: 10.1159/000334489] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The modulation of cortical activity by GABAergic interneurons is required for normal brain function and is achieved through the immense level of heterogeneity within this neuronal population. Cortical interneurons share a common origin in the ventral telencephalon, yet during the maturation process diverse subtypes are generated that form the characteristic laminar arrangement observed in the adult brain. The long distance tangential and short-range radial migration into the cortical plate is regulated by a combination of intrinsic and extrinsic signalling mechanisms, and a great deal of progress has been made to understand these developmental events. In this review, we will summarize current findings regarding the molecular control of subtype specification and provide a detailed account of the migratory cues influencing interneuron migration and lamination. Furthermore, a dysfunctional GABAergic system is associated with a number of neurological and psychiatric conditions, and some of these may have a developmental aetiology with alterations in interneuron generation and migration. We will discuss the notion of additional sources of interneuron progenitors found in human and non-human primates and illustrate how the disruption of early developmental events can instigate a loss in GABAergic function.
Collapse
Affiliation(s)
- Clare Faux
- Centre for Neuroscience, University of Melbourne, Parkville, Vic, Australia
| | | | | | | |
Collapse
|
175
|
Lee Y, Shull ERP, Frappart PO, Katyal S, Enriquez-Rios V, Zhao J, Russell HR, Brown EJ, McKinnon PJ. ATR maintains select progenitors during nervous system development. EMBO J 2012; 31:1177-89. [PMID: 22266795 DOI: 10.1038/emboj.2011.493] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 12/19/2011] [Indexed: 01/09/2023] Open
Abstract
The ATR (ATM (ataxia telangiectasia mutated) and rad3-related) checkpoint kinase is considered critical for signalling DNA replication stress and its dysfunction can lead to the neurodevelopmental disorder, ATR-Seckel syndrome. To understand how ATR functions during neurogenesis, we conditionally deleted Atr broadly throughout the murine nervous system, or in a restricted manner in the dorsal telencephalon. Unexpectedly, in both scenarios, Atr loss impacted neurogenesis relatively late during neural development involving only certain progenitor populations. Whereas the Atr-deficient embryonic cerebellar external germinal layer underwent p53- (and p16(Ink4a/Arf))-independent proliferation arrest, other brain regions suffered apoptosis that was partially p53 dependent. In contrast to other organs, in the nervous system, p53 loss did not worsen the outcome of Atr inactivation. Coincident inactivation of Atm also did not affect the phenotype after Atr deletion, supporting non-overlapping physiological roles for these related DNA damage-response kinases in the brain. Rather than an essential general role in preventing replication stress, our data indicate that ATR functions to monitor genomic integrity in a selective spatiotemporal manner during neurogenesis.
Collapse
Affiliation(s)
- Youngsoo Lee
- Department of Genetics, St Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
176
|
Stolp H, Neuhaus A, Sundramoorthi R, Molnár Z. The Long and the Short of it: Gene and Environment Interactions During Early Cortical Development and Consequences for Long-Term Neurological Disease. Front Psychiatry 2012; 3:50. [PMID: 22701439 PMCID: PMC3372875 DOI: 10.3389/fpsyt.2012.00050] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 05/01/2012] [Indexed: 01/21/2023] Open
Abstract
Cortical development is a complex amalgamation of proliferation, migration, differentiation, and circuit formation. These processes follow defined timescales and are controlled by a combination of intrinsic and extrinsic factors. It is currently unclear how robust and flexible these processes are and whether the developing brain has the capacity to recover from disruptions. What is clear is that there are a number of cognitive disorders or conditions that are elicited as a result of disrupted cortical development, although it may take a long time for the full pathophysiology of the conditions to be realized clinically. The critical window for the manifestation of a neurodevelopmental disorder is prolonged, and there is the potential for a complex interplay between genes and environment. While there have been extended investigations into the genetic basis of a number of neurological and mental disorders, limited definitive associations have been discovered. Many environmental factors, including inflammation and stress, have been linked to neurodevelopmental disorders, and it may be that a better understanding of the interplay between genes and environment will speed progress in this field. In particular, the development of the brain needs to be considered in the context of the whole materno-fetal unit as the degree of the metabolic, endocrine, or inflammatory responses, for example, will greatly influence the environment in which the brain develops. This review will emphasize the importance of extending neurodevelopmental studies to the contribution of the placenta, vasculature, cerebrospinal fluid, and to maternal and fetal immune response. These combined investigations are more likely to reveal genetic and environmental factors that influence the different stages of neuronal development and potentially lead to the better understanding of the etiology of neurological and mental disorders such as autism, epilepsy, cerebral palsy, and schizophrenia.
Collapse
Affiliation(s)
- Helen Stolp
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
| | | | | | | |
Collapse
|
177
|
Langer D, Helmchen F. Post hoc immunostaining of GABAergic neuronal subtypes following in vivo two-photon calcium imaging in mouse neocortex. Pflugers Arch 2011; 463:339-54. [PMID: 22134770 PMCID: PMC3261390 DOI: 10.1007/s00424-011-1048-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 09/28/2011] [Accepted: 10/17/2011] [Indexed: 01/11/2023]
Abstract
GABAergic neurons in the neocortex are diverse with regard to morphology, physiology, and axonal targeting pattern, indicating functional specializations within the cortical microcircuitry. Little information is available, however, about functional properties of distinct subtypes of GABAergic neurons in the intact brain. Here, we combined in vivo two-photon calcium imaging in supragranular layers of the mouse neocortex with post hoc immunohistochemistry against the three calcium-binding proteins parvalbumin, calretinin, and calbindin in order to assign subtype marker profiles to neuronal activity. Following coronal sectioning of fixed brains, we matched cells in corresponding volumes of image stacks acquired in vivo and in fixed brain slices. In GAD67-GFP mice, more than 95% of the GABAergic cells could be unambiguously matched, even in large volumes comprising more than a thousand interneurons. Triple immunostaining revealed a depth-dependent distribution of interneuron subtypes with increasing abundance of PV-positive neurons with depth. Most importantly, the triple-labeling approach was compatible with previous in vivo calcium imaging following bulk loading of Oregon Green 488 BAPTA-1, which allowed us to classify spontaneous calcium transients recorded in vivo according to the neurochemically defined GABAergic subtypes. Moreover, we demonstrate that post hoc immunostaining can also be applied to wild-type mice expressing the genetically encoded calcium indicator Yellow Cameleon 3.60 in cortical neurons. Our approach is a general and flexible method to distinguish GABAergic subtypes in cell populations previously imaged in the living animal. It should thus facilitate dissecting the functional roles of these subtypes in neural circuitry.
Collapse
Affiliation(s)
- Dominik Langer
- Department of Neurophysiology, Brain Research Institute, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | | |
Collapse
|
178
|
Self-organizing circuit assembly through spatiotemporally coordinated neuronal migration within geometric constraints. PLoS One 2011; 6:e28156. [PMID: 22132234 PMCID: PMC3222678 DOI: 10.1371/journal.pone.0028156] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 11/02/2011] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Neurons are dynamically coupled with each other through neurite-mediated adhesion during development. Understanding the collective behavior of neurons in circuits is important for understanding neural development. While a number of genetic and activity-dependent factors regulating neuronal migration have been discovered on single cell level, systematic study of collective neuronal migration has been lacking. Various biological systems are shown to be self-organized, and it is not known if neural circuit assembly is self-organized. Besides, many of the molecular factors take effect through spatial patterns, and coupled biological systems exhibit emergent property in response to geometric constraints. How geometric constraints of the patterns regulate neuronal migration and circuit assembly of neurons within the patterns remains unexplored. METHODOLOGY/PRINCIPAL FINDINGS We established a two-dimensional model for studying collective neuronal migration of a circuit, with hippocampal neurons from embryonic rats on Matrigel-coated self-assembled monolayers (SAMs). When the neural circuit is subject to geometric constraints of a critical scale, we found that the collective behavior of neuronal migration is spatiotemporally coordinated. Neuronal somata that are evenly distributed upon adhesion tend to aggregate at the geometric center of the circuit, forming mono-clusters. Clustering formation is geometry-dependent, within a critical scale from 200 µm to approximately 500 µm. Finally, somata clustering is neuron-type specific, and glutamatergic and GABAergic neurons tend to aggregate homo-philically. CONCLUSIONS/SIGNIFICANCE We demonstrate self-organization of neural circuits in response to geometric constraints through spatiotemporally coordinated neuronal migration, possibly via mechanical coupling. We found that such collective neuronal migration leads to somata clustering, and mono-cluster appears when the geometric constraints fall within a critical scale. The discovery of geometry-dependent collective neuronal migration and the formation of somata clustering in vitro shed light on neural development in vivo.
Collapse
|
179
|
Anastasiades PG, Butt SJB. Decoding the transcriptional basis for GABAergic interneuron diversity in the mouse neocortex. Eur J Neurosci 2011; 34:1542-52. [DOI: 10.1111/j.1460-9568.2011.07904.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
180
|
Ma T, Zhang Q, Cai Y, You Y, Rubenstein JLR, Yang Z. A subpopulation of dorsal lateral/caudal ganglionic eminence-derived neocortical interneurons expresses the transcription factor Sp8. Cereb Cortex 2011; 22:2120-30. [PMID: 22021915 DOI: 10.1093/cercor/bhr296] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cortical GABAergic interneurons in rodents originate from subpallial progenitors and tangentially migrate to the cortex. While the majority of mouse neocortical interneurons are derived from the medial and caudal ganglionic eminence (MGE and CGE, respectively), it remains unknown whether the lateral ganglionic eminence (LGE) also contributes to a subpopulation of cortical interneurons. Here, we show that the transcription factor Sp8 is expressed in one-fifth of adult cortical interneurons, which appear to be derived from both the dorsal LGE and the dorsal CGE (dLGE and dCGE, respectively). Compared with the MGE-derived cortical interneurons, dLGE/dCGE-derived Sp8-expressing (Sp8+) ones are born at later embryonic stages with peak production occurring at embryonic day 15.5. They tangentially migrate mainly along the subventricular/intermediate zone (SVZ/IZ) route; some continue to express mitotic markers (Ki67 and PH3) in the neonatal cortical SVZ/IZ. Sp8+ interneurons continue to radially migrate from the SVZ/IZ into the cortical layers at early postnatal stages. In contrast to MGE-derived interneurons, dLGE/dCGE-derived Sp8+ interneurons follow an outside-in layering pattern, preferentially occupying superficial cortical layers.
Collapse
Affiliation(s)
- Tong Ma
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
| | | | | | | | | | | |
Collapse
|