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Lacagnina AF, Dong TN, Iyer RR, Khan S, Mohamed MK, Clem RL. Ventral hippocampal interneurons govern extinction and relapse of contextual associations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.28.568835. [PMID: 38077077 PMCID: PMC10705382 DOI: 10.1101/2023.11.28.568835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Contextual associations are critical for survival but must be extinguished when new conditions render them nonproductive. By most accounts, extinction forms a new memory that competes with the original association for control over behavior, but the mechanisms underlying this competition remain largely enigmatic. Here we find the retrieval of contextual fear conditioning and extinction yield contrasting patterns of activity in prefrontal cortex and ventral hippocampus. Within ventral CA1, activation of somatostatin-expressing interneurons (SST-INs) occurs preferentially during extinction retrieval and correlates with differences in input synaptic transmission. Optogenetic manipulation of these cells but not parvalbumin interneurons (PV-INs) elicits bidirectional changes in fear expression following extinction, and the ability of SST-INs to gate fear is specific to the context in which extinction was acquired. A similar pattern of results was obtained following reward-based extinction. These data show that ventral hippocampal SST-INs are critical for extinguishing prior associations and thereby gate relapse of both aversive and appetitive responses.
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2
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Mercier MS, Magloire V, Cornford JH, Kullmann DM. Long-term potentiation in neurogliaform interneurons modulates excitation-inhibition balance in the temporoammonic pathway. J Physiol 2022; 600:4001-4017. [PMID: 35876215 PMCID: PMC9540908 DOI: 10.1113/jp282753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 07/19/2022] [Indexed: 11/08/2022] Open
Abstract
Apical dendrites of pyramidal neurons integrate information from higher-order cortex and thalamus, and gate signalling and plasticity at proximal synapses. In the hippocampus, neurogliaform cells and other interneurons located within stratum lacunosum-moleculare (SLM) mediate powerful inhibition of CA1 pyramidal neuron distal dendrites. Is the recruitment of such inhibition itself subject to use-dependent plasticity, and if so, what induction rules apply? Here we show that interneurons in mouse SLM exhibit Hebbian NMDA receptor-dependent long-term potentiation (LTP). Such plasticity can be induced by selective optogenetic stimulation of afferents in the temporoammonic pathway from the entorhinal cortex (EC), but not by equivalent stimulation of afferents from the thalamic nucleus reuniens. We further show that theta-burst patterns of afferent firing induces LTP in neurogliaform interneurons identified using neuron-derived neurotrophic factor (Ndnf)-Cre mice. Theta-burst activity of EC afferents led to an increase in disynaptic feed-forward inhibition, but not monosynaptic excitation, of CA1 pyramidal neurons. Activity-dependent synaptic plasticity in SLM interneurons thus alters the excitation-inhibition balance at EC inputs to the apical dendrites of pyramidal neurons, implying a dynamic role for these interneurons in gating CA1 dendritic computations. KEY POINTS: Electrogenic phenomena in distal dendrites of principal neurons in the hippocampus have a major role in gating synaptic plasticity at afferent synapses on proximal dendrites. Apical dendrites also receive powerful feed-forward inhibition, mediated in large part by neurogliaform neurons. Here we show that theta-burst activity in afferents from the entorhinal cortex (EC) induces 'Hebbian' long-term potentiation (LTP) at excitatory synapses recruiting these GABAergic cells. LTP in interneurons innervating apical dendrites increases disynaptic inhibition of principal neurons, thus shifting the excitation-inhibition balance in the temporoammonic (TA) pathway in favour of inhibition, with implications for computations and learning rules in proximal dendrites.
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Affiliation(s)
- Marion S. Mercier
- UCL Queen Square Institute of NeurologyDepartment of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
| | - Vincent Magloire
- UCL Queen Square Institute of NeurologyDepartment of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
| | - Jonathan H. Cornford
- UCL Queen Square Institute of NeurologyDepartment of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
| | - Dimitri M. Kullmann
- UCL Queen Square Institute of NeurologyDepartment of Clinical and Experimental EpilepsyUniversity College LondonLondonUK
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3
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Sakalar E, Klausberger T, Lasztóczi B. Neurogliaform cells dynamically decouple neuronal synchrony between brain areas. Science 2022; 377:324-328. [DOI: 10.1126/science.abo3355] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Effective communication across brain areas requires distributed neuronal networks to dynamically synchronize or decouple their ongoing activity. GABA
ergic
interneurons lock ensembles to network oscillations, but there remain questions regarding how synchrony is actively disengaged to allow for new communication partners. We recorded the activity of identified interneurons in the CA1 hippocampus of awake mice. Neurogliaform cells (NGFCs)—which provide GABA
ergic
inhibition to distal dendrites of pyramidal cells—strongly coupled their firing to those gamma oscillations synchronizing local networks with cortical inputs. Rather than strengthening such synchrony, action potentials of NGFCs decoupled pyramidal cell activity from cortical gamma oscillations but did not reduce their firing nor affect local oscillations. Thus, NGFCs regulate information transfer by temporarily disengaging the synchrony without decreasing the activity of communicating networks.
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Affiliation(s)
- Ece Sakalar
- Division of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Thomas Klausberger
- Division of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Bálint Lasztóczi
- Division of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
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4
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Attili SM, Moradi K, Wheeler DW, Ascoli GA. Quantification of neuron types in the rodent hippocampal formation by data mining and numerical optimization. Eur J Neurosci 2022; 55:1724-1741. [PMID: 35301768 PMCID: PMC10026515 DOI: 10.1111/ejn.15639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 01/25/2022] [Accepted: 02/28/2022] [Indexed: 11/29/2022]
Abstract
Quantifying the population sizes of distinct neuron types in different anatomical regions is an essential step towards establishing a brain cell census. Although estimates exist for the total neuronal populations in different species, the number and definition of each specific neuron type are still intensively investigated. Hippocampome.org is an open-source knowledge base with morphological, physiological and molecular information for 122 neuron types in the rodent hippocampal formation. While such framework identifies all known neuron types in this system, their relative abundances remain largely unknown. This work quantitatively estimates the counts of all Hippocampome.org neuron types by literature mining and numerical optimization. We report the number of neurons in each type identified by main neurotransmitter (glutamate or GABA) and axonal-dendritic patterns throughout 26 subregions and layers of the dentate gyrus, Ammon's horn, subiculum and entorhinal cortex. We produce by sensitivity analysis reliable numerical ranges for each type and summarize the amounts across broad neuronal families defined by biomarkers expression and firing dynamics. Study of density distributions indicates that the number of dendritic-targeting interneurons, but not of other neuronal classes, is independent of anatomical volumes. All extracted values, experimental evidence and related software code are released on Hippocampome.org.
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Affiliation(s)
- Sarojini M. Attili
- Center for Neural Informatics, Structures, & Plasticity, Interdisciplinary Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| | - Keivan Moradi
- Center for Neural Informatics, Structures, & Plasticity, Interdisciplinary Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| | - Diek W. Wheeler
- Bioengineering Department and Volgenau School of Engineering, George Mason University, Fairfax, VA, USA
| | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, & Plasticity, Interdisciplinary Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
- Bioengineering Department and Volgenau School of Engineering, George Mason University, Fairfax, VA, USA
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5
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Ruiter M, Herstel LJ, Wierenga CJ. Reduction of Dendritic Inhibition in CA1 Pyramidal Neurons in Amyloidosis Models of Early Alzheimer's Disease. J Alzheimers Dis 2021; 78:951-964. [PMID: 33074225 PMCID: PMC7739974 DOI: 10.3233/jad-200527] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background: In an early stage of Alzheimer’s disease (AD), before the formation of amyloid plaques, neuronal network hyperactivity has been reported in both patients and animal models. This suggests an underlying disturbance of the balance between excitation and inhibition. Several studies have highlighted the role of somatic inhibition in early AD, while less is known about dendritic inhibition. Objective: In this study we investigated how inhibitory synaptic currents are affected by elevated Aβ levels. Methods: We performed whole-cell patch clamp recordings of CA1 pyramidal neurons in organotypic hippocampal slice cultures after treatment with Aβ-oligomers and in hippocampal brain slices from AppNL-F-G mice (APP-KI). Results: We found a reduction of spontaneous inhibitory postsynaptic currents (sIPSCs) in CA1 pyramidal neurons in organotypic slices after 24 h Aβ treatment. sIPSCs with slow rise times were reduced, suggesting a specific loss of dendritic inhibitory inputs. As miniature IPSCs and synaptic density were unaffected, these results suggest a decrease in activity-dependent transmission after Aβ treatment. We observed a similar, although weaker, reduction in sIPSCs in CA1 pyramidal neurons from APP-KI mice compared to control. When separated by sex, the strongest reduction in sIPSC frequency was found in slices from male APP-KI mice. Consistent with hyperexcitability in pyramidal cells, dendritically targeting interneurons received slightly more excitatory input. GABAergic action potentials had faster kinetics in APP-KI slices. Conclusion: Our results show that Aβ affects dendritic inhibition via impaired action potential driven release, possibly due to altered kinetics of GABAergic action potentials. Reduced dendritic inhibition may contribute to neuronal hyperactivity in early AD.
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Affiliation(s)
- Marvin Ruiter
- Department of Cell Biology, Neurobiology and Biophysics, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Lotte J Herstel
- Department of Cell Biology, Neurobiology and Biophysics, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Corette J Wierenga
- Department of Cell Biology, Neurobiology and Biophysics, Faculty of Science, Utrecht University, Utrecht, The Netherlands
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6
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Ozsvár A, Komlósi G, Oláh G, Baka J, Molnár G, Tamás G. Predominantly linear summation of metabotropic postsynaptic potentials follows coactivation of neurogliaform interneurons. eLife 2021; 10:65634. [PMID: 34308838 PMCID: PMC8360660 DOI: 10.7554/elife.65634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 07/14/2021] [Indexed: 01/13/2023] Open
Abstract
Summation of ionotropic receptor-mediated responses is critical in neuronal computation by shaping input-output characteristics of neurons. However, arithmetics of summation for metabotropic signals are not known. We characterized the combined ionotropic and metabotropic output of neocortical neurogliaform cells (NGFCs) using electrophysiological and anatomical methods in the rat cerebral cortex. These experiments revealed that GABA receptors are activated outside release sites and confirmed coactivation of putative NGFCs in superficial cortical layers in vivo. Triple recordings from presynaptic NGFCs converging to a postsynaptic neuron revealed sublinear summation of ionotropic GABAA responses and linear summation of metabotropic GABAB responses. Based on a model combining properties of volume transmission and distributions of all NGFC axon terminals, we predict that in 83% of cases one or two NGFCs can provide input to a point in the neuropil. We suggest that interactions of metabotropic GABAergic responses remain linear even if most superficial layer interneurons specialized to recruit GABAB receptors are simultaneously active.
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Affiliation(s)
- Attila Ozsvár
- MTA-SZTE Research Group for Cortical Microcircuits of the Hungarian Academy of Sciences,, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Gergely Komlósi
- MTA-SZTE Research Group for Cortical Microcircuits of the Hungarian Academy of Sciences,, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Gáspár Oláh
- MTA-SZTE Research Group for Cortical Microcircuits of the Hungarian Academy of Sciences,, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Judith Baka
- MTA-SZTE Research Group for Cortical Microcircuits of the Hungarian Academy of Sciences,, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Gábor Molnár
- MTA-SZTE Research Group for Cortical Microcircuits of the Hungarian Academy of Sciences,, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Gábor Tamás
- MTA-SZTE Research Group for Cortical Microcircuits of the Hungarian Academy of Sciences,, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
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7
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Webster JF, Vroman R, Beerens S, Sakata S, Wozny C. NDNF is selectively expressed by neocortical, but not habenular neurogliaform cells. Eur J Neurosci 2021; 53:3561-3575. [PMID: 33866632 DOI: 10.1111/ejn.15237] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 11/28/2022]
Abstract
The lateral habenula (LHb) is a brain structure which is known to be pathologically hyperactive in depression, whereby it shuts down the brains' reward systems. Interestingly, inhibition of the LHb has been shown to have an antidepressant effect, hence making the LHb a fascinating subject of study for developing novel antidepressant therapies. Despite this however, the exact mechanisms by which inhibitory signalling is processed within the LHb remain incompletely understood. Some studies have proposed the existence of locally targeting inhibitory interneuron populations within the LHb. One such population is believed to be akin to neocortical neurogliaform cells, yet specific molecular markers for studying these neurons are sparse and hence their function remains elusive. Recently, neuron-derived neurotrophic factor (NDNF) has been proposed as one such marker for neocortical neurogliaform cells. Using a combination of histological, physiological and optogenetic tools, we hence sought to first validate if NDNF was selectively expressed by such inhibitory neurons within the neocortex, and then if it was confined to a similar population within the LHb. While we report this to be true for the neocortex, we find no such evidence within the LHb; rather that NDNF is expressed without restriction to a particular neuronal subpopulation. These results hence indicate that molecular markers can represent broadly diverse populations of neurons on a region-to-region basis and that therefore each population as defined by molecular marker expression should be validated in each brain structure.
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Affiliation(s)
- Jack F Webster
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Rozan Vroman
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Sanne Beerens
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Shuzo Sakata
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Christian Wozny
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK.,MSH Medical School Hamburg, Medical University, Hamburg, Germany
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8
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Miczán V, Kelemen K, Glavinics JR, László ZI, Barti B, Kenesei K, Kisfali M, Katona I. NECAB1 and NECAB2 are Prevalent Calcium-Binding Proteins of CB1/CCK-Positive GABAergic Interneurons. Cereb Cortex 2021; 31:1786-1806. [PMID: 33230531 PMCID: PMC7869086 DOI: 10.1093/cercor/bhaa326] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/21/2020] [Accepted: 10/08/2020] [Indexed: 12/13/2022] Open
Abstract
The molecular repertoire of the "Ca2+-signaling toolkit" supports the specific kinetic requirements of Ca2+-dependent processes in different neuronal types. A well-known example is the unique expression pattern of calcium-binding proteins, such as parvalbumin, calbindin, and calretinin. These cytosolic Ca2+-buffers control presynaptic and somatodendritic processes in a cell-type-specific manner and have been used as neurochemical markers of GABAergic interneuron types for decades. Surprisingly, to date no typifying calcium-binding proteins have been found in CB1 cannabinoid receptor/cholecystokinin (CB1/CCK)-positive interneurons that represent a large population of GABAergic cells in cortical circuits. Because CB1/CCK-positive interneurons display disparate presynaptic and somatodendritic Ca2+-transients compared with other interneurons, we tested the hypothesis that they express alternative calcium-binding proteins. By in silico data mining in mouse single-cell RNA-seq databases, we identified high expression of Necab1 and Necab2 genes encoding N-terminal EF-hand calcium-binding proteins 1 and 2, respectively, in CB1/CCK-positive interneurons. Fluorescent in situ hybridization and immunostaining revealed cell-type-specific distribution of NECAB1 and NECAB2 throughout the isocortex, hippocampal formation, and basolateral amygdala complex. Combination of patch-clamp electrophysiology, confocal, and STORM super-resolution microscopy uncovered subcellular nanoscale differences indicating functional division of labor between the two calcium-binding proteins. These findings highlight NECAB1 and NECAB2 as predominant calcium-binding proteins in CB1/CCK-positive interneurons.
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Affiliation(s)
- Vivien Miczán
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest 1083, Hungary
- Roska Tamás Doctoral School of Sciences and Technology, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Krisztina Kelemen
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest 1083, Hungary
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, Târgu Mureș 540142, Romania
| | - Judit R Glavinics
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest 1083, Hungary
| | - Zsófia I László
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest 1083, Hungary
- Szentágothai János Doctoral School of Neuroscience, Semmelweis University, Budapest 1083, Hungary
| | - Benjámin Barti
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest 1083, Hungary
- Szentágothai János Doctoral School of Neuroscience, Semmelweis University, Budapest 1083, Hungary
| | - Kata Kenesei
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest 1083, Hungary
| | - Máté Kisfali
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest 1083, Hungary
| | - István Katona
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest 1083, Hungary
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
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9
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Geiller T, Vancura B, Terada S, Troullinou E, Chavlis S, Tsagkatakis G, Tsakalides P, Ócsai K, Poirazi P, Rózsa BJ, Losonczy A. Large-Scale 3D Two-Photon Imaging of Molecularly Identified CA1 Interneuron Dynamics in Behaving Mice. Neuron 2020; 108:968-983.e9. [PMID: 33022227 PMCID: PMC7736348 DOI: 10.1016/j.neuron.2020.09.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/16/2020] [Accepted: 09/08/2020] [Indexed: 01/26/2023]
Abstract
Cortical computations are critically reliant on their local circuit, GABAergic cells. In the hippocampus, a large body of work has identified an unprecedented diversity of GABAergic interneurons with pronounced anatomical, molecular, and physiological differences. Yet little is known about the functional properties and activity dynamics of the major hippocampal interneuron classes in behaving animals. Here we use fast, targeted, three-dimensional (3D) two-photon calcium imaging coupled with immunohistochemistry-based molecular identification to retrospectively map in vivo activity onto multiple classes of interneurons in the mouse hippocampal area CA1 during head-fixed exploration and goal-directed learning. We find examples of preferential subtype recruitment with quantitative differences in response properties and feature selectivity during key behavioral tasks and states. These results provide new insights into the collective organization of local inhibitory circuits supporting navigational and mnemonic functions of the hippocampus.
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Affiliation(s)
- Tristan Geiller
- Department of Neuroscience, Columbia University, New York, NY, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Bert Vancura
- Department of Neuroscience, Columbia University, New York, NY, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Satoshi Terada
- Department of Neuroscience, Columbia University, New York, NY, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Eirini Troullinou
- Institute of Computer Science, Foundation for Research and Technology Hellas, Heraklion, 70013, Greece
- Department of Computer Science, University of Crete, Heraklion, 70013, Greece
| | - Spyridon Chavlis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology-Hellas (FORTH), Heraklion, Crete, 700 13, Greece
| | | | - Panagiotis Tsakalides
- Institute of Computer Science, Foundation for Research and Technology Hellas, Heraklion, 70013, Greece
- Department of Computer Science, University of Crete, Heraklion, 70013, Greece
| | - Katalin Ócsai
- Faculty of Information Technology, Pázmány Péter University, Budapest
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology-Hellas (FORTH), Heraklion, Crete, 700 13, Greece
| | - Balázs J Rózsa
- Faculty of Information Technology, Pázmány Péter University, Budapest
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Eötvös Loránd Research Network, Budapest, Hungary
| | - Attila Losonczy
- Department of Neuroscience, Columbia University, New York, NY, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- The Kavli Institute for Brain Science, Columbia University, New York, NY, USA
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10
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Minimizing shrinkage of acute brain slices using metal spacers during histological embedding. Brain Struct Funct 2020; 225:2577-2589. [PMID: 32918613 PMCID: PMC7544706 DOI: 10.1007/s00429-020-02141-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 09/02/2020] [Indexed: 01/05/2023]
Abstract
The morphological structure of neurons provides the basis for their functions and is a major focus of contemporary neuroscience studies. Intracellular staining of single cells in acute slices is a well-established approach, offering high-resolution information on neuronal morphology, complementing their physiology. Despite major technical advances, however, a common histological artifact often precludes precise morphological analysis: shrinkage of the sampled tissue after embedding for microscopy. Here, we describe a new approach using a metal spacer, sandwiched between two coverslips to reduce shrinkage of whole-mount slice preparations during embedding with aqueous mounting medium under a coverslip. This approach additionally allows imaging the slices from both sides to obtain better quality images of deeper structures. We demonstrate that the use of this spacer system can efficiently and stably reduce the shrinkage of slices, whereas conventional embedding methods without spacer or with agar spacer cause severe, progressive shrinkage after embedding. We further show that the shrinkage of slices is not uniform and artifacts in morphology and anatomical parameters produced cannot be compensated using linear correction algorithms. Our study, thus, emphasizes the importance of preventing the deformation of slice preparations and offers an effective means for reducing shrinkage and associated artifacts during embedding.
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11
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Capogna M, Castillo PE, Maffei A. The ins and outs of inhibitory synaptic plasticity: Neuron types, molecular mechanisms and functional roles. Eur J Neurosci 2020; 54:6882-6901. [PMID: 32663353 DOI: 10.1111/ejn.14907] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 01/05/2023]
Abstract
GABAergic interneurons are highly diverse, and their synaptic outputs express various forms of plasticity. Compelling evidence indicates that activity-dependent changes of inhibitory synaptic transmission play a significant role in regulating neural circuits critically involved in learning and memory and circuit refinement. Here, we provide an updated overview of inhibitory synaptic plasticity with a focus on the hippocampus and neocortex. To illustrate the diversity of inhibitory interneurons, we discuss the case of two highly divergent interneuron types, parvalbumin-expressing basket cells and neurogliaform cells, which support unique roles on circuit dynamics. We also present recent progress on the molecular mechanisms underlying long-term, activity-dependent plasticity of fast inhibitory transmission. Lastly, we discuss the role of inhibitory synaptic plasticity in neuronal circuits' function. The emerging picture is that inhibitory synaptic transmission in the CNS is extremely diverse, undergoes various mechanistically distinct forms of plasticity and contributes to a much more refined computational role than initially thought. Both the remarkable diversity of inhibitory interneurons and the various forms of plasticity expressed by GABAergic synapses provide an amazingly rich inhibitory repertoire that is central to a variety of complex neural circuit functions, including memory.
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Affiliation(s)
- Marco Capogna
- Department of Biomedicine, Danish National Research Foundation Center of Excellence PROMEMO, Aarhus University, Aarhus, Denmark
| | - Pablo E Castillo
- Dominck P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Arianna Maffei
- Center for Neural Circuit Dynamics and Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
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12
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Ecker A, Romani A, Sáray S, Káli S, Migliore M, Falck J, Lange S, Mercer A, Thomson AM, Muller E, Reimann MW, Ramaswamy S. Data-driven integration of hippocampal CA1 synaptic physiology in silico. Hippocampus 2020; 30:1129-1145. [PMID: 32520422 PMCID: PMC7687201 DOI: 10.1002/hipo.23220] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 04/20/2020] [Accepted: 05/07/2020] [Indexed: 12/31/2022]
Abstract
The anatomy and physiology of monosynaptic connections in rodent hippocampal CA1 have been extensively studied in recent decades. Yet, the resulting knowledge remains disparate and difficult to reconcile. Here, we present a data‐driven approach to integrate the current state‐of‐the‐art knowledge on the synaptic anatomy and physiology of rodent hippocampal CA1, including axo‐dendritic innervation patterns, number of synapses per connection, quantal conductances, neurotransmitter release probability, and short‐term plasticity into a single coherent resource. First, we undertook an extensive literature review of paired recordings of hippocampal neurons and compiled experimental data on their synaptic anatomy and physiology. The data collected in this manner is sparse and inhomogeneous due to the diversity of experimental techniques used by different groups, which necessitates the need for an integrative framework to unify these data. To this end, we extended a previously developed workflow for the neocortex to constrain a unifying in silico reconstruction of the synaptic physiology of CA1 connections. Our work identifies gaps in the existing knowledge and provides a complementary resource toward a more complete quantification of synaptic anatomy and physiology in the rodent hippocampal CA1 region.
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Affiliation(s)
- András Ecker
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Campus Biotech, Geneva, Switzerland
| | - Armando Romani
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Campus Biotech, Geneva, Switzerland
| | - Sára Sáray
- Institute of Experimental Medicine, Budapest, Hungary.,Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Szabolcs Káli
- Institute of Experimental Medicine, Budapest, Hungary.,Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Michele Migliore
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Joanne Falck
- UCL School of Pharmacy, University College London, London, UK
| | - Sigrun Lange
- UCL School of Pharmacy, University College London, London, UK.,School of Life Sciences, University of Westminster, London, UK
| | - Audrey Mercer
- UCL School of Pharmacy, University College London, London, UK
| | - Alex M Thomson
- UCL School of Pharmacy, University College London, London, UK
| | - Eilif Muller
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Campus Biotech, Geneva, Switzerland
| | - Michael W Reimann
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Campus Biotech, Geneva, Switzerland
| | - Srikanth Ramaswamy
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Campus Biotech, Geneva, Switzerland
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13
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Oláh VJ, Lukacsovich D, Winterer J, Arszovszki A, Lőrincz A, Nusser Z, Földy C, Szabadics J. Functional specification of CCK+ interneurons by alternative isoforms of Kv4.3 auxiliary subunits. eLife 2020; 9:58515. [PMID: 32490811 PMCID: PMC7269670 DOI: 10.7554/elife.58515] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 05/20/2020] [Indexed: 01/18/2023] Open
Abstract
CCK-expressing interneurons (CCK+INs) are crucial for controlling hippocampal activity. We found two firing phenotypes of CCK+INs in rat hippocampal CA3 area; either possessing a previously undetected membrane potential-dependent firing or regular firing phenotype, due to different low-voltage-activated potassium currents. These different excitability properties destine the two types for distinct functions, because the former is essentially silenced during realistic 8–15 Hz oscillations. By contrast, the general intrinsic excitability, morphology and gene-profiles of the two types were surprisingly similar. Even the expression of Kv4.3 channels were comparable, despite evidences showing that Kv4.3-mediated currents underlie the distinct firing properties. Instead, the firing phenotypes were correlated with the presence of distinct isoforms of Kv4 auxiliary subunits (KChIP1 vs. KChIP4e and DPP6S). Our results reveal the underlying mechanisms of two previously unknown types of CCK+INs and demonstrate that alternative splicing of few genes, which may be viewed as a minor change in the cells’ whole transcriptome, can determine cell-type identity.
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Affiliation(s)
- Viktor János Oláh
- Laboratory of Cellular Neuropharmacology, Institute of Experimental Medicine, Budapest, Hungary.,János Szentágothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - David Lukacsovich
- Laboratory of Neural Connectivity, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Jochen Winterer
- Laboratory of Neural Connectivity, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Antónia Arszovszki
- Laboratory of Cellular Neuropharmacology, Institute of Experimental Medicine, Budapest, Hungary
| | - Andrea Lőrincz
- Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Zoltan Nusser
- Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Csaba Földy
- Laboratory of Neural Connectivity, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - János Szabadics
- Laboratory of Cellular Neuropharmacology, Institute of Experimental Medicine, Budapest, Hungary
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14
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Gosztonyi G, Ludwig H, Bode L, Kao M, Sell M, Petrusz P, Halász B. Obesity induced by Borna disease virus in rats: key roles of hypothalamic fast-acting neurotransmitters and inflammatory infiltrates. Brain Struct Funct 2020; 225:1459-1482. [PMID: 32394093 DOI: 10.1007/s00429-020-02063-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/21/2020] [Indexed: 12/30/2022]
Abstract
Human obesity epidemic is increasing worldwide with major adverse consequences on health. Among other possible causes, the hypothesis of an infectious contribution is worth it to be considered. Here, we report on an animal model of virus-induced obesity which might help to better understand underlying processes in human obesity. Eighty Wistar rats, between 30 and 60 days of age, were intracerebrally inoculated with Borna disease virus (BDV-1), a neurotropic negative-strand RNA virus infecting an unusually broad host spectrum including humans. Half of the rats developed fatal encephalitis, while the other half, after 3-4 months, continuously gained weight. At tripled weights, rats were sacrificed by trans-cardial fixative perfusion. Neuropathology revealed prevailing inflammatory infiltrates in the median eminence (ME), progressive degeneration of neurons of the paraventricular nucleus, the entorhinal cortex and the amygdala, and a strikingly high-grade involution of the hippocampus with hydrocephalus. Immune histology revealed that major BDV-1 antigens were preferentially present at glutamatergic receptor sites, while GABAergic areas remained free from BDV-1. Virus-induced suppression of the glutamatergic system caused GABAergic predominance. In the hypothalamus, this shifted the energy balance to the anabolic appetite-stimulating side governed by GABA, allowing for excessive fat accumulation in obese rats. Furthermore, inflammatory infiltrates in the ME and ventro-medial arcuate nucleus hindered free access of appetite-suppressing hormones leptin and insulin. The hormone transport system in hypothalamic areas outside the ME became blocked by excessively produced leptin, leading to leptin resistance. The resulting hyperleptinemic milieu combined with suppressed glutamatergic mechanisms was a characteristic feature of the found metabolic pathology. In conclusion, the study provided clear evidence that BDV-1 induced obesity in the rat model is the result of interdependent structural and functional metabolic changes. They can be explained by an immunologically induced hypothalamic microcirculation-defect, combined with a disturbance of neurotransmitter regulatory systems. The proposed mechanism may also have implications for human health. BDV-1 infection has been frequently found in depressive patients. Independently, comorbidity between depression and obesity has been reported, either. Future studies should address the exciting question of whether BDV-1 infection could be a link, whatsoever, between these two conditions.
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Affiliation(s)
- Georg Gosztonyi
- Institute of Neuropathology, Charité, University Medicine Berlin, 10117, Berlin, Germany.
| | - Hanns Ludwig
- Freelance Bornavirus Workgroup, 14163, Berlin, Germany
| | - Liv Bode
- Freelance Bornavirus Workgroup, 14163, Berlin, Germany
| | - Moujahed Kao
- Landesbetrieb Hessisches Landeslabor, 35392, Giessen, Germany
| | - Manfred Sell
- Division of Pathology, Martin Luther Hospital, 12351, Berlin, Germany
| | - Peter Petrusz
- Department of Cell and Developmental Biology, University of North Carolina At Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Béla Halász
- Neuromorphological and Neuroendocrine Research Laboratory, Semmelweis University, 1094, Budapest, Hungary
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15
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Tukker JJ, Beed P, Schmitz D, Larkum ME, Sachdev RNS. Up and Down States and Memory Consolidation Across Somatosensory, Entorhinal, and Hippocampal Cortices. Front Syst Neurosci 2020; 14:22. [PMID: 32457582 PMCID: PMC7227438 DOI: 10.3389/fnsys.2020.00022] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/03/2020] [Indexed: 01/01/2023] Open
Abstract
In the course of a day, brain states fluctuate, from conscious awake information-acquiring states to sleep states, during which previously acquired information is further processed and stored as memories. One hypothesis is that memories are consolidated and stored during "offline" states such as sleep, a process thought to involve transfer of information from the hippocampus to other cortical areas. Up and Down states (UDS), patterns of activity that occur under anesthesia and sleep states, are likely to play a role in this process, although the nature of this role remains unclear. Here we review what is currently known about these mechanisms in three anatomically distinct but interconnected cortical areas: somatosensory cortex, entorhinal cortex, and the hippocampus. In doing so, we consider the role of this activity in the coordination of "replay" during sleep states, particularly during hippocampal sharp-wave ripples. We conclude that understanding the generation and propagation of UDS may provide key insights into the cortico-hippocampal dialogue linking archi- and neocortical areas during memory formation.
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Affiliation(s)
- John J Tukker
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Neuroscience Research Center, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Prateep Beed
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Neuroscience Research Center, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany
| | - Dietmar Schmitz
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Neuroscience Research Center, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.,Berlin Institute of Health, Berlin, Germany.,Cluster of Excellence NeuroCure, Berlin, Germany.,Einstein Center for Neurosciences Berlin, Berlin, Germany
| | - Matthew E Larkum
- Cluster of Excellence NeuroCure, Berlin, Germany.,Einstein Center for Neurosciences Berlin, Berlin, Germany.,Institut für Biologie, Humboldt Universität, Berlin, Germany
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16
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A Toolbox of Criteria for Distinguishing Cajal-Retzius Cells from Other Neuronal Types in the Postnatal Mouse Hippocampus. eNeuro 2020; 7:ENEURO.0516-19.2019. [PMID: 31907212 PMCID: PMC7004485 DOI: 10.1523/eneuro.0516-19.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 01/05/2023] Open
Abstract
The study of brain circuits depends on a clear understanding of the role played by different neuronal populations. Therefore, the unambiguous identification of different cell types is essential for the correct interpretation of experimental data. Here, we emphasize to the broader neuroscience community the importance of recognizing the persistent presence of Cajal-Retzius cells in the molecular layers of the postnatal hippocampus, and then we suggest a variety of criteria for distinguishing Cajal-Retzius cells from other neurons of the hippocampal molecular layers, such as GABAergic interneurons and semilunar granule cells. The toolbox of criteria that we have investigated (in male and female mice) can be useful both for anatomical and functional experiments, and relies on the quantitative study of neuronal somatic/nuclear morphology, location and developmental profile, expression of specific molecular markers (GAD67, reelin, COUP-TFII, calretinin, and p73), single cell anatomy, and electrophysiological properties. We conclude that Cajal-Retzius cells are small, non-GABAergic neurons that are tightly associated with the hippocampal fissure (HF), and that, within this area of interest, selectively express the proteins p73 and calretinin. We highlight the dangers of using markers such as reelin or COUP-TFII to identify Cajal-Retzius cells or GABAergic interneurons because of their poor specificity. Lastly, we examine neurons of the postnatal hippocampal molecular layers and show cell type-specific differences in their dendritic/axonal morphologies and density distributions, as well as in their membrane properties and spontaneous synaptic inputs. These parameters can be used to distinguish biocytin-filled and/or electrophysiologically recorded neurons and should be considered to avoid interpretational mistakes.
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17
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Komendantov AO, Venkadesh S, Rees CL, Wheeler DW, Hamilton DJ, Ascoli GA. Quantitative firing pattern phenotyping of hippocampal neuron types. Sci Rep 2019; 9:17915. [PMID: 31784578 PMCID: PMC6884469 DOI: 10.1038/s41598-019-52611-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/20/2019] [Indexed: 01/19/2023] Open
Abstract
Systematically organizing the anatomical, molecular, and physiological properties of cortical neurons is important for understanding their computational functions. Hippocampome.org defines 122 neuron types in the rodent hippocampal formation based on their somatic, axonal, and dendritic locations, putative excitatory/inhibitory outputs, molecular marker expression, and biophysical properties. We augmented the electrophysiological data of this knowledge base by collecting, quantifying, and analyzing the firing responses to depolarizing current injections for every hippocampal neuron type from published experiments. We designed and implemented objective protocols to classify firing patterns based on 5 transients (delay, adapting spiking, rapidly adapting spiking, transient stuttering, and transient slow-wave bursting) and 4 steady states (non-adapting spiking, persistent stuttering, persistent slow-wave bursting, and silence). This automated approach revealed 9 unique (plus one spurious) families of firing pattern phenotypes while distinguishing potential new neuronal subtypes. Novel statistical associations emerged between firing responses and other electrophysiological properties, morphological features, and molecular marker expression. The firing pattern parameters, experimental conditions, spike times, references to the original empirical evidences, and analysis scripts are released open-source through Hippocampome.org for all neuron types, greatly enhancing the existing search and browse capabilities. This information, collated online in human- and machine-accessible form, will help design and interpret both experiments and model simulations.
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Affiliation(s)
- Alexander O Komendantov
- Krasnow Institute for Advanced Study, George Mason University, 4400 University Drive, MS 2A1, Fairfax, Virginia, 2230, USA.
| | - Siva Venkadesh
- Krasnow Institute for Advanced Study, George Mason University, 4400 University Drive, MS 2A1, Fairfax, Virginia, 2230, USA
| | - Christopher L Rees
- Krasnow Institute for Advanced Study, George Mason University, 4400 University Drive, MS 2A1, Fairfax, Virginia, 2230, USA
| | - Diek W Wheeler
- Krasnow Institute for Advanced Study, George Mason University, 4400 University Drive, MS 2A1, Fairfax, Virginia, 2230, USA
| | - David J Hamilton
- Krasnow Institute for Advanced Study, George Mason University, 4400 University Drive, MS 2A1, Fairfax, Virginia, 2230, USA
| | - Giorgio A Ascoli
- Krasnow Institute for Advanced Study, George Mason University, 4400 University Drive, MS 2A1, Fairfax, Virginia, 2230, USA.
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18
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Venkadesh S, Komendantov AO, Wheeler DW, Hamilton DJ, Ascoli GA. Simple models of quantitative firing phenotypes in hippocampal neurons: Comprehensive coverage of intrinsic diversity. PLoS Comput Biol 2019; 15:e1007462. [PMID: 31658260 PMCID: PMC6837624 DOI: 10.1371/journal.pcbi.1007462] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 11/07/2019] [Accepted: 10/07/2019] [Indexed: 12/02/2022] Open
Abstract
Patterns of periodic voltage spikes elicited by a neuron help define its dynamical identity. Experimentally recorded spike trains from various neurons show qualitatively distinguishable features such as delayed spiking, spiking with or without frequency adaptation, and intrinsic bursting. Moreover, the input-dependent responses of a neuron not only show different quantitative features, such as higher spike frequency for a stronger input current injection, but can also exhibit qualitatively different responses, such as spiking and bursting under different input conditions, thus forming a complex phenotype of responses. In previous work, the comprehensive knowledge base of hippocampal neuron types Hippocampome.org systematically characterized various spike pattern phenotypes experimentally identified from 120 neuron types/subtypes. In this paper, we present a complete set of simple phenomenological models that quantitatively reproduce the diverse and complex phenotypes of hippocampal neurons. In addition to point-neuron models, we created compact multi-compartment models with up to four compartments, which will allow spatial segregation of synaptic integration in network simulations. Electrotonic compartmentalization observed in our compact multi-compartment models is qualitatively consistent with experimental observations. The models were created using an automated pipeline based on evolutionary algorithms. This work maps 120 neuron types/subtypes in the rodent hippocampus to a low-dimensional model space and adds another dimension to the knowledge accumulated in Hippocampome.org. Computationally efficient representations of intrinsic dynamics, along with other pieces of knowledge available in Hippocampome.org, provide a biologically realistic platform to explore the large-scale interactions of various neuron types at the mesoscopic level.
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Affiliation(s)
- Siva Venkadesh
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States of America
| | - Alexander O. Komendantov
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States of America
| | - Diek W. Wheeler
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States of America
| | - David J. Hamilton
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States of America
| | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States of America
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19
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Melonakos ED, White JA, Fernandez FR. A model of cholinergic suppression of hippocampal ripples through disruption of balanced excitation/inhibition. Hippocampus 2018; 29:773-786. [PMID: 30417958 DOI: 10.1002/hipo.23051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 10/02/2018] [Accepted: 10/31/2018] [Indexed: 11/11/2022]
Abstract
Sharp wave-ripples (140-220 Hz) are patterns of brain activity observed in the local field potential of the hippocampus which are present during memory consolidation. As rodents switch from memory consolidation to memory encoding behaviors, cholinergic inputs to the hippocampus from neurons in the medial septum-diagonal band of Broca cause a marked reduction in ripple incidence. The mechanism for this disruption in ripple power is not fully understood. In isolated neurons, the major effect of cholinergic input on hippocampal neurons is depolarization of the membrane potential, which affects both hippocampal pyramidal neurons and inhibitory interneurons. Using an existing model of ripple-frequency oscillations that includes both pyramidal neurons and interneurons, we investigated the mechanism whereby depolarizing inputs to these neurons can affect ripple power and frequency. We observed that ripple power and frequency are maintained, as long as inputs to pyramidal neurons and interneurons are balanced. Preferential drive to pyramidal neurons or interneurons, however, affects ripple power and can disrupt ripple oscillations by pushing ripple frequency higher or lower. Thus, an imbalance in drive to pyramidal neurons and interneurons provides a means whereby cholinergic input can suppress hippocampal ripples.
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Affiliation(s)
- Eric D Melonakos
- Department of Bioengineering, University of Utah, Salt Lake City, Utah
| | - John A White
- Department of Bioengineering, University of Utah, Salt Lake City, Utah.,Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Fernando R Fernandez
- Department of Bioengineering, University of Utah, Salt Lake City, Utah.,Department of Biomedical Engineering, Boston University, Boston, Massachusetts
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20
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Booker SA, Vida I. Morphological diversity and connectivity of hippocampal interneurons. Cell Tissue Res 2018; 373:619-641. [PMID: 30084021 PMCID: PMC6132631 DOI: 10.1007/s00441-018-2882-2] [Citation(s) in RCA: 102] [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: 02/27/2018] [Accepted: 07/03/2018] [Indexed: 12/21/2022]
Abstract
The mammalian forebrain is constructed from ensembles of neurons that form local microcircuits giving rise to the exquisite cognitive tasks the mammalian brain can perform. Hippocampal neuronal circuits comprise populations of relatively homogenous excitatory neurons, principal cells and exceedingly heterogeneous inhibitory neurons, the interneurons. Interneurons release GABA from their axon terminals and are capable of controlling excitability in every cellular compartment of principal cells and interneurons alike; thus, they provide a brake on excess activity, control the timing of neuronal discharge and provide modulation of synaptic transmission. The dendritic and axonal morphology of interneurons, as well as their afferent and efferent connections within hippocampal circuits, is central to their ability to differentially control excitability, in a cell-type- and compartment-specific manner. This review aims to provide an up-to-date compendium of described hippocampal interneuron subtypes, with respect to their morphology, connectivity, neurochemistry and physiology, a full understanding of which will in time help to explain the rich diversity of neuronal function.
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Affiliation(s)
- Sam A Booker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK.
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD, UK.
| | - Imre Vida
- Institute for Integrative Neuroanatomy, Charité - Universitätmedizin Berlin, Berlin, Germany.
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21
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Hartzell AL, Martyniuk KM, Brigidi GS, Heinz DA, Djaja NA, Payne A, Bloodgood BL. NPAS4 recruits CCK basket cell synapses and enhances cannabinoid-sensitive inhibition in the mouse hippocampus. eLife 2018; 7:35927. [PMID: 30052197 PMCID: PMC6105310 DOI: 10.7554/elife.35927] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/19/2018] [Indexed: 12/30/2022] Open
Abstract
Experience-dependent expression of immediate-early gene transcription factors (IEG-TFs) can transiently change the transcriptome of active neurons and initiate persistent changes in cellular function. However, the impact of IEG-TFs on circuit connectivity and function is poorly understood. We investigate the specificity with which the IEG-TF NPAS4 governs experience-dependent changes in inhibitory synaptic input onto CA1 pyramidal neurons (PNs). We show that novel sensory experience selectively enhances somatic inhibition mediated by cholecystokinin-expressing basket cells (CCKBCs) in an NPAS4-dependent manner. NPAS4 specifically increases the number of synapses made onto PNs by individual CCKBCs without altering synaptic properties. Additionally, we find that sensory experience-driven NPAS4 expression enhances depolarization-induced suppression of inhibition (DSI), a short-term form of cannabinoid-mediated plasticity expressed at CCKBC synapses. Our results indicate that CCKBC inputs are a major target of the NPAS4-dependent transcriptional program in PNs and that NPAS4 is an important regulator of plasticity mediated by endogenous cannabinoids.
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Affiliation(s)
- Andrea L Hartzell
- Neuroscience Graduate Program, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States.,Division of Biological Sciences, Section of Neurobiology, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States
| | - Kelly M Martyniuk
- Division of Biological Sciences, Section of Neurobiology, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States
| | - G Stefano Brigidi
- Division of Biological Sciences, Section of Neurobiology, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States
| | - Daniel A Heinz
- Division of Biological Sciences, Section of Neurobiology, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States.,Biological Sciences Graduate Program, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States
| | - Nathalie A Djaja
- Division of Biological Sciences, Section of Neurobiology, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States
| | - Anja Payne
- Neuroscience Graduate Program, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States.,Division of Biological Sciences, Section of Neurobiology, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States
| | - Brenda L Bloodgood
- Neuroscience Graduate Program, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States.,Division of Biological Sciences, Section of Neurobiology, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, United States
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22
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Kulik Á, Booker SA, Vida I. Differential distribution and function of GABABRs in somato-dendritic and axonal compartments of principal cells and interneurons in cortical circuits. Neuropharmacology 2018; 136:80-91. [DOI: 10.1016/j.neuropharm.2017.10.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 12/24/2022]
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23
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Kang YJ, Lewis HES, Young MW, Govindaiah G, Greenfield LJ, Garcia-Rill E, Lee SH. Cell Type-specific Intrinsic Perithreshold Oscillations in Hippocampal GABAergic Interneurons. Neuroscience 2018; 376:80-93. [PMID: 29462702 PMCID: PMC5978001 DOI: 10.1016/j.neuroscience.2018.02.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/08/2018] [Accepted: 02/09/2018] [Indexed: 01/01/2023]
Abstract
The hippocampus plays a critical role in learning, memory, and spatial processing through coordinated network activity including theta and gamma oscillations. Recent evidence suggests that hippocampal subregions (e.g., CA1) can generate these oscillations at the network level, at least in part, through GABAergic interneurons. However, it is unclear whether specific GABAergic interneurons generate intrinsic theta and/or gamma oscillations at the single-cell level. Since major types of CA1 interneurons (i.e., parvalbumin-positive basket cells (PVBCs), cannabinoid type 1 receptor-positive basket cells (CB1BCs), Schaffer collateral-associated cells (SCAs), neurogliaform cells and ivy cells) are thought to play key roles in network theta and gamma oscillations in the hippocampus, we tested the hypothesis that these cells generate intrinsic perithreshold oscillations at the single-cell level. We performed whole-cell patch-clamp recordings from GABAergic interneurons in the CA1 region of the mouse hippocampus in the presence of synaptic blockers to identify intrinsic perithreshold membrane potential oscillations. The majority of PVBCs (83%), but not the other interneuron subtypes, produced intrinsic perithreshold gamma oscillations if the membrane potential remained above -45 mV. In contrast, CB1BCs, SCAs, neurogliaform cells, ivy cells, and the remaining PVBCs (17%) produced intrinsic theta, but not gamma, oscillations. These oscillations were prevented by blockers of persistent sodium current. These data demonstrate that the major types of hippocampal interneurons produce distinct frequency bands of intrinsic perithreshold membrane oscillations.
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Affiliation(s)
- Young-Jin Kang
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | | | - Mason William Young
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Gubbi Govindaiah
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Lazar John Greenfield
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; Department of Neurology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Sang-Hun Lee
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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24
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Ferreira-Junior NC, Lagatta DC, Resstel LBM. Glutamatergic, GABAergic, and endocannabinoid neurotransmissions within the dorsal hippocampus modulate the cardiac baroreflex function in rats. Pflugers Arch 2017; 470:395-411. [DOI: 10.1007/s00424-017-2083-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 10/04/2017] [Accepted: 10/20/2017] [Indexed: 01/18/2023]
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25
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Pelkey KA, Chittajallu R, Craig MT, Tricoire L, Wester JC, McBain CJ. Hippocampal GABAergic Inhibitory Interneurons. Physiol Rev 2017; 97:1619-1747. [PMID: 28954853 DOI: 10.1152/physrev.00007.2017] [Citation(s) in RCA: 481] [Impact Index Per Article: 68.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/16/2017] [Accepted: 05/26/2017] [Indexed: 12/11/2022] Open
Abstract
In the hippocampus GABAergic local circuit inhibitory interneurons represent only ~10-15% of the total neuronal population; however, their remarkable anatomical and physiological diversity allows them to regulate virtually all aspects of cellular and circuit function. Here we provide an overview of the current state of the field of interneuron research, focusing largely on the hippocampus. We discuss recent advances related to the various cell types, including their development and maturation, expression of subtype-specific voltage- and ligand-gated channels, and their roles in network oscillations. We also discuss recent technological advances and approaches that have permitted high-resolution, subtype-specific examination of their roles in numerous neural circuit disorders and the emerging therapeutic strategies to ameliorate such pathophysiological conditions. The ultimate goal of this review is not only to provide a touchstone for the current state of the field, but to help pave the way for future research by highlighting where gaps in our knowledge exist and how a complete appreciation of their roles will aid in future therapeutic strategies.
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Affiliation(s)
- Kenneth A Pelkey
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ramesh Chittajallu
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Michael T Craig
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ludovic Tricoire
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Jason C Wester
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Chris J McBain
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
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Mercer A, Thomson AM. Cornu Ammonis Regions-Antecedents of Cortical Layers? Front Neuroanat 2017; 11:83. [PMID: 29018334 PMCID: PMC5622992 DOI: 10.3389/fnana.2017.00083] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/08/2017] [Indexed: 12/13/2022] Open
Abstract
Studying neocortex and hippocampus in parallel, we are struck by the similarities. All three to four layered allocortices and the six layered mammalian neocortex arise in the pallium. All receive and integrate multiple cortical and subcortical inputs, provide multiple outputs and include an array of neuronal classes. During development, each cell positions itself to sample appropriate local and distant inputs and to innervate appropriate targets. Simpler cortices had already solved the need to transform multiple coincident inputs into serviceable outputs before neocortex appeared in mammals. Why then do phylogenetically more recent cortices need multiple pyramidal cell layers? A simple answer is that more neurones can compute more complex functions. The dentate gyrus and hippocampal CA regions-which might be seen as hippocampal antecedents of neocortical layers-lie side by side, albeit around a tight bend. Were the millions of cells of rat neocortex arranged in like fashion, the surface area of the CA pyramidal cell layers would be some 40 times larger. Even if evolution had managed to fold this immense sheet into the space available, the distances between neurones that needed to be synaptically connected would be huge and to maintain the speed of information transfer, massive, myelinated fiber tracts would be needed. How much more practical to stack the "cells that fire and wire together" into narrow columns, while retaining the mechanisms underlying the extraordinary precision with which circuits form. This demonstrably efficient arrangement presents us with challenges, however, not the least being to categorize the baffling array of neuronal subtypes in each of five "pyramidal layers." If we imagine the puzzle posed by this bewildering jumble of apical dendrites, basal dendrites and axons, from many different pyramidal and interneuronal classes, that is encountered by a late-arriving interneurone insinuating itself into a functional circuit, we can perhaps begin to understand why definitive classification, covering every aspect of each neurone's structure and function, is such a challenge. Here, we summarize and compare the development of these two cortices, the properties of their neurones, the circuits they form and the ordered, unidirectional flow of information from one hippocampal region, or one neocortical layer, to another.
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Affiliation(s)
- Audrey Mercer
- Department of Pharmacology, School of Pharmacy, University College London, London, United Kingdom
| | - Alex M. Thomson
- Department of Pharmacology, School of Pharmacy, University College London, London, United Kingdom
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Afferent specific role of NMDA receptors for the circuit integration of hippocampal neurogliaform cells. Nat Commun 2017; 8:152. [PMID: 28751664 PMCID: PMC5532276 DOI: 10.1038/s41467-017-00218-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 06/13/2017] [Indexed: 01/28/2023] Open
Abstract
Appropriate integration of GABAergic interneurons into nascent cortical circuits is critical for ensuring normal information processing within the brain. Network and cognitive deficits associated with neurological disorders, such as schizophrenia, that result from NMDA receptor-hypofunction have been mainly attributed to dysfunction of parvalbumin-expressing interneurons that paradoxically express low levels of synaptic NMDA receptors. Here, we reveal that throughout postnatal development, thalamic, and entorhinal cortical inputs onto hippocampal neurogliaform cells are characterized by a large NMDA receptor-mediated component. This NMDA receptor-signaling is prerequisite for developmental programs ultimately responsible for the appropriate long-range AMPAR-mediated recruitment of neurogliaform cells. In contrast, AMPAR-mediated input at local Schaffer-collateral synapses on neurogliaform cells remains normal following NMDA receptor-ablation. These afferent specific deficits potentially impact neurogliaform cell mediated inhibition within the hippocampus and our findings reveal circuit loci implicating this relatively understudied interneuron subtype in the etiology of neurodevelopmental disorders characterized by NMDA receptor-hypofunction.Proper brain function depends on the correct assembly of excitatory and inhibitory neurons into neural circuits. Here the authors show that during early postnatal development in mice, NMDAR signaling via activity of long-range synaptic inputs onto neurogliaform cells is required for their appropriate integration into the hippocampal circuitry.
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28
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Dolleman-van der Weel MJ, Lopes da Silva FH, Witter MP. Interaction of nucleus reuniens and entorhinal cortex projections in hippocampal field CA1 of the rat. Brain Struct Funct 2016; 222:2421-2438. [PMID: 28008472 DOI: 10.1007/s00429-016-1350-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 12/14/2016] [Indexed: 02/03/2023]
Abstract
The nucleus reuniens (RE) and entorhinal cortex (EC) provide monosynaptic excitatory inputs to the apical dendrites of pyramidal cells and to interneurons with dendrites in stratum lacunosum moleculare (LM) of hippocampal field CA1. However, whether the RE and EC inputs interact at the cellular level is unknown. In this electrophysiological in vivo study, low-frequency stimulation was used to selectively activate each projection at its origin; field excitatory postsynaptic potentials (fEPSPs) were recorded in CA1. We applied (1) paired pulses to RE or EC, (2) combined paired pulses to RE and EC, and (3) simultaneously paired pulses to RE/EC. The main findings are that: (a) stimulation of either RE- or EC-evoked subthreshold fEPSPs, displaying paired pulse facilitation (PPF), (b) subthreshold fEPSPs evoked by combined stimulation did not display heterosynaptic PPF, and (c) simultaneous stimulation of RE/EC resulted in enhanced subthreshold fEPSPs in proximal LM displaying a nonlinear interaction. CSD analyses of RE/EC-evoked depth profiles revealed a nonlinear enlargement of the 'LM sink-radiatum source' configuration and the appearance of an additional small sink-source pair close to stratum pyramidale, likely reflecting (peri)somatic inhibition. The nonlinear interaction between both inputs indicates that RE and EC axons form synapses, at least partly, onto the same dendritic compartments of CA1 pyramidal cells. We propose that low-frequency activation of the RE-CA1 input facilitates the entorhinal-hippocampal dialogue, and may synchronize the neocortical-hippocampal slow oscillation which is relevant for hippocampal-dependent memory consolidation.
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Affiliation(s)
- M J Dolleman-van der Weel
- Department of Anatomy and Neurosciences, VU University Medical Center, 1081 BT, Amsterdam, The Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands
| | - F H Lopes da Silva
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands
- Department of Bioengineering, Instituto Superior Técnico, Lisbon Technical University, 1049-001, Lisbon, Portugal
| | - M P Witter
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, MTFS, Norwegian University of Science and Technology (NTNU), Postboks 8905, 7491, Trondheim, Norway.
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Wyskiel DR, Andrade R. Serotonin excites hippocampal CA1 GABAergic interneurons at the stratum radiatum-stratum lacunosum moleculare border. Hippocampus 2016; 26:1107-14. [PMID: 27328460 PMCID: PMC4996712 DOI: 10.1002/hipo.22611] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2016] [Indexed: 11/07/2022]
Abstract
The hippocampus receives robust serotonergic innervation that is thought to control the excitability of both pyramidal cells and GABAergic interneurons. Previous work has addressed serotonergic regulation of pyramidal cells but considerable gaps remain in our understanding of how serotonin regulates different interneuron subclasses. 5-HT2A receptors (5-HT2A Rs) appear to localize predominantly, if not solely, on interneurons in the hippocampus and have been implicated in the regulation of hippocampal function including mnemonic and novelty recognition processes. Interneurons are functionally diverse. Therefore in the current work, we have used a BAC transgenic mouse line expressing EGFP under the control of the 5-HT2A R promoter to identify the interneuron subtype(s) regulated by serotonin via 5-HT2A Rs. We find that EGFP expression in this mouse identifies a group of interneurons that resides predominantly along the border of the stratum radiatum (SR) and stratum lacunosum moleculare (SLM) of the CA1 region. We then show that these cells are depolarized and excited by serotonin acting through 5-HT2A Rs and appear to belong predominantly to the perforant pathway-associated and Schaffer collateral/commissural pathway-associated subtypes. These results indicate that serotonin interneurons expressing 5-HT2A Rs are localized primarily along the SR-SLM border of the CA1 region and represent a newly identified target for serotonin regulation in the hippocampus. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Daniel R Wyskiel
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan
| | - Rodrigo Andrade
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan
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Wendling F, Gerber U, Cosandier-Rimele D, Nica A, De Montigny J, Raineteau O, Kalitzin S, Lopes da Silva F, Benquet P. Brain (Hyper)Excitability Revealed by Optimal Electrical Stimulation of GABAergic Interneurons. Brain Stimul 2016; 9:919-932. [PMID: 27576186 DOI: 10.1016/j.brs.2016.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 04/29/2016] [Accepted: 07/10/2016] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND Neurological disorders are often characterized by an excessive and prolonged imbalance between neural excitatory and inhibitory processes. An ubiquitous finding among these disorders is the disrupted function of inhibitory GABAergic interneurons. OBJECTIVE The objective is to propose a novel stimulation procedure able to evaluate the efficacy of inhibition imposed by GABAergic interneurons onto pyramidal cells from evoked responses observed in local field potentials (LFPs). METHODS Using a computational modeling approach combined with in vivo and in vitro electrophysiological recordings, we analyzed the impact of electrical extracellular, local, bipolar stimulation (ELBS) on brain tissue. We implemented the ELBS effects in a neuronal population model in which we can tune the excitation-inhibition ratio and we investigated stimulation-related parameters. Computer simulations led to sharp predictions regarding: i) the shape of evoked responses as observed in local field potentials, ii) the type of cells (pyramidal neurons and interneurons) contributing to these field responses and iii) the optimal tuning of stimulation parameters (intensity and frequency) to evoke meaningful responses. These predictions were tested in vivo (mouse). Neurobiological mechanisms were assessed in vitro (hippocampal slices). RESULTS Appropriately-tuned ELBS allows for preferential activation of GABAergic interneurons. A quantitative neural network excitability index (NNEI) is proposed. It is computed from stimulation-induced responses as reflected in local field potentials. NNEI was used in four patients with focal epilepsy. Results show that it can readily reveal hyperexcitable brain regions. CONCLUSION Well-tuned ELBS and NNEI can be used to locally probe brain regions and quantify the (hyper)excitability of the underlying brain tissue.
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Affiliation(s)
- F Wendling
- INSERM U1099, LTSI, Rennes, France; Université de Rennes 1, LTSI, Rennes, France.
| | - U Gerber
- Brain Research Institute, Zurich, Switzerland
| | | | - A Nica
- Neurology Department, Functional Explorations Department, Epilepsy Surgery Unit, CHU, Rennes, France
| | - J De Montigny
- INSERM U1099, LTSI, Rennes, France; Université de Rennes 1, LTSI, Rennes, France
| | - O Raineteau
- Brain Research Institute, Zurich, Switzerland
| | - S Kalitzin
- Foundation of Epilepsy Institutions of the Netherlands (SEIN), Heemstede, The Netherlands
| | - F Lopes da Silva
- Center of Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, The Netherlands
| | - P Benquet
- INSERM U1099, LTSI, Rennes, France; Université de Rennes 1, LTSI, Rennes, France
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Kohus Z, Káli S, Rovira‐Esteban L, Schlingloff D, Papp O, Freund TF, Hájos N, Gulyás AI. Properties and dynamics of inhibitory synaptic communication within the CA3 microcircuits of pyramidal cells and interneurons expressing parvalbumin or cholecystokinin. J Physiol 2016; 594:3745-74. [PMID: 27038232 PMCID: PMC4929320 DOI: 10.1113/jp272231] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/21/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS To understand how a network operates, its elements must be identified and characterized, and the interactions of the elements need to be studied in detail. In the present study, we describe quantitatively the connectivity of two classes of inhibitory neurons in the hippocampal CA3 area (parvalbumin-positive and cholecystokinin-positive interneurons), a key region for the generation of behaviourally relevant synchronous activity patterns. We describe how interactions among these inhibitory cells and their local excitatory target neurons evolve over the course of physiological and pathological activity patterns. The results of the present study enable the construction of precise neuronal network models that may help us understand how network dynamics is generated and how it can underlie information processing and pathological conditions in the brain. We show how inhibitory dynamics between parvalbumin-positive basket cells and pyramidal cells could contribute to sharp wave-ripple generation. ABSTRACT Different hippocampal activity patterns are determined primarily by the interaction of excitatory cells and different types of interneurons. To understand the mechanisms underlying the generation of different network dynamics, the properties of synaptic transmission need to be uncovered. Perisomatic inhibition is critical for the generation of sharp wave-ripples, gamma oscillations and pathological epileptic activities. Therefore, we aimed to quantitatively and systematically characterize the temporal properties of the synaptic transmission between perisomatic inhibitory neurons and pyramidal cells in the CA3 area of mouse hippocampal slices, using action potential patterns recorded during physiological and pathological network states. Parvalbumin-positive (PV+) and cholecystokinin-positive (CCK+) interneurons showed distinct intrinsic physiological features. Interneurons of the same type formed reciprocally connected subnetworks, whereas the connectivity between interneuron classes was sparse. The characteristics of unitary interactions depended on the identity of both synaptic partners, whereas the short-term plasticity of synaptic transmission depended mainly on the presynaptic cell type. PV+ interneurons showed frequency-dependent depression, whereas more complex dynamics characterized the output of CCK+ interneurons. We quantitatively captured the dynamics of transmission at these different types of connection with simple mathematical models, and describe in detail the response to physiological and pathological discharge patterns. Our data suggest that the temporal propeties of PV+ interneuron transmission may contribute to sharp wave-ripple generation. These findings support the view that intrinsic and synaptic features of PV+ cells make them ideally suited for the generation of physiological network oscillations, whereas CCK+ cells implement a more subtle, graded control in the hippocampus.
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Affiliation(s)
- Z. Kohus
- Institute of Experimental MedicineHungarian Academy of SciencesBudapestHungary
- János Szentágothai, PhD Program of Semmelweis UniversityBudapestHungary
| | - S. Káli
- Institute of Experimental MedicineHungarian Academy of SciencesBudapestHungary
- Péter Pázmány Catholic UniversityFaculty of Information TechnologyBudapestHungary
| | - L. Rovira‐Esteban
- Institute of Experimental MedicineHungarian Academy of SciencesBudapestHungary
| | - D. Schlingloff
- Institute of Experimental MedicineHungarian Academy of SciencesBudapestHungary
- János Szentágothai, PhD Program of Semmelweis UniversityBudapestHungary
| | - O. Papp
- Institute of Experimental MedicineHungarian Academy of SciencesBudapestHungary
| | - T. F. Freund
- Institute of Experimental MedicineHungarian Academy of SciencesBudapestHungary
- Péter Pázmány Catholic UniversityFaculty of Information TechnologyBudapestHungary
| | - N. Hájos
- Institute of Experimental MedicineHungarian Academy of SciencesBudapestHungary
| | - A. I. Gulyás
- Institute of Experimental MedicineHungarian Academy of SciencesBudapestHungary
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Name-calling in the hippocampus (and beyond): coming to terms with neuron types and properties. Brain Inform 2016; 4:1-12. [PMID: 27747821 PMCID: PMC5319951 DOI: 10.1007/s40708-016-0053-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 05/24/2016] [Indexed: 01/25/2023] Open
Abstract
Widely spread naming inconsistencies in neuroscience pose a vexing obstacle to effective communication within and across areas of expertise. This problem is particularly acute when identifying neuron types and their properties. Hippocampome.org is a web-accessible neuroinformatics resource that organizes existing data about essential properties of all known neuron types in the rodent hippocampal formation. Hippocampome.org links evidence supporting the assignment of a property to a type with direct pointers to quotes and figures. Mining this knowledge from peer-reviewed reports reveals the troubling extent of terminological ambiguity and undefined terms. Examples span simple cases of using multiple synonyms and acronyms for the same molecular biomarkers (or other property) to more complex cases of neuronal naming. New publications often use different terms without mapping them to previous terms. As a result, neurons of the same type are assigned disparate names, while neurons of different types are bestowed the same name. Furthermore, non-unique properties are frequently used as names, and several neuron types are not named at all. In order to alleviate this nomenclature confusion regarding hippocampal neuron types and properties, we introduce a new functionality of Hippocampome.org: a fully searchable, curated catalog of human and machine-readable definitions, each linked to the corresponding neuron and property terms. Furthermore, we extend our robust approach to providing each neuron type with an informative name and unique identifier by mapping all encountered synonyms and homonyms.
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Akgül G, McBain CJ. Diverse roles for ionotropic glutamate receptors on inhibitory interneurons in developing and adult brain. J Physiol 2016; 594:5471-90. [PMID: 26918438 DOI: 10.1113/jp271764] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 02/10/2016] [Indexed: 01/07/2023] Open
Abstract
Glutamate receptor-mediated recruitment of GABAergic inhibitory interneurons is a critical determinant of network processing. Early studies observed that many, but not all, interneuron glutamatergic synapses contain AMPA receptors that are GluA2-subunit lacking and Ca(2+) permeable, making them distinct from AMPA receptors at most principal cell synapses. Subsequent studies demonstrated considerable alignment of synaptic AMPA and NMDA receptor subunit composition within specific subtypes of interneurons, suggesting that both receptor expression profiles are developmentally and functionally linked. Indeed glutamate receptor expression profiles are largely predicted by the embryonic origins of cortical interneurons within the medial and caudal ganglionic eminences of the developing telencephalon. Distinct complements of AMPA and NMDA receptors within different interneuron subpopulations contribute to the differential recruitment of functionally divergent interneuron subtypes by common afferent inputs for appropriate feed-forward and feedback inhibitory drive and network entrainment. In contrast, the lesser-studied kainate receptors, which are often present at both pre- and postsynaptic sites, appear to follow an independent developmental expression profile. Loss of specific ionotropic glutamate receptor (iGluR) subunits during interneuron development has dramatic consequences for both cellular and network function, often precipitating circuit inhibition-excitation imbalances and in some cases lethality. Here we briefly review recent findings highlighting the roles of iGluRs in interneuron development.
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Affiliation(s)
- Gülcan Akgül
- Porter Neuroscience Research Centre, Rm3C903, Lincoln Drive, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA
| | - Chris J McBain
- Porter Neuroscience Research Centre, Rm3C903, Lincoln Drive, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA.
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Booker SA, Althof D, Gross A, Loreth D, Müller J, Unger A, Fakler B, Varro A, Watanabe M, Gassmann M, Bettler B, Shigemoto R, Vida I, Kulik Á. KCTD12 Auxiliary Proteins Modulate Kinetics of GABABReceptor-Mediated Inhibition in Cholecystokinin-Containing Interneurons. Cereb Cortex 2016; 27:2318-2334. [DOI: 10.1093/cercor/bhw090] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Basu J, Zaremba JD, Cheung SK, Hitti FL, Zemelman BV, Losonczy A, Siegelbaum SA. Gating of hippocampal activity, plasticity, and memory by entorhinal cortex long-range inhibition. Science 2016; 351:aaa5694. [PMID: 26744409 PMCID: PMC4920085 DOI: 10.1126/science.aaa5694] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The cortico-hippocampal circuit is critical for storage of associational memories. Most studies have focused on the role in memory storage of the excitatory projections from entorhinal cortex to hippocampus. However, entorhinal cortex also sends inhibitory projections, whose role in memory storage and cortico-hippocampal activity remains largely unexplored. We found that these long-range inhibitory projections enhance the specificity of contextual and object memory encoding. At the circuit level, these γ-aminobutyric acid (GABA)-releasing projections target hippocampal inhibitory neurons and thus act as a disinhibitory gate that transiently promotes the excitation of hippocampal CA1 pyramidal neurons by suppressing feedforward inhibition. This enhances the ability of CA1 pyramidal neurons to fire synaptically evoked dendritic spikes and to generate a temporally precise form of heterosynaptic plasticity. Long-range inhibition from entorhinal cortex may thus increase the precision of hippocampal-based long-term memory associations by assessing the salience of mnemonormation to the immediate sensory input.
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Affiliation(s)
- Jayeeta Basu
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA.
| | - Jeffrey D Zaremba
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA
| | - Stephanie K Cheung
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA
| | - Frederick L Hitti
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA
| | | | - Attila Losonczy
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA
| | - Steven A Siegelbaum
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA.
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Abstract
Recent research into local-circuit GABAergic inhibitory interneurons of the mammalian central nervous system has provided unprecedented insight into the mechanics of neuronal circuitry and its dysfunction. Inhibitory interneurons consist of a broad array of anatomically and neurochemically diverse cell types, and this suggests that each occupies an equally diverse functional role. Although neurogliaform cells were observed by Cajal over a century ago, our understanding of the functional role of this class of interneurons is in its infancy. However, it is rapidly becoming clear that this cell type operates under a distinct repertoire of rules to provide novel forms of inhibitory control of numerous afferent pathways.
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Multiple Forms of Endocannabinoid and Endovanilloid Signaling Regulate the Tonic Control of GABA Release. J Neurosci 2015; 35:10039-57. [PMID: 26157003 DOI: 10.1523/jneurosci.4112-14.2015] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
UNLABELLED Persistent CB1 cannabinoid receptor activity limits neurotransmitter release at various synapses throughout the brain. However, it is not fully understood how constitutively active CB1 receptors, tonic endocannabinoid signaling, and its regulation by multiple serine hydrolases contribute to the synapse-specific calibration of neurotransmitter release probability. To address this question at perisomatic and dendritic GABAergic synapses in the mouse hippocampus, we used a combination of paired whole-cell patch-clamp recording, liquid chromatography/tandem mass spectrometry, stochastic optical reconstruction microscopy super-resolution imaging, and immunogold electron microscopy. Unexpectedly, application of the CB1 antagonist and inverse agonist AM251 [N-1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-1-piperidinyl-1H-pyrazole-3-carboxamide], but not the neutral antagonist NESS0327 [8-chloro-1-(2,4-dichlorophenyl)-N-piperidin-1-yl-5,6-dihydro-4H-benzo[2,3]cyclohepta[2,4-b]pyrazole-3-carboxamine], significantly increased synaptic transmission between CB1-positive perisomatic interneurons and CA1 pyramidal neurons. JZL184 (4-nitrophenyl 4-[bis(1,3-benzodioxol-5-yl)(hydroxy)methyl]piperidine-1-carboxylate), a selective inhibitor of monoacylglycerol lipase (MGL), the presynaptic degrading enzyme of the endocannabinoid 2-arachidonoylglycerol (2-AG), elicited a robust increase in 2-AG levels and concomitantly decreased GABAergic transmission. In contrast, inhibition of fatty acid amide hydrolase (FAAH) by PF3845 (N-pyridin-3-yl-4-[[3-[5-(trifluoromethyl)pyridin-2-yl]oxyphenyl]methyl]piperidine-1-carboxamide) elevated endocannabinoid/endovanilloid anandamide levels but did not change GABAergic synaptic activity. However, FAAH inhibitors attenuated tonic 2-AG increase and also decreased its synaptic effects. This antagonistic interaction required the activation of the transient receptor potential vanilloid receptor TRPV1, which was concentrated on postsynaptic intracellular membrane cisternae at perisomatic GABAergic symmetrical synapses. Interestingly, neither AM251, JZL184, nor PF3845 affected CB1-positive dendritic interneuron synapses. Together, these findings are consistent with the possibility that constitutively active CB1 receptors substantially influence perisomatic GABA release probability and indicate that the synaptic effects of tonic 2-AG release are tightly controlled by presynaptic MGL activity and also by postsynaptic endovanilloid signaling and FAAH activity. SIGNIFICANCE STATEMENT Tonic cannabinoid signaling plays a critical role in the regulation of synaptic transmission. However, the mechanistic details of how persistent CB1 cannabinoid receptor activity inhibits neurotransmitter release have remained elusive. Therefore, electrophysiological recordings, lipid measurements, and super-resolution imaging were combined to elucidate those signaling molecules and mechanisms that underlie tonic cannabinoid signaling. The findings indicate that constitutive CB1 activity has pivotal function in the tonic control of hippocampal GABA release. Moreover, the endocannabinoid 2-arachidonoylglycerol (2-AG) is continuously generated postsynaptically, but its synaptic effect is regulated strictly by presynaptic monoacylglycerol lipase activity. Finally, anandamide signaling antagonizes tonic 2-AG signaling via activation of postsynaptic transient receptor potential vanilloid TRPV1 receptors. This unexpected mechanistic diversity may be necessary to fine-tune GABA release probability under various physiological and pathophysiological conditions.
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Galván EJ, Pérez-Rosello T, Gómez-Lira G, Lara E, Gutiérrez R, Barrionuevo G. Synapse-specific compartmentalization of signaling cascades for LTP induction in CA3 interneurons. Neuroscience 2015; 290:332-45. [PMID: 25637803 DOI: 10.1016/j.neuroscience.2015.01.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/15/2015] [Accepted: 01/15/2015] [Indexed: 11/28/2022]
Abstract
Inhibitory interneurons with somata in strata radiatum and lacunosum-molecular (SR/L-M) of hippocampal area CA3 receive excitatory input from pyramidal cells via the recurrent collaterals (RCs), and the dentate gyrus granule cells via the mossy fibers (MFs). Here we demonstrate that Hebbian long-term potentiation (LTP) at RC synapses on SR/L-M interneurons requires the concomitant activation of calcium-impermeable AMPARs (CI-AMPARs) and N-methyl-d-aspartate receptors (NMDARs). RC LTP was prevented by voltage clamping the postsynaptic cell during high-frequency stimulation (HFS; 3 trains of 100 pulses delivered at 100 Hz every 10s), with intracellular injections of the Ca(2+) chelator BAPTA (20mM), and with the NMDAR antagonist D-AP5. In separate experiments, RC and MF inputs converging onto the same interneuron were sequentially activated. We found that RC LTP induction was blocked by inhibitors of the calcium/calmodulin-dependent protein kinase II (CaMKII; KN-62, 10 μM or KN-93, 10 μM) but MF LTP was CaMKII independent. Conversely, the application of the protein kinase A (PKA) activators forskolin/IBMX (50 μM/25 μM) potentiated MF EPSPs but not RC EPSPs. Together these data indicate that the aspiny dendrites of SR/L-M interneurons compartmentalize synapse-specific Ca(2+) signaling required for LTP induction at RC and MF synapses. We also show that the two signal transduction cascades converge to activate a common effector, protein kinase C (PKC). Specifically, LTP at RC and MF synapses on the same SR/LM interneuron was blocked by postsynaptic injections of chelerythrine (10 μM). These data indicate that both forms of LTP share a common mechanism involving PKC-dependent signaling modulation.
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Affiliation(s)
- E J Galván
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, Mexico.
| | - T Pérez-Rosello
- Department of Physiology, Northwestern University, Chicago, IL, USA
| | - G Gómez-Lira
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, Mexico
| | - E Lara
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, Mexico
| | - R Gutiérrez
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, Mexico
| | - G Barrionuevo
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
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Cell-specific STORM super-resolution imaging reveals nanoscale organization of cannabinoid signaling. Nat Neurosci 2014; 18:75-86. [PMID: 25485758 PMCID: PMC4281300 DOI: 10.1038/nn.3892] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 10/31/2014] [Indexed: 02/07/2023]
Abstract
A major challenge in neuroscience is to determine the nanoscale position and quantity of signaling molecules in a cell type- and subcellular compartment-specific manner. We developed a new approach to this problem by combining cell-specific physiological and anatomical characterization with super-resolution imaging and studied the molecular and structural parameters shaping the physiological properties of synaptic endocannabinoid signaling in the mouse hippocampus. We found that axon terminals of perisomatically projecting GABAergic interneurons possessed increased CB1 receptor number, active-zone complexity and receptor/effector ratio compared with dendritically projecting interneurons, consistent with higher efficiency of cannabinoid signaling at somatic versus dendritic synapses. Furthermore, chronic Δ(9)-tetrahydrocannabinol administration, which reduces cannabinoid efficacy on GABA release, evoked marked CB1 downregulation in a dose-dependent manner. Full receptor recovery required several weeks after the cessation of Δ(9)-tetrahydrocannabinol treatment. These findings indicate that cell type-specific nanoscale analysis of endogenous protein distribution is possible in brain circuits and identify previously unknown molecular properties controlling endocannabinoid signaling and cannabis-induced cognitive dysfunction.
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Optogenetic activation of cajal-retzius cells reveals their glutamatergic output and a novel feedforward circuit in the developing mouse hippocampus. J Neurosci 2014; 34:13018-32. [PMID: 25253849 DOI: 10.1523/jneurosci.1407-14.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cajal-Retzius cells orchestrate the development of cortical circuits by secreting the glycoprotein reelin. However, their computational functions are still unknown. In fact, the nature of their postsynaptic targets, major neurotransmitter released, as well as the class of postsynaptic receptors activated by their firing remain unclear. Here, we have addressed these questions by activating Cajal-Retzius cells optogenetically in mouse hippocampal slices. Light delivered to stratum lacunosum-moleculare triggered EPSCs both on local interneurons and on pyramidal cells. Responses recorded under voltage-clamp conditions had identical short latencies and similar amplitudes, but were kinetically different (i.e., faster in interneurons vs pyramidal cells). In both cases, responses were blocked by TTX, indicating that they were generated by action potential-dependent release. Responses in interneurons were rescued by the addition of 4-AP to TTX, and decreased when presynaptic firing in Cajal-Retzius cells was reduced by the chemokine CXCL12, indicating the existence of a direct Cajal-Retzius cell-interneuron monosynaptic connection. Although the combined application of 4-AP and TTX did not rescue responses in pyramidal cells, neither were they affected by the GABAA receptor blocker gabazine, which would be expected if they were polysynaptic. Both connections showed physiological and pharmacological properties indicating the involvement of AMPA- and NMDA-type glutamate receptors. The connectivity from presynaptic Cajal-Retzius cells to interneurons was strong enough to generate long-latency feedforward GABAergic input onto pyramidal cells. We propose that this newly defined Cajal-Retzius cell-dependent microcircuit may regulate synaptic plasticity and dendritic development in stratum lacunosum-moleculare, thus impacting the integrative properties of the developing hippocampus.
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Booker SA, Song J, Vida I. Whole-cell patch-clamp recordings from morphologically- and neurochemically-identified hippocampal interneurons. J Vis Exp 2014:e51706. [PMID: 25350149 DOI: 10.3791/51706] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
GABAergic inhibitory interneurons play a central role within neuronal circuits of the brain. Interneurons comprise a small subset of the neuronal population (10-20%), but show a high level of physiological, morphological, and neurochemical heterogeneity, reflecting their diverse functions. Therefore, investigation of interneurons provides important insights into the organization principles and function of neuronal circuits. This, however, requires an integrated physiological and neuroanatomical approach for the selection and identification of individual interneuron types. Whole-cell patch-clamp recording from acute brain slices of transgenic animals, expressing fluorescent proteins under the promoters of interneuron-specific markers, provides an efficient method to target and electrophysiologically characterize intrinsic and synaptic properties of specific interneuron types. Combined with intracellular dye labeling, this approach can be extended with post-hoc morphological and immunocytochemical analysis, enabling systematic identification of recorded neurons. These methods can be tailored to suit a broad range of scientific questions regarding functional properties of diverse types of cortical neurons.
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Affiliation(s)
- Sam A Booker
- Institute of Integrative Neuroanatomy, NeuroCure Cluster of Excellence, Charité Universitätmedizin
| | - Jie Song
- Institute of Integrative Neuroanatomy, NeuroCure Cluster of Excellence, Charité Universitätmedizin
| | - Imre Vida
- Institute of Integrative Neuroanatomy, NeuroCure Cluster of Excellence, Charité Universitätmedizin;
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Hosp JA, Strüber M, Yanagawa Y, Obata K, Vida I, Jonas P, Bartos M. Morpho-physiological criteria divide dentate gyrus interneurons into classes. Hippocampus 2014; 24:189-203. [PMID: 24108530 PMCID: PMC4165310 DOI: 10.1002/hipo.22214] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 09/13/2013] [Accepted: 10/02/2013] [Indexed: 12/14/2022]
Abstract
GABAergic inhibitory interneurons control fundamental aspects of neuronal network function. Their functional roles are assumed to be defined by the identity of their input synapses, the architecture of their dendritic tree, the passive and active membrane properties and finally the nature of their postsynaptic targets. Indeed, interneurons display a high degree of morphological and physiological heterogeneity. However, whether their morphological and physiological characteristics are correlated and whether interneuron diversity can be described by a continuum of GABAergic cell types or by distinct classes has remained unclear. Here we perform a detailed morphological and physiological characterization of GABAergic cells in the dentate gyrus, the input region of the hippocampus. To achieve an unbiased and efficient sampling and classification we used knock-in mice expressing the enhanced green fluorescent protein (eGFP) in glutamate decarboxylase 67 (GAD67)-positive neurons and performed cluster analysis. We identified five interneuron classes, each of them characterized by a distinct set of anatomical and physiological parameters. Cross-correlation analysis further revealed a direct relation between morphological and physiological properties indicating that dentate gyrus interneurons fall into functionally distinct classes which may differentially control neuronal network activity.
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Affiliation(s)
- Jonas A Hosp
- Institute for Physiology I, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 779104, Freiburg, Germany
- Clinical Neurorehabilitation, Department of Neurology, University of Zurich8091, Zurich, Switzerland
| | - Michael Strüber
- Institute for Physiology I, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 779104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM) and Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg79104, Freiburg, Germany
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University3-39-22, Showa-Machi, Japan
| | - Kunihiko Obata
- Laboratory of Neurochemistry, National Institute for Physiological Sciences444-8585, Myodaiji, Okazaki, Japan
| | - Imre Vida
- Institute for Integrative Neuroanatomy, Charité Berlin, Phillipstraße 1210115, Berlin, Germany
| | - Peter Jonas
- IST Austria (Institute of Science and Technology Austria), Am Campus 13400, Klosterneuburg, Austria
| | - Marlene Bartos
- Institute for Physiology I, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 779104, Freiburg, Germany
- *Correspondence to: Prof. Dr. M. Bartos, Institut für Physiologie I, Universität Freiburg, Hermann-Herder Strasse 7, D-79108 Freiburg, Germany. E-mail:
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Abstract
Little is known about how neuron firing recorded in vivo retrogradely influences synaptic strength. We injected the firing of a rat hippocampal neurogliaform cell (NGFC), a widely expressed GABAergic neuron type, detected in vivo during theta rhythm, into NGFCs of rat or neuronal nitric oxide synthase (nNOS)-Cre-tdTomato mouse recorded in vitro. We found that the "in vivo firing pattern" produced a transient firing-induced suppression of synaptic inhibition (FSI) evoked by a presynaptic NGFC. Imaging experiments demonstrate that FSI was associated with action potential backpropagation (bAP) and a supralinear increase in dendritic Ca(2+). The application of the L-type Ca(2+) channel antagonist nimodipine blocked FSI. Further pharmacological experiments, such as the application of a nitric oxide-sensitive guanylyl cyclase (NO-sGC) receptor antagonist, a NOS inhibitor, and NO donors, suggested that NO released from postsynaptic cells mediated FSI and likely activated presynaptic receptors to inhibit GABA release. The in vivo firing pattern modulated the size of unitary EPSPs impinging on NGFCs through FSI and not via a direct effect on excitatory synaptic transmission. Our data demonstrate: (1) retrograde signaling initiated by in vivo firing pattern, (2) interneuron bAPs detected with fast temporal resolution, and (3) a novel role for NO expressed by specific interneuron types.
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Huang CC, Lin YS, Lee CC, Hsu KS. Cell type-specific expression of Eps8 in the mouse hippocampus. BMC Neurosci 2014; 15:26. [PMID: 24533597 PMCID: PMC3937003 DOI: 10.1186/1471-2202-15-26] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 02/13/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Epidermal growth factor receptor substrate 8 (Eps8) is a multifunctional protein that regulates actin cytoskeleton dynamics and architecture through its barbed-end capping and bundling activities. In cultured hippocampal neurons, Eps8 is enriched at dendritic spine heads and is required for spine morphogenesis; however, the detailed expression pattern of Eps8 in the hippocampus has not yet been explored. RESULTS Here, we demonstrate that endogenous Eps8 protein is restrictively expressed in neurons (NeuN-positive), but not in glial cells (glial fibrillary acidic protein-positive) in area CA1 of the mouse hippocampus. Surprisingly, Eps8 immunoreactivity is rarely found in pyramidal cell somata, but is expressed predominantly in the somata and dendrites of 67 kDa isoform of glutamic acid decarboxylase-expressing GABAergic interneurons in the stratum radiatum and at the border of stratum radiatum and lacunosum-moleculare of area CA1. On the basis of co-localizing markers, we found that Eps8 is not present in perisomatic inhibitory parvalbumin-expressing cells or calretinin-expressing interneurons. However, Eps8 is richly expressed in calbindin-expressing interneurons. Furthermore, Eps8 is also present in cholecystokinin-expressing interneurons, but not in somatostatin-expressing interneurons in area CA1 stratum pyramidale and stratum radiatum. CONCLUSIONS These results reveal a previously unknown cell type-specific expression pattern of endogenous Eps8 protein in the mouse hippocampus and speculate that the role of Eps8 in controlling and orchestrating neuronal morphogenesis and structural plasticity might be more prominent in interneurons than in pyramidal cells of the hippocampus.
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Affiliation(s)
| | | | | | - Kuei-Sen Hsu
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan.
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CA1 pyramidal cell theta-burst firing triggers endocannabinoid-mediated long-term depression at both somatic and dendritic inhibitory synapses. J Neurosci 2013; 33:13743-57. [PMID: 23966696 DOI: 10.1523/jneurosci.0817-13.2013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Endocannabinoids (eCBs) are retrograde lipid messengers that, by targeting presynaptic type 1 cannabinoid receptors (CB1Rs), mediate short- and long-term synaptic depression of neurotransmitter release throughout the brain. Short-term depression is typically triggered by postsynaptic, depolarization-induced calcium rises, whereas long-term depression is induced by synaptic activation of Gq/11 protein-coupled receptors. Here we report that a physiologically relevant pattern of postsynaptic activity, in the form of theta-burst firing (TBF) of hippocampal CA1 pyramidal neurons, can trigger long-term depression of inhibitory transmission (iLTD) in rat hippocampal slices. Paired recordings between CA1 interneurons and pyramidal cells, followed by post hoc morphological reconstructions of the interneurons' axon, revealed that somatic and dendritic inhibitory synaptic inputs equally expressed TBF-induced iLTD. Simultaneous recordings from neighboring pyramidal cells demonstrated that eCB signaling triggered by TBF was highly restricted to only a single, active cell. Furthermore, pairing submaximal endogenous activation of metabotropic glutamate or muscarinic acetylcholine receptors with submaximal TBF unmasked associative iLTD. Although CB1Rs are also expressed at Schaffer-collateral excitatory terminals, long-term plasticity under various recording conditions was spared at these synapses. Consistent with this observation, TBF also shifted the balance of excitation and inhibition in favor of excitatory throughput, thereby altering information flow through the CA1 circuit. Given the near ubiquity of burst-firing activity patterns and CB1R expression in the brain, the properties described here may be a general means by which neurons fine tune the strength of their inputs in a cell-wide and cell-specific manner.
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Li Q, Fleming RL, Acheson SK, Madison RD, Moore SD, Risher ML, Wilson WA, Swartzwelder HS. Long-term modulation of A-type K(+) conductances in hippocampal CA1 interneurons in rats after chronic intermittent ethanol exposure during adolescence or adulthood. Alcohol Clin Exp Res 2013; 37:2074-85. [PMID: 23889304 DOI: 10.1111/acer.12204] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 04/29/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND Chronic alcohol use, especially exposure to alcohol during adolescence or young adulthood, is closely associated with cognitive deficits that may persist into adulthood. Therefore, it is essential to identify possible neuronal mechanisms underlying the observed deficits in learning and memory. Hippocampal interneurons play a pivotal role in regulating hippocampus-dependent learning and memory by exerting strong inhibition on excitatory pyramidal cells. The function of these interneurons is regulated not only by synaptic inputs from other types of neurons but is also precisely governed by their own intrinsic membrane ionic conductances. The voltage-gated A-type potassium current (IA ) regulates the intrinsic membrane properties of neurons, and disruption of IA is responsible for many neuropathological processes including learning and memory deficits. Thus, it represents a previously unexplored cellular mechanism whereby chronic ethanol (EtOH) may alter hippocampal memory-related functioning. METHODS Using whole-cell electrophysiological recording methods, we investigated the enduring effects of chronic intermittent ethanol (CIE) exposure during adolescence or adulthood on IA in rat CA1 interneurons. RESULTS We found that the mean peak amplitude of IA was significantly reduced after CIE in either adolescence or adulthood, but IA density was attenuated after CIE in adolescence but not after CIE in adulthood. In addition, the voltage-dependent steady-state activation and inactivation of IA were altered in interneurons after CIE. CONCLUSIONS These findings suggest that CIE can cause long-term changes in IA channels in interneurons and thus may alter their inhibitory influences on memory-related local hippocampal circuits, which could be, in turn, responsible for learning and memory impairments observed after chronic EtOH exposure.
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Affiliation(s)
- Qiang Li
- Durham VA Medical Center , Duke University Medical Center, Durham, North Carolina; Department of Psychiatry , Duke University Medical Center, Durham, North Carolina; Department of Neurosugery , Duke University Medical Center, Durham, North Carolina
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Bezaire MJ, Soltesz I. Quantitative assessment of CA1 local circuits: knowledge base for interneuron-pyramidal cell connectivity. Hippocampus 2013; 23:751-85. [PMID: 23674373 DOI: 10.1002/hipo.22141] [Citation(s) in RCA: 224] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 04/25/2013] [Accepted: 04/26/2013] [Indexed: 12/17/2022]
Abstract
In this work, through a detailed literature review, data-mining, and extensive calculations, we provide a current, quantitative estimate of the cellular and synaptic constituents of the CA1 region of the rat hippocampus. Beyond estimating the cell numbers of GABAergic interneuron types, we calculate their convergence onto CA1 pyramidal cells and compare it with the known input synapses on CA1 pyramidal cells. The convergence calculation and comparison are also made for excitatory inputs to CA1 pyramidal cells. In addition, we provide a summary of the excitatory and inhibitory convergence onto interneurons. The quantitative knowledge base assembled and synthesized here forms the basis for data-driven, large-scale computational modeling efforts. Additionally, this work highlights specific instances where the available data are incomplete, which should inspire targeted experimental projects toward a more complete quantification of the CA1 neurons and their connectivity.
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Affiliation(s)
- Marianne J Bezaire
- Department of Anatomy and Neurobiology, University of California, Irvine, California
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Hanson JE, Weber M, Meilandt WJ, Wu T, Luu T, Deng L, Shamloo M, Sheng M, Scearce-Levie K, Zhou Q. GluN2B antagonism affects interneurons and leads to immediate and persistent changes in synaptic plasticity, oscillations, and behavior. Neuropsychopharmacology 2013; 38:1221-33. [PMID: 23340518 PMCID: PMC3656364 DOI: 10.1038/npp.2013.19] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Although antagonists to GluN2B-containing N-methyl-D-aspartate receptors (NMDARs) have been widely considered to be neuroprotective under certain pathological conditions, their immediate and lasting impacts on synaptic, circuit, and cognitive functions are poorly understood. In hippocampal slices, we found that the GluN2B-selective antagonist Ro25-6981 (Ro25) reduced synaptic NMDAR responses and consequently neuronal output in a subpopulation of GABAergic interneurons, but not pyramidal neurons. Consistent with these effects, Ro25 reduced GABAergic responses in pyramidal neurons and hence could affect circuit functions by altering the excitation/inhibition balance in the brain. In slices from Ts65Dn mice, a Down syndrome model with excess inhibition and cognitive impairment, acutely applied Ro25-rescued long-term potentiation (LTP) and gamma oscillation deficits, whereas prolonged dosing induced persistent rescue of LTP. In contrast, Ro25 did not impact LTP in wild-type (wt) mice but reduced gamma oscillations both acutely and following prolonged treatment. Although acute Ro25 treatment impaired memory performance in wt mice, memory deficits in Ts65Dn mice were unchanged. Thus, GluN2B-NMDARs contribute to the excitation/inhibition balance via impacts on interneurons, and blocking GluN2B-NMDARs can alter functions that depend on this balance, including synaptic plasticity, gamma oscillations, and memory. That prolonged GluN2B antagonism leads to persistent changes in synaptic and circuit functions, and that the influence of GluN2B antagonism differs between wt and disease model mice, provide critical insight into the therapeutic potential and possible liabilities of GluN2B antagonists.
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Affiliation(s)
- Jesse E Hanson
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | - Martin Weber
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | - William J Meilandt
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | - Tiffany Wu
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | - Tom Luu
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | - Lunbin Deng
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | - Mehrdad Shamloo
- Stanford Behavioral and Functional Neuroscience Laboratory, Stanford, CA, USA
| | - Morgan Sheng
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | | | - Qiang Zhou
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA,Department of Neuroscience, Genentech, Inc., 1 DNA Way, MS 230B, South San Francisco, CA 94080, USA, Tel: +1 650 467 7750, Fax: +1 650 225 4000, E-mail:
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Synaptic kainate receptors in CA1 interneurons gate the threshold of theta-frequency-induced long-term potentiation. J Neurosci 2013; 32:18215-26. [PMID: 23238735 DOI: 10.1523/jneurosci.2327-12.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Theta oscillations (4-12 Hz) in neuronal networks are known to predispose the synapses involved to plastic changes and may underlie their association with learning behaviors. The lowered threshold for synaptic plasticity during theta oscillations is thought to be due to decreased GABAergic inhibition. Interneuronal kainate receptors (KARs) regulate GABAergic transmission and are implicated in theta activity; however, the physiological significance of this regulation is unknown. In rat hippocampus, we show that during theta activity, there is excitatory postsynaptic drive to CA1 interneurons mediated by KARs. This promotes feedforward inhibition of pyramidal neurons, raising the threshold for induction of theta-burst long-term potentiation. These results identify a novel mechanism whereby the activation of postsynaptic KARs in CA1 interneurons gate changes in synaptic efficacy to a physiologically relevant patterned stimulation.
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50
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Tricoire L, Vitalis T. Neuronal nitric oxide synthase expressing neurons: a journey from birth to neuronal circuits. Front Neural Circuits 2012; 6:82. [PMID: 23227003 PMCID: PMC3514612 DOI: 10.3389/fncir.2012.00082] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 10/25/2012] [Indexed: 12/17/2022] Open
Abstract
Nitric oxide (NO) is an important signaling molecule crucial for many physiological processes such as synaptic plasticity, vasomotricity, and inflammation. Neuronal nitric oxide synthase (nNOS) is the enzyme responsible for the synthesis of NO by neurons. In the juvenile and mature hippocampus and neocortex nNOS is primarily expressed by subpopulations of GABAergic interneurons. Over the past two decades, many advances have been achieved in the characterization of neocortical and hippocampal nNOS expressing neurons. In this review, we summarize past and present studies that have characterized the electrophysiological, morphological, molecular, and synaptic properties of these neurons. We also discuss recent studies that have shed light on the developmental origins and specification of GABAergic neurons with specific attention to neocortical and hippocampal nNOS expressing GABAergic neurons. Finally, we summarize the roles of NO and nNOS-expressing inhibitory neurons.
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Affiliation(s)
- Ludovic Tricoire
- CNRS-UMR 7102, Laboratoire de Neurobiologie des Processus Adaptatifs, Université Pierre et Marie Curie Paris, France
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