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Iannone AF, Akgül G, Zhang R, Wacks S, Hussein N, Macias CG, Donatelle A, Bauriedel JMJ, Wright C, Abramov D, Johnson MA, Govek EE, Burré J, Milner TA, De Marco García NV. The chemokine Cxcl14 regulates interneuron differentiation in layer I of the somatosensory cortex. Cell Rep 2024; 43:114531. [PMID: 39058591 DOI: 10.1016/j.celrep.2024.114531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 06/10/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
Spontaneous and sensory-evoked activity sculpts developing circuits. Yet, how these activity patterns intersect with cellular programs regulating the differentiation of neuronal subtypes is not well understood. Through electrophysiological and in vivo longitudinal analyses, we show that C-X-C motif chemokine ligand 14 (Cxcl14), a gene previously characterized for its association with tumor invasion, is expressed by single-bouquet cells (SBCs) in layer I (LI) of the somatosensory cortex during development. Sensory deprivation at neonatal stages markedly decreases Cxcl14 expression. Additionally, we report that loss of function of this gene leads to increased intrinsic excitability of SBCs-but not LI neurogliaform cells-and augments neuronal complexity. Furthermore, Cxcl14 loss impairs sensory map formation and compromises the in vivo recruitment of superficial interneurons by sensory inputs. These results indicate that Cxcl14 is required for LI differentiation and demonstrate the emergent role of chemokines as key players in cortical network development.
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Affiliation(s)
- Andrew F Iannone
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA; Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10021, USA
| | - Gülcan Akgül
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Robin Zhang
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Sam Wacks
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Nisma Hussein
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Carmen Ginelly Macias
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Alexander Donatelle
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Julia M J Bauriedel
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Cora Wright
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Debra Abramov
- Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10021, USA; Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Megan A Johnson
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Eve-Ellen Govek
- Laboratory of Developmental Neurobiology, The Rockefeller University, New York, NY 10065, USA
| | - Jacqueline Burré
- Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Natalia V De Marco García
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.
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2
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Machold R, Rudy B. Genetic approaches to elucidating cortical and hippocampal GABAergic interneuron diversity. Front Cell Neurosci 2024; 18:1414955. [PMID: 39113758 PMCID: PMC11303334 DOI: 10.3389/fncel.2024.1414955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 07/08/2024] [Indexed: 08/10/2024] Open
Abstract
GABAergic interneurons (INs) in the mammalian forebrain represent a diverse population of cells that provide specialized forms of local inhibition to regulate neural circuit activity. Over the last few decades, the development of a palette of genetic tools along with the generation of single-cell transcriptomic data has begun to reveal the molecular basis of IN diversity, thereby providing deep insights into how different IN subtypes function in the forebrain. In this review, we outline the emerging picture of cortical and hippocampal IN speciation as defined by transcriptomics and developmental origin and summarize the genetic strategies that have been utilized to target specific IN subtypes, along with the technical considerations inherent to each approach. Collectively, these methods have greatly facilitated our understanding of how IN subtypes regulate forebrain circuitry via cell type and compartment-specific inhibition and thus have illuminated a path toward potential therapeutic interventions for a variety of neurocognitive disorders.
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Affiliation(s)
- Robert Machold
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
| | - Bernardo Rudy
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Anesthesiology, Perioperative Care and Pain Medicine, New York University Grossman School of Medicine, New York, NY, United States
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3
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Huang S, Rizzo D, Wu SJ, Xu Q, Ziane L, Alghamdi N, Stafford DA, Daigle TL, Tasic B, Zeng H, Ibrahim LA, Fishell G. Neurogliaform Cells Exhibit Laminar-specific Responses in the Visual Cortex and Modulate Behavioral State-dependent Cortical Activity. RESEARCH SQUARE 2024:rs.3.rs-4530873. [PMID: 39011116 PMCID: PMC11247929 DOI: 10.21203/rs.3.rs-4530873/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
Neurogliaform cells are a distinct type of GABAergic cortical interneurons known for their 'volume transmission' output property. However, their activity and function within cortical circuits remain unclear. Here, we developed two genetic tools to target these neurons and examine their function in the primary visual cortex. We found that the spontaneous activity of neurogliaform cells positively correlated with locomotion. Silencing these neurons increased spontaneous activity during locomotion and impaired visual responses in L2/3 pyramidal neurons. Furthermore, the contrast-dependent visual response of neurogliaform cells varies with their laminar location and is constrained by their morphology and input connectivity. These findings demonstrate the importance of neurogliaform cells in regulating cortical behavioral state-dependent spontaneous activity and indicate that their functional engagement during visual stimuli is influenced by their laminar positioning and connectivity.
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Affiliation(s)
- Shuhan Huang
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Program in Neuroscience, Harvard University, Cambridge, MA 02138, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Daniella Rizzo
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Sherry Jingjing Wu
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Qing Xu
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Past address: Center for Genomics & Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Leena Ziane
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Norah Alghamdi
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - David A Stafford
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94708, USA
| | - Tanya L Daigle
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Bosiljka Tasic
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Leena Ali Ibrahim
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Gord Fishell
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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4
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Huang S, Rizzo D, Wu SJ, Xu Q, Ziane L, Alghamdi N, Stafford DA, Daigle TL, Tasic B, Zeng H, Ibrahim LA, Fishell G. Neurogliaform Cells Exhibit Laminar-specific Responses in the Visual Cortex and Modulate Behavioral State-dependent Cortical Activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.05.597539. [PMID: 38895403 PMCID: PMC11185653 DOI: 10.1101/2024.06.05.597539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Neurogliaform cells are a distinct type of GABAergic cortical interneurons known for their "volume transmission" output property. However, their activity and function within cortical circuits remain unclear. Here, we developed two genetic tools to target these neurons and examine their function in the primary visual cortex. We found that the spontaneous activity of neurogliaform cells positively correlated with locomotion. Silencing these neurons increased spontaneous activity during locomotion and impaired visual responses in L2/3 pyramidal neurons. Furthermore, the contrast-dependent visual response of neurogliaform cells varies with their laminar location and is constrained by their morphology and input connectivity. These findings demonstrate the importance of neurogliaform cells in regulating cortical behavioral state-dependent spontaneous activity and indicate that their functional engagement during visual stimuli is influenced by their laminar positioning and connectivity.
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Affiliation(s)
- Shuhan Huang
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Program in Neuroscience, Harvard University, Cambridge, MA 02138, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Daniella Rizzo
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Sherry Jingjing Wu
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Qing Xu
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Past address: Center for Genomics & Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Leena Ziane
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Norah Alghamdi
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - David A Stafford
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94708, USA
| | - Tanya L Daigle
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Bosiljka Tasic
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Leena Ali Ibrahim
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Gord Fishell
- Harvard Medical School, Blavatnik Institute, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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5
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Machold R, Dellal S, Valero M, Zurita H, Kruglikov I, Meng JH, Hanson JL, Hashikawa Y, Schuman B, Buzsáki G, Rudy B. Id2 GABAergic interneurons comprise a neglected fourth major group of cortical inhibitory cells. eLife 2023; 12:e85893. [PMID: 37665123 PMCID: PMC10581691 DOI: 10.7554/elife.85893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 08/21/2023] [Indexed: 09/05/2023] Open
Abstract
Cortical GABAergic interneurons (INs) represent a diverse population of mainly locally projecting cells that provide specialized forms of inhibition to pyramidal neurons and other INs. Most recent work on INs has focused on subtypes distinguished by expression of Parvalbumin (PV), Somatostatin (SST), or Vasoactive Intestinal Peptide (VIP). However, a fourth group that includes neurogliaform cells (NGFCs) has been less well characterized due to a lack of genetic tools. Here, we show that these INs can be accessed experimentally using intersectional genetics with the gene Id2. We find that outside of layer 1 (L1), the majority of Id2 INs are NGFCs that express high levels of neuropeptide Y (NPY) and exhibit a late-spiking firing pattern, with extensive local connectivity. While much sparser, non-NGFC Id2 INs had more variable properties, with most cells corresponding to a diverse group of INs that strongly expresses the neuropeptide CCK. In vivo, using silicon probe recordings, we observed several distinguishing aspects of NGFC activity, including a strong rebound in activity immediately following the cortical down state during NREM sleep. Our study provides insights into IN diversity and NGFC distribution and properties, and outlines an intersectional genetics approach for further study of this underappreciated group of INs.
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Affiliation(s)
- Robert Machold
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Shlomo Dellal
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Manuel Valero
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Hector Zurita
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Ilya Kruglikov
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - John Hongyu Meng
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
- Center for Neural Science, New York UniversityNew YorkUnited States
| | - Jessica L Hanson
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Yoshiko Hashikawa
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Benjamin Schuman
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - György Buzsáki
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
- Department of Neuroscience and Physiology, New York University Grossman School of MedicineNew YorkUnited States
| | - Bernardo Rudy
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
- Department of Neuroscience and Physiology, New York University Grossman School of MedicineNew YorkUnited States
- Department of Anesthesiology, Perioperative Care and Pain Medicine, New York University Grossman School of MedicineNew YorkUnited States
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6
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Guan W, Li B. Diverse Roles of Serotonergic Projections to the Basolateral Amygdala. Neurosci Bull 2023; 39:1463-1465. [PMID: 37029325 PMCID: PMC10465427 DOI: 10.1007/s12264-023-01061-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/05/2023] [Indexed: 04/09/2023] Open
Affiliation(s)
- Wuqiang Guan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Bo Li
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA.
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7
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Mercier MS, Magloire V, Cornford JH, Kullmann DM. Long-term potentiation in neurogliaform interneurons modulates excitation-inhibition balance in the temporoammonic pathway. J Physiol 2022; 600:4001-4017. [PMID: 35876215 PMCID: PMC9540908 DOI: 10.1113/jp282753] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 07/19/2022] [Indexed: 11/08/2022] Open
Abstract
Apical dendrites of pyramidal neurons integrate information from higher-order cortex and thalamus, and gate signalling and plasticity at proximal synapses. In the hippocampus, neurogliaform cells and other interneurons located within stratum lacunosum-moleculare (SLM) mediate powerful inhibition of CA1 pyramidal neuron distal dendrites. Is the recruitment of such inhibition itself subject to use-dependent plasticity, and if so, what induction rules apply? Here we show that interneurons in mouse SLM exhibit Hebbian NMDA receptor-dependent long-term potentiation (LTP). Such plasticity can be induced by selective optogenetic stimulation of afferents in the temporoammonic pathway from the entorhinal cortex (EC), but not by equivalent stimulation of afferents from the thalamic nucleus reuniens. We further show that theta-burst patterns of afferent firing induces LTP in neurogliaform interneurons identified using neuron-derived neurotrophic factor (Ndnf)-Cre mice. Theta-burst activity of EC afferents led to an increase in disynaptic feed-forward inhibition, but not monosynaptic excitation, of CA1 pyramidal neurons. Activity-dependent synaptic plasticity in SLM interneurons thus alters the excitation-inhibition balance at EC inputs to the apical dendrites of pyramidal neurons, implying a dynamic role for these interneurons in gating CA1 dendritic computations. KEY POINTS: Electrogenic phenomena in distal dendrites of principal neurons in the hippocampus have a major role in gating synaptic plasticity at afferent synapses on proximal dendrites. Apical dendrites also receive powerful feed-forward inhibition, mediated in large part by neurogliaform neurons. Here we show that theta-burst activity in afferents from the entorhinal cortex (EC) induces 'Hebbian' long-term potentiation (LTP) at excitatory synapses recruiting these GABAergic cells. LTP in interneurons innervating apical dendrites increases disynaptic inhibition of principal neurons, thus shifting the excitation-inhibition balance in the temporoammonic (TA) pathway in favour of inhibition, with implications for computations and learning rules in proximal dendrites.
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Affiliation(s)
- Marion S. Mercier
- UCL Queen Square Institute of NeurologyDepartment of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
| | - Vincent Magloire
- UCL Queen Square Institute of NeurologyDepartment of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
| | - Jonathan H. Cornford
- UCL Queen Square Institute of NeurologyDepartment of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
| | - Dimitri M. Kullmann
- UCL Queen Square Institute of NeurologyDepartment of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
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8
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Naumann LB, Keijser J, Sprekeler H. Invariant neural subspaces maintained by feedback modulation. eLife 2022; 11:76096. [PMID: 35442191 PMCID: PMC9106332 DOI: 10.7554/elife.76096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
Sensory systems reliably process incoming stimuli in spite of changes in context. Most recent models accredit this context invariance to an extraction of increasingly complex sensory features in hierarchical feedforward networks. Here, we study how context-invariant representations can be established by feedback rather than feedforward processing. We show that feedforward neural networks modulated by feedback can dynamically generate invariant sensory representations. The required feedback can be implemented as a slow and spatially diffuse gain modulation. The invariance is not present on the level of individual neurons, but emerges only on the population level. Mechanistically, the feedback modulation dynamically reorients the manifold of neural activity and thereby maintains an invariant neural subspace in spite of contextual variations. Our results highlight the importance of population-level analyses for understanding the role of feedback in flexible sensory processing.
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9
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Keeping the Balance: GABAB Receptors in the Developing Brain and Beyond. Brain Sci 2022; 12:brainsci12040419. [PMID: 35447949 PMCID: PMC9031223 DOI: 10.3390/brainsci12040419] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 12/16/2022] Open
Abstract
The main neurotransmitter in the brain responsible for the inhibition of neuronal activity is γ-aminobutyric acid (GABA). It plays a crucial role in circuit formation during development, both via its primary effects as a neurotransmitter and also as a trophic factor. The GABAB receptors (GABABRs) are G protein-coupled metabotropic receptors; on one hand, they can influence proliferation and migration; and, on the other, they can inhibit cells by modulating the function of K+ and Ca2+ channels, doing so on a slower time scale and with a longer-lasting effect compared to ionotropic GABAA receptors. GABABRs are expressed pre- and post-synaptically, at both glutamatergic and GABAergic terminals, thus being able to shape neuronal activity, plasticity, and the balance between excitatory and inhibitory synaptic transmission in response to varying levels of extracellular GABA concentration. Furthermore, given their subunit composition and their ability to form complexes with several associated proteins, GABABRs display heterogeneity with regard to their function, which makes them a promising target for pharmacological interventions. This review will describe (i) the latest results concerning GABABRs/GABABR-complex structures, their function, and the developmental time course of their appearance and functional integration in the brain, (ii) their involvement in manifestation of various pathophysiological conditions, and (iii) the current status of preclinical and clinical studies involving GABABR-targeting drugs.
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10
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Transcriptomically-Guided Pharmacological Experiments in Neocortical and Hippocampal NPY-Positive GABAergic Interneurons. eNeuro 2022; 9:ENEURO.0005-22.2022. [PMID: 35437266 PMCID: PMC9045474 DOI: 10.1523/eneuro.0005-22.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/25/2022] [Accepted: 03/30/2022] [Indexed: 12/13/2022] Open
Abstract
Cortical GABAergic interneurons have been shown to fulfil important roles by inhibiting excitatory principal neurons. Recent transcriptomic studies have confirmed seminal discoveries that used anatomic and electrophysiological methods highlighting the existence of multiple different classes of GABAergic interneurons. Although some of these studies have emphasized that inter-regional differences may exist for a given class, the extent of such differences remains unknown. To address this problem, we used single-cell Patch-RNAseq to characterize neuropeptide Y (NPY)-positive GABAergic interneurons in superficial layers of the primary auditory cortex (AC) and in distal layers of area CA3 in mice. We found that more than 300 genes are differentially expressed in NPY-positive neurons between these two brain regions. For example, the AMPA receptor (AMPAR) auxiliary subunit Shisa9/CKAMP44 and the 5HT2a receptor (5HT2aR) are significantly higher expressed in auditory NPY-positive neurons. These findings guided us to perform pharmacological experiments that revealed a role for 5HT2aRs in auditory NPY-positive neurons. Specifically, although the application of 5HT led to a depolarization of both auditory and CA3 NPY-positive neurons, the 5HT2aR antagonist ketanserin only reversed membrane potential changes in auditory NPY-positive neurons. Our study demonstrates the potential of single-cell transcriptomic studies in guiding directed pharmacological experiments.
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11
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Law RG, Pugliese S, Shin H, Sliva DD, Lee S, Neymotin S, Moore C, Jones SR. Thalamocortical Mechanisms Regulating the Relationship between Transient Beta Events and Human Tactile Perception. Cereb Cortex 2022; 32:668-688. [PMID: 34401898 PMCID: PMC8841599 DOI: 10.1093/cercor/bhab221] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 04/20/2021] [Accepted: 05/25/2021] [Indexed: 12/27/2022] Open
Abstract
Transient neocortical events with high spectral power in the 15-29 Hz beta band are among the most reliable predictors of sensory perception. Prestimulus beta event rates in primary somatosensory cortex correlate with sensory suppression, most effectively 100-300 ms before stimulus onset. However, the neural mechanisms underlying this perceptual association are unknown. We combined human magnetoencephalography (MEG) measurements with biophysical neural modeling to test potential cellular and circuit mechanisms that underlie observed correlations between prestimulus beta events and tactile detection. Extending prior studies, we found that simulated bursts from higher-order, nonlemniscal thalamus were sufficient to drive beta event generation and to recruit slow supragranular inhibition acting on a 300 ms timescale to suppress sensory information. Further analysis showed that the same beta-generating mechanism can lead to facilitated perception for a brief period when beta events occur simultaneously with tactile stimulation before inhibition is recruited. These findings were supported by close agreement between model-derived predictions and empirical MEG data. The postevent suppressive mechanism explains an array of studies that associate beta with decreased processing, whereas the during-event facilitatory mechanism may demand a reinterpretation of the role of beta events in the context of coincident timing.
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Affiliation(s)
- Robert G Law
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
- Center for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, RI 02908, USA
- Department of Psychiatry, Harvard Medical School, Cambridge, MA 02215, USA
| | - Sarah Pugliese
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Hyeyoung Shin
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Danielle D Sliva
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Shane Lee
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI 02903, USA
- Norman Prince Neurosciences Institute, Rhode Island Hospital, Providence, RI 02903, USA
| | - Samuel Neymotin
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
- Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Christopher Moore
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Stephanie R Jones
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
- Center for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, RI 02908, USA
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12
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Gutman-Wei AY, Brown SP. Mechanisms Underlying Target Selectivity for Cell Types and Subcellular Domains in Developing Neocortical Circuits. Front Neural Circuits 2021; 15:728832. [PMID: 34630048 PMCID: PMC8497978 DOI: 10.3389/fncir.2021.728832] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/25/2021] [Indexed: 11/25/2022] Open
Abstract
The cerebral cortex contains numerous neuronal cell types, distinguished by their molecular identity as well as their electrophysiological and morphological properties. Cortical function is reliant on stereotyped patterns of synaptic connectivity and synaptic function among these neuron types, but how these patterns are established during development remains poorly understood. Selective targeting not only of different cell types but also of distinct postsynaptic neuronal domains occurs in many brain circuits and is directed by multiple mechanisms. These mechanisms include the regulation of axonal and dendritic guidance and fine-scale morphogenesis of pre- and postsynaptic processes, lineage relationships, activity dependent mechanisms and intercellular molecular determinants such as transmembrane and secreted molecules, many of which have also been implicated in neurodevelopmental disorders. However, many studies of synaptic targeting have focused on circuits in which neuronal processes target different lamina, such that cell-type-biased connectivity may be confounded with mechanisms of laminar specificity. In the cerebral cortex, each cortical layer contains cell bodies and processes from intermingled neuronal cell types, an arrangement that presents a challenge for the development of target-selective synapse formation. Here, we address progress and future directions in the study of cell-type-biased synaptic targeting in the cerebral cortex. We highlight challenges to identifying developmental mechanisms generating stereotyped patterns of intracortical connectivity, recent developments in uncovering the determinants of synaptic target selection during cortical synapse formation, and current gaps in the understanding of cortical synapse specificity.
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Affiliation(s)
- Alan Y. Gutman-Wei
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Solange P. Brown
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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13
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Shin H, Adesnik H. NDNF interneurons, Spartans of the cortical column: Small in number, strong in impact. Neuron 2021; 109:2041-2042. [PMID: 34237275 DOI: 10.1016/j.neuron.2021.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
NDNF selectively labels neurogliaform inhibitory interneurons of layer 1. In this issue of Neuron, Cohen-Kashi Malina et al. (2021) show that NDNF activity is highly correlated with arousal level. During high arousal state, NDNF inhibits the dendrites while disinhibiting the soma of nearby pyramidal neurons.
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Affiliation(s)
- Hyeyoung Shin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Hillel Adesnik
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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14
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Marriott BA, Do AD, Zahacy R, Jackson J. Topographic gradients define the projection patterns of the claustrum core and shell in mice. J Comp Neurol 2021; 529:1607-1627. [PMID: 32975316 PMCID: PMC8048916 DOI: 10.1002/cne.25043] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/14/2020] [Accepted: 09/17/2020] [Indexed: 01/05/2023]
Abstract
The claustrum is densely connected to the cortex and participates in brain functions such as attention and sleep. Although some studies have reported the widely divergent organization of claustrum projections, others describe parallel claustrocortical connections to different cortical regions. Therefore, the details underlying how claustrum neurons broadcast information to cortical networks remain incompletely understood. Using multicolor retrograde tracing we determined the density, topography, and co-projection pattern of 14 claustrocortical pathways, in mice. We spatially registered these pathways to a common coordinate space and found that the claustrocortical system is topographically organized as a series of overlapping spatial modules, continuously distributed across the dorsoventral claustrum axis. The claustrum core projects predominantly to frontal-midline cortical regions, whereas the dorsal and ventral shell project to the cortical motor system and temporal lobe, respectively. Anatomically connected cortical regions receive common input from a subset of claustrum neurons shared by neighboring modules, whereas spatially separated regions of cortex are innervated by different claustrum modules. Therefore, each output module exhibits a unique position within the claustrum and overlaps substantially with other modules projecting to functionally related cortical regions. Claustrum inhibitory cells containing parvalbumin, somatostatin, and neuropeptide Y also show unique topographical distributions, suggesting different output modules are controlled by distinct inhibitory circuit motifs. The topographic organization of excitatory and inhibitory cell types may enable parallel claustrum outputs to independently coordinate distinct cortical networks.
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Affiliation(s)
- Brian A. Marriott
- Neuroscience and Mental Health InstituteUniversity of AlbertaEdmontonAlbertaCanada
| | - Alison D. Do
- Department of PhysiologyUniversity of AlbertaEdmontonAlbertaCanada
| | - Ryan Zahacy
- Neuroscience and Mental Health InstituteUniversity of AlbertaEdmontonAlbertaCanada
| | - Jesse Jackson
- Neuroscience and Mental Health InstituteUniversity of AlbertaEdmontonAlbertaCanada
- Department of PhysiologyUniversity of AlbertaEdmontonAlbertaCanada
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15
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Schuman B, Dellal S, Prönneke A, Machold R, Rudy B. Neocortical Layer 1: An Elegant Solution to Top-Down and Bottom-Up Integration. Annu Rev Neurosci 2021; 44:221-252. [PMID: 33730511 DOI: 10.1146/annurev-neuro-100520-012117] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many of our daily activities, such as riding a bike to work or reading a book in a noisy cafe, and highly skilled activities, such as a professional playing a tennis match or a violin concerto, depend upon the ability of the brain to quickly make moment-to-moment adjustments to our behavior in response to the results of our actions. Particularly, they depend upon the ability of the neocortex to integrate the information provided by the sensory organs (bottom-up information) with internally generated signals such as expectations or attentional signals (top-down information). This integration occurs in pyramidal cells (PCs) and their long apical dendrite, which branches extensively into a dendritic tuft in layer 1 (L1). The outermost layer of the neocortex, L1 is highly conserved across cortical areas and species. Importantly, L1 is the predominant input layer for top-down information, relayed by a rich, dense mesh of long-range projections that provide signals to the tuft branches of the PCs. Here, we discuss recent progress in our understanding of the composition of L1 and review evidence that L1 processing contributes to functions such as sensory perception, cross-modal integration, controlling states of consciousness, attention, and learning.
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Affiliation(s)
- Benjamin Schuman
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA;
| | - Shlomo Dellal
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA;
| | - Alvar Prönneke
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA;
| | - Robert Machold
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA;
| | - Bernardo Rudy
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA; .,Department of Anesthesiology, Perioperative Care and Pain Medicine, New York University School of Medicine, New York, NY 10016, USA
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16
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Burns TF, Rajan R. Sensing and processing whisker deflections in rodents. PeerJ 2021; 9:e10730. [PMID: 33665005 PMCID: PMC7906041 DOI: 10.7717/peerj.10730] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/17/2020] [Indexed: 11/20/2022] Open
Abstract
The classical view of sensory information mainly flowing into barrel cortex at layer IV, moving up for complex feature processing and lateral interactions in layers II and III, then down to layers V and VI for output and corticothalamic feedback is becoming increasingly undermined by new evidence. We review the neurophysiology of sensing and processing whisker deflections, emphasizing the general processing and organisational principles present along the entire sensory pathway—from the site of physical deflection at the whiskers to the encoding of deflections in the barrel cortex. Many of these principles support the classical view. However, we also highlight the growing number of exceptions to these general principles, which complexify the system and which investigators should be mindful of when interpreting their results. We identify gaps in the literature for experimentalists and theorists to investigate, not just to better understand whisker sensation but also to better understand sensory and cortical processing.
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Affiliation(s)
- Thomas F Burns
- Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Ramesh Rajan
- Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
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17
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Bird AD, Deters LH, Cuntz H. Excess Neuronal Branching Allows for Local Innervation of Specific Dendritic Compartments in Mature Cortex. Cereb Cortex 2020; 31:1008-1031. [DOI: 10.1093/cercor/bhaa271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/14/2020] [Accepted: 08/14/2020] [Indexed: 12/12/2022] Open
Abstract
Abstract
The connectivity of cortical microcircuits is a major determinant of brain function; defining how activity propagates between different cell types is key to scaling our understanding of individual neuronal behavior to encompass functional networks. Furthermore, the integration of synaptic currents within a dendrite depends on the spatial organization of inputs, both excitatory and inhibitory. We identify a simple equation to estimate the number of potential anatomical contacts between neurons; finding a linear increase in potential connectivity with cable length and maximum spine length, and a decrease with overlapping volume. This enables us to predict the mean number of candidate synapses for reconstructed cells, including those realistically arranged. We identify an excess of potential local connections in mature cortical data, with densities of neurite higher than is necessary to reliably ensure the possible implementation of any given axo-dendritic connection. We show that the number of local potential contacts allows specific innervation of distinct dendritic compartments.
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Affiliation(s)
- A D Bird
- Frankfurt Institute for Advanced Studies, Frankfurt-am-Main 60438, Germany
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with the Max Planck Society, Frankfurt-am-Main 60528, Germany
| | - L H Deters
- Frankfurt Institute for Advanced Studies, Frankfurt-am-Main 60438, Germany
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with the Max Planck Society, Frankfurt-am-Main 60528, Germany
| | - H Cuntz
- Frankfurt Institute for Advanced Studies, Frankfurt-am-Main 60438, Germany
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with the Max Planck Society, Frankfurt-am-Main 60528, Germany
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18
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Staiger JF, Petersen CCH. Neuronal Circuits in Barrel Cortex for Whisker Sensory Perception. Physiol Rev 2020; 101:353-415. [PMID: 32816652 DOI: 10.1152/physrev.00019.2019] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The array of whiskers on the snout provides rodents with tactile sensory information relating to the size, shape and texture of objects in their immediate environment. Rodents can use their whiskers to detect stimuli, distinguish textures, locate objects and navigate. Important aspects of whisker sensation are thought to result from neuronal computations in the whisker somatosensory cortex (wS1). Each whisker is individually represented in the somatotopic map of wS1 by an anatomical unit named a 'barrel' (hence also called barrel cortex). This allows precise investigation of sensory processing in the context of a well-defined map. Here, we first review the signaling pathways from the whiskers to wS1, and then discuss current understanding of the various types of excitatory and inhibitory neurons present within wS1. Different classes of cells can be defined according to anatomical, electrophysiological and molecular features. The synaptic connectivity of neurons within local wS1 microcircuits, as well as their long-range interactions and the impact of neuromodulators, are beginning to be understood. Recent technological progress has allowed cell-type-specific connectivity to be related to cell-type-specific activity during whisker-related behaviors. An important goal for future research is to obtain a causal and mechanistic understanding of how selected aspects of tactile sensory information are processed by specific types of neurons in the synaptically connected neuronal networks of wS1 and signaled to downstream brain areas, thus contributing to sensory-guided decision-making.
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Affiliation(s)
- Jochen F Staiger
- University Medical Center Göttingen, Institute for Neuroanatomy, Göttingen, Germany; and Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Carl C H Petersen
- University Medical Center Göttingen, Institute for Neuroanatomy, Göttingen, Germany; and Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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19
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Chittajallu R, Auville K, Mahadevan V, Lai M, Hunt S, Calvigioni D, Pelkey KA, Zaghloul KA, McBain CJ. Activity-dependent tuning of intrinsic excitability in mouse and human neurogliaform cells. eLife 2020; 9:57571. [PMID: 32496194 PMCID: PMC7299336 DOI: 10.7554/elife.57571] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/02/2020] [Indexed: 12/15/2022] Open
Abstract
The ability to modulate the efficacy of synaptic communication between neurons constitutes an essential property critical for normal brain function. Animal models have proved invaluable in revealing a wealth of diverse cellular mechanisms underlying varied plasticity modes. However, to what extent these processes are mirrored in humans is largely uncharted thus questioning their relevance in human circuit function. In this study, we focus on neurogliaform cells, that possess specialized physiological features enabling them to impart a widespread inhibitory influence on neural activity. We demonstrate that this prominent neuronal subtype, embedded in both mouse and human neural circuits, undergo remarkably similar activity-dependent modulation manifesting as epochs of enhanced intrinsic excitability. In principle, these evolutionary conserved plasticity routes likely tune the extent of neurogliaform cell mediated inhibition thus constituting canonical circuit mechanisms underlying human cognitive processing and behavior.
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Affiliation(s)
- Ramesh Chittajallu
- Laboratory of Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Kurt Auville
- Laboratory of Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Vivek Mahadevan
- Laboratory of Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Mandy Lai
- Laboratory of Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Steven Hunt
- Laboratory of Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Daniela Calvigioni
- Laboratory of Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Kenneth A Pelkey
- Laboratory of Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Kareem A Zaghloul
- Surgical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Chris J McBain
- Laboratory of Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
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20
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Preserving Inhibition during Developmental Hearing Loss Rescues Auditory Learning and Perception. J Neurosci 2019; 39:8347-8361. [PMID: 31451577 DOI: 10.1523/jneurosci.0749-19.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 12/15/2022] Open
Abstract
Transient periods of childhood hearing loss can induce deficits in aural communication that persist long after auditory thresholds have returned to normal, reflecting long-lasting impairments to the auditory CNS. Here, we asked whether these behavioral deficits could be reversed by treating one of the central impairments: reduction of inhibitory strength. Male and female gerbils received bilateral earplugs to induce a mild, reversible hearing loss during the critical period of auditory cortex development. After earplug removal and the return of normal auditory thresholds, we trained and tested animals on an amplitude modulation detection task. Transient developmental hearing loss induced both learning and perceptual deficits, which were entirely corrected by treatment with a selective GABA reuptake inhibitor (SGRI). To explore the mechanistic basis for these behavioral findings, we recorded the amplitudes of GABAA and GABAB receptor-mediated IPSPs in auditory cortical and thalamic brain slices. In hearing loss-reared animals, cortical IPSP amplitudes were significantly reduced within a few days of hearing loss onset, and this reduction persisted into adulthood. SGRI treatment during the critical period prevented the hearing loss-induced reduction of IPSP amplitudes; but when administered after the critical period, it only restored GABAB receptor-mediated IPSP amplitudes. These effects were driven, in part, by the ability of SGRI to upregulate α1 subunit-dependent GABAA responses. Similarly, SGRI prevented the hearing loss-induced reduction of GABAA and GABAB IPSPs in the ventral nucleus of the medial geniculate body. Thus, by maintaining, or subsequently rescuing, GABAergic transmission in the central auditory thalamocortical pathway, some perceptual and cognitive deficits induced by developmental hearing loss can be prevented.SIGNIFICANCE STATEMENT Even a temporary period of childhood hearing loss can induce communication deficits that persist long after auditory thresholds return to normal. These deficits may arise from long-lasting central impairments, including the loss of synaptic inhibition. Here, we asked whether hearing loss-induced behavioral deficits could be reversed by reinstating normal inhibitory strength. Gerbils reared with transient hearing loss displayed both learning and perceptual deficits. However, when animals were treated with a selective GABA reuptake inhibitor during or after hearing loss, behavioral deficits were entirely corrected. This behavioral recovery was correlated with the return of normal thalamic and cortical inhibitory function. Thus, some perceptual and cognitive deficits induced by developmental hearing loss were prevented with a treatment that rescues a central synaptic property.
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21
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Emmenegger V, Qi G, Wang H, Feldmeyer D. Morphological and Functional Characterization of Non-fast-Spiking GABAergic Interneurons in Layer 4 Microcircuitry of Rat Barrel Cortex. Cereb Cortex 2019; 28:1439-1457. [PMID: 29329401 PMCID: PMC6093438 DOI: 10.1093/cercor/bhx352] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Indexed: 12/23/2022] Open
Abstract
GABAergic interneurons are notorious for their heterogeneity, despite constituting a small fraction of the neuronal population in the neocortex. Classification of interneurons is crucial for understanding their widespread cortical functions as they provide a complex and dynamic network, balancing excitation and inhibition. Here, we investigated different types of non-fast-spiking (nFS) interneurons in Layer 4 (L4) of rat barrel cortex using whole-cell patch-clamp recordings with biocytin-filling. Based on a quantitative analysis on a combination of morphological and electrophysiological parameters, we identified 5 distinct types of L4 nFS interneurons: 1) trans-columnar projecting interneurons, 2) locally projecting non-Martinotti-like interneurons, 3) supra-granular projecting Martinotti-like interneurons, 4) intra-columnar projecting VIP-like interneurons, and 5) locally projecting neurogliaform-like interneurons. Trans-columnar projecting interneurons are one of the most striking interneuron types, which have not been described so far in Layer 4. They feature extensive axonal collateralization not only in their home barrel but also in adjacent barrels. Furthermore, we identified that most of the L4 nFS interneurons express somatostatin, while few are positive for the transcription factor Prox1. The morphological and electrophysiological characterization of different L4 nFS interneuron types presented here provides insights into their synaptic connectivity and functional role in cortical information processing.
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Affiliation(s)
- Vishalini Emmenegger
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Department of Biosystems Sciences and Engineering, Bio Engineering Lab, ETH Zürich, Basel, Switzerland
| | - Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
| | - Haijun Wang
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- School of Electronic Engineering, Nanjing Xiaozhuang University, Nanjing, P.R. China
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
- Address correspondence to Dirk Feldmeyer, Institute of Neuroscience and Medicine (INM-2), Research Centre Jülich, D-52425 Jülich, Germany.
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22
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Four Unique Interneuron Populations Reside in Neocortical Layer 1. J Neurosci 2018; 39:125-139. [PMID: 30413647 DOI: 10.1523/jneurosci.1613-18.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 10/05/2018] [Accepted: 10/29/2018] [Indexed: 11/21/2022] Open
Abstract
Sensory perception depends on neocortical computations that contextually adjust sensory signals in different internal and environmental contexts. Neocortical layer 1 (L1) is the main target of cortical and subcortical inputs that provide "top-down" information for context-dependent sensory processing. Although L1 is devoid of excitatory cells, it contains the distal "tuft" dendrites of pyramidal cells (PCs) located in deeper layers. L1 also contains a poorly characterized population of GABAergic interneurons (INs), which regulate the impact that different top-down inputs have on PCs. A poor comprehension of L1 IN subtypes and how they affect PC activity has hampered our understanding of the mechanisms that underlie contextual modulation of sensory processing. We used novel genetic strategies in male and female mice combined with electrophysiological and morphological methods to help resolve differences that were unclear when using only electrophysiological and/or morphological approaches. We discovered that L1 contains four distinct populations of INs, each with a unique molecular profile, morphology, and electrophysiology, including a previously overlooked IN population (named here "canopy cells") representing 40% of L1 INs. In contrast to what is observed in other layers, most L1 neurons appear to be unique to the layer, highlighting the specialized character of the signal processing that takes place in L1. This new understanding of INs in L1, as well as the application of genetic methods based on the markers described here, will enable investigation of the cellular and circuit mechanisms of top-down processing in L1 with unprecedented detail.SIGNIFICANCE STATEMENT Neocortical layer 1 (L1) is the main target of corticocortical and subcortical projections that mediate top-down or context-dependent sensory perception. However, this unique layer is often referred to as "enigmatic" because its neuronal composition has been difficult to determine. Using a combination of genetic, electrophysiological, and morphological approaches that helped to resolve differences that were unclear when using a single approach, we were able to decipher the neuronal composition of L1. We identified markers that distinguish L1 neurons and found that the layer contains four populations of GABAergic interneurons, each with unique molecular profiles, morphologies, and electrophysiological properties. These findings provide a new framework for studying the circuit mechanisms underlying the processing of top-down inputs in neocortical L1.
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23
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Magloire V, Mercier MS, Kullmann DM, Pavlov I. GABAergic Interneurons in Seizures: Investigating Causality With Optogenetics. Neuroscientist 2018; 25:344-358. [PMID: 30317911 PMCID: PMC6745605 DOI: 10.1177/1073858418805002] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Seizures are complex pathological network events characterized by excessive and
hypersynchronized activity of neurons, including a highly diverse population of
GABAergic interneurons. Although the primary function of inhibitory interneurons
under normal conditions is to restrain excitation in the brain, this system
appears to fail intermittently, allowing runaway excitation. Recent developments
in optogenetics, combined with genetic tools and advanced electrophysiological
and imaging techniques, allow us for the first time to assess the causal roles
of identified cell-types in network dynamics. While these methods have greatly
increased our understanding of cortical microcircuits in epilepsy, the roles
played by individual GABAergic cell-types in controlling ictogenesis remain
incompletely resolved. Indeed, the ability of interneurons to suppress epileptic
discharges varies across different subtypes, and an accumulating body of
evidence paradoxically implicates some interneuron subtypes in the initiation
and maintenance of epileptiform activity. Here, we bring together findings from
this growing field and discuss what can be inferred regarding the causal role of
different GABAergic cell-types in seizures.
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Affiliation(s)
- Vincent Magloire
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, UCL, London, UK
| | - Marion S Mercier
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, UCL, London, UK
| | - Dimitri M Kullmann
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, UCL, London, UK
| | - Ivan Pavlov
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, UCL, London, UK
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24
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Learning-Related Plasticity in Dendrite-Targeting Layer 1 Interneurons. Neuron 2018; 100:684-699.e6. [PMID: 30269988 PMCID: PMC6226614 DOI: 10.1016/j.neuron.2018.09.001] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 08/09/2018] [Accepted: 08/31/2018] [Indexed: 11/23/2022]
Abstract
A wealth of data has elucidated the mechanisms by which sensory inputs are encoded in the neocortex, but how these processes are regulated by the behavioral relevance of sensory information is less understood. Here, we focus on neocortical layer 1 (L1), a key location for processing of such top-down information. Using Neuron-Derived Neurotrophic Factor (NDNF) as a selective marker of L1 interneurons (INs) and in vivo 2-photon calcium imaging, electrophysiology, viral tracing, optogenetics, and associative memory, we find that L1 NDNF-INs mediate a prolonged form of inhibition in distal pyramidal neuron dendrites that correlates with the strength of the memory trace. Conversely, inhibition from Martinotti cells remains unchanged after conditioning but in turn tightly controls sensory responses in NDNF-INs. These results define a genetically addressable form of dendritic inhibition that is highly experience dependent and indicate that in addition to disinhibition, salient stimuli are encoded at elevated levels of distal dendritic inhibition. Video Abstract
NDNF is a selective marker for neocortical layer 1 interneurons NDNF interneurons mediate prolonged inhibition of distal pyramidal neuron dendrites Inhibition from Martinotti cells tightly controls NDNF interneuron responses Dendritic inhibition by NDNF interneurons is highly experience dependent
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25
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Jackson J, Karnani MM, Zemelman BV, Burdakov D, Lee AK. Inhibitory Control of Prefrontal Cortex by the Claustrum. Neuron 2018; 99:1029-1039.e4. [PMID: 30122374 PMCID: PMC6168643 DOI: 10.1016/j.neuron.2018.07.031] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 06/17/2018] [Accepted: 07/18/2018] [Indexed: 11/21/2022]
Abstract
The claustrum is a small subcortical nucleus that has extensive excitatory connections with many cortical areas. While the anatomical connectivity from the claustrum to the cortex has been studied intensively, the physiological effect and underlying circuit mechanisms of claustrocortical communication remain elusive. Here we show that the claustrum provides strong, widespread, and long-lasting feedforward inhibition of the prefrontal cortex (PFC) sufficient to silence ongoing neural activity. This claustrocortical feedforward inhibition was predominantly mediated by interneurons containing neuropeptide Y, and to a lesser extent those containing parvalbumin. Therefore, in contrast to other long-range excitatory inputs to the PFC, the claustrocortical pathway is designed to provide overall inhibition of cortical activity. This unique circuit organization allows the claustrum to rapidly and powerfully suppress cortical networks and suggests a distinct role for the claustrum in regulating cognitive processes in prefrontal circuits. The claustrum strongly inhibits, rather than excites, prefrontal cortex Prefrontal NPY and PV interneurons are activated by the claustrum Claustrocortical feedforward inhibition is predominantly mediated by NPY neurons
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Affiliation(s)
- Jesse Jackson
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA; Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| | | | - Boris V Zemelman
- Department of Neuroscience, Center for Learning and Memory, University of Texas, University Station, C7000 Austin, TX 78712, USA
| | - Denis Burdakov
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Albert K Lee
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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Hay YA, Naudé J, Faure P, Lambolez B. Target Interneuron Preference in Thalamocortical Pathways Determines the Temporal Structure of Cortical Responses. Cereb Cortex 2018; 29:2815-2831. [DOI: 10.1093/cercor/bhy148] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 05/03/2018] [Accepted: 06/04/2018] [Indexed: 11/14/2022] Open
Abstract
Abstract
Sensory processing relies on fast detection of changes in environment, as well as integration of contextual cues over time. The mechanisms by which local circuits of the cerebral cortex simultaneously perform these opposite processes remain obscure. Thalamic “specific” nuclei relay sensory information, whereas “nonspecific” nuclei convey information on the environmental and behavioral contexts. We expressed channelrhodopsin in the ventrobasal specific (sensory) or the rhomboid nonspecific (contextual) thalamic nuclei. By selectively activating each thalamic pathway, we found that nonspecific inputs powerfully activate adapting (slow-responding) interneurons but weakly connect fast-spiking interneurons, whereas specific inputs exhibit opposite interneuron preference. Specific inputs thereby induce rapid feedforward inhibition that limits response duration, whereas, in the same cortical area, nonspecific inputs elicit delayed feedforward inhibition that enables lasting recurrent excitation. Using a mean field model, we confirm that cortical response dynamics depends on the type of interneuron targeted by thalamocortical inputs and show that efficient recruitment of adapting interneurons prolongs the cortical response and allows the summation of sensory and contextual inputs. Hence, target choice between slow- and fast-responding inhibitory neurons endows cortical networks with a simple computational solution to perform both sensory detection and integration.
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Affiliation(s)
- Y Audrey Hay
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Paris, France
| | - Jérémie Naudé
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Paris, France
| | - Philippe Faure
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Paris, France
| | - Bertrand Lambolez
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Paris, France
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27
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Audette NJ, Urban-Ciecko J, Matsushita M, Barth AL. POm Thalamocortical Input Drives Layer-Specific Microcircuits in Somatosensory Cortex. Cereb Cortex 2018; 28:1312-1328. [PMID: 28334225 PMCID: PMC6093433 DOI: 10.1093/cercor/bhx044] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 02/03/2017] [Indexed: 12/11/2022] Open
Abstract
Higher-order thalamic nuclei, such as the posterior medial nucleus (POm) in the somatosensory system or the pulvinar in the visual system, densely innervate the cortex and can influence perception and plasticity. To systematically evaluate how higher-order thalamic nuclei can drive cortical circuits, we investigated cell-type selective responses to POm stimulation in mouse primary somatosensory (barrel) cortex, using genetically targeted whole-cell recordings in acute brain slices. We find that ChR2-evoked thalamic input selectively targets specific cell types in the neocortex, revealing layer-specific modules for the summation and processing of POm input. Evoked activity in pyramidal neurons from deep layers is fast and synchronized by rapid feedforward inhibition from GABAergic parvalbumin-expressing neurons, and activity in superficial layers is weaker and prolonged, facilitated by slow inhibition from GABAergic neurons expressing the 5HT3a receptor. Somatostatin-expressing GABAergic neurons do not receive direct input in either layer and their spontaneous activity is suppressed during POm stimulation. This novel pattern of weak, delayed, thalamus-evoked inhibition in layer 2 suggests a longer integration window for incoming sensory information and may facilitate stimulus detection and plasticity in superficial pyramidal neurons.
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Affiliation(s)
- Nicholas J Audette
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, USA
| | - Joanna Urban-Ciecko
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, USA
| | - Megumi Matsushita
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, USA
| | - Alison L Barth
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, USA
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Pelkey KA, Chittajallu R, Craig MT, Tricoire L, Wester JC, McBain CJ. Hippocampal GABAergic Inhibitory Interneurons. Physiol Rev 2017; 97:1619-1747. [PMID: 28954853 DOI: 10.1152/physrev.00007.2017] [Citation(s) in RCA: 495] [Impact Index Per Article: 70.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/16/2017] [Accepted: 05/26/2017] [Indexed: 12/11/2022] Open
Abstract
In the hippocampus GABAergic local circuit inhibitory interneurons represent only ~10-15% of the total neuronal population; however, their remarkable anatomical and physiological diversity allows them to regulate virtually all aspects of cellular and circuit function. Here we provide an overview of the current state of the field of interneuron research, focusing largely on the hippocampus. We discuss recent advances related to the various cell types, including their development and maturation, expression of subtype-specific voltage- and ligand-gated channels, and their roles in network oscillations. We also discuss recent technological advances and approaches that have permitted high-resolution, subtype-specific examination of their roles in numerous neural circuit disorders and the emerging therapeutic strategies to ameliorate such pathophysiological conditions. The ultimate goal of this review is not only to provide a touchstone for the current state of the field, but to help pave the way for future research by highlighting where gaps in our knowledge exist and how a complete appreciation of their roles will aid in future therapeutic strategies.
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Affiliation(s)
- Kenneth A Pelkey
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ramesh Chittajallu
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Michael T Craig
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ludovic Tricoire
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Jason C Wester
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Chris J McBain
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
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Abstract
Cortical networks are composed of glutamatergic excitatory projection neurons and local GABAergic inhibitory interneurons that gate signal flow and sculpt network dynamics. Although they represent a minority of the total neocortical neuronal population, GABAergic interneurons are highly heterogeneous, forming functional classes based on their morphological, electrophysiological, and molecular features, as well as connectivity and in vivo patterns of activity. Here we review our current understanding of neocortical interneuron diversity and the properties that distinguish cell types. We then discuss how the involvement of multiple cell types, each with a specific set of cellular properties, plays a crucial role in diversifying and increasing the computational power of a relatively small number of simple circuit motifs forming cortical networks. We illustrate how recent advances in the field have shed light onto the mechanisms by which GABAergic inhibition contributes to network operations.
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Afferent specific role of NMDA receptors for the circuit integration of hippocampal neurogliaform cells. Nat Commun 2017; 8:152. [PMID: 28751664 PMCID: PMC5532276 DOI: 10.1038/s41467-017-00218-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 06/13/2017] [Indexed: 01/28/2023] Open
Abstract
Appropriate integration of GABAergic interneurons into nascent cortical circuits is critical for ensuring normal information processing within the brain. Network and cognitive deficits associated with neurological disorders, such as schizophrenia, that result from NMDA receptor-hypofunction have been mainly attributed to dysfunction of parvalbumin-expressing interneurons that paradoxically express low levels of synaptic NMDA receptors. Here, we reveal that throughout postnatal development, thalamic, and entorhinal cortical inputs onto hippocampal neurogliaform cells are characterized by a large NMDA receptor-mediated component. This NMDA receptor-signaling is prerequisite for developmental programs ultimately responsible for the appropriate long-range AMPAR-mediated recruitment of neurogliaform cells. In contrast, AMPAR-mediated input at local Schaffer-collateral synapses on neurogliaform cells remains normal following NMDA receptor-ablation. These afferent specific deficits potentially impact neurogliaform cell mediated inhibition within the hippocampus and our findings reveal circuit loci implicating this relatively understudied interneuron subtype in the etiology of neurodevelopmental disorders characterized by NMDA receptor-hypofunction.Proper brain function depends on the correct assembly of excitatory and inhibitory neurons into neural circuits. Here the authors show that during early postnatal development in mice, NMDAR signaling via activity of long-range synaptic inputs onto neurogliaform cells is required for their appropriate integration into the hippocampal circuitry.
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31
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GABAB Receptors Tune Cortical Feedback to the Olfactory Bulb. J Neurosci 2017; 36:8289-304. [PMID: 27511004 DOI: 10.1523/jneurosci.3823-15.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 06/09/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Sensory perception emerges from the confluence of sensory inputs that encode the composition of external environment and top-down feedback that conveys information from higher brain centers. In olfaction, sensory input activity is initially processed in the olfactory bulb (OB), serving as the first central relay before being transferred to the olfactory cortex. In addition, the OB receives dense connectivity from feedback projections, so the OB has the capacity to implement a wide array of sensory neuronal computation. However, little is known about the impact and the regulation of this cortical feedback. Here, we describe a novel mechanism to gate glutamatergic feedback selectively from the anterior olfactory cortex (AOC) to the OB. Combining in vitro and in vivo electrophysiological recordings, optogenetics, and fiber-photometry-based calcium imaging applied to wild-type and conditional transgenic mice, we explore the functional consequences of circuit-specific GABA type-B receptor (GABABR) manipulation. We found that activation of presynaptic GABABRs specifically depresses synaptic transmission from the AOC to OB inhibitory interneurons, but spares direct excitation to principal neurons. As a consequence, feedforward inhibition of spontaneous and odor-evoked activity of principal neurons is diminished. We also show that tunable cortico-bulbar feedback is critical for generating beta, but not gamma, OB oscillations. Together, these results show that GABABRs on cortico-bulbar afferents gate excitatory transmission in a target-specific manner and thus shape how the OB integrates sensory inputs and top-down information. SIGNIFICANCE STATEMENT The olfactory bulb (OB) receives top-down inputs from the olfactory cortex that produce direct excitation and feedforward inhibition onto mitral and tufted cells, the principal neurons. The functional role of this feedback and the mechanisms regulating the balance of feedback excitation and inhibition remain unknown. We found that GABAB receptors are expressed in cortico-bulbar axons that synapse on granule cells and receptor activation reduces the feedforward inhibition of spontaneous and odor-driven mitral and tufted cells' firing activity. In contrast, direct excitatory inputs to these principal neurons remain unchanged. This study demonstrates that activation of GABAB receptors biases the excitation/inhibition balance provided by cortical inputs to the OB, leading to profound effects on early stages of sensory information processing.
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32
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Feldmeyer D, Qi G, Emmenegger V, Staiger JF. Inhibitory interneurons and their circuit motifs in the many layers of the barrel cortex. Neuroscience 2017; 368:132-151. [PMID: 28528964 DOI: 10.1016/j.neuroscience.2017.05.027] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 10/19/2022]
Abstract
Recent years have seen substantial progress in studying the structural and functional properties of GABAergic interneurons and their roles in the neuronal networks of barrel cortex. Although GABAergic interneurons represent only about 12% of the total number of neocortical neurons, they are extremely diverse with respect to their structural and functional properties. It has become clear that barrel cortex interneurons not only serve the maintenance of an appropriate excitation/inhibition balance but also are directly involved in sensory processing. In this review we present different interneuron types and their axonal projection pattern framework in the context of the laminar and columnar organization of the barrel cortex. The main focus is here on the most prominent interneuron types, i.e. basket cells, chandelier cells, Martinotti cells, bipolar/bitufted cells and neurogliaform cells, but interneurons with more unusual axonal domains will also be mentioned. We describe their developmental origin, their classification with respect to molecular, morphological and intrinsic membrane and synaptic properties. Most importantly, we will highlight the most prominent circuit motifs these interneurons are involved in and in which way they serve feed-forward inhibition, feedback inhibition and disinhibition. Finally, this will be put into context to their functional roles in sensory signal perception and processing in the whisker system and beyond.
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Affiliation(s)
- Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2, Research Center Jülich, D-52425 Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany; Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), D-52074 Aachen, Germany.
| | - Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2, Research Center Jülich, D-52425 Jülich, Germany
| | - Vishalini Emmenegger
- Institute of Neuroscience and Medicine, INM-2, Research Center Jülich, D-52425 Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany
| | - Jochen F Staiger
- Institute for Neuroanatomy, University Medical Center Göttingen, Georg-August-University, Göttingen D-37075, Germany.
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Neurophysiological and BOLD signal uncoupling of giant somatosensory evoked potentials in progressive myoclonic epilepsy: a case-series study. Sci Rep 2017; 7:44664. [PMID: 28294187 PMCID: PMC5353703 DOI: 10.1038/srep44664] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/13/2017] [Indexed: 01/27/2023] Open
Abstract
In progressive myoclonic epilepsy (PME), a rare epileptic syndrome caused by a variety of genetic disorders, the combination of peripheral stimulation and functional magnetic resonance imaging (fMRI) can shed light on the mechanisms underlying cortical dysfunction. The aim of the study is to investigate sensorimotor network modifications in PME by assessing the relationship between neurophysiological findings and blood oxygen level dependent (BOLD) activation. Somatosensory-evoked potential (SSEP) obtained briefly before fMRI and BOLD activation during median-nerve electrical stimulation were recorded in four subjects with typical PME phenotype and compared with normative data. Giant scalp SSEPs with enlarger N20-P25 complex compared to normal data (mean amplitude of 26.2 ± 8.2 μV after right stimulation and 27.9 ± 3.7 μV after left stimulation) were detected. Statistical group analysis showed a reduced BOLD activation in response to median nerve stimulation in PMEs compared to controls over the sensorimotor (SM) areas and an increased response over subcortical regions (p < 0.01, Z > 2.3, corrected). PMEs show dissociation between neurophysiological and BOLD findings of SSEPs (giant SSEP with reduced BOLD activation over SM). A direct pathway connecting a highly restricted area of the somatosensory cortex with the thalamus can be hypothesized to support the higher excitability of these areas.
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34
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Wahlstrom-Helgren S, Klyachko VA. Dynamic balance of excitation and inhibition rapidly modulates spike probability and precision in feed-forward hippocampal circuits. J Neurophysiol 2016; 116:2564-2575. [PMID: 27605532 DOI: 10.1152/jn.00413.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 09/07/2016] [Indexed: 12/11/2022] Open
Abstract
Feed-forward inhibitory (FFI) circuits are important for many information-processing functions. FFI circuit operations critically depend on the balance and timing between the excitatory and inhibitory components, which undergo rapid dynamic changes during neural activity due to short-term plasticity (STP) of both components. How dynamic changes in excitation/inhibition (E/I) balance during spike trains influence FFI circuit operations remains poorly understood. In the current study we examined the role of STP in the FFI circuit functions in the mouse hippocampus. Using a coincidence detection paradigm with simultaneous activation of two Schaffer collateral inputs, we found that the spiking probability in the target CA1 neuron was increased while spike precision concomitantly decreased during high-frequency bursts compared with a single spike. Blocking inhibitory synaptic transmission revealed that dynamics of inhibition predominately modulates the spike precision but not the changes in spiking probability, whereas the latter is modulated by the dynamics of excitation. Further analyses combining whole cell recordings and simulations of the FFI circuit suggested that dynamics of the inhibitory circuit component may influence spiking behavior during bursts by broadening the width of excitatory postsynaptic responses and that the strength of this modulation depends on the basal E/I ratio. We verified these predictions using a mouse model of fragile X syndrome, which has an elevated E/I ratio, and found a strongly reduced modulation of postsynaptic response width during bursts. Our results suggest that changes in the dynamics of excitatory and inhibitory circuit components due to STP play important yet distinct roles in modulating the properties of FFI circuits.
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Affiliation(s)
- Sarah Wahlstrom-Helgren
- Departments of Cell Biology & Physiology and Biomedical Engineering, Center for the Investigation of Membrane Excitable Diseases, Washington University School of Medicine, St. Louis, Missouri
| | - Vitaly A Klyachko
- Departments of Cell Biology & Physiology and Biomedical Engineering, Center for the Investigation of Membrane Excitable Diseases, Washington University School of Medicine, St. Louis, Missouri
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van Versendaal D, Levelt CN. Inhibitory interneurons in visual cortical plasticity. Cell Mol Life Sci 2016; 73:3677-91. [PMID: 27193323 PMCID: PMC5002041 DOI: 10.1007/s00018-016-2264-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 04/30/2016] [Accepted: 05/03/2016] [Indexed: 01/01/2023]
Abstract
For proper maturation of the neocortex and acquisition of specific functions and skills, exposure to sensory stimuli is vital during critical periods of development when synaptic connectivity is highly malleable. To preserve reliable cortical processing, it is essential that these critical periods end after which learning becomes more conditional and active interaction with the environment becomes more important. How these age-dependent forms of plasticity are regulated has been studied extensively in the primary visual cortex. This has revealed that inhibitory innervation plays a crucial role and that a temporary decrease in inhibition is essential for plasticity to take place. Here, we discuss how different interneuron subsets regulate plasticity during different stages of cortical maturation. We propose a theory in which different interneuron subsets select the sources of neuronal input that undergo plasticity.
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Affiliation(s)
- Daniëlle van Versendaal
- Department of Molecular Visual Plasticity, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA, Amsterdam, The Netherlands
| | - Christiaan N Levelt
- Department of Molecular Visual Plasticity, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA, Amsterdam, The Netherlands. .,Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, de Boelelaan 1085, 1081HV, Amsterdam, The Netherlands.
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Interneuron Transcriptional Dysregulation Causes Frequency-Dependent Alterations in the Balance of Inhibition and Excitation in Hippocampus. J Neurosci 2016; 35:15276-90. [PMID: 26586816 DOI: 10.1523/jneurosci.1834-15.2015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Circuit dysfunction in complex brain disorders such as schizophrenia and autism is caused by imbalances between inhibitory and excitatory synaptic transmission (I/E). Short-term plasticity differentially alters responses from excitatory and inhibitory synapses, causing the I/E ratio to change as a function of frequency. However, little is known about I/E ratio dynamics in complex brain disorders. Transcriptional dysregulation in interneurons, particularly parvalbumin interneurons, is a consistent pathophysiological feature of schizophrenia. Peroxisome proliferator activated receptor γ coactivator 1α (PGC-1α) is a transcriptional coactivator that in hippocampus is highly concentrated in inhibitory interneurons and regulates parvalbumin transcription. Here, we used PGC-1α(-/-) mice to investigate effects of interneuron transcriptional dysregulation on the dynamics of the I/E ratio at the synaptic and circuit level in hippocampus. We find that loss of PGC-1α increases the I/E ratio onto CA1 pyramidal cells in response to Schaffer collateral stimulation in slices from young adult mice. The underlying mechanism is enhanced basal inhibition, including increased inhibition from parvalbumin interneurons. This decreases the spread of activation in CA1 and dramatically limits pyramidal cell spiking, reducing hippocampal output. The I/E ratio and CA1 output are partially restored by paired-pulse stimulation at short intervals, indicating frequency-dependent effects. However, circuit dysfunction persists, indicated by alterations in kainate-induced gamma oscillations and impaired nest building. Together, these results show that transcriptional dysregulation in hippocampal interneurons causes frequency-dependent alterations in I/E ratio and circuit function, suggesting that PGC-1α deficiency in psychiatric and neurological disorders contributes to disease by causing functionally relevant alterations in I/E balance. SIGNIFICANCE STATEMENT Alteration in the inhibitory and excitatory synaptic transmission (I/E) balance is a fundamental principle underlying the circuit dysfunction observed in many neuropsychiatric and neurodevelopmental disorders. The I/E ratio is dynamic, continuously changing because of synaptic short-term plasticity. We show here that transcriptional dysregulation in interneurons, particularly parvalbumin interneurons, causes frequency-dependent alterations in the I/E ratio and in circuit function in hippocampus. Peroxisome proliferator activated receptor γ coactivator 1α (PGC-1α-deficient) mice have enhanced inhibition in CA1, the opposite of what is seen in cortex. This study fills an important gap in current understanding of how changes in inhibition in complex brain disorders affect I/E dynamics, leading to region-specific circuit dysfunction and behavioral impairment. This study also provides a conceptual framework for analyzing the effects of short-term plasticity on the I/E balance in disease models.
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37
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Jiang X, Shen S, Cadwell CR, Berens P, Sinz F, Ecker AS, Patel S, Tolias AS. Principles of connectivity among morphologically defined cell types in adult neocortex. Science 2015; 350:aac9462. [PMID: 26612957 DOI: 10.1126/science.aac9462] [Citation(s) in RCA: 535] [Impact Index Per Article: 59.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Since the work of Ramón y Cajal in the late 19th and early 20th centuries, neuroscientists have speculated that a complete understanding of neuronal cell types and their connections is key to explaining complex brain functions. However, a complete census of the constituent cell types and their wiring diagram in mature neocortex remains elusive. By combining octuple whole-cell recordings with an optimized avidin-biotin-peroxidase staining technique, we carried out a morphological and electrophysiological census of neuronal types in layers 1, 2/3, and 5 of mature neocortex and mapped the connectivity between more than 11,000 pairs of identified neurons. We categorized 15 types of interneurons, and each exhibited a characteristic pattern of connectivity with other interneuron types and pyramidal cells. The essential connectivity structure of the neocortical microcircuit could be captured by only a few connectivity motifs.
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Affiliation(s)
- Xiaolong Jiang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
| | - Shan Shen
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Cathryn R Cadwell
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Philipp Berens
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA. Bernstein Centre for Computational Neuroscience, Tübingen, Germany. Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany. Werner Reichardt Center for Integrative Neuroscience and Institute of Theoretical Physics, University of Tübingen, Tübingen, Germany
| | - Fabian Sinz
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Alexander S Ecker
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA. Bernstein Centre for Computational Neuroscience, Tübingen, Germany. Werner Reichardt Center for Integrative Neuroscience and Institute of Theoretical Physics, University of Tübingen, Tübingen, Germany. Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Saumil Patel
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Andreas S Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA. Bernstein Centre for Computational Neuroscience, Tübingen, Germany.
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Rózsa M, Baka J, Bordé S, Rózsa B, Katona G, Tamás G. Unitary GABAergic volume transmission from individual interneurons to astrocytes in the cerebral cortex. Brain Struct Funct 2015; 222:651-659. [PMID: 26683686 DOI: 10.1007/s00429-015-1166-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/27/2015] [Indexed: 01/06/2023]
Abstract
Communication between individual GABAergic cells and their target neurons is mediated by synapses and, in the case of neurogliaform cells (NGFCs), by unitary volume transmission. Effects of non-synaptic volume transmission might involve non-neuronal targets, and astrocytes not receiving GABAergic synapses but expressing GABA receptors are suitable for evaluating this hypothesis. Testing several cortical interneuron types in slices of the rat cerebral cortex, we show selective unitary transmission from NGFCs to astrocytes with an early, GABAA receptor and GABA transporter-mediated component and a late component that results from the activation of GABA transporters and neuronal GABAB receptors. We could not detect Ca2+ influx in astrocytes associated with unitary GABAergic responses. Our experiments identify a presynaptic cell-type-specific, GABA-mediated communication pathway from individual neurons to astrocytes, assigning a role for unitary volume transmission in the control of ionic and neurotransmitter homeostasis.
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Affiliation(s)
- Márton Rózsa
- MTA-SZTE Research Group for Cortical Microcircuits, Department of Anatomy, Physiology and Neuroscience, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary
| | - Judith Baka
- MTA-SZTE Research Group for Cortical Microcircuits, Department of Anatomy, Physiology and Neuroscience, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary
| | - Sándor Bordé
- MTA-SZTE Research Group for Cortical Microcircuits, Department of Anatomy, Physiology and Neuroscience, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary
| | - Balázs Rózsa
- Two-Photon Imaging Center, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, 1083, Hungary
| | - Gergely Katona
- Two-Photon Imaging Center, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, 1083, Hungary
| | - Gábor Tamás
- MTA-SZTE Research Group for Cortical Microcircuits, Department of Anatomy, Physiology and Neuroscience, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary.
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Abstract
Recent research into local-circuit GABAergic inhibitory interneurons of the mammalian central nervous system has provided unprecedented insight into the mechanics of neuronal circuitry and its dysfunction. Inhibitory interneurons consist of a broad array of anatomically and neurochemically diverse cell types, and this suggests that each occupies an equally diverse functional role. Although neurogliaform cells were observed by Cajal over a century ago, our understanding of the functional role of this class of interneurons is in its infancy. However, it is rapidly becoming clear that this cell type operates under a distinct repertoire of rules to provide novel forms of inhibitory control of numerous afferent pathways.
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Wahlstrom-Helgren S, Klyachko VA. GABAB receptor-mediated feed-forward circuit dysfunction in the mouse model of fragile X syndrome. J Physiol 2015; 593:5009-24. [PMID: 26282581 DOI: 10.1113/jp271190] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 08/12/2015] [Indexed: 12/18/2022] Open
Abstract
KEY POINTS Cortico-hippocampal feed-forward circuits formed by the temporoammonic (TA) pathway exhibit a marked increase in excitation/inhibition ratio and abnormal spike modulation functions in Fmr1 knock-out (KO) mice. Inhibitory, but not excitatory, synapse dysfunction underlies cortico-hippocampal feed-forward circuit abnormalities in Fmr1 KO mice. GABA release is reduced in TA-associated inhibitory synapses of Fmr1 KO mice in a GABAB receptor-dependent manner. Inhibitory synapse and feed-forward circuit defects are mediated predominately by presynaptic GABAB receptor signalling in the TA pathway of Fmr1 KO mice. GABAB receptor-mediated inhibitory synapse defects are circuit-specific and are not observed in the Schaffer collateral pathway-associated inhibitory synapses in stratum radiatum. ABSTRACT Circuit hyperexcitability has been implicated in neuropathology of fragile X syndrome, the most common inheritable cause of intellectual disability. Yet, how canonical unitary circuits are affected in this disorder remains poorly understood. Here, we examined this question in the context of the canonical feed-forward inhibitory circuit formed by the temporoammonic (TA) branch of the perforant path, the major cortical input to the hippocampus. TA feed-forward circuits exhibited a marked increase in excitation/inhibition ratio and major functional defects in spike modulation tasks in Fmr1 knock-out (KO) mice, a fragile X mouse model. Changes in feed-forward circuits were caused specifically by inhibitory, but not excitatory, synapse defects. TA-associated inhibitory synapses exhibited increase in paired-pulse ratio and in the coefficient of variation of IPSPs, consistent with decreased GABA release probability. TA-associated inhibitory synaptic transmission in Fmr1 KO mice was also more sensitive to inhibition of GABAB receptors, suggesting an increase in presynaptic GABAB receptor (GABAB R) signalling. Indeed, the differences in inhibitory synaptic transmission between Fmr1 KO and wild-type (WT) mice were eliminated by a GABAB R antagonist. Inhibition of GABAB Rs or selective activation of presynaptic GABAB Rs also abolished the differences in the TA feed-forward circuit properties between Fmr1 KO and WT mice. These GABAB R-mediated defects were circuit-specific and were not observed in the Schaffer collateral pathway-associated inhibitory synapses. Our results suggest that the inhibitory synapse dysfunction in the cortico-hippocampal pathway of Fmr1 KO mice causes hyperexcitability and feed-forward circuit defects, which are mediated in part by a presynaptic GABAB R-dependent reduction in GABA release.
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Affiliation(s)
- Sarah Wahlstrom-Helgren
- Departments of Cell Biology and Physiology, Biomedical Engineering, Center for the Investigation of Membrane Excitable Diseases, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Vitaly A Klyachko
- Departments of Cell Biology and Physiology, Biomedical Engineering, Center for the Investigation of Membrane Excitable Diseases, Washington University School of Medicine, St Louis, MO, 63110, USA
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Bartley AF, Dobrunz LE. Short-term plasticity regulates the excitation/inhibition ratio and the temporal window for spike integration in CA1 pyramidal cells. Eur J Neurosci 2015; 41:1402-15. [PMID: 25903384 DOI: 10.1111/ejn.12898] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/27/2015] [Accepted: 03/16/2015] [Indexed: 12/21/2022]
Abstract
Many neurodevelopmental and neuropsychiatric disorders involve an imbalance between excitation and inhibition caused by synaptic alterations. The proper excitation/inhibition (E/I) balance is especially critical in CA1 pyramidal cells, because they control hippocampal output. Activation of Schaffer collateral axons causes direct excitation of CA1 pyramidal cells, quickly followed by disynaptic feedforward inhibition, stemming from synaptically induced firing of GABAergic interneurons. Both excitatory and inhibitory synapses are modulated by short-term plasticity, potentially causing dynamic tuning of the E/I ratio. However, the effects of short-term plasticity on the E/I ratio in CA1 pyramidal cells are not yet known. To determine this, we recorded disynaptic inhibitory postsynaptic currents and the E/I ratio in CA1 pyramidal cells in acute hippocampal slices from juvenile mice. We found that, whereas inhibitory synapses had paired-pulse depression, disynaptic inhibition instead had paired-pulse facilitation (≤ 200-ms intervals), caused by increased recruitment of feedforward interneurons. Although enhanced disynaptic inhibition helped to constrain paired-pulse facilitation of excitation, the E/I ratio was still larger on the second pulse, increasing pyramidal cell spiking. Surprisingly, this occurred without compromising the precision of spike timing. The E/I balance regulates the temporal spike integration window from multiple inputs; here, we showed that paired-pulse stimulation can broaden the spike integration window. Together, our findings show that the combined effects of short-term plasticity of disynaptic inhibition and monosynaptic excitation alter the E/I balance in CA1 pyramidal cells, leading to dynamic modulation of spike probability and the spike integration window. Short-term plasticity is therefore an important mechanism for modulating signal processing of hippocampal output.
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Affiliation(s)
- Aundrea F Bartley
- Department of Neurobiology, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd, SHEL 902, Birmingham, AL, 35294, USA
| | - Lynn E Dobrunz
- Department of Neurobiology, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd, SHEL 902, Birmingham, AL, 35294, USA
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Contributions of diverse excitatory and inhibitory neurons to recurrent network activity in cerebral cortex. J Neurosci 2015; 35:1089-105. [PMID: 25609625 DOI: 10.1523/jneurosci.2279-14.2015] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The recurrent synaptic architecture of neocortex allows for self-generated network activity. One form of such activity is the Up state, in which neurons transiently receive barrages of excitatory and inhibitory synaptic inputs that depolarize many neurons to spike threshold before returning to a relatively quiescent Down state. The extent to which different cell types participate in Up states is still unclear. Inhibitory interneurons have particularly diverse intrinsic properties and synaptic connections with the local network, suggesting that different interneurons might play different roles in activated network states. We have studied the firing, subthreshold behavior, and synaptic conductances of identified cell types during Up and Down states in layers 5 and 2/3 in mouse barrel cortex in vitro. We recorded from pyramidal cells and interneurons expressing parvalbumin (PV), somatostatin (SOM), vasoactive intestinal peptide (VIP), or neuropeptide Y. PV cells were the most active interneuron subtype during the Up state, yet the other subtypes also received substantial synaptic conductances and often generated spikes. In all cell types except PV cells, the beginning of the Up state was dominated by synaptic inhibition, which decreased thereafter; excitation was more persistent, suggesting that inhibition is not the dominant force in terminating Up states. Compared with barrel cortex, SOM and VIP cells were much less active in entorhinal cortex during Up states. Our results provide a measure of functional connectivity of various neuron types in barrel cortex and suggest differential roles for interneuron types in the generation and control of persistent network activity.
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Koelbl C, Helmstaedter M, Lübke J, Feldmeyer D. A barrel-related interneuron in layer 4 of rat somatosensory cortex with a high intrabarrel connectivity. Cereb Cortex 2015; 25:713-25. [PMID: 24076498 PMCID: PMC4318534 DOI: 10.1093/cercor/bht263] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Synaptic connections between identified fast-spiking (FS), parvalbumin (PV)-positive interneurons, and excitatory spiny neurons in layer 4 (L4) of the barrel cortex were investigated using patch-clamp recordings and simultaneous biocytin fillings. Three distinct clusters of FS L4 interneurons were identified based on their axonal morphology relative to the barrel column suggesting that these neurons do not constitute a homogeneous interneuron population. One L4 FS interneuron type had an axonal domain strictly confined to a L4 barrel and was therefore named "barrel-confined inhibitory interneuron" (BIn). BIns established reliable inhibitory synaptic connections with L4 spiny neurons at a high connectivity rate of 67%, of which 69% were reciprocal. Unitary IPSPs at these connections had a mean amplitude of 0.9 ± 0.8 mV with little amplitude variation and weak short-term synaptic depression. We found on average 3.7 ± 1.3 putative inhibitory synaptic contacts that were not restricted to perisomatic areas. In conclusion, we characterized a novel type of barrel cortex interneuron in the major thalamo-recipient layer 4 forming dense synaptic networks with L4 spiny neurons. These networks constitute an efficient and powerful inhibitory feedback system, which may serve to rapidly reset the barrel microcircuitry following sensory activation.
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Affiliation(s)
- Christian Koelbl
- Department of Cell Physiology, Max Planck Institute of Medical Research, Jahnstr. 20, D-69120 Heidelberg, Germany
- Current address: Section of Cardiovascular Medicine, Boston University Medical Center, 88 East Newton Street, Boston, MA 02118, USA
| | - Moritz Helmstaedter
- Department of Cell Physiology, Max Planck Institute of Medical Research, Jahnstr. 20, D-69120 Heidelberg, Germany
- Current address: Structure of Neocortical Circuits Group, Max Planck Institute of Neurobiology, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Joachim Lübke
- Institute for Neuroscience and Medicine, INM-2, Research Centre Jülich, Leo-Brandt-Str., D-52425 Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Pauwelstr. 30, D-52074 Aachen, Germany
- Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA-Brain), D-52074, Aachen, Germany
| | - Dirk Feldmeyer
- Institute for Neuroscience and Medicine, INM-2, Research Centre Jülich, Leo-Brandt-Str., D-52425 Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Pauwelstr. 30, D-52074 Aachen, Germany
- Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA-Brain), D-52074, Aachen, Germany
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Scimemi A. Structure, function, and plasticity of GABA transporters. Front Cell Neurosci 2014; 8:161. [PMID: 24987330 PMCID: PMC4060055 DOI: 10.3389/fncel.2014.00161] [Citation(s) in RCA: 159] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 05/27/2014] [Indexed: 11/13/2022] Open
Abstract
GABA transporters belong to a large family of neurotransmitter:sodium symporters. They are widely expressed throughout the brain, with different levels of expression in different brain regions. GABA transporters are present in neurons and in astrocytes and their activity is crucial to regulate the extracellular concentration of GABA under basal conditions and during ongoing synaptic events. Numerous efforts have been devoted to determine the structural and functional properties of GABA transporters. There is also evidence that the expression of GABA transporters on the cell membrane and their lateral mobility can be modulated by different intracellular signaling cascades. The strength of individual synaptic contacts and the activity of entire neuronal networks may be finely tuned by altering the density, distribution and diffusion rate of GABA transporters within the cell membrane. These findings are intriguing because they suggest the existence of complex regulatory systems that control the plasticity of GABAergic transmission in the brain. Here we review the current knowledge on the structural and functional properties of GABA transporters and highlight the molecular mechanisms that alter the expression and mobility of GABA transporters at central synapses.
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Arroyo S, Bennett C, Hestrin S. Nicotinic modulation of cortical circuits. Front Neural Circuits 2014; 8:30. [PMID: 24734005 PMCID: PMC3975109 DOI: 10.3389/fncir.2014.00030] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 03/10/2014] [Indexed: 01/09/2023] Open
Abstract
The ascending cholinergic neuromodulatory system sends projections throughout cortex and has been shown to play an important role in a number of cognitive functions including arousal, working memory, and attention. However, despite a wealth of behavioral and anatomical data, understanding how cholinergic synapses modulate cortical function has been limited by the inability to selectively activate cholinergic axons. Now, with the development of optogenetic tools and cell-type specific Cre-driver mouse lines, it has become possible to stimulate cholinergic axons from the basal forebrain (BF) and probe cholinergic synapses in the cortex for the first time. Here we review recent work studying the cell-type specificity of nicotinic signaling in the cortex, synaptic mechanisms mediating cholinergic transmission, and the potential functional role of nicotinic modulation.
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Affiliation(s)
- Sergio Arroyo
- Department of Comparative Medicine, Stanford University School of Medicine Stanford, CA, USA
| | - Corbett Bennett
- Department of Comparative Medicine, Stanford University School of Medicine Stanford, CA, USA
| | - Shaul Hestrin
- Department of Comparative Medicine, Stanford University School of Medicine Stanford, CA, USA
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46
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Griffen TC, Maffei A. GABAergic synapses: their plasticity and role in sensory cortex. Front Cell Neurosci 2014; 8:91. [PMID: 24723851 PMCID: PMC3972456 DOI: 10.3389/fncel.2014.00091] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 03/12/2014] [Indexed: 12/17/2022] Open
Abstract
The mammalian neocortex is composed of a variety of cell types organized in a highly interconnected circuit. GABAergic neurons account for only about 20% of cortical neurons. However, they show widespread connectivity and a high degree of diversity in morphology, location, electrophysiological properties and gene expression. In addition, distinct populations of inhibitory neurons have different sensory response properties, capacities for plasticity and sensitivities to changes in sensory experience. In this review we summarize experimental evidence regarding the properties of GABAergic neurons in primary sensory cortex. We will discuss how distinct GABAergic neurons and different forms of GABAergic inhibitory plasticity may contribute to shaping sensory cortical circuit activity and function.
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Affiliation(s)
- Trevor C Griffen
- SUNY Eye Research Consortium Buffalo, NY, USA ; Program in Neuroscience, SUNY - Stony Brook Stony Brook, NY, USA ; Medical Scientist Training Program, SUNY - Stony Brook Stony Brook, NY, USA
| | - Arianna Maffei
- SUNY Eye Research Consortium Buffalo, NY, USA ; Department of Neurobiology and Behavior, SUNY - Stony Brook Stony Brook, NY, USA
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47
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Karnani MM, Agetsuma M, Yuste R. A blanket of inhibition: functional inferences from dense inhibitory connectivity. Curr Opin Neurobiol 2014; 26:96-102. [PMID: 24440415 DOI: 10.1016/j.conb.2013.12.015] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 01/13/2023]
Abstract
The function of neocortical interneurons is still unclear, and, as often happens, one may be able to draw functional insights from considering the structure. In this spirit we describe recent structural results and discuss their potential functional implications. Most GABAergic interneurons innervate nearby pyramidal neurons very densely and without any apparent specificity, as if they were extending a 'blanket of inhibition', contacting pyramidal neurons often in an overlapping fashion. While subtypes of interneurons specifically target subcellular compartments of pyramidal cells, and they also target different layers selectively, they appear to treat all neighboring pyramidal cells the same and innervate them massively. We explore the functional implications and temporal properties of dense, overlapping inhibition by four interneuron populations.
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Affiliation(s)
- Mahesh M Karnani
- Department of Biological Sciences, Columbia University, New York, NY 10027, United States.
| | - Masakazu Agetsuma
- Department of Biological Sciences, Columbia University, New York, NY 10027, United States
| | - Rafael Yuste
- Department of Biological Sciences, Columbia University, New York, NY 10027, United States.
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48
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The emerging role of GABAB receptors as regulators of network dynamics: fast actions from a 'slow' receptor? Curr Opin Neurobiol 2013; 26:15-21. [PMID: 24650499 DOI: 10.1016/j.conb.2013.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/10/2013] [Accepted: 10/11/2013] [Indexed: 12/25/2022]
Abstract
Convention holds that ionotropic receptors mediate fast neurotransmission and that 'slow' G-protein coupled metabotropic receptors have a secondary, modulatory role in the control of neuronal networks. Here, we discuss recent evidence showing that activation of metabotropic GABAB receptors in cortical layer 1 can powerfully inhibit principal cell activity and that their activation can rapidly halt ongoing network activity. Inputs from both within and without the cortex converge upon layer 1 where they target various populations of interneurons, including neurogliaform cells. We argue that neurogliaform cells are the main effector of a powerful inhibitory circuit that, acting through GABAB receptors, can be differentially recruited by long-range connections to serve in roles as diverse as conscious perception and memory consolidation.
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49
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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]
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