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Lourenço J, Koukouli F, Bacci A. Synaptic inhibition in the neocortex: Orchestration and computation through canonical circuits and variations on the theme. Cortex 2020; 132:258-280. [PMID: 33007640 DOI: 10.1016/j.cortex.2020.08.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/28/2020] [Accepted: 08/31/2020] [Indexed: 12/15/2022]
Abstract
The neocortex plays a crucial role in all basic and abstract cognitive functions. Conscious mental processes are achieved through a correct flow of information within and across neocortical networks, whose particular activity state results from a tight balance between excitation and inhibition. The proper equilibrium between these indissoluble forces is operated with multiscale organization: along the dendro-somatic axis of single neurons and at the network level. Fast synaptic inhibition is assured by a multitude of inhibitory interneurons. During cortical activities, these cells operate a finely tuned division of labor that is epitomized by their detailed connectivity scheme. Recent results combining the use of mouse genetics, cutting-edge optical and neurophysiological approaches have highlighted the role of fast synaptic inhibition in driving cognition-related activity through a canonical cortical circuit, involving several major interneuron subtypes and principal neurons. Here we detail the organization of this cortical blueprint and we highlight the crucial role played by different neuron types in fundamental cortical computations. In addition, we argue that this canonical circuit is prone to many variations on the theme, depending on the resolution of the classification of neuronal types, and the cortical area investigated. Finally, we discuss how specific alterations of distinct inhibitory circuits can underlie several devastating brain diseases.
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Affiliation(s)
- Joana Lourenço
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de L'Hôpital, 75013, Paris, France.
| | - Fani Koukouli
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de L'Hôpital, 75013, Paris, France
| | - Alberto Bacci
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de L'Hôpital, 75013, Paris, France.
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52
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Kim YS, Choi J, Yoon BE. Neuron-Glia Interactions in Neurodevelopmental Disorders. Cells 2020; 9:cells9102176. [PMID: 32992620 PMCID: PMC7601502 DOI: 10.3390/cells9102176] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/24/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
Recent studies have revealed synaptic dysfunction to be a hallmark of various psychiatric diseases, and that glial cells participate in synapse formation, development, and plasticity. Glial cells contribute to neuroinflammation and synaptic homeostasis, the latter being essential for maintaining the physiological function of the central nervous system (CNS). In particular, glial cells undergo gliotransmission and regulate neuronal activity in tripartite synapses via ion channels (gap junction hemichannel, volume regulated anion channel, and bestrophin-1), receptors (for neurotransmitters and cytokines), or transporters (GLT-1, GLAST, and GATs) that are expressed on glial cell membranes. In this review, we propose that dysfunction in neuron-glia interactions may contribute to the pathogenesis of neurodevelopmental disorders. Understanding the mechanisms of neuron-glia interaction for synapse formation and maturation will contribute to the development of novel therapeutic targets of neurodevelopmental disorders.
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Affiliation(s)
- Yoo Sung Kim
- Department of Molecular Biology, Dankook University, Cheonan 31116, Korea; (Y.S.K.); (J.C.)
| | - Juwon Choi
- Department of Molecular Biology, Dankook University, Cheonan 31116, Korea; (Y.S.K.); (J.C.)
| | - Bo-Eun Yoon
- Department of Molecular Biology, Dankook University, Cheonan 31116, Korea; (Y.S.K.); (J.C.)
- Department of Nanobiomedical science, Dankook University, Cheonan 31116, Korea
- Correspondence: ; Tel.: +82-41-529-6085
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53
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Sherif MA, Neymotin SA, Lytton WW. In silico hippocampal modeling for multi-target pharmacotherapy in schizophrenia. NPJ SCHIZOPHRENIA 2020; 6:25. [PMID: 32958782 PMCID: PMC7506542 DOI: 10.1038/s41537-020-00109-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 06/23/2020] [Indexed: 02/08/2023]
Abstract
Treatment of schizophrenia has had limited success in treating core cognitive symptoms. The evidence of multi-gene involvement suggests that multi-target therapy may be needed. Meanwhile, the complexity of schizophrenia pathophysiology and psychopathology, coupled with the species-specificity of much of the symptomatology, places limits on analysis via animal models, in vitro assays, and patient assessment. Multiscale computer modeling complements these traditional modes of study. Using a hippocampal CA3 computer model with 1200 neurons, we examined the effects of alterations in NMDAR, HCN (Ih current), and GABAAR on information flow (measured with normalized transfer entropy), and in gamma activity in local field potential (LFP). We found that altering NMDARs, GABAAR, Ih, individually or in combination, modified information flow in an inverted-U shape manner, with information flow reduced at low and high levels of these parameters. Theta-gamma phase-amplitude coupling also had an inverted-U shape relationship with NMDAR augmentation. The strong information flow was associated with an intermediate level of synchrony, seen as an intermediate level of gamma activity in the LFP, and an intermediate level of pyramidal cell excitability. Our results are consistent with the idea that overly low or high gamma power is associated with pathological information flow and information processing. These data suggest the need for careful titration of schizophrenia pharmacotherapy to avoid extremes that alter information flow in different ways. These results also identify gamma power as a potential biomarker for monitoring pathology and multi-target pharmacotherapy.
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Affiliation(s)
- Mohamed A Sherif
- Department of Psychiatry, VA Connecticut Healthcare System, 950 Campbell Avenue, West Haven, CT, USA.
- Department of Psychiatry, Yale University, New Haven, CT, USA.
- Biomedical Engineering Graduate Program, SUNY Downstate Medical Center/NYU Tandon School of Engineering, Brooklyn, NY, USA.
| | - Samuel A Neymotin
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - William W Lytton
- Biomedical Engineering Graduate Program, SUNY Downstate Medical Center/NYU Tandon School of Engineering, Brooklyn, NY, USA
- Department of Physiology and Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY, USA
- Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY, USA
- Department of Neurology, Kings County Hospital Center, Brooklyn, NY, USA
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54
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Sekulić V, Yi F, Garrett T, Guet-McCreight A, Lawrence JJ, Skinner FK. Integration of Within-Cell Experimental Data With Multi-Compartmental Modeling Predicts H-Channel Densities and Distributions in Hippocampal OLM Cells. Front Cell Neurosci 2020; 14:277. [PMID: 33093823 PMCID: PMC7527636 DOI: 10.3389/fncel.2020.00277] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/05/2020] [Indexed: 12/13/2022] Open
Abstract
Determining biophysical details of spatially extended neurons is a challenge that needs to be overcome if we are to understand the dynamics of brain function from cellular perspectives. Moreover, we now know that we should not average across recordings from many cells of a given cell type to obtain quantitative measures such as conductance since measures can vary multiple-fold for a given cell type. In this work we examine whether a tight combination of experimental and computational work can address this challenge. The oriens-lacunosum/moleculare (OLM) interneuron operates as a “gate” that controls incoming sensory and ongoing contextual information in the CA1 of the hippocampus, making it essential to understand how its biophysical properties contribute to memory function. OLM cells fire phase-locked to the prominent hippocampal theta rhythms, and we previously used computational models to show that OLM cells exhibit high or low theta spiking resonance frequencies that depend respectively on whether their dendrites have hyperpolarization-activated cation channels (h-channels) or not. However, whether OLM cells actually possess dendritic h-channels is unknown at present. We performed a set of whole-cell recordings of OLM cells from mouse hippocampus and constructed three multi-compartment models using morphological and electrophysiological parameters extracted from the same OLM cell, including per-cell pharmacologically isolated h-channel currents. We found that the models best matched experiments when h-channels were present in the dendrites of each of the three model cells created. This strongly suggests that h-channels must be present in OLM cell dendrites and are not localized to their somata. Importantly, this work shows that a tight integration of model and experiment can help tackle the challenge of characterizing biophysical details and distributions in spatially extended neurons. Full spiking models were built for two of the OLM cells, matching their current clamp cell-specific electrophysiological recordings. Overall, our work presents a technical advancement in modeling OLM cells. Our models are available to the community to use to gain insight into cellular dynamics underlying hippocampal function.
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Affiliation(s)
- Vladislav Sekulić
- Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Feng Yi
- Department of Biomedical and Pharmaceutical Sciences, Center for Biomolecular Structure and Dynamics, Center for Structural and Functional Neuroscience, University of Montana, Missoula, MT, United States
| | - Tavita Garrett
- Neuroscience Graduate Program and Vollum Institute, Oregon Health & Science University, Portland, OR, United States
| | - Alexandre Guet-McCreight
- Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - J Josh Lawrence
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, United States.,Center for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, United States.,Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Frances K Skinner
- Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Departments of Medicine (Neurology) and Physiology, University of Toronto, Toronto, ON, Canada
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55
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Goode TD, Tanaka KZ, Sahay A, McHugh TJ. An Integrated Index: Engrams, Place Cells, and Hippocampal Memory. Neuron 2020; 107:805-820. [PMID: 32763146 PMCID: PMC7486247 DOI: 10.1016/j.neuron.2020.07.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/17/2020] [Accepted: 07/13/2020] [Indexed: 01/10/2023]
Abstract
The hippocampus and its extended network contribute to encoding and recall of episodic experiences. Drawing from recent anatomical, physiological, and behavioral studies, we propose that hippocampal engrams function as indices to mediate memory recall. We broaden this idea to discuss potential relationships between engrams and hippocampal place cells, as well as the molecular, cellular, physiological, and circuit determinants of engrams that permit flexible routing of information to intra- and extrahippocampal circuits for reinstatement, a feature critical to memory indexing. Incorporating indexing into frameworks of memory function opens new avenues of study and even therapies for hippocampal dysfunction.
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Affiliation(s)
- Travis D Goode
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Kazumasa Z Tanaka
- Memory Research Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Kunigami-gun, Okinawa, Japan
| | - Amar Sahay
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wakoshi, Saitama, Japan.
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56
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Nakamura Y, Morrow DH, Nathanson AJ, Henley JM, Wilkinson KA, Moss SJ. Phosphorylation on Ser-359 of the α2 subunit in GABA type A receptors down-regulates their density at inhibitory synapses. J Biol Chem 2020; 295:12330-12342. [PMID: 32620552 PMCID: PMC7458806 DOI: 10.1074/jbc.ra120.014303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/25/2020] [Indexed: 11/06/2022] Open
Abstract
GABA type A receptors (GABAARs) mediate fast synaptic inhibition and are trafficked to functionally diverse synapses. However, the precise molecular mechanisms that regulate the synaptic targeting of these receptors are unclear. Whereas it has been previously shown that phosphorylation events in α4, β, and γ subunits of GABAARs govern their function and trafficking, phosphorylation of other subunits has not yet been demonstrated. Here, we show that the α2 subunit of GABAARs is phosphorylated at Ser-359 and enables dynamic regulation of GABAAR binding to the scaffolding proteins gephyrin and collybistin. We initially identified Ser-359 phosphorylation by MS analysis, and additional experiments revealed that it is regulated by the activities of cAMP-dependent protein kinase (PKA) and the protein phosphatase 1 (PP1) and/or PP2A. GST-based pulldowns and coimmunoprecipitation experiments demonstrate preferential binding of both gephyrin and collybistin to WT and an S359A phosphonull variant, but not to an S359D phosphomimetic variant. Furthermore, the decreased capacity of the α2 S359D variant to bind collybistin and gephyrin decreased the density of synaptic α2-containing GABAAR clusters and caused an absence of α2 enrichment in the axon initial segment. These results suggest that PKA-mediated phosphorylation and PP1/PP2A-dependent dephosphorylation of the α2 subunit play a role in the dynamic regulation of GABAAR accumulation at inhibitory synapses, thereby regulating the strength of synaptic inhibition. The MS data have been deposited to ProteomeXchange, with the data set identifier PXD019597.
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Affiliation(s)
- Yasuko Nakamura
- School of Biochemistry, Centre for Synaptic Plasticity, University of Bristol, Bristol, United Kingdom
| | - Danielle H. Morrow
- Department of Neuroscience, Tufts University, School of Medicine, Boston, Massachusetts, USA
| | - Anna J. Nathanson
- Department of Neuroscience, Tufts University, School of Medicine, Boston, Massachusetts, USA
| | - Jeremy M. Henley
- School of Biochemistry, Centre for Synaptic Plasticity, University of Bristol, Bristol, United Kingdom
| | - Kevin A. Wilkinson
- School of Biochemistry, Centre for Synaptic Plasticity, University of Bristol, Bristol, United Kingdom
| | - Stephen J. Moss
- Department of Neuroscience, Tufts University, School of Medicine, Boston, Massachusetts, USA,Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom,For correspondence: S. J. Moss,
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57
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Nathanson AJ, Zhang Y, Smalley JL, Ollerhead TA, Rodriguez Santos MA, Andrews PM, Wobst HJ, Moore YE, Brandon NJ, Hines RM, Davies PA, Moss SJ. Identification of a Core Amino Acid Motif within the α Subunit of GABA ARs that Promotes Inhibitory Synaptogenesis and Resilience to Seizures. Cell Rep 2020; 28:670-681.e8. [PMID: 31315046 PMCID: PMC8283774 DOI: 10.1016/j.celrep.2019.06.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 05/08/2019] [Accepted: 06/03/2019] [Indexed: 12/12/2022] Open
Abstract
SUMMARY The fidelity of inhibitory neurotransmission is dependent on the accumulation of γ-aminobutyric acid type A receptors (GABAARs) at the appropriate synaptic sites. Synaptic GABAARs are constructed from α(1–3), β(1–3), and γ2 subunits, and neurons can target these subtypes to specific synapses. Here, we identify a 15-amino acid inhibitory synapse targeting motif (ISTM) within the α2 subunit that promotes the association between GABAARs and the inhibitory scaffold proteins collybistin and gephyrin. Using mice in which the ISTM has been introduced into the α1 subunit (Gabra1–2 mice), we show that the ISTM is critical for axo-axonic synapse formation, the efficacy of GABAergic neurotransmission, and seizure sensitivity. The Gabra1–2 mutation rescues seizure-induced lethality in Gabra2–1 mice, which lack axo-axonic synapses due to the deletion of the ISTM from the α2 subunit. Taken together, our data demonstrate that the ISTM plays a critical role in promoting inhibitory synapse formation, both in the axonic and somatodendritic compartments. In Brief Molecular mechanisms regulating specific synaptic GABAAR accumulation are critical for the fidelity of inhibitory neurotransmission. Nathanson et al. show that strengthening the interaction between α1-GABAARs and collybistin via genetic manipulation results in augmented synaptic targeting of these receptors, enhanced inhibitory neurotransmission, and seizure resilience.
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Affiliation(s)
- Anna J Nathanson
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Yihui Zhang
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Joshua L Smalley
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Thomas A Ollerhead
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | | | - Peter M Andrews
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Heike J Wobst
- AstraZeneca Neuroscience, IMED Biotech Unit, R&D, Boston, MA 02451, USA
| | - Yvonne E Moore
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Nicholas J Brandon
- AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA 02111, USA; AstraZeneca Neuroscience, IMED Biotech Unit, R&D, Boston, MA 02451, USA
| | - Rochelle M Hines
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Paul A Davies
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA 02111, USA; Department of Neuroscience, Physiology and Pharmacology, University College, London WC1E 6BT, UK.
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58
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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: 49] [Impact Index Per Article: 12.3] [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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59
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Abstract
Cortical interneurons display striking differences in shape, physiology, and other attributes, challenging us to appropriately classify them. We previously suggested that interneuron types should be defined by their role in cortical processing. Here, we revisit the question of how to codify their diversity based upon their division of labor and function as controllers of cortical information flow. We suggest that developmental trajectories provide a guide for appreciating interneuron diversity and argue that subtype identity is generated using a configurational (rather than combinatorial) code of transcription factors that produce attractor states in the underlying gene regulatory network. We present our updated three-stage model for interneuron specification: an initial cardinal step, allocating interneurons into a few major classes, followed by definitive refinement, creating subclasses upon settling within the cortex, and lastly, state determination, reflecting the incorporation of interneurons into functional circuit ensembles. We close by discussing findings indicating that major interneuron classes are both evolutionarily ancient and conserved. We propose that the complexity of cortical circuits is generated by phylogenetically old interneuron types, complemented by an evolutionary increase in principal neuron diversity. This suggests that a natural neurobiological definition of interneuron types might be derived from a match between their developmental origin and computational function.
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Affiliation(s)
- Gord Fishell
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA;
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, Massachusetts 02142, USA
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Adam Kepecs
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, Missouri 63130, USA;
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60
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Functionally distinct Purkinje cell types show temporal precision in encoding locomotion. Proc Natl Acad Sci U S A 2020; 117:17330-17337. [PMID: 32632015 PMCID: PMC7382291 DOI: 10.1073/pnas.2005633117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Purkinje cells, the principal neurons of cerebellar computations, are believed to comprise a uniform neuronal population of cells, each with similar functional properties. Here, we show an undiscovered heterogeneity of adult zebrafish Purkinje cells, revealing the existence of anatomically and functionally distinct cell types. Dual patch-clamp recordings showed that the cerebellar circuit contains all Purkinje cell types that cross-communicate extensively using chemical and electrical synapses. Further activation of spinal central pattern generators (CPGs) revealed unique phase-locked activity from each Purkinje cell type during the locomotor cycle. Thus, we show intricately organized Purkinje cell networks in the adult zebrafish cerebellum that encode the locomotion rhythm differentially, and we suggest that these organizational properties may also apply to other cerebellar functions.
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61
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Davis P, Gaitanis J. Neuromodulation for the Treatment of Epilepsy: A Review of Current Approaches and Future Directions. Clin Ther 2020; 42:1140-1154. [DOI: 10.1016/j.clinthera.2020.05.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 02/08/2023]
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62
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Khan AR, Geiger L, Wiborg O, Czéh B. Stress-Induced Morphological, Cellular and Molecular Changes in the Brain-Lessons Learned from the Chronic Mild Stress Model of Depression. Cells 2020; 9:cells9041026. [PMID: 32326205 PMCID: PMC7226496 DOI: 10.3390/cells9041026] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/14/2020] [Accepted: 04/19/2020] [Indexed: 02/07/2023] Open
Abstract
Major depressive disorder (MDD) is a severe illness imposing an increasing social and economic burden worldwide. Numerous rodent models have been developed to investigate the pathophysiology of MDD. One of the best characterized and most widely used models is the chronic mild stress (CMS) model which was developed more than 30 years ago by Paul Willner. More than 2000 published studies used this model, mainly to assess novel compounds with potential antidepressant efficacy. Most of these studies examined the behavioral consequences of stress and concomitant drug intervention. Much fewer studies focused on the CMS-induced neurobiological changes. However, the stress-induced cellular and molecular changes are important as they may serve as potential translational biomarkers and increase our understanding of the pathophysiology of MDD. Here, we summarize current knowledge on the structural and molecular alterations in the brain that have been described using the CMS model. We discuss the latest neuroimaging and postmortem histopathological data as well as molecular changes including recent findings on microRNA levels. Different chronic stress paradigms occasionally deliver dissimilar findings, but the available experimental data provide convincing evidence that the CMS model has a high translational value. Future studies examining the neurobiological changes in the CMS model in combination with clinically effective antidepressant drug intervention will likely deliver further valuable information on the pathophysiology of MDD.
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Affiliation(s)
- Ahmad Raza Khan
- Centre of Biomedical Research, Sanjay Gandhi Post Graduate Institute (SGPGI) Campus, Lucknow-226017, U.P, India;
| | - Lili Geiger
- Neurobiology of Stress Research Group, Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary;
- Department of Laboratory Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary
| | - Ove Wiborg
- Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark;
| | - Boldizsár Czéh
- Neurobiology of Stress Research Group, Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary;
- Department of Laboratory Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary
- Correspondence:
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63
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Markicevic M, Fulcher BD, Lewis C, Helmchen F, Rudin M, Zerbi V, Wenderoth N. Cortical Excitation:Inhibition Imbalance Causes Abnormal Brain Network Dynamics as Observed in Neurodevelopmental Disorders. Cereb Cortex 2020; 30:4922-4937. [PMID: 32313923 PMCID: PMC7391279 DOI: 10.1093/cercor/bhaa084] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Abnormal brain development manifests itself at different spatial scales. However, whether abnormalities at the cellular level can be diagnosed from network activity measured with functional magnetic resonance imaging (fMRI) is largely unknown, yet of high clinical relevance. Here a putative mechanism reported in neurodevelopmental disorders, that is, excitation-to-inhibition ratio (E:I), was chemogenetically increased within cortical microcircuits of the mouse brain and measured via fMRI. Increased E:I caused a significant "reduction" of long-range connectivity, irrespective of whether excitatory neurons were facilitated or inhibitory Parvalbumin (PV) interneurons were suppressed. Training a classifier on fMRI signals, we were able to accurately classify cortical areas exhibiting increased E:I. This classifier was validated in an independent cohort of Fmr1y/- knockout mice, a model for autism with well-documented loss of parvalbumin neurons and chronic alterations of E:I. Our findings demonstrate a promising novel approach towards inferring microcircuit abnormalities from macroscopic fMRI measurements.
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Affiliation(s)
- Marija Markicevic
- Neural Control of Movement Lab, HEST, ETH Zürich, 8093 Zurich, Switzerland.,Neuroscience Center Zurich, University and ETH Zurich, 8057 Zurich, Switzerland
| | - Ben D Fulcher
- School of Physics, The University of Sydney, NSW 2006, Australia
| | - Christopher Lewis
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Fritjof Helmchen
- Neuroscience Center Zurich, University and ETH Zurich, 8057 Zurich, Switzerland.,Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Markus Rudin
- Neuroscience Center Zurich, University and ETH Zurich, 8057 Zurich, Switzerland.,Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland.,Institute for Biomedical Engineering, University and ETH Zurich, 8093 Zurich, Switzerland
| | - Valerio Zerbi
- Neural Control of Movement Lab, HEST, ETH Zürich, 8093 Zurich, Switzerland.,Neuroscience Center Zurich, University and ETH Zurich, 8057 Zurich, Switzerland
| | - Nicole Wenderoth
- Neural Control of Movement Lab, HEST, ETH Zürich, 8093 Zurich, Switzerland.,Neuroscience Center Zurich, University and ETH Zurich, 8057 Zurich, Switzerland
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64
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Neonatal Injury Evokes Persistent Deficits in Dynorphin Inhibitory Circuits within the Adult Mouse Superficial Dorsal Horn. J Neurosci 2020; 40:3882-3895. [PMID: 32291327 DOI: 10.1523/jneurosci.0029-20.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/18/2020] [Accepted: 04/04/2020] [Indexed: 12/22/2022] Open
Abstract
Neonatal tissue damage induces long-term deficits in inhibitory synaptic transmission within the spinal superficial dorsal horn (SDH) that include a reduction in primary afferent-evoked, feedforward inhibition onto adult projection neurons. However, the subpopulations of mature GABAergic interneurons which are compromised by early-life injury have yet to be identified. The present research illuminates the persistent effects of neonatal surgical injury on the function of inhibitory SDH interneurons derived from the prodynorphin (DYN) lineage, a population that synapses directly onto lamina I spinoparabrachial neurons and is known to suppress mechanical pain and itch in adults. The results demonstrate that hindpaw incision at postnatal day 3 (P3) significantly decreased the strength of primary afferent-evoked glutamatergic drive onto DYN neurons within the adult mouse SDH while increasing the appearance of afferent-evoked inhibition onto the same population. Neonatal injury also dampened the intrinsic membrane excitability of mature DYN neurons, and reduced their action potential discharge in response to sensory input, compared with naive littermate controls. Furthermore, P3 incision decreased the efficacy of inhibitory DYN synapses onto adult spinoparabrachial neurons, which reflected a prolonged reduction in the probability of GABA release. Collectively, the data suggest that early-life tissue damage may persistently constrain the ability of spinal DYN interneurons to limit ascending nociceptive transmission to the adult brain. This is predicted to contribute to the loss of feedforward inhibition onto mature projection neurons, and the "priming" of nociceptive circuits in the developing spinal cord, following injuries during the neonatal period.SIGNIFICANCE STATEMENT Neonatal injury has lasting effects on pain processing in the adult CNS, including a reduction in feedforward inhibition onto ascending projection neurons in the spinal dorsal horn. While it is clear that spinal GABAergic interneurons are comprised of multiple subpopulations that play distinct roles in somatosensation, the identity of those interneurons which are compromised by tissue damage during early life remains unknown. Here we document persistent deficits in spinal inhibitory circuits involving dynorphin-lineage interneurons previously implicated in gating mechanical pain and itch. Notably, neonatal injury reduced the strength of dynorphin-lineage inhibitory synapses onto mature lamina I spinoparabrachial neurons, a major output of the spinal nociceptive network, which could contribute to the priming of pain pathways by early tissue damage.
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65
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Torres-Gomez S, Blonde JD, Mendoza-Halliday D, Kuebler E, Everest M, Wang XJ, Inoue W, Poulter MO, Martinez-Trujillo J. Changes in the Proportion of Inhibitory Interneuron Types from Sensory to Executive Areas of the Primate Neocortex: Implications for the Origins of Working Memory Representations. Cereb Cortex 2020; 30:4544-4562. [PMID: 32227119 DOI: 10.1093/cercor/bhaa056] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Neuronal spiking activity encoding working memory (WM) is robust in primate association cortices but weak or absent in early sensory cortices. This may be linked to changes in the proportion of neuronal types across areas that influence circuits' ability to generate recurrent excitation. We recorded neuronal activity from areas middle temporal (MT), medial superior temporal (MST), and the lateral prefrontal cortex (LPFC) of monkeys performing a WM task and classified neurons as narrow (NS) and broad spiking (BS). The ratio NS/BS decreased from MT > MST > LPFC. We analyzed the Allen Institute database of ex vivo mice/human intracellular recordings to interpret our data. Our analysis suggests that NS neurons correspond to parvalbumin (PV) or somatostatin (SST) interneurons while BS neurons are pyramidal (P) cells or vasoactive intestinal peptide (VIP) interneurons. We labeled neurons in monkey tissue sections of MT/MST and LPFC and found that the proportion of PV in cortical layers 2/3 decreased, while the proportion of CR cells increased from MT/MST to LPFC. Assuming that primate CR/CB/PV cells perform similar computations as mice VIP/SST/PV cells, our results suggest that changes in the proportion of CR and PV neurons in layers 2/3 cells may favor the emergence of activity encoding WM in association areas.
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Affiliation(s)
- Santiago Torres-Gomez
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Robarts Research Institute and the Brain and Mind Institute, Western University, London, Ontario, N6A 5B7, Canada
| | - Jackson D Blonde
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Robarts Research Institute and the Brain and Mind Institute, Western University, London, Ontario, N6A 5B7, Canada
| | - Diego Mendoza-Halliday
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Eric Kuebler
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Robarts Research Institute and the Brain and Mind Institute, Western University, London, Ontario, N6A 5B7, Canada
| | - Michelle Everest
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Robarts Research Institute and the Brain and Mind Institute, Western University, London, Ontario, N6A 5B7, Canada
| | - Xiao Jing Wang
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - Wataru Inoue
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Robarts Research Institute and the Brain and Mind Institute, Western University, London, Ontario, N6A 5B7, Canada
| | - Michael O Poulter
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Robarts Research Institute and the Brain and Mind Institute, Western University, London, Ontario, N6A 5B7, Canada
| | - Julio Martinez-Trujillo
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Robarts Research Institute and the Brain and Mind Institute, Western University, London, Ontario, N6A 5B7, Canada.,Department of Psychiatry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, N6A5B7, Canada
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66
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Zhang Q, Zeng Y, Yang T. Computational Investigation of Contributions from Different Subtypes of Interneurons in Prefrontal Cortex for Information Maintenance. Sci Rep 2020; 10:4671. [PMID: 32170199 PMCID: PMC7070096 DOI: 10.1038/s41598-020-61647-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/28/2020] [Indexed: 11/22/2022] Open
Abstract
Interneurons play crucial roles in neocortex associated with high-level cognitive functions; however, the specific division of labor is still under investigation. Interneurons are exceptionally diverse in their morphological appearance and functional properties. In this study, we modify a prefrontal multicolumn circuit in which five subtypes of inhibitory interneurons play distinct roles in the maintenance of transient information. These interneurons are classified according to the extending range of axonal projections. Our work simplifies the division of labor between different types of interneurons for the maintenance of information and the principle of functional redundancy of the brain from the perspective of computational modeling. This model presents a framework to understand the cooperation between different interneurons in a recurrent cortical circuit.
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Affiliation(s)
- Qian Zhang
- Research Center for Brain-inspired Intelligence, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Yi Zeng
- Research Center for Brain-inspired Intelligence, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
- National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Taoyi Yang
- Research Center for Brain-inspired Intelligence, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China
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67
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Boillat Y, Xin L, van der Zwaag W, Gruetter R. Metabolite concentration changes associated with positive and negative BOLD responses in the human visual cortex: A functional MRS study at 7 Tesla. J Cereb Blood Flow Metab 2020; 40:488-500. [PMID: 30755134 PMCID: PMC7026843 DOI: 10.1177/0271678x19831022] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Negative blood oxygenation-level dependent (BOLD) signal observed during task execution in functional magnetic resonance imaging (fMRI) can be caused by different mechanisms, such as a blood-stealing effect or neuronal deactivation. Electrophysiological recordings showed that neuronal deactivation underlies the negative BOLD observed in the occipital lobe during visual stimulation. In this study, the metabolic demand of such a response was studied by measuring local metabolite concentration changes during a visual checkerboard stimulation using functional magnetic resonance spectroscopy (fMRS) at 7 Tesla. The results showed increases of glutamate and lactate concentrations during the positive BOLD response, consistent with previous fMRS studies. In contrast, during the negative BOLD response, decreasing concentrations of glutamate, lactate and gamma-aminobutyric acid (GABA) were found, suggesting a reduction of glycolytic and oxidative metabolic demand below the baseline. Additionally, the respective changes of the BOLD signal, glutamate and lactate concentrations of both groups suggest that a local increase of inhibitory activity might occur during the negative BOLD response.
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Affiliation(s)
- Yohan Boillat
- Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Lijing Xin
- Animal imaging and technology core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Wietske van der Zwaag
- Animal imaging and technology core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Spinoza Centre for Neuroimaging, Amsterdam, Netherlands
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Animal imaging and technology core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology, University of Geneva, Geneva, Switzerland.,Department of Radiology, University of Lausanne, Lausanne, Switzerland
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68
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Jeong H, Kim D, Song M, Paik SB, Jung MW. Distinct roles of parvalbumin- and somatostatin-expressing neurons in flexible representation of task variables in the prefrontal cortex. Prog Neurobiol 2020; 187:101773. [PMID: 32070716 DOI: 10.1016/j.pneurobio.2020.101773] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 02/11/2020] [Indexed: 11/26/2022]
Abstract
A hallmark of the prefrontal cortex (PFC) is flexible representation of task-relevant variables. To investigate roles of different interneuron subtypes in this process, we examined discharge characteristics and inactivation effects of parvalbumin (PV)- and somatostatin (SST)-expressing neurons in the mouse PFC during probabilistic classical conditioning. We found activity patterns and inactivation effects differed between PV and SST neurons: SST neurons conveyed cue-associated quantitative value signals until trial outcome, whereas PV neurons maintained valence signals even after trial outcome. Also, PV, but not SST, neuronal population showed opposite responses to reward and punishment. Moreover, inactivation of PV, but not SST, neurons affected outcome responses and activity reversal of pyramidal neurons. Modeling suggested opposite responses of PV neurons to reward and punishment as an efficient mechanism for facilitating rapid cue-outcome contingency learning. Our results suggest primary roles of mPFC PV neurons in rapid value updating and SST neurons in predicting values of upcoming events.
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Affiliation(s)
- Huijeong Jeong
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Dohoung Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, 34141, Republic of Korea
| | - Min Song
- Program of Brain and Cognitive Engineering, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Se-Bum Paik
- Program of Brain and Cognitive Engineering, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Min Whan Jung
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea; Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, 34141, Republic of Korea.
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69
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Assous M. Emergence of novel functions in striatal low‐threshold spike interneurons (Commentary on Gazan et al., 2019). Eur J Neurosci 2020; 52:3490-3492. [DOI: 10.1111/ejn.14663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/04/2019] [Accepted: 12/19/2019] [Indexed: 01/04/2023]
Affiliation(s)
- Maxime Assous
- Center for Molecular and Behavioral Neuroscience Rutgers University Newark NJ USA
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70
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Polepalli JS, Gooch H, Sah P. Diversity of interneurons in the lateral and basal amygdala. NPJ SCIENCE OF LEARNING 2020; 5:10. [PMID: 32802405 PMCID: PMC7400739 DOI: 10.1038/s41539-020-0071-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 05/29/2020] [Indexed: 05/06/2023]
Abstract
The basolateral amygdala (BLA) is a temporal lobe structure that contributes to a host of behaviors. In particular, it is a central player in learning about aversive events and thus assigning emotional valence to sensory events. It is a cortical-like structure and contains glutamatergic pyramidal neurons and GABAergic interneurons. It is divided into the lateral (LA) and basal (BA) nuclei that have distinct cell types and connections. Interneurons in the BLA are a heterogenous population, some of which have been implicated in specific functional roles. Here we use optogenetics and slice electrophysiology to investigate the innervation, postsynaptic receptor stoichiometry, and plasticity of excitatory inputs onto interneurons within the BLA. Interneurons were divided into six groups based on their discharge properties, each of which received input from the auditory thalamus (AT) and auditory cortex (AC). Auditory innervation was concentrated in the LA, and optogenetic stimulation evoked robust synaptic responses in nearly all interneurons, drove many cells to threshold, and evoked disynaptic inhibition in most interneurons. Auditory input to the BA was sparse, innervated fewer interneurons, and evoked smaller synaptic responses. Biophysically, the subunit composition and distribution of AMPAR and NMDAR also differed between the two nuclei, with fewer BA IN expressing calcium permeable AMPAR, and a higher proportion expressing GluN2B-containing NMDAR. Finally, unlike LA interneurons, LTP could not be induced in the BA. These findings show that interneurons in the LA and BA are physiologically distinct populations and suggest they may have differing roles during associative learning.
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Affiliation(s)
- Jai S. Polepalli
- Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072 Australia
- Department of Anatomy, Yong Yoo Lin School of Medicine, National University of Singapore, Singapore, 117594 Singapore
| | - Helen Gooch
- Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072 Australia
| | - Pankaj Sah
- Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072 Australia
- Brain Research Centre and Department of Biology, Southern University of Science and Technology, Nanshan District, Shenzhen, Guangdong Province P.R. China
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71
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Hughes BA, Crofton EJ, O'Buckley TK, Herman MA, Morrow AL. Chronic ethanol exposure alters prelimbic prefrontal cortical Fast-Spiking and Martinotti interneuron function with differential sex specificity in rat brain. Neuropharmacology 2020; 162:107805. [PMID: 31589884 PMCID: PMC7027948 DOI: 10.1016/j.neuropharm.2019.107805] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/17/2019] [Accepted: 10/01/2019] [Indexed: 12/11/2022]
Abstract
Chronic ethanol exposure results in numerous neurobiological adaptations that promote deficits in medial prefrontal cortical (mPFC) function associated with blunted inhibitory control and elevated anxiety during withdrawal. Studies exploring alcohol dependence-related changes in this region have largely investigated adaptations in glutamatergic signaling, with inhibitory neurotransmission remaining relatively understudied. To address this, we used biochemical and electrophysiological methods to evaluate the effects of ethanol on the activity of deep-layer prelimbic mPFC Fast-Spiking (FS) and Martinotti interneurons after chronic ethanol exposure in male and female rats. We report that chronic alcohol exposure significantly impairs FS neuron excitability in both males and females. Interestingly, we observed a marked sex difference in the baseline activity of Martinotti cells that furthermore displayed differential sex-specific responses to alcohol exposure. In addition, alcohol effects on Martinotti neuron excitability negatively correlated with hyperpolarization-activated currents mediated by hyperpolarization-activated cyclic nucleotide gated (HCN) channels, indicative of a causal relationship. Analysis of HCN1 protein expression also revealed a substantial sex difference, although no effect of ethanol on HCN1 protein expression was observed. Taken together, these findings further elucidate the complex adaptations that occur in the mPFC after chronic ethanol exposure and reveal fundamental differences in interneuron activity between sexes. Furthermore, this disparity may reflect innate differences in intracortical microcircuit function between male and female rats, and offers a tenable circuit-level explanation for sex-dependent behavioral responses to alcohol.
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Affiliation(s)
- Benjamin A Hughes
- Department of Psychiatry, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA; Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA
| | - Elizabeth J Crofton
- Department of Psychiatry, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA; Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA
| | - Todd K O'Buckley
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA
| | - Melissa A Herman
- Department of Pharmacology, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA; Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA
| | - A Leslie Morrow
- Department of Psychiatry, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA; Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, 27599, NC, USA.
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72
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Voloh B, Womelsdorf T. Cell-Type Specific Burst Firing Interacts with Theta and Beta Activity in Prefrontal Cortex During Attention States. Cereb Cortex 2019; 28:4348-4364. [PMID: 29136106 DOI: 10.1093/cercor/bhx287] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Indexed: 12/25/2022] Open
Abstract
Population-level theta and beta band activity in anterior cingulate and prefrontal cortices (ACC/PFC) are prominent signatures of self-controlled, adaptive behaviors. But how these rhythmic activities are linked to cell-type specific activity has remained unclear. Here, we suggest such a cell-to-systems level linkage. We found that the rate of burst spiking events is enhanced particularly during attention states and that attention-specific burst spikes have a unique temporal relationship to local theta and beta band population-level activities. For the 5-10 Hz theta frequency range, bursts coincided with transient increases of local theta power relative to nonbursts, particularly for bursts of putative interneurons. For the 16-30 Hz beta frequency, bursts of putative interneurons phase synchronized stronger than nonbursts, and were associated with larger beta power modulation. In contrast, burst of putative pyramidal cells showed similar beta power modulation as nonbursts, but were accompanied by stronger beta power only when they occurred early in the beta cycle. These findings suggest that in the ACC/PFC during attention states, mechanisms underlying burst firing are intimately linked to narrow band population-level activities, providing a cell-type specific window into rhythmic inhibitory gating and the emergence of rhythmically coherent network states during goal directed behavior.
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Affiliation(s)
- B Voloh
- Department of Biology, Centre for Vision Research, York University, Toronto, Ontario, Canada.,Department of Psychology, Vanderbilt University, PMB 407817, 2301 Vanderbilt Place, Nashville, TN, USA
| | - T Womelsdorf
- Department of Biology, Centre for Vision Research, York University, Toronto, Ontario, Canada.,Department of Psychology, Vanderbilt University, PMB 407817, 2301 Vanderbilt Place, Nashville, TN, USA
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73
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Pinto HPP, de Oliveira Lucas EL, Carvalho VR, Mourão FAG, de Oliveira Guarnieri L, Mendes EMAM, de Castro Medeiros D, Moraes MFD. Seizure Susceptibility Corrupts Inferior Colliculus Acoustic Integration. Front Syst Neurosci 2019; 13:63. [PMID: 31780904 PMCID: PMC6851260 DOI: 10.3389/fnsys.2019.00063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/11/2019] [Indexed: 01/20/2023] Open
Abstract
Evidence suggests that the pathophysiology associated with epileptic susceptibility may disturb the functional connectivity of neural circuits and compromise the brain functions, even when seizures are absent. Although memory impairment is a common comorbidity found in patients with epilepsy, it is still unclear whether more caudal structures may play a role in cognitive deficits, particularly in those cases where there is no evidence of hippocampal sclerosis. This work used a genetically selected rat strain for seizure susceptibility (Wistar audiogenic rat, WAR) and distinct behavioral (motor and memory-related tasks) and electrophysiological (inferior colliculus, IC) approaches to access acoustic primary integrative network properties. The IC neural assemblies' response was evaluated by auditory transient (focusing on bottom-up processing) and steady-state evoked response (ASSR, centering on feedforward and feedback forces over neural circuitry). The results show that WAR displayed no disturbance in motor performance or hippocampus-dependent memory tasks. Nonetheless, WAR animals exhibited significative impairment for auditory fear conditioning (AFC) along with no indicative of IC plastic changes between the pre-conditioning and test phases (ASSR coherence analysis). Furthermore, WAR's IC response to transient stimuli presented shorter latency and higher amplitude compared with Wistar; and the ASSR analysis showed similar results for WAR and Wistar animals under subthreshold dose of pentylenetetrazol (pro-convulsive drug) for seizure-induction. Our work demonstrated alterations at WAR IC neural network processing, which may explain the associated disturbance on AFC memory.
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Affiliation(s)
- Hyorrana Priscila Pereira Pinto
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Eric Levi de Oliveira Lucas
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vinícius Rezende Carvalho
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Flávio Afonso Gonçalves Mourão
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Leonardo de Oliveira Guarnieri
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Eduardo Mazoni Andrade Marçal Mendes
- Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Daniel de Castro Medeiros
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Márcio Flávio Dutra Moraes
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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74
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Banaie Boroujeni K, Tiesinga P, Womelsdorf T. Adaptive spike-artifact removal from local field potentials uncovers prominent beta and gamma band neuronal synchronization. J Neurosci Methods 2019; 330:108485. [PMID: 31705936 DOI: 10.1016/j.jneumeth.2019.108485] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/26/2019] [Accepted: 10/29/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND Many neurons synchronize their action potentials to the phase of local field potential (LFP) fluctuations in one or more frequency bands. Analyzing this spike-to-LFP synchronization is challenging, however, when neural spikes and LFP are generated in the same local circuit, because the spike's action potential waveform leak into the LFP and distort phase synchrony estimates. Existing approaches to address this spike bleed-through artifact relied on removing the average action potential waveforms of neurons, but this leaves artifacts in the LFP and distorts synchrony estimates. NEW METHOD We describe a spike-removal method that surpasses these limitations by decomposing individual action potentials into their frequency components before their removal from the LFP. The adaptively estimated frequency components allow for variable spread, strength and temporal variation of the spike artifact. RESULTS This adaptive approach effectively removes spike bleed-through artifacts in synthetic data with known ground truth, and in single neuron and LFP recordings in nonhuman primate striatum. For a large population of neurons with both narrow and broad action potential waveforms, the use of adaptive artifact removal uncovered 20-35 Hz beta and 35-45 Hz gamma band spike-LFP synchronization that would have remained contaminated otherwise. COMPARISON WITH EXISTING METHODS We demonstrate that adaptive spike-artifact removal cleans LFP data that remained contaminated when applying existing Bayesian and non-Bayesian methods of average spike-artifact removal. CONCLUSIONS Applying adaptive spike-removal from field potentials allows to estimate the phase at which neurons synchronize and the consistency of their phase-locked firing for both beta and low gamma frequencies. These metrics may prove essential to understand cell-to-circuit neuronal interactions in multiple brain systems.
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Affiliation(s)
| | - Paul Tiesinga
- Donders Institute for Brain, Cognition and Behaviour Radboud University Nijmegen, 6525 EN Nijmegen, Netherlands
| | - Thilo Womelsdorf
- Department of Psychology, Vanderbilt University, Nashville, TN 37240, United States; Department of Biology, Centre for Vision Research, York University, 4700 Keele Street, Toronto, Ontario M6J 1P3, Canada.
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75
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Nathanson AJ, Davies PA, Moss SJ. Inhibitory Synapse Formation at the Axon Initial Segment. Front Mol Neurosci 2019; 12:266. [PMID: 31749683 PMCID: PMC6848228 DOI: 10.3389/fnmol.2019.00266] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/17/2019] [Indexed: 11/28/2022] Open
Abstract
The axon initial segment (AIS) is the site of action potential (AP) initiation in most neurons and is thus a critical site in the regulation of neuronal excitability. Normal function within the discrete AIS compartment requires intricate molecular machinery to ensure the proper concentration and organization of voltage-gated and ligand-gated ion channels; in humans, dysfunction at the AIS due to channel mutations is commonly associated with epileptic disorders. In this review, we will examine the molecular mechanisms underlying the formation of the only synapses found at the AIS: synapses containing γ-aminobutyric type A receptors (GABAARs). GABAARs are heteropentamers assembled from 19 possible subunits and are the primary mediators of fast synaptic inhibition in the brain. Although the total GABAAR population is incredibly heterogeneous, only one specific GABAAR subtype—the α2-containing receptor—is enriched at the AIS. These AIS synapses are innervated by GABAergic chandelier cells, and this inhibitory signaling is thought to contribute to the tight control of AP firing. Here, we will summarize the progress made in understanding the regulation of GABAAR synapse formation, concentrating on post-translational modifications of subunits and on interactions with intracellular proteins. We will then discuss subtype-specific synapse formation, with a focus on synapses found at the AIS, and how these synapses influence neuronal excitation.
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Affiliation(s)
- Anna J Nathanson
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Paul A Davies
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States.,AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA, United States.,Department of Neuroscience, Physiology and Pharmacology, University College, London, United Kingdom
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76
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Qiu F, Mao X, Liu P, Wu J, Zhang Y, Sun D, Zhu Y, Gong L, Shao M, Fan K, Chen J, Lu J, Jiang Y, Zhang Y, Curia G, Li A, He M. microRNA Deficiency in VIP+ Interneurons Leads to Cortical Circuit Dysfunction. Cereb Cortex 2019; 30:2229-2249. [PMID: 33676371 DOI: 10.1093/cercor/bhz236] [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: 01/01/2019] [Revised: 01/01/2019] [Accepted: 01/01/2019] [Indexed: 12/13/2022] Open
Abstract
Genetically distinct GABAergic interneuron subtypes play diverse roles in cortical circuits. Previous studies revealed that microRNAs (miRNAs) are differentially expressed in cortical interneuron subtypes, and are essential for the normal migration, maturation, and survival of medial ganglionic eminence-derived interneuron subtypes. How miRNAs function in vasoactive intestinal peptide expressing (VIP+) interneurons derived from the caudal ganglionic eminence remains elusive. Here, we conditionally removed Dicer in postmitotic VIP+ interneurons to block miRNA biogenesis. We found that the intrinsic and synaptic properties of VIP+ interneurons and pyramidal neurons were concordantly affected prior to a progressive loss of VIP+ interneurons. In vivo recording further revealed elevated cortical local field potential power. Mutant mice had a shorter life span but exhibited better spatial working memory and motor coordination. Our results demonstrate that miRNAs are indispensable for the function and survival of VIP+ interneurons, and highlight a key role of VIP+ interneurons in cortical circuits.
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Affiliation(s)
- Fang Qiu
- Department of Neurology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Xingfeng Mao
- Jiangsu Key Laboratory of Brain Disease and Bioinformation, Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Xuzhou 221004, China
| | - Penglai Liu
- Jiangsu Key Laboratory of Brain Disease and Bioinformation, Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Xuzhou 221004, China
| | - Jinyun Wu
- Department of Neurology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Yuan Zhang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Daijing Sun
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Yueyan Zhu
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Ling Gong
- Department of Neurology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Mengmeng Shao
- Department of Anatomy and Physiology, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Keyang Fan
- Department of Neurology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Junjie Chen
- Department of Neurology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Jiangteng Lu
- Department of Anatomy and Physiology, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Yan Jiang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Yubin Zhang
- Department of Toxicology, School of Public Health, Fudan University, Shanghai 200032, China
| | - Giulia Curia
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena 41121, Italy.,Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41121, Italy
| | - Anan Li
- Jiangsu Key Laboratory of Brain Disease and Bioinformation, Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Xuzhou 221004, China
| | - Miao He
- Department of Neurology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
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77
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Why context matters? Divisive normalization and canonical microcircuits in psychiatric disorders. Neurosci Res 2019; 156:130-140. [PMID: 31628970 DOI: 10.1016/j.neures.2019.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/30/2019] [Accepted: 09/04/2019] [Indexed: 11/20/2022]
Abstract
Neural activity on cellular, regional, and behavioral levels shows context-dependence. Here we suggest the processing of input-output relationships in terms divisive normalization (DN), including (i) summing/averaging inputs and (ii) normalizing output against input stages, as a computational mechanism to underlie context-dependence. Input summation and output normalization are mediated by input-output relationships in canonical microcircuits (CM). DN/CM are altered in psychiatric disorders like schizophrenia or depression whose various symptoms can be characterized by abnormal context-dependence.
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78
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Christenson Wick Z, Tetzlaff MR, Krook-Magnuson E. Novel long-range inhibitory nNOS-expressing hippocampal cells. eLife 2019; 8:46816. [PMID: 31609204 PMCID: PMC6839902 DOI: 10.7554/elife.46816] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 10/11/2019] [Indexed: 12/21/2022] Open
Abstract
The hippocampus, a brain region that is important for spatial navigation and episodic memory, benefits from a rich diversity of neuronal cell-types. Through the use of an intersectional genetic viral vector approach in mice, we report novel hippocampal neurons which we refer to as LINCs, as they are long-range inhibitory neuronal nitric oxide synthase (nNOS)-expressing cells. LINCs project to several extrahippocampal regions including the tenia tecta, diagonal band, and retromammillary nucleus, but also broadly target local CA1 cells. LINCs are thus both interneurons and projection neurons. LINCs display regular spiking non-pyramidal firing patterns, are primarily located in the stratum oriens or pyramidale, have sparsely spiny dendrites, and do not typically express somatostatin, VIP, or the muscarinic acetylcholine receptor M2. We further demonstrate that LINCs can strongly influence hippocampal function and oscillations, including interregional coherence. The identification and characterization of these novel cells advances our basic understanding of both hippocampal circuitry and neuronal diversity.
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Affiliation(s)
- Zoé Christenson Wick
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, United States
| | - Madison R Tetzlaff
- Neuroscience Department, University of Minnesota, Minneapolis, United States
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79
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Abstract
Neocortical cells form classes that likely take on unique functional roles in the cortical microcircuit. A new study finds that, with sufficient sampling, the electrophysiological signature of cells distinguishes four cell classes across primate frontal and parietal cortex.
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80
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Ryu H, Campbell SA. Geometric analysis of synchronization in neuronal networks with global inhibition and coupling delays. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180129. [PMID: 31329073 PMCID: PMC6661332 DOI: 10.1098/rsta.2018.0129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/10/2019] [Indexed: 05/26/2023]
Abstract
We study synaptically coupled neuronal networks to identify the role of coupling delays in network synchronized behaviour. We consider a network of excitable, relaxation oscillator neurons where two distinct populations, one excitatory and one inhibitory, are coupled with time-delayed synapses. The excitatory population is uncoupled, while the inhibitory population is tightly coupled without time delay. A geometric singular perturbation analysis yields existence and stability conditions for periodic solutions where the excitatory cells are synchronized and different phase relationships between the excitatory and inhibitory populations can occur, along with formulae for the periods of such solutions. In particular, we show that if there are no delays in the coupling, oscillations where the excitatory population is synchronized cannot occur. Numerical simulations are conducted to supplement and validate the analytical results. The analysis helps to explain how coupling delays in either excitatory or inhibitory synapses contribute to producing synchronized rhythms. This article is part of the theme issue 'Nonlinear dynamics of delay systems'.
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Affiliation(s)
- Hwayeon Ryu
- Department of Mathematics, University of Hartford, West Hartford, CT 06117, USA
| | - Sue Ann Campbell
- Department of Applied Mathematics, Centre for Theoretical Neuroscience, University of Waterloo, Waterloo, Ontario, CanadaN2L 3G1
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81
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Huang ZJ, Paul A. The diversity of GABAergic neurons and neural communication elements. Nat Rev Neurosci 2019; 20:563-572. [PMID: 31222186 PMCID: PMC8796706 DOI: 10.1038/s41583-019-0195-4] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2019] [Indexed: 12/18/2022]
Abstract
The phenotypic diversity of cortical GABAergic neurons is probably necessary for their functional versatility in shaping the spatiotemporal dynamics of neural circuit operations underlying cognition. Deciphering the logic of this diversity requires comprehensive analysis of multi-modal cell features and a framework of neuronal identity that reflects biological mechanisms and principles. Recent high-throughput single-cell analyses have generated unprecedented data sets characterizing the transcriptomes, morphology and electrophysiology of interneurons. We posit that cardinal interneuron types can be defined by their synaptic communication properties, which are encoded in key transcriptional signatures. This conceptual framework integrates multi-modal cell features, captures neuronal input-output properties fundamental to circuit operation and may advance understanding of the appropriate granularity of neuron types, towards a biologically grounded and operationally useful interneuron taxonomy.
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Affiliation(s)
- Z Josh Huang
- Cold Spring Harbor Laboratory, New York, NY, USA.
| | - Anirban Paul
- Cold Spring Harbor Laboratory, New York, NY, USA
- Department of Neural & Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, USA
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82
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Kaminer J, Espinoza D, Bhimani S, Tepper JM, Koos T, Shiflett MW. Loss of striatal tyrosine-hydroxylase interneurons impairs instrumental goal-directed behavior. Eur J Neurosci 2019; 50:2653-2662. [PMID: 30941837 PMCID: PMC6742547 DOI: 10.1111/ejn.14412] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/13/2019] [Accepted: 03/21/2019] [Indexed: 11/30/2022]
Abstract
The striatum mediates a broad range of cognitive and motor functions. Within the striatum, recently discovered tyrosine hydroxylase expressing interneurons (THINs) provide a source of intrastriatal synaptic connectivity that is critical for regulating striatal activity, yet the role of THIN's in behavior remains unknown. Given the important role of the striatum in reward-based behaviors, we investigated whether loss of striatal THINs would impact instrumental behavior in mice. We selectively ablated striatal THINs in TH-Cre mice using chemogenetic techniques, and then tested THIN-lesioned or control mice on three reward-based striatal-dependent instrumental tests: (a) progressive ratio test; (b) choice test following selective-satiety induced outcome devaluation; (c) outcome reinstatement test. Both striatal-THIN-lesioned and control mice acquired an instrumental response for flavored food pellets, and their behavior did not differ in the progressive ratio test, suggesting intact effort to obtain rewards. However, striatal THIN lesions markedly impaired choice performance following selective-satiety induced outcome devaluation. Unlike control mice, THIN-lesioned mice did not adjust their choice of actions following a change in outcome value. In the outcome reinstatement test THIN-lesioned and control mice showed response invigoration by outcome presentation, suggesting the incentive properties of outcomes were not disrupted by THIN lesions. Overall, we found that striatal THIN lesions selectively impaired goal-directed behavior, while preserving motoric and appetitive behaviors. These findings are the first to describe a function of striatal THINs in reward-based behavior, and further illustrate the important role for intrastriatal interneuronal connectivity in behavioral functions ascribed to the striatum more generally.
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Affiliation(s)
- Jaime Kaminer
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, New Jersey
| | - Diego Espinoza
- Department of Psychology, Rutgers, The State University of New Jersey, Newark, New Jersey
| | - Shaznaan Bhimani
- Department of Psychology, Rutgers, The State University of New Jersey, Newark, New Jersey
| | - James M Tepper
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, New Jersey
| | - Tibor Koos
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, New Jersey
| | - Michael W Shiflett
- Department of Psychology, Rutgers, The State University of New Jersey, Newark, New Jersey
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83
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Cutsuridis V. Memory Prosthesis: Is It Time for a Deep Neuromimetic Computing Approach? Front Neurosci 2019; 13:667. [PMID: 31333399 PMCID: PMC6624412 DOI: 10.3389/fnins.2019.00667] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/11/2019] [Indexed: 11/13/2022] Open
Abstract
Memory loss, one of the most dreaded afflictions of the human condition, presents considerable burden on the world's health care system and it is recognized as a major challenge in the elderly. There are only a few neuromodulation treatments for memory dysfunctions. Open loop deep brain stimulation is such a treatment for memory improvement, but with limited success and conflicting results. In recent years closed-loop neuroprosthesis systems able to simultaneously record signals during behavioral tasks and generate with the use of internal neural factors the precise timing of stimulation patterns are presented as attractive alternatives and show promise in memory enhancement and restoration. A few such strides have already been made in both animals and humans, but with limited insights into their mechanisms of action. Here, I discuss why a deep neuromimetic computing approach linking multiple levels of description, mimicking the dynamics of brain circuits, interfaced with recording and stimulating electrodes could enhance the performance of current memory prosthesis systems, shed light into the neurobiology of learning and memory and accelerate the progress of memory prosthesis research. I propose what the necessary components (nodes, structure, connectivity, learning rules, and physiological responses) of such a deep neuromimetic model should be and what type of data are required to train/test its performance, so it can be used as a true substitute of damaged brain areas capable of restoring/enhancing their missing memory formation capabilities. Considerations to neural circuit targeting, tissue interfacing, electrode placement/implantation, and multi-network interactions in complex cognition are also provided.
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84
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Palagina G, Meyer JF, Smirnakis SM. Inhibitory Units: An Organizing Nidus for Feature-Selective SubNetworks in Area V1. J Neurosci 2019; 39:4931-4944. [PMID: 30979814 PMCID: PMC6670246 DOI: 10.1523/jneurosci.2275-18.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 03/28/2019] [Accepted: 04/01/2019] [Indexed: 01/05/2023] Open
Abstract
Neuronal circuits often display small-world network architecture characterized by neuronal cliques of dense local connectivity communicating with each other through a limited number of cells that participate in multiple cliques. The principles by which such cliques organize to encode information remain poorly understood. Similarly tuned pyramidal cells that preferentially target each other may form multicellular encoding units performing distinct computational tasks. The existence of such units can reflect upon both spontaneous and stimulus-driven population events.We applied two-photon calcium imaging to study spontaneous population bursts in layer 2/3 of area V1 in male C57BL/6 mice. To identify potential small-world cliques, we searched for pyramidal cells whose calcium events had a consistent temporal relationship with the events of local inhibitory interneurons. This was guided by the intuition that groups of neurons whose synchronous firing represents a temporally coherent computational unit should be inhibited together. Pyramidal members of these interneuron-centered clusters on average displayed stronger functional connectivity between each other than with nonmember pyramidal neurons. The structure of the clusters evolved during postnatal development: cluster size and overlap between clusters decreased with developmental maturation. Pyramidal neurons in a cluster showed higher than chance tuning function similarity between each other and with the linked interneuron. Thus, spontaneous population events in V1 are shaped by small-world subnetworks of pyramidal neurons that share functional properties and work as a coherent unit with a local interneuron. These interneuron-pyramidal cell partnerships may represent a fundamental neocortical unit of computation at the population level.SIGNIFICANCE STATEMENT Neuronal circuit in layer 2/3 of mouse area V1 possesses small-world network architecture, where cliques of densely interconnected neurons ("small worlds") communicate via restricted number of hub cells. We show that: (1) in mouse V1 individual small-world cliques preferably incorporate pyramidal neurons with similar visual feature tuning, and (2) ongoing population activity of such pyramidal neuron clique is temporally linked to the activity of the local interneuron sharing its feature tuning with the clique members. Functional grouping of similarly tuned interneurons and pyramidal cells into cliques may ensure that ensembles of functionally alike pyramidal cells recruited during perceptual tasks and spontaneous activity are also turned off together as a unit, with interneurons serving as organizers of linked pyramidal ensemble activity.
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Affiliation(s)
- Ganna Palagina
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School Boston, Massachusetts 02115,
- Jamaica Plain Veterans Administration Hospital, Boston, Massachusetts 02130, and
| | | | - Stelios M Smirnakis
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School Boston, Massachusetts 02115
- Jamaica Plain Veterans Administration Hospital, Boston, Massachusetts 02130, and
- Baylor College of Medicine, Houston, Texas 77030
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85
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Riedemann T. Diversity and Function of Somatostatin-Expressing Interneurons in the Cerebral Cortex. Int J Mol Sci 2019; 20:E2952. [PMID: 31212931 PMCID: PMC6627222 DOI: 10.3390/ijms20122952] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 06/08/2019] [Accepted: 06/14/2019] [Indexed: 02/01/2023] Open
Abstract
Inhibitory interneurons make up around 10-20% of the total neuron population in the cerebral cortex. A hallmark of inhibitory interneurons is their remarkable diversity in terms of morphology, synaptic connectivity, electrophysiological and neurochemical properties. It is generally understood that there are three distinct and non-overlapping interneuron classes in the mouse neocortex, namely, parvalbumin-expressing, 5-HT3A receptor-expressing and somatostatin-expressing interneuron classes. Each class is, in turn, composed of a multitude of subclasses, resulting in a growing number of interneuron classes and subclasses. In this review, I will focus on the diversity of somatostatin-expressing interneurons (SOM+ INs) in the cerebral cortex and elucidate their function in cortical circuits. I will then discuss pathological consequences of a malfunctioning of SOM+ INs in neurological disorders such as major depressive disorder, and present future avenues in SOM research and brain pathologies.
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Affiliation(s)
- Therese Riedemann
- Ludwig-Maximilians-University, Biomedical Center, Physiological Genomics, Großhaderner Str. 9, 82152 Planegg-Martinsried, Germany.
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86
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Electrophysiological monitoring of inhibition in mammalian species, from rodents to humans. Neurobiol Dis 2019; 130:104500. [PMID: 31195126 DOI: 10.1016/j.nbd.2019.104500] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 05/31/2019] [Accepted: 06/06/2019] [Indexed: 01/20/2023] Open
Abstract
GABAergic interneurons constitute a highly diverse family of neurons that play a critical role in cortical functions. Due to their prominent role in cortical network dynamics, genetic, developmental, or other dysfunctions in GABAergic neurons have been linked to neurological disorders such as epilepsy. Thus, it is crucial to investigate the interaction of these various neurons and to develop methods to specifically and directly monitor inhibitory activity in vivo. While research in small mammals has benefited from a wealth of recent technological development, bridging the gap to large mammals and humans remains a challenge. This is of particular interest since single neuron monitoring with intracranial electrodes in epileptic patients is developing quickly, opening new avenues for understanding the role of different cell types in epilepsy. Here, we review currently available techniques that monitor inhibitory activity in the brain and the respective validations in rodents. Finally, we discuss the future developments of these techniques and how knowledge from animal research can be translated to the study of neuronal circuit dynamics in the human brain.
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87
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Mederos S, Perea G. GABAergic-astrocyte signaling: A refinement of inhibitory brain networks. Glia 2019; 67:1842-1851. [PMID: 31145508 PMCID: PMC6772151 DOI: 10.1002/glia.23644] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 12/13/2022]
Abstract
Interneurons play a critical role in precise control of network operation. Indeed, higher brain capabilities such as working memory, cognitive flexibility, attention, or social interaction rely on the action of GABAergic interneurons. Evidence from excitatory neurons and synapses has revealed astrocytes as integral elements of synaptic transmission. However, GABAergic interneurons can also engage astrocyte signaling; therefore, it is tempting to speculate about different scenarios where, based on particular interneuron cell type, GABAergic‐astrocyte interplay would be involved in diverse outcomes of brain function. In this review, we will highlight current data supporting the existence of dynamic GABAergic‐astrocyte communication and its impact on the inhibitory‐regulated brain responses, bringing new perspectives on the ways astrocytes might contribute to efficient neuronal coding.
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Affiliation(s)
- Sara Mederos
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Madrid, Spain
| | - Gertrudis Perea
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Madrid, Spain
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88
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Short-Term Exposure to Enriched Environment in Adult Rats Restores MK-801-Induced Cognitive Deficits and GABAergic Interneuron Immunoreactivity Loss. Mol Neurobiol 2019; 55:26-41. [PMID: 28822057 DOI: 10.1007/s12035-017-0715-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Perinatal injections of N-methyl-D-aspartate (NMDA) receptor antagonist in rodents emulate some cognitive impairments and neurochemical alterations, such as decreased GABAergic (gamma aminobutyric acid) interneuron immunoreactivity, also found in schizophrenia. These features are pervasive, and developing neuroprotective or neurorestorative strategies is of special interest. In this work, we aimed to investigate if a short exposure to enriched environment (EE) in early adulthood (P55-P73) was an effective strategy to improve cognitive dysfunction and to restore interneuron expression in medial prefrontal cortex (mPFC) and hippocampus (HPC). For that purpose, we administered MK-801 intraperitoneally to Long Evans rats from postnatal days 10 to 20. Twenty-four hours after the last injection, MK-801 produced a transient decrease in spontaneous motor activity and exploration, but those abnormalities were absent at P24 and P55. The open field test on P73 manifested that EE reduced anxiety-like behavior. In addition, MK-801-treated rats showed cognitive impairment in novel object recognition test that was reversed by EE. We quantified different interneuron populations based on their calcium-binding protein expression (parvalbumin, calretinin, and calbindin), glutamic acid decarboxylase 67, and neuronal nuclei-positive cells by means of unbiased stereology and found that EE enhanced interneuron immunoreactivity up to normal values in MK-801-treated rats. Our results demonstrate that a timely intervention with EE is a powerful tool to reverse long-lasting changes in cognition and neurochemical markers of interneurons in an animal model of schizophrenia.
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89
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Bengoetxea H, Rico-Barrio I, Ortuzar N, Murueta-Goyena A, Lafuente JV. Environmental Enrichment Reverses Tyrosine Kinase Inhibitor-Mediated Impairment Through BDNF-TrkB Pathway. Mol Neurobiol 2019; 55:43-59. [PMID: 28842826 DOI: 10.1007/s12035-017-0716-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Exposure to an enriched environment (EE) has neuroprotective benefits and improves recovery from brain injury due to, among other, increased neurotrophic factor expression. Through these neurotrophins, important cortical and hippocampal changes occur. Vandetanib acts as a tyrosine kinase inhibitor of cell receptors, among others, the vascular endothelial growth factor receptor (VEGFR). Our aim was to investigate the effectiveness of EE counteracting cognitive and cellular effects after tyrosine kinase receptor blockade. Animals were reared under standard laboratory condition or EE; both groups received vandetanib or vehicle. Visuospatial learning was tested with Morris water maze. Neuronal, interneuronal, and vascular densities were measured by inmunohistochemistry and histochemistry techniques. Quantifications were performed in the hippocampus and in the visual cortex. Brain-derived neurotrophic factor (BDNF), tyrosine kinase B receptor (TrkB), Akt, and Erk were measured by Western blot technique. Vandetanib produces a significant decrease in vascular and neuronal densities and reduction in the expression of molecules involved in survival and proliferation processes such as phospho-Akt/Akt and phospho-Erk/Erk. These results correlated to a cognitive impairment in visuospatial test. On the other hand, animals reared in an EE are able to reverse the negative effects, activating PI3K-AKT and MAP kinase pathways mediated by BDNF-TrkB binding. Present results provide novel and consistent evidences about the usefulness of living in EE as a strategy to improve deleterious effects of blocking neurotrophic pathways by vandetanib and the notable role of the BDNF-TrkB pathway to balance the neurovascular unit and cognitive effects.
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Affiliation(s)
- Harkaitz Bengoetxea
- Laboratory of Clinical and Experimental Neuroscience (LaNCE), Department of Neuroscience, Faculty of Medicine and Surgery, University of the Basque Country (UPV/EHU), 48940, Leioa, Bizkaia, Spain.
| | - Irantzu Rico-Barrio
- Department of Neuroscience, Faculty of Medicine and Surgery, University of the Basque Country (UPV/EHU), Barrio Sarriena, E-48940, Leioa, Bizkaia, Spain
| | - Naiara Ortuzar
- Laboratory of Clinical and Experimental Neuroscience (LaNCE), Department of Neuroscience, Faculty of Medicine and Surgery, University of the Basque Country (UPV/EHU), 48940, Leioa, Bizkaia, Spain
| | - Ane Murueta-Goyena
- Laboratory of Clinical and Experimental Neuroscience (LaNCE), Department of Neuroscience, Faculty of Medicine and Surgery, University of the Basque Country (UPV/EHU), 48940, Leioa, Bizkaia, Spain
| | - José V Lafuente
- Laboratory of Clinical and Experimental Neuroscience (LaNCE), Department of Neuroscience, Faculty of Medicine and Surgery, University of the Basque Country (UPV/EHU), 48940, Leioa, Bizkaia, Spain.,Nanoneurosurgery Group, BioCruces Health Research Institute, Barakaldo, Bizkaia, Spain.,Faculty of Health Science, Universidad Autónoma de Chile, Santiago de Chile, Chile
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90
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Hughes BA, Bohnsack JP, O'Buckley TK, Herman MA, Morrow AL. Chronic Ethanol Exposure and Withdrawal Impair Synaptic GABA A Receptor-Mediated Neurotransmission in Deep-Layer Prefrontal Cortex. Alcohol Clin Exp Res 2019; 43:822-832. [PMID: 30860602 DOI: 10.1111/acer.14015] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 03/05/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND The prefrontal cortex (PFC) acts as an integrative hub for the processing of cortical and subcortical input into meaningful efferent signaling, permitting complex associative behaviors. PFC dysfunction is consistently observed with ethanol (EtOH) dependence and is a core component of the pathology of alcohol use disorders in current models of addiction. While intracortical gamma-aminobutryric acid (GABA)ergic neurotransmission is understood to be essential for maintaining coordinated network activity within the cortex, relatively little is known regarding functional GABAergic adaptations in PFC during EtOH dependence. METHODS In the present study, male and female (> postnatal day 60) Sprague-Dawley rats were administered EtOH (5.0 g/kg; intragastric gavage) for 14 to 15 consecutive days. Twenty-four hours after the final administration, animals were sacrificed and brains extracted for electrophysiological recordings of isolated GABAA receptor-mediated currents or analysis of GABAA receptor subunit protein expression in deep-layer PFC neurons. RESULTS Chronic EtOH exposure significantly attenuated activity-dependent spontaneous GABAA receptor-mediated inhibitory postsynaptic current (IPSC) frequency with no effect on amplitude. Furthermore, analysis of IPSC decay kinetics revealed a significant enhancement of IPSC decay time that was associated with decrements in expression of the α1 GABAA receptor subunit, indicative of further impaired phasic inhibition. These phenomena occurred irrespective of neuron projection destination and sex. Based on previous observations by our laboratory of an epigenetic mechanism for EtOH-induced changes in cortical GABAA receptor subunit expression, the histone deacetylase inhibitor Trichostatin A was administered to water- and EtOH-exposed animals, and prevented EtOH-induced changes in spontaneous IPSC frequency, IPSC decay kinetics, and GABAA receptor subunit expression. CONCLUSIONS Taken together, these results demonstrate that chronic EtOH exposure impairs synaptic inhibitory neurotransmission in deep-layer pyramidal neurons of the medial PFC in both male and female rats. These maladaptations occur in neurons projecting to numerous regions implicated in the sequelae of EtOH dependence, offering a mechanistic link between the manifestation of PFC dysfunction and negative affective states observed with extended consumption.
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Affiliation(s)
- Benjamin A Hughes
- Department of Psychiatry , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Pharmacology , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Bowles Center for Alcohol Studies , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - John Peyton Bohnsack
- Department of Pharmacology , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Bowles Center for Alcohol Studies , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Todd K O'Buckley
- Bowles Center for Alcohol Studies , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Melissa A Herman
- Department of Pharmacology , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Bowles Center for Alcohol Studies , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - A Leslie Morrow
- Department of Psychiatry , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Pharmacology , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Bowles Center for Alcohol Studies , School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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91
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The Role of AMPARs in the Maturation and Integration of Caudal Ganglionic Eminence-Derived Interneurons into Developing Hippocampal Microcircuits. Sci Rep 2019; 9:5435. [PMID: 30931998 PMCID: PMC6443733 DOI: 10.1038/s41598-019-41920-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/19/2019] [Indexed: 12/25/2022] Open
Abstract
In the hippocampal CA1, caudal ganglionic eminence (CGE)-derived interneurons are recruited by activation of glutamatergic synapses comprising GluA2-containing calcium-impermeable AMPARs and exert inhibitory regulation of the local microcircuit. However, the role played by AMPARs in maturation of the developing circuit is unknown. We demonstrate that elimination of the GluA2 subunit (GluA2 KO) of AMPARs in CGE-derived interneurons, reduces spontaneous EPSC frequency coupled to a reduction in dendritic glutamatergic synapse density. Removal of GluA1&2&3 subunits (GluA1-3 KO) in CGE-derived interneurons, almost completely eliminated sEPSCs without further reducing synapse density, but increased dendritic branching. Moreover, in GluA1-3 KOs, the number of interneurons invading the hippocampus increased in the early postnatal period but converged with WT numbers later due to increased apoptosis. However, the CCK-containing subgroup increased in number, whereas the VIP-containing subgroup decreased. Both feedforward and feedback inhibitory input onto pyramidal neurons was decreased in GluA1-3 KO. These combined anatomical, synaptic and circuit alterations, were accompanied with a wide range of behavioural abnormalities in GluA1-3 KO mice compared to GluA2 KO and WT. Thus, AMPAR subunits differentially contribute to numerous aspects of the development and maturation of CGE-derived interneurons and hippocampal circuitry that are essential for normal behaviour.
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92
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Unsupervised excitation: GABAergic dysfunctions in Alzheimer’s disease. Brain Res 2019; 1707:216-226. [DOI: 10.1016/j.brainres.2018.11.042] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 10/31/2018] [Accepted: 11/27/2018] [Indexed: 12/22/2022]
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93
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Abstract
Inhibition shapes activity and signal processing in neural networks through numerous mechanisms mediated by many different cell types. Here, we examined how one type of GABAergic interneuron in the retina, the A17 amacrine cell, influences visual information processing. Our results suggest that A17s, which make reciprocal feedback inhibitory synapses onto rod bipolar cell (RBC) synaptic terminals, extend the luminance range over which RBC synapses compute temporal contrast and enhance the reliability of contrast signals over this range. Inhibition from other amacrine cells does not influence these computational features. Although A17-mediated feedback is mediated by both GABAA and GABAC receptors, the latter plays the primary role in extending the range of contrast computation. These results identify specific functions for an inhibitory interneuron subtype, as well as specific synaptic receptors, in a behaviorally relevant neural computation.
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Affiliation(s)
- Nicholas W. Oesch
- Synaptic Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892-3701
- Present address: University of California, San Diego, Department of Psychology, Department of Ophthalmology, 9500 Gilman Drive MC#0109, La Jolla, CA 92093-0109
| | - Jeffrey S. Diamond
- Synaptic Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892-3701
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94
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Pivik R, Andres A, Tennal KB, Gu Y, Downs H, Bellando BJ, Jarratt K, Cleves MA, Badger TM. Resting gamma power during the postnatal critical period for GABAergic system development is modulated by infant diet and sex. Int J Psychophysiol 2019; 135:73-94. [DOI: 10.1016/j.ijpsycho.2018.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 11/14/2018] [Accepted: 11/19/2018] [Indexed: 12/13/2022]
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95
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Hyper-diversity of CRH interneurons in mouse hippocampus. Brain Struct Funct 2018; 224:583-598. [PMID: 30456559 DOI: 10.1007/s00429-018-1793-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 11/09/2018] [Indexed: 12/20/2022]
Abstract
Hippocampal inhibitory interneurons comprise an anatomically, neurochemically and electrophysiologically diverse population of cells that are essential for the generation of the oscillatory activity underlying hippocampal spatial and episodic memory processes. Here, we aimed to characterize a population of interneurons that express the stress-related neuropeptide corticotropin-releasing hormone (CRH) within existing interneuronal categories through the use of combined electrophysiological and immunocytochemical approaches. Focusing on CA1 strata pyramidale and radiatum of mouse hippocampus, CRH interneurons were found to exhibit a heterogeneous neurochemical phenotype with parvalbumin, cholecystokinin and calretinin co-expression observed to varying degrees. In contrast, CRH and somatostatin were never co-expressed. Electrophysiological categorization identified heterogeneous firing pattern of CRH neurons, with two distinct subtypes within stratum pyramidale and stratum radiatum. Together, these findings indicate that CRH-expressing interneurons do not segregate into any single distinct subtype of interneuron using conventional criteria. Rather our findings suggest that CRH is likely co-expressed in subpopulations of previously described hippocampal interneurons. In addition, the observed heterogeneity suggests that distinct CRH interneuron subtypes may have specific functional roles in the both physiological and pathophysiological hippocampal processes.
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96
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Lateral inhibition by Martinotti interneurons is facilitated by cholinergic inputs in human and mouse neocortex. Nat Commun 2018; 9:4101. [PMID: 30291244 PMCID: PMC6173769 DOI: 10.1038/s41467-018-06628-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 09/12/2018] [Indexed: 12/31/2022] Open
Abstract
A variety of inhibitory pathways encompassing different interneuron types shape activity of neocortical pyramidal neurons. While basket cells (BCs) mediate fast lateral inhibition between pyramidal neurons, Somatostatin-positive Martinotti cells (MCs) mediate a delayed form of lateral inhibition. Neocortical circuits are under control of acetylcholine, which is crucial for cortical function and cognition. Acetylcholine modulates MC firing, however, precisely how cholinergic inputs affect cortical lateral inhibition is not known. Here, we find that cholinergic inputs selectively augment and speed up lateral inhibition between pyramidal neurons mediated by MCs, but not by BCs. Optogenetically activated cholinergic inputs depolarize MCs through activation of ß2 subunit-containing nicotinic AChRs, not muscarinic AChRs, without affecting glutamatergic inputs to MCs. We find that these mechanisms are conserved in human neocortex. Cholinergic inputs thus enable cortical pyramidal neurons to recruit more MCs, and can thereby dynamically highlight specific circuit motifs, favoring MC-mediated pathways over BC-mediated pathways. Parvalbumin and somatostatin expressing interneurons mediate lateral inhibition between cortical neurons. Here the authors report the mechanisms by which acetylcholine from the basal forebrain selectively augments lateral inhibition via Martinotti cells and show that this is conserved in humans.
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97
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Higher ambient synaptic glutamate at inhibitory versus excitatory neurons differentially impacts NMDA receptor activity. Nat Commun 2018; 9:4000. [PMID: 30275542 PMCID: PMC6167324 DOI: 10.1038/s41467-018-06512-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 08/31/2018] [Indexed: 01/28/2023] Open
Abstract
Selective disruption of synaptic drive to inhibitory neurons could contribute to the pathophysiology of various brain disorders. We have previously identified a GluN2A-selective positive allosteric modulator, GNE-8324, that selectively enhances N-methyl-d-aspartate receptor (NMDAR)-mediated synaptic responses in inhibitory but not excitatory neurons. Here, we demonstrate that differences in NMDAR subunit composition do not underlie this selective potentiation. Rather, a higher ambient glutamate level in the synaptic cleft of excitatory synapses on inhibitory neurons is a key factor. We show that increasing expression of glutamate transporter 1 (GLT-1) eliminates GNE-8324 potentiation in inhibitory neurons, while decreasing GLT-1 activity enables potentiation in excitatory neurons. Our results reveal an unsuspected difference between excitatory synapses onto different neuronal types, and a more prominent activation of synaptic NMDARs by ambient glutamate in inhibitory than excitatory neurons. This difference has implications for tonic NMDAR activity/signaling and the selective modulation of inhibitory neuron activity to treat brain disorders. Inhibitory interneurons play important roles in brain circuits and in several neuropsychiatric disorders. Here, the authors show that excitatory synapses onto interneurons vs. excitatory neurons differ in their ambient synaptic glutamate level, a finding with important implications for selective pharmacological targeting of inhibitory neuron NMDA receptors.
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98
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Jazmati D, Neubacher U, Funke K. Neuropeptide Y as a possible homeostatic element for changes in cortical excitability induced by repetitive transcranial magnetic stimulation. Brain Stimul 2018. [DOI: 10.1016/j.brs.2018.02.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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99
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Takeuchi N, Sugiyama S, Inui K, Kanemoto K, Nishihara M. Long-latency suppression of auditory and somatosensory change-related cortical responses. PLoS One 2018; 13:e0199614. [PMID: 29944700 PMCID: PMC6019261 DOI: 10.1371/journal.pone.0199614] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 04/29/2018] [Indexed: 11/19/2022] Open
Abstract
Sensory suppression is a mechanism that attenuates selective information. As for long-latency suppression in auditory and somatosensory systems, paired-pulse suppression, observed as 2 identical stimuli spaced by approximately 500 ms, is widely known, though its mechanism remains to be elucidated. In the present study, we investigated the relationship between auditory and somatosensory long-latency suppression of change-related cortical responses using magnetoencephalography. Somatosensory change-related responses were evoked by an abrupt increase in stimulus strength in a train of current-constant square wave pulses at 100 Hz to the left median nerve at the wrist. Furthermore, auditory change-related responses were elicited by an increase in sound pressure by 15 dB in a continuous sound composed of a train of 25-ms pure tones. Binaural stimulation was used in Experiment 1, while monaural stimulation was used in Experiment 2. For both somatosensory and auditory stimuli, the conditioning and test stimuli were identical, and inserted at 2400 and 3000 ms, respectively. The results showed clear suppression of the test response in the bilateral parisylvian region, but not in the postcentral gyrus of the contralateral hemisphere in the somatosensory system. Similarly, the test response in the bilateral supratemporal plane (N100m) was suppressed in the auditory system. Furthermore, there was a significant correlation between suppression of right N100m and right parisylvian activity, suggesting that similar mechanisms are involved in both. Finally, a high test-retest reliability for suppression was seen with both modalities. Suppression revealed in the present study is considered to reflect sensory inhibition ability in individual subjects.
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Affiliation(s)
- Nobuyuki Takeuchi
- Neuropsychiatric Department, Aichi Medical University, Nagakute, Japan
- * E-mail:
| | - Shunsuke Sugiyama
- Department of Psychiatry and Psychotherapy, Gifu University, Gifu, Japan
| | - Koji Inui
- Institute of Human Developmental Research, Aichi Human Service Center, Kasugai, Japan
- Department of Integrative Physiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Kousuke Kanemoto
- Neuropsychiatric Department, Aichi Medical University, Nagakute, Japan
| | - Makoto Nishihara
- Neuropsychiatric Department, Aichi Medical University, Nagakute, Japan
- Multidisciplinary Pain Center, Aichi Medical University, Nagakute, Japan
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100
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Billeh YN, Schaub MT. Feedforward architectures driven by inhibitory interactions. J Comput Neurosci 2017; 44:63-74. [PMID: 29139049 DOI: 10.1007/s10827-017-0669-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 10/10/2017] [Accepted: 10/17/2017] [Indexed: 11/25/2022]
Abstract
Directed information transmission is paramount for many social, physical, and biological systems. For neural systems, scientists have studied this problem under the paradigm of feedforward networks for decades. In most models of feedforward networks, activity is exclusively driven by excitatory neurons and the wiring patterns between them, while inhibitory neurons play only a stabilizing role for the network dynamics. Motivated by recent experimental discoveries of hippocampal circuitry, cortical circuitry, and the diversity of inhibitory neurons throughout the brain, here we illustrate that one can construct such networks even if the connectivity between the excitatory units in the system remains random. This is achieved by endowing inhibitory nodes with a more active role in the network. Our findings demonstrate that apparent feedforward activity can be caused by a much broader network-architectural basis than often assumed.
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Affiliation(s)
- Yazan N Billeh
- Computation and Neural Systems Program, California Institute of Technology, Pasadena, CA, USA.
- Allen Institute for Brain Science, Seattle, WA, USA.
| | - Michael T Schaub
- ICTEAM, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Engineering Science, University of Oxford, Oxford, UK.
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