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Reich N, Hölscher C. Cholecystokinin (CCK): a neuromodulator with therapeutic potential in Alzheimer's and Parkinson's disease. Front Neuroendocrinol 2024; 73:101122. [PMID: 38346453 DOI: 10.1016/j.yfrne.2024.101122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/04/2024] [Accepted: 01/25/2024] [Indexed: 02/16/2024]
Abstract
Cholecystokinin (CCK) is a neuropeptide modulating digestion, glucose levels, neurotransmitters and memory. Recent studies suggest that CCK exhibits neuroprotective effects in Alzheimer's disease (AD) and Parkinson's disease (PD). Thus, we review the physiological function and therapeutic potential of CCK. The neuropeptide facilitates hippocampal glutamate release and gates GABAergic basket cell activity, which improves declarative memory acquisition, but inhibits consolidation. Cortical CCK alters recognition memory and enhances audio-visual processing. By stimulating CCK-1 receptors (CCK-1Rs), sulphated CCK-8 elicits dopamine release in the substantia nigra and striatum. In the mesolimbic pathway, CCK release is triggered by dopamine and terminates reward responses via CCK-2Rs. Importantly, activation of hippocampal and nigral CCK-2Rs is neuroprotective by evoking AMPK activation, expression of mitochondrial fusion modulators and autophagy. Other benefits include vagus nerve/CCK-1R-mediated expression of brain-derived neurotrophic factor, intestinal protection and suppression of inflammation. We also discuss caveats and the therapeutic combination of CCK with other peptide hormones.
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Affiliation(s)
- Niklas Reich
- The ALBORADA Drug Discovery Institute, University of Cambridge, Island Research Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0AH, UK; Faculty of Health and Medicine, Biomedical & Life Sciences Division, Lancaster University, Lancaster LA1 4YQ, UK.
| | - Christian Hölscher
- Second associated Hospital, Neurology Department, Shanxi Medical University, Taiyuan, Shanxi, China; Henan Academy of Innovations in Medical Science, Neurodegeneration research group, Xinzhen, Henan province, China
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Nguyen R, Sivakumaran S, Lambe EK, Kim JC. Ventral hippocampal cholecystokinin interneurons gate contextual reward memory. iScience 2024; 27:108824. [PMID: 38303709 PMCID: PMC10831933 DOI: 10.1016/j.isci.2024.108824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 11/06/2023] [Accepted: 01/03/2024] [Indexed: 02/03/2024] Open
Abstract
Associating contexts with rewards depends on hippocampal circuits, with local inhibitory interneurons positioned to play an important role in shaping activity. Here, we demonstrate that the encoding of context-reward memory requires a ventral hippocampus (vHPC) to nucleus accumbens (NAc) circuit that is gated by cholecystokinin (CCK) interneurons. In a sucrose conditioned place preference (CPP) task, optogenetically inhibiting vHPC-NAc terminals impaired the acquisition of place preference. Transsynaptic rabies tracing revealed vHPC-NAc neurons were monosynaptically innervated by CCK interneurons. Using intersectional genetic targeting of CCK interneurons, ex vivo optogenetic activation of CCK interneurons increased GABAergic transmission onto vHPC-NAc neurons, while in vivo optogenetic inhibition of CCK interneurons increased cFos in these projection neurons. Notably, CCK interneuron inhibition during sucrose CPP learning increased time spent in the sucrose-associated location, suggesting enhanced place-reward memory. Our findings reveal a previously unknown hippocampal microcircuit crucial for modulating the strength of contextual reward learning.
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Affiliation(s)
- Robin Nguyen
- Department of Psychology, University of Toronto, Toronto, ON, Canada
| | | | - Evelyn K. Lambe
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Department of OBGYN, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Jun Chul Kim
- Department of Psychology, University of Toronto, Toronto, ON, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
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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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Nagy-Pál P, Veres JM, Fekete Z, Karlócai MR, Weisz F, Barabás B, Reéb Z, Hájos N. Structural Organization of Perisomatic Inhibition in the Mouse Medial Prefrontal Cortex. J Neurosci 2023; 43:6972-6987. [PMID: 37640552 PMCID: PMC10586541 DOI: 10.1523/jneurosci.0432-23.2023] [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: 03/09/2023] [Revised: 08/11/2023] [Accepted: 08/18/2023] [Indexed: 08/31/2023] Open
Abstract
Perisomatic inhibition profoundly controls neural function. However, the structural organization of inhibitory circuits giving rise to the perisomatic inhibition in the higher-order cortices is not completely known. Here, we performed a comprehensive analysis of those GABAergic cells in the medial prefrontal cortex (mPFC) that provide inputs onto the somata and proximal dendrites of pyramidal neurons. Our results show that most GABAergic axonal varicosities contacting the perisomatic region of superficial (layer 2/3) and deep (layer 5) pyramidal cells express parvalbumin (PV) or cannabinoid receptor type 1 (CB1). Further, we found that the ratio of PV/CB1 GABAergic inputs is larger on the somatic membrane surface of pyramidal tract neurons in comparison with those projecting to the contralateral hemisphere. Our morphologic analysis of in vitro labeled PV+ basket cells (PVBC) and CCK/CB1+ basket cells (CCKBC) revealed differences in many features. PVBC dendrites and axons arborized preferentially within the layer where their soma was located. In contrast, the axons of CCKBCs expanded throughout layers, although their dendrites were found preferentially either in superficial or deep layers. Finally, using anterograde trans-synaptic tracing we observed that PVBCs are preferentially innervated by thalamic and basal amygdala afferents in layers 5a and 5b, respectively. Thus, our results suggest that PVBCs can control the local circuit operation in a layer-specific manner via their characteristic arborization, whereas CCKBCs rather provide cross-layer inhibition in the mPFC.SIGNIFICANCE STATEMENT Inhibitory cells in cortical circuits are crucial for the precise control of local network activity. Nevertheless, in higher-order cortical areas that are involved in cognitive functions like decision-making, working memory, and cognitive flexibility, the structural organization of inhibitory cell circuits is not completely understood. In this study we show that perisomatic inhibitory control of excitatory cells in the medial prefrontal cortex is performed by two types of basket cells endowed with different morphologic properties that provide inhibitory inputs with distinct layer specificity on cells projecting to disparate areas. Revealing this difference in innervation strategy of the two basket cell types is a key step toward understanding how they fulfill their distinct roles in cortical network operations.
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Affiliation(s)
- Petra Nagy-Pál
- Eötvös Loránd Research Network Institute of Experimental Medicine, 1083 Budapest, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University, 1085 Budapest, Hungary
| | - Judit M Veres
- Eötvös Loránd Research Network Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Zsuzsanna Fekete
- Eötvös Loránd Research Network Institute of Experimental Medicine, 1083 Budapest, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University, 1085 Budapest, Hungary
| | - Mária R Karlócai
- Eötvös Loránd Research Network Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Filippo Weisz
- Eötvös Loránd Research Network Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Bence Barabás
- Eötvös Loránd Research Network Institute of Experimental Medicine, 1083 Budapest, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University, 1085 Budapest, Hungary
| | - Zsófia Reéb
- Eötvös Loránd Research Network Institute of Experimental Medicine, 1083 Budapest, Hungary
- Doctoral School of Biology, Institute of Biology, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Norbert Hájos
- Eötvös Loránd Research Network Institute of Experimental Medicine, 1083 Budapest, Hungary
- Linda and Jack Gill Center for Molecular Bioscience, Indiana University Bloomington, Bloomington, Indiana 47405
- Program in Neuroscience, Department of Psychological and Brain Sciences, Indiana University Bloomington, Bloomington, Indiana 47405
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Tzilivaki A, Tukker JJ, Maier N, Poirazi P, Sammons RP, Schmitz D. Hippocampal GABAergic interneurons and memory. Neuron 2023; 111:3154-3175. [PMID: 37467748 PMCID: PMC10593603 DOI: 10.1016/j.neuron.2023.06.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/04/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023]
Abstract
One of the most captivating questions in neuroscience revolves around the brain's ability to efficiently and durably capture and store information. It must process continuous input from sensory organs while also encoding memories that can persist throughout a lifetime. What are the cellular-, subcellular-, and network-level mechanisms that underlie this remarkable capacity for long-term information storage? Furthermore, what contributions do distinct types of GABAergic interneurons make to this process? As the hippocampus plays a pivotal role in memory, our review focuses on three aspects: (1) delineation of hippocampal interneuron types and their connectivity, (2) interneuron plasticity, and (3) activity patterns of interneurons during memory-related rhythms, including the role of long-range interneurons and disinhibition. We explore how these three elements, together showcasing the remarkable diversity of inhibitory circuits, shape the processing of memories in the hippocampus.
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Affiliation(s)
- Alexandra Tzilivaki
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; Einstein Center for Neurosciences, Chariteplatz 1, 10117 Berlin, Germany; NeuroCure Cluster of Excellence, Chariteplatz 1, 10117 Berlin, Germany
| | - John J Tukker
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany
| | - Nikolaus Maier
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany
| | - Panayiota Poirazi
- Foundation for Research and Technology Hellas (FORTH), Institute of Molecular Biology and Biotechnology (IMBB), N. Plastira 100, Heraklion, Crete, Greece
| | - Rosanna P Sammons
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany
| | - Dietmar Schmitz
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; Einstein Center for Neurosciences, Chariteplatz 1, 10117 Berlin, Germany; NeuroCure Cluster of Excellence, Chariteplatz 1, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany; Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin, Philippstrasse. 13, 10115 Berlin, Germany; Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125 Berlin, Germany.
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Hernández-Frausto M, Bilash OM, Masurkar AV, Basu J. Local and long-range GABAergic circuits in hippocampal area CA1 and their link to Alzheimer's disease. Front Neural Circuits 2023; 17:1223891. [PMID: 37841892 PMCID: PMC10570439 DOI: 10.3389/fncir.2023.1223891] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 09/08/2023] [Indexed: 10/17/2023] Open
Abstract
GABAergic inhibitory neurons are the principal source of inhibition in the brain. Traditionally, their role in maintaining the balance of excitation-inhibition has been emphasized. Beyond homeostatic functions, recent circuit mapping and functional manipulation studies have revealed a wide range of specific roles that GABAergic circuits play in dynamically tilting excitation-inhibition coupling across spatio-temporal scales. These span from gating of compartment- and input-specific signaling, gain modulation, shaping input-output functions and synaptic plasticity, to generating signal-to-noise contrast, defining temporal windows for integration and rate codes, as well as organizing neural assemblies, and coordinating inter-regional synchrony. GABAergic circuits are thus instrumental in controlling single-neuron computations and behaviorally-linked network activity. The activity dependent modulation of sensory and mnemonic information processing by GABAergic circuits is pivotal for the formation and maintenance of episodic memories in the hippocampus. Here, we present an overview of the local and long-range GABAergic circuits that modulate the dynamics of excitation-inhibition and disinhibition in the main output area of the hippocampus CA1, which is crucial for episodic memory. Specifically, we link recent findings pertaining to GABAergic neuron molecular markers, electrophysiological properties, and synaptic wiring with their function at the circuit level. Lastly, given that area CA1 is particularly impaired during early stages of Alzheimer's disease, we emphasize how these GABAergic circuits may contribute to and be involved in the pathophysiology.
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Affiliation(s)
- Melissa Hernández-Frausto
- Neuroscience Institute, New York University Langone Health, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Olesia M. Bilash
- Neuroscience Institute, New York University Langone Health, New York, NY, United States
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
| | - Arjun V. Masurkar
- Neuroscience Institute, New York University Langone Health, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY, United States
- Center for Cognitive Neurology, Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Jayeeta Basu
- Neuroscience Institute, New York University Langone Health, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
- Center for Neural Science, New York University, New York, NY, United States
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7
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Bilash OM, Chavlis S, Johnson CD, Poirazi P, Basu J. Lateral entorhinal cortex inputs modulate hippocampal dendritic excitability by recruiting a local disinhibitory microcircuit. Cell Rep 2023; 42:111962. [PMID: 36640337 DOI: 10.1016/j.celrep.2022.111962] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 10/31/2022] [Accepted: 12/20/2022] [Indexed: 01/06/2023] Open
Abstract
The lateral entorhinal cortex (LEC) provides multisensory information to the hippocampus, directly to the distal dendrites of CA1 pyramidal neurons. LEC neurons perform important functions for episodic memory processing, coding for contextually salient elements of an environment or experience. However, we know little about the functional circuit interactions between the LEC and the hippocampus. We combine functional circuit mapping and computational modeling to examine how long-range glutamatergic LEC projections modulate compartment-specific excitation-inhibition dynamics in hippocampal area CA1. We demonstrate that glutamatergic LEC inputs can drive local dendritic spikes in CA1 pyramidal neurons, aided by the recruitment of a disinhibitory VIP interneuron microcircuit. Our circuit mapping and modeling further reveal that LEC inputs also recruit CCK interneurons that may act as strong suppressors of dendritic spikes. These results highlight a cortically driven GABAergic microcircuit mechanism that gates nonlinear dendritic computations, which may support compartment-specific coding of multisensory contextual features within the hippocampus.
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Affiliation(s)
- Olesia M Bilash
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University Grossman School of Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Spyridon Chavlis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology-Hellas (FORTH), Heraklion, Crete 70013, Greece
| | - Cara D Johnson
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University Grossman School of Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology-Hellas (FORTH), Heraklion, Crete 70013, Greece.
| | - Jayeeta Basu
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University Grossman School of Medicine, NYU Langone Health, New York, NY 10016, USA; Center for Neural Science, New York University, New York, NY 10003, USA; Department of Psychiatry, New York University Grossman School of Medicine, NYU Langone Health, New York, NY 10016, USA.
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8
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Balog M, Anderson A, Gurumurthy CB, Quadros RM, Korade Z, Mirnics K. Knock-in mouse models for studying somatostatin and cholecystokinin expressing cells. J Neurosci Methods 2022; 381:109704. [PMID: 36070817 DOI: 10.1016/j.jneumeth.2022.109704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/29/2022] [Accepted: 09/01/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Somatostatin (SST) and cholecystokinin (CCK) are peptide hormones that regulate the endocrine system, cell proliferation and neurotransmission. NEW METHOD We utilized the novel Easi-CRISPR system to generate two knock-in mouse strains with Cre recombinase in SST- and CCK-expressing cells and validated their utility in the developing and adult brain tissues. RESULTS The full nomenclature for the newly generated strains are C57BL/6-Sstem1(P2A-iCre-T2A-mCherry)Mirn and C57BL/6-Cckem1(iCre-T2A-mCherry-P2A)Mirn. For the Sst locus, a P2A-iCre-T2A-mCherry cassette was inserted immediately upstream of the stop codon (C terminus fusion). For the Cck locus, iCre-P2A-mCherry-T2A cassette was inserted at the start codon (N terminus fusion). Knock-in mice were generated using the Easi-CRISPR method. Developmental and adult SST and CCK expressions were preserved and showed an appropriate expression pattern in both models, with an active fluorescent tag in both animal lines. COMPARISON WITH EXISTING METHODS Knock-in mouse models to study cell types that produce these critically important molecules are limited to date. The knock-in mice we generated can be used as reporters to study development, physiology, or pathophysiology of SST and CCK expressing cells - without interference with native expression of SST and CCK. In addition, they can be used as Cre driver models to conditionally delete floxed genes in SST and CCK expressing cells across various tissues. CONCLUSIONS These two mouse models serve as valuable tools for in vitro and in vivo research studies related to SST and CCK biology across the lifespan and across different tissue types.
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Affiliation(s)
- Marta Balog
- Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center Omaha, NE, USA; Department of Medical Biology and Genetics, Faculty of Medicine, University of Osijek, Osijek, Croatia
| | - Allison Anderson
- Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center Omaha, NE, USA
| | - Channabasavaiah B Gurumurthy
- Mouse Genome Engineering Core Facility, University of Nebraska Medical Center, Omaha, NE, USA; Department of Pharmacology and Experimental Neuroscience, College of Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Rolen M Quadros
- Mouse Genome Engineering Core Facility, University of Nebraska Medical Center, Omaha, NE, USA
| | - Zeljka Korade
- Department of Pediatrics, University of Nebraska Medical Center Omaha, NE, USA; Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center Omaha, NE, USA; Child Health Research Institute, University of Nebraska Medical Center Omaha, NE, USA.
| | - Karoly Mirnics
- Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center Omaha, NE, USA; Department of Pharmacology and Experimental Neuroscience, College of Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Pediatrics, University of Nebraska Medical Center Omaha, NE, USA; Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center Omaha, NE, USA; Child Health Research Institute, University of Nebraska Medical Center Omaha, NE, USA.
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9
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The role of inhibitory circuits in hippocampal memory processing. Nat Rev Neurosci 2022; 23:476-492. [DOI: 10.1038/s41583-022-00599-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2022] [Indexed: 11/08/2022]
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10
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Miller DS, Wright KM. Neuronal Dystroglycan regulates postnatal development of CCK/cannabinoid receptor-1 interneurons. Neural Dev 2021; 16:4. [PMID: 34362433 PMCID: PMC8349015 DOI: 10.1186/s13064-021-00153-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/20/2021] [Indexed: 12/02/2022] Open
Abstract
Background The development of functional neural circuits requires the precise formation of synaptic connections between diverse neuronal populations. The molecular pathways that allow GABAergic interneuron subtypes in the mammalian brain to initially recognize their postsynaptic partners remain largely unknown. The transmembrane glycoprotein Dystroglycan is localized to inhibitory synapses in pyramidal neurons, where it is required for the proper function of CCK+ interneurons. However, the precise temporal requirement for Dystroglycan during inhibitory synapse development has not been examined. Methods In this study, we use NEXCre or Camk2aCreERT2 to conditionally delete Dystroglycan from newly-born or adult pyramidal neurons, respectively. We then analyze forebrain development from postnatal day 3 through adulthood, with a particular focus on CCK+ interneurons. Results In the absence of postsynaptic Dystroglycan in developing pyramidal neurons, presynaptic CCK+ interneurons fail to elaborate their axons and largely disappear from the cortex, hippocampus, amygdala, and olfactory bulb during the first two postnatal weeks. Other interneuron subtypes are unaffected, indicating that CCK+ interneurons are unique in their requirement for postsynaptic Dystroglycan. Dystroglycan does not appear to be required in adult pyramidal neurons to maintain CCK+ interneurons. Bax deletion did not rescue CCK+ interneurons in Dystroglycan mutants during development, suggesting that they are not eliminated by canonical apoptosis. Rather, we observed increased innervation of the striatum, suggesting that the few remaining CCK+ interneurons re-directed their axons to neighboring areas where Dystroglycan expression remained intact. Conclusion Together these findings show that Dystroglycan functions as part of a synaptic partner recognition complex that is required early for CCK+ interneuron development in the forebrain. Supplementary Information The online version contains supplementary material available at 10.1186/s13064-021-00153-1.
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Affiliation(s)
- Daniel S Miller
- Neuroscience Graduate Program, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science University, VIB 3435A, 3181 SW Sam Jackson Park Road, L474, Portland, OR, 97239-3098, USA.
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11
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Jahangir M, Zhou JS, Lang B, Wang XP. GABAergic System Dysfunction and Challenges in Schizophrenia Research. Front Cell Dev Biol 2021; 9:663854. [PMID: 34055795 PMCID: PMC8160111 DOI: 10.3389/fcell.2021.663854] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 04/06/2021] [Indexed: 12/13/2022] Open
Abstract
Despite strenuous studies since the last century, the precise cause and pathology of schizophrenia are still largely unclear and arguably controversial. Although many hypotheses have been proposed to explain the etiology of schizophrenia, the definitive genes or core pathological mechanism remains absent. Among these hypotheses, however, GABAergic dysfunction stands out as a common feature consistently reported in schizophrenia, albeit a satisfactory mechanism that could be exploited for therapeutic purpose has not been developed yet. This review is focusing on the progress made to date in the field in terms of understanding the mechanisms involving dysfunctional GABAergic system and loops identified in schizophrenia research.
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Affiliation(s)
- Muhammad Jahangir
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Jian-Song Zhou
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Bing Lang
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Xiao-Ping Wang
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
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12
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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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13
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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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14
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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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15
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Cholecystokinin-Expressing Interneurons of the Medial Prefrontal Cortex Mediate Working Memory Retrieval. J Neurosci 2020; 40:2314-2331. [PMID: 32005764 DOI: 10.1523/jneurosci.1919-19.2020] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 01/20/2020] [Accepted: 01/23/2020] [Indexed: 12/14/2022] Open
Abstract
Distinct components of working memory are coordinated by different classes of inhibitory interneurons in the PFC, but the role of cholecystokinin (CCK)-positive interneurons remains enigmatic. In humans, this major population of interneurons shows histological abnormalities in schizophrenia, an illness in which deficient working memory is a core defining symptom and the best predictor of long-term functional outcome. Yet, CCK interneurons as a molecularly distinct class have proved intractable to examination by typical molecular methods due to widespread expression of CCK in the pyramidal neuron population. Using an intersectional approach in mice of both sexes, we have succeeded in labeling, interrogating, and manipulating CCK interneurons in the mPFC. Here, we describe the anatomical distribution, electrophysiological properties, and postsynaptic connectivity of CCK interneurons, and evaluate their role in cognition. We found that CCK interneurons comprise a larger proportion of the mPFC interneurons compared with parvalbumin interneurons, targeting a wide range of neuronal subtypes with a distinct connectivity pattern. Phase-specific optogenetic inhibition revealed that CCK, but not parvalbumin, interneurons play a critical role in the retrieval of working memory. These findings shine new light on the relationship between cortical CCK interneurons and cognition and offer a new set of tools to investigate interneuron dysfunction and cognitive impairments associated with schizophrenia.SIGNIFICANCE STATEMENT Cholecystokinin-expressing interneurons outnumber other interneuron populations in key brain areas involved in cognition and memory, including the mPFC. However, they have proved intractable to examination as experimental techniques have lacked the necessary selectivity. To the best of our knowledge, the present study is the first to report detailed properties of cortical cholecystokinin interneurons, revealing their anatomical organization, electrophysiological properties, postsynaptic connectivity, and behavioral function in working memory.
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16
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PSA-NCAM Colocalized with Cholecystokinin-Expressing Cells in the Hippocampus Is Involved in Mediating Antidepressant Efficacy. J Neurosci 2019; 40:825-842. [PMID: 31801810 DOI: 10.1523/jneurosci.1779-19.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/30/2019] [Accepted: 11/25/2019] [Indexed: 11/21/2022] Open
Abstract
The extracellular glycan polysialic acid linked to neural cell adhesion molecule (PSA-NCAM) is principally expressed in the developing brain and the adult neurogenic regions. Although colocalization of PSA-NCAM with cholecystokinin (CCK) was found in the adult brain, the role of PSA-NCAM remains unclear. In this study, we aimed to elucidate the functional significance of PSA-NCAM in the CA1 region of the male mouse hippocampus. Combined fluorescence in situ hybridization and immunohistochemistry showed that few vesicular glutamate transporter 3-negative/CCK-positive (VGluT3-/CCK+) cells were colocalized with PSA-NCAM, but most of the VGluT3+/CCK+ cells were colocalized with PSA-NCAM. The somata of PSA-NCAM+/CCK+ cells were highly innervated by serotonergic boutons than those of PSA-NCAM-/CCK+ cells. The expression ratios of 5-HT3A receptors and p11, a serotonin receptor-interacting protein, were higher in PSA-NCAM+/CCK+ cells than in PSA-NCAM-/CCK+ cells. Pharmacological digestion of PSA-NCAM impaired the efficacy of antidepressant fluoxetine (FLX), a selective serotonin reuptake inhibitor, but not the efficacy of benzodiazepine anxiolytic diazepam. A Western blot showed that restraint stress decreased the expressions of p11 and mature brain-derived neurotrophic factor (BDNF), and FLX increased them. Interestingly, the FLX-induced elevation of expression of p11, but not mature BDNF, was impaired by the digestion of PSA-NCAM. Quantitative reverse transcription-polymerase chain reaction showed that restraint stress reduced the expression of polysialyltransferase ST8Sia IV and FLX elevated it. Collectively, PSA-NCAM colocalized with VGluT3+/CCK+ cells in the CA1 region of the hippocampus may play a unique role in the regulation of antidepressant efficacy via the serotonergic pathway.SIGNIFICANCE STATEMENT Polysialic acid (PSA) is composed of eight or more α2,8-linked sialic acids. Here, we examined the functional significance of polysialic acid linked to the neural cell adhesion molecule (PSA-NCAM) in the adult mouse hippocampus. Few vesicular glutamate transporter 3-negative/cholecystokinin-positive (VGluT3-/CCK+) cells were colocalized with PSA-NCAM, but most of the VGluT3+/CCK+ cells were colocalized with PSA-NCAM. The expression ratios of 5-HT3A receptors and p11, a serotonin receptor-interacting protein, were higher in PSA-NCAM+/CCK+ cells than in PSA-NCAM-/CCK+ cells. The efficacy of antidepressants, but not anxiolytics, was impaired by the digestion of PSA-NCAM. The antidepressant-induced increase in p11 expression was inhibited following PSA-NCAM digestion. We hence hypothesize that PSA-NCAM colocalized with VGluT3+/CCK+ cells may play a unique role in regulating antidepressant efficacy.
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17
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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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18
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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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19
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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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20
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Harris KD, Hochgerner H, Skene NG, Magno L, Katona L, Bengtsson Gonzales C, Somogyi P, Kessaris N, Linnarsson S, Hjerling-Leffler J. Classes and continua of hippocampal CA1 inhibitory neurons revealed by single-cell transcriptomics. PLoS Biol 2018; 16:e2006387. [PMID: 29912866 PMCID: PMC6029811 DOI: 10.1371/journal.pbio.2006387] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/03/2018] [Accepted: 05/22/2018] [Indexed: 01/19/2023] Open
Abstract
Understanding any brain circuit will require a categorization of its constituent neurons. In hippocampal area CA1, at least 23 classes of GABAergic neuron have been proposed to date. However, this list may be incomplete; additionally, it is unclear whether discrete classes are sufficient to describe the diversity of cortical inhibitory neurons or whether continuous modes of variability are also required. We studied the transcriptomes of 3,663 CA1 inhibitory cells, revealing 10 major GABAergic groups that divided into 49 fine-scale clusters. All previously described and several novel cell classes were identified, with three previously described classes unexpectedly found to be identical. A division into discrete classes, however, was not sufficient to describe the diversity of these cells, as continuous variation also occurred between and within classes. Latent factor analysis revealed that a single continuous variable could predict the expression levels of several genes, which correlated similarly with it across multiple cell types. Analysis of the genes correlating with this variable suggested it reflects a range from metabolically highly active faster-spiking cells that proximally target pyramidal cells to slower-spiking cells targeting distal dendrites or interneurons. These results elucidate the complexity of inhibitory neurons in one of the simplest cortical structures and show that characterizing these cells requires continuous modes of variation as well as discrete cell classes.
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Affiliation(s)
- Kenneth D. Harris
- University College London Institute of Neurology, London, United Kingdom
- University College London Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Hannah Hochgerner
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Nathan G. Skene
- University College London Institute of Neurology, London, United Kingdom
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Lorenza Magno
- University College London Wolfson Institute for Biomedical Research, London, United Kingdom
| | - Linda Katona
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Carolina Bengtsson Gonzales
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Peter Somogyi
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Nicoletta Kessaris
- University College London Wolfson Institute for Biomedical Research, London, United Kingdom
| | - Sten Linnarsson
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Jens Hjerling-Leffler
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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21
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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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22
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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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23
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McKenzie S. Inhibition shapes the organization of hippocampal representations. Hippocampus 2017; 28:659-671. [PMID: 28921762 DOI: 10.1002/hipo.22803] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 01/12/2023]
Abstract
Hippocampal neurons become tuned to stimuli that predict behaviorally salient outcomes. This plasticity suggests that memory formation depends upon shifts in how different anatomical inputs can drive hippocampal activity. Here, I present evidence that inhibitory neurons can provide such a mechanism for learning-related changes in the tuning of pyramidal cells. Inhibitory currents arriving on the dendrites of pyramidal cells determine whether an excitatory input can drive action potential output. Specificity and plasticity of this dendritic modulation allows for precise, modifiable changes in how afferent inputs are integrated, a process that defines a neuron's receptive field. In addition, feedback inhibition plays a fundamental role in biasing which excitatory neurons may be co-active. By defining the rules of synchrony and the rules of input integration, interneurons likely play an important role in the organization of memory representation within the hippocampus.
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Affiliation(s)
- Sam McKenzie
- NYU Langone Medical Center, 450 E29th Street, 9th Floor, New York, New York 10016
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24
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Abstract
Cortical networks are composed of glutamatergic excitatory projection neurons and local GABAergic inhibitory interneurons that gate signal flow and sculpt network dynamics. Although they represent a minority of the total neocortical neuronal population, GABAergic interneurons are highly heterogeneous, forming functional classes based on their morphological, electrophysiological, and molecular features, as well as connectivity and in vivo patterns of activity. Here we review our current understanding of neocortical interneuron diversity and the properties that distinguish cell types. We then discuss how the involvement of multiple cell types, each with a specific set of cellular properties, plays a crucial role in diversifying and increasing the computational power of a relatively small number of simple circuit motifs forming cortical networks. We illustrate how recent advances in the field have shed light onto the mechanisms by which GABAergic inhibition contributes to network operations.
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25
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Rovira-Esteban L, Péterfi Z, Vikór A, Máté Z, Szabó G, Hájos N. Morphological and physiological properties of CCK/CB1R-expressing interneurons in the basal amygdala. Brain Struct Funct 2017; 222:3543-3565. [PMID: 28391401 DOI: 10.1007/s00429-017-1417-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 03/30/2017] [Indexed: 12/31/2022]
Abstract
Principal neurons in cortical regions including the basal nucleus of the amygdala (BA) are innervated by several types of inhibitory cells, one of which expresses the neuropeptide cholecystokinin (CCK) and the type 1 cannabinoid receptor (CB1R). CCK/CB1R-expressing interneurons may have a profound impact on amygdalar function by controlling its output. However, very little is known about their properties, and therefore their role in circuit operation cannot be predicted. To characterize the CCK/CB1R-expressing interneurons in the BA, we combined in vitro electrophysiological recordings and neuroanatomical techniques in a transgenic mouse that expresses DsRed fluorescent protein under the control of the CCK promoter. We found that the majority of CCK/CB1R-positive interneurons expressed either the type 3 vesicular glutamate transporter (VGluT3) or the Ca2+ binding protein calbindin (Calb). VGluT3+ CCK/CB1R-expressing interneurons targeted the soma of principal neurons more often than Calb+ CCK/CB1R-expressing interneurons, but the dendritic morphology and membrane properties of these two neurochemically distinct interneuron types were not significantly different. The results of paired recordings showed that the unitary IPSC properties of VGluT3+ or Calb+ CCK/CB1R-expressing interneurons recorded in principal neurons were indistinguishable. We verified that endocannabinoids at the output synapses of CCK/CB1R-expressing interneurons could potently reduce the unitary IPSC magnitude. In summary, independent of the neurochemical content, CCK/CB1R-expressing interneurons have similar physiological and morphological properties, providing an endocannabinoid-sensitive synaptic inhibition onto the amygdalar principal neurons.
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Affiliation(s)
- Laura Rovira-Esteban
- Lendület Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Zoltán Péterfi
- Lendület Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Attila Vikór
- Lendület Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Zoltán Máté
- Division of Medical Gene Technology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Gábor Szabó
- Division of Medical Gene Technology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Norbert Hájos
- Lendület Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
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26
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Veres JM, Nagy GA, Hájos N. Perisomatic GABAergic synapses of basket cells effectively control principal neuron activity in amygdala networks. eLife 2017; 6. [PMID: 28060701 PMCID: PMC5218536 DOI: 10.7554/elife.20721] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/16/2016] [Indexed: 12/17/2022] Open
Abstract
Efficient control of principal neuron firing by basket cells is critical for information processing in cortical microcircuits, however, the relative contribution of their perisomatic and dendritic synapses to spike inhibition is still unknown. Using in vitro electrophysiological paired recordings we reveal that in the mouse basal amygdala cholecystokinin- and parvalbumin-containing basket cells provide equally potent control of principal neuron spiking. We performed pharmacological manipulations, light and electron microscopic investigations to show that, although basket cells innervate the entire somato-denditic membrane surface of principal neurons, the spike controlling effect is achieved primarily via the minority of synapses targeting the perisomatic region. As the innervation patterns of individual basket cells on their different postsynaptic partners show high variability, the impact of inhibitory control accomplished by single basket cells is also variable. Our results show that both basket cell types can powerfully regulate the activity in amygdala networks predominantly via their perisomatic synapses. DOI:http://dx.doi.org/10.7554/eLife.20721.001
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Affiliation(s)
- Judit M Veres
- 'Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.,János Szentágothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Gergő A Nagy
- 'Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Norbert Hájos
- 'Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
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27
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Persistent inhibitory circuit defects and disrupted social behaviour following in utero exogenous cannabinoid exposure. Mol Psychiatry 2017; 22:56-67. [PMID: 26976041 PMCID: PMC5025333 DOI: 10.1038/mp.2016.17] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 01/15/2016] [Accepted: 01/20/2016] [Indexed: 01/10/2023]
Abstract
Placental transfer of Δ9-tetrahydrocannabinol (THC) during pregnancy has the potential to interfere with endogenous cannabinoid (CB) regulation of fetal nervous system development in utero. Here we examined the effect of maternal CB intake on mouse hippocampal interneurons largely focusing on cholecystokinin-expressing interneurons (CCK-INTs), a prominent CB subtype-1 receptor (CB1R) expressing neuronal population throughout development. Maternal treatment with THC or the synthetic CB1R agonist WIN55,212-2 (WIN) produced a significant loss of CCK-INTs in the offspring. Further, residual CCK-INTs in animals prenatally treated with WIN displayed decreased dendritic complexity. Consistent with these anatomical deficits, pups born to CB-treated dams exhibited compromised CCK-INT-mediated feedforward and feedback inhibition. Moreover, pups exposed to WIN in utero lacked constitutive CB1R-mediated suppression of inhibition from residual CCK-INTs and displayed altered social behavior. Our findings add to a growing list of potential cell/circuit underpinnings that may underlie cognitive impairments in offspring of mothers that abuse marijuana during pregnancy.
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28
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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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29
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Alexander A, Soltesz I. Hippogate: a break-in from entorhinal cortex. Nat Neurosci 2016; 19:530-2. [DOI: 10.1038/nn.4253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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30
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Vereczki VK, Veres JM, Müller K, Nagy GA, Rácz B, Barsy B, Hájos N. Synaptic Organization of Perisomatic GABAergic Inputs onto the Principal Cells of the Mouse Basolateral Amygdala. Front Neuroanat 2016; 10:20. [PMID: 27013983 PMCID: PMC4779893 DOI: 10.3389/fnana.2016.00020] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/18/2016] [Indexed: 12/27/2022] Open
Abstract
Spike generation is most effectively controlled by inhibitory inputs that target the perisomatic region of neurons. Despite the critical importance of this functional domain, very little is known about the organization of the GABAergic inputs contacting the perisomatic region of principal cells (PCs) in the basolateral amygdala. Using immunocytochemistry combined with in vitro single-cell labeling we determined the number and sources of GABAergic inputs of PCs at light and electron microscopic levels in mice. We found that the soma and proximal dendrites of PCs were innervated primarily by two neurochemically distinct basket cell types expressing parvalbumin (PVBC) or cholecystokinin and CB1 cannabinoid receptors (CCK/CB1BC). The innervation of the initial segment of PC axons was found to be parceled out by PVBCs and axo-axonic cells (AAC), as the majority of GABAergic inputs onto the region nearest to the soma (between 0 and 10 μm) originated from PVBCs, while the largest portion of the axon initial segment was innervated by AACs. Detailed morphological investigations revealed that the three perisomatic region-targeting interneuron types significantly differed in dendritic and axonal arborization properties. We found that, although individual PVBCs targeted PCs via more terminals than CCK/CB1BCs, similar numbers (15–17) of the two BC types converge onto single PCs, whereas fewer (6–7) AACs innervate the axon initial segment of single PCs. Furthermore, we estimated that a PVBC and a CCK/CB1BC may target 800–900 and 700–800 PCs, respectively, while an AAC can innervate 600–650 PCs. Thus, BCs and AACs innervate ~10 and 20% of PC population, respectively, within their axonal cloud. Our results collectively suggest, that these interneuron types may be differently affiliated within the local amygdalar microcircuits in order to fulfill specific functions in network operation during various brain states.
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Affiliation(s)
- Viktória K Vereczki
- Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of SciencesBudapest, Hungary; Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis UniversityBudapest, Hungary
| | - Judit M Veres
- Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of SciencesBudapest, Hungary; János Szentágothai School of Neurosciences, Semmelweis UniversityBudapest, Hungary
| | - Kinga Müller
- Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Gergö A Nagy
- Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Bence Rácz
- Department of Anatomy and Histology, Szent István UniversityBudapest, Hungary; Electronmicroscopy Research Group, Faculty of Veterinary Science, Szent István UniversityBudapest, Hungary
| | - Boglárka Barsy
- Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Norbert Hájos
- Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
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31
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Chen F, du Jardin KG, Waller JA, Sanchez C, Nyengaard JR, Wegener G. Vortioxetine promotes early changes in dendritic morphology compared to fluoxetine in rat hippocampus. Eur Neuropsychopharmacol 2016; 26:234-245. [PMID: 26711685 DOI: 10.1016/j.euroneuro.2015.12.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/20/2015] [Accepted: 12/01/2015] [Indexed: 12/28/2022]
Abstract
Preclinical studies reveal that the multimodal antidepressant vortioxetine enhances long-term potentiation and dendritic branching compared to a selective serotonin reuptake inhibitor (SSRI). In the present study, we investigated vortioxetine׳s effects on spines and dendritic morphology in rat hippocampus at two time points compared to the SSRI, fluoxetine. Rats were dosed for 1 and 4 weeks with vortioxetine and fluoxetine at doses relevant for antidepressant activity. Dendritic morphology of pyramidal neurons (i.e., dendritic length, dendritic branch, spine number and density, and Sholl analysis) was examined in Golgi-stained sections from hippocampal CA1. After 1 week of treatment, vortioxetine significantly increased spine number (apical and basal dendrites), spine density (only basal), dendritic length (only apical), and dendritic branch number (apical and basal), whereas fluoxetine had no effect. After 4 weeks of treatment, vortioxetine significantly increased all measures of dendritic spine morphology as did fluoxetine except for spine density of basal dendrites. The number of intersections in the apical and basal dendrites was also significantly increased for both treatments after 4 weeks compared to control. In addition, 4 weeks of vortioxetine treatment, but not fluoxetine, promoted a decrease in spine neck length. In conclusion, 1-week vortioxetine treatment induced changes in spine number and density and dendritic morphology, whereas an equivalent dose of fluoxetine had no effects. Decreased spine neck length following 4-week vortioxetine treatment suggests a transition to mature spine morphology. This implies that vortioxetine׳s effects on spine and dendritic morphology are mediated by mechanisms that go beyond serotonin reuptake inhibition.
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Affiliation(s)
- Fenghua Chen
- Stereology and Electron Microscopy Laboratory, Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, DK-8000 Aarhus C, Denmark; Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, DK-8240 Risskov, Denmark.
| | - Kristian Gaarn du Jardin
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, DK-8240 Risskov, Denmark
| | - Jessica A Waller
- Sourcing and Scientific Excellence at Lundbeck Research USA, Inc., Paramus, NJ 07652-1431, USA
| | - Connie Sanchez
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, DK-8240 Risskov, Denmark; Sourcing and Scientific Excellence at Lundbeck Research USA, Inc., Paramus, NJ 07652-1431, USA
| | - Jens R Nyengaard
- Stereology and Electron Microscopy Laboratory, Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
| | - Gregers Wegener
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, DK-8240 Risskov, Denmark; Centre for Pharmaceutical Excellence, School of Pharmacy, North-West University, Potchefstroom 2520, South Africa
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32
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Jappy D, Valiullina F, Draguhn A, Rozov A. GABABR-Dependent Long-Term Depression at Hippocampal Synapses between CB1-Positive Interneurons and CA1 Pyramidal Cells. Front Cell Neurosci 2016; 10:4. [PMID: 26858602 PMCID: PMC4729905 DOI: 10.3389/fncel.2016.00004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/04/2016] [Indexed: 12/31/2022] Open
Abstract
Activity induced long lasting modifications of synaptic efficacy have been extensively studied in excitatory synapses, however, long term plasticity is also a property of inhibitory synapses. Inhibitory neurons in the hippocampal CA1 region can be subdivided according to the compartment they target on the pyramidal cell. Some interneurons preferentially innervate the perisomatic area and axon hillock of the pyramidal cells while others preferentially target dendritic branches and spines. Another characteristic feature allowing functional classification of interneurons is cell type specific expression of different neurochemical markers and receptors. In the hippocampal CA1 region, nearly 90% of the interneurons expressing cannabinoid type 1 receptors (CB1R) also express cholecystokinin (CCK). Therefore, the functional presence of CB1 receptors can be used for identification of the inhibitory input from CCK positive (CCK+) interneurons to CA1 pyramidal cells. The goal of this study was to explore the nature of long term plasticity at the synapses between interneurons expressing CB1Rs (putative CCK+) and pyramidal neurons in the CA1 region of the hippocampus in vitro. We found that theta burst stimulation triggered robust long-term depression (LTD) at this synapse. The locus of LTD induction was postsynaptic and required activation of GABAB receptors. We also showed that LTD at this synaptic connection involves GABABR-dependent suppression of adenylyl cyclase and consequent reduction of PKA activity. In this respect, CB1+ to pyramidal cell synapses differ from the majority of the other hippocampal inhibitory connections where theta burst stimulation results in long-term potentiation.
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Affiliation(s)
- Dave Jappy
- OpenLab of Neurobiology, Kazan Federal University Kazan, Russia
| | | | - Andreas Draguhn
- Department of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany
| | - Andrei Rozov
- OpenLab of Neurobiology, Kazan Federal UniversityKazan, Russia; Department of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany
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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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Wheeler DW, White CM, Rees CL, Komendantov AO, Hamilton DJ, Ascoli GA. Hippocampome.org: a knowledge base of neuron types in the rodent hippocampus. eLife 2015; 4. [PMID: 26402459 PMCID: PMC4629441 DOI: 10.7554/elife.09960] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 09/23/2015] [Indexed: 12/12/2022] Open
Abstract
Hippocampome.org is a comprehensive knowledge base of neuron types in the rodent hippocampal formation (dentate gyrus, CA3, CA2, CA1, subiculum, and entorhinal cortex). Although the hippocampal literature is remarkably information-rich, neuron properties are often reported with incompletely defined and notoriously inconsistent terminology, creating a formidable challenge for data integration. Our extensive literature mining and data reconciliation identified 122 neuron types based on neurotransmitter, axonal and dendritic patterns, synaptic specificity, electrophysiology, and molecular biomarkers. All ∼3700 annotated properties are individually supported by specific evidence (∼14,000 pieces) in peer-reviewed publications. Systematic analysis of this unprecedented amount of machine-readable information reveals novel correlations among neuron types and properties, the potential connectivity of the full hippocampal circuitry, and outstanding knowledge gaps. User-friendly browsing and online querying of Hippocampome.org may aid design and interpretation of both experiments and simulations. This powerful, simple, and extensible neuron classification endeavor is unique in its detail, utility, and completeness. DOI:http://dx.doi.org/10.7554/eLife.09960.001 The hippocampus is a seahorse-shaped region of the brain that is responsible for learning, emotions, and memory. Like other regions of the brain, it contains many types of neurons that send information to each other by releasing chemicals called neurotransmitters across junctions known as synapses. Identifying all the different neuron types in the hippocampus is an important step towards understanding in detail how this brain region works. Thousands of articles have been published that attempt to characterize the neurons in the hippocampus, but many of these studies report only some of the properties of a new neuron type. It is also often difficult to compare the results of different studies, as many different approaches have been used to investigate neuron types, and different studies often use different terms to describe similar features. Wheeler et al. have now created a resource called Hippocampome.org that combines approximately 14,000 pieces of experimental evidence about neuron types in the rat hippocampus into a unified database. Analyzing these data has revealed about 3700 different neuron properties. By primarily considering the pattern formed by the branched axons and dendrites, the outputs and inputs that extend out of a neuron, Wheeler et al. have identified over a hundred different neuron types. This classification system also considers how selectively the neuron forms synapses with other cells and the identity of the neurotransmitter released by the neuron. In the future, other features of the neurons will also be incorporated into the system to help refine the classifications. All of this information is online and freely available at Hippocampome.org. This resource is expected to provide a solid basis for analyzing how the hippocampus works, by helping researchers to design and interpret experiments and simulations. DOI:http://dx.doi.org/10.7554/eLife.09960.002
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Affiliation(s)
- Diek W Wheeler
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, United States
| | - Charise M White
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, United States
| | - Christopher L Rees
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, United States
| | | | - David J Hamilton
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, United States
| | - Giorgio A Ascoli
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, United States
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35
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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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Botcher NA, Falck JE, Thomson AM, Mercer A. Distribution of interneurons in the CA2 region of the rat hippocampus. Front Neuroanat 2014; 8:104. [PMID: 25309345 PMCID: PMC4176080 DOI: 10.3389/fnana.2014.00104] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 09/08/2014] [Indexed: 12/23/2022] Open
Abstract
The CA2 region of the mammalian hippocampus is a unique region with its own distinctive properties, inputs and pathologies. Disruption of inhibitory circuits in this region appears to be linked with the pathology of specific psychiatric disorders, promoting interest in its local circuitry, its role in hippocampal function and its dysfunction in disease. In previous studies, CA2 interneurons, including a novel subclass of CA2 dendrite-preferring interneurons that has not been identified in other CA regions, have been shown to display physiological, synaptic and morphological properties unique to this sub-field and may therefore play a crucial role in the hippocampal circuitry. The distributions of immuno-labeled interneurons in dorsal CA2 were studied and compared with those of interneurons in CA1 and CA3. Like those in CA1 and CA3, the somata of CA2 parvalbumin-immunoperoxidase-labeled interneurons were located primarily in Stratum Pyramidale (SP) and Stratum Oriens (SO), with very few cells in Stratum Radiatum (SR) and none in Stratum Lacunosum Moleculare (SLM). There was, however, a greater proportion of GAD-positive cells were immunopositive for PV in SP in CA2 than in CA1 or CA3. CA2 SP also contained a larger density of somatostatin-, calbindin-, and VIP-immunopositive somata than CA1 and/or CA3. Like those in CA1 and CA3, CCK-immunopositive somata in CA2 were mostly located in SR. Reelin- and NPY- immunolabeled cell bodies were located in all layers of the three CA regions. However, a higher density of Reelin-positive somata was found in SP and SR of CA2 than in CA1 or CA3.
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Affiliation(s)
- Nicola A Botcher
- Department of Pharmacology, University College London School of Pharmacy London, UK
| | - Joanne E Falck
- Department of Pharmacology, University College London School of Pharmacy London, UK
| | - Alex M Thomson
- Department of Pharmacology, University College London School of Pharmacy London, UK
| | - Audrey Mercer
- Department of Pharmacology, University College London School of Pharmacy London, UK
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Szabó GG, Papp OI, Máté Z, Szabó G, Hájos N. Anatomically heterogeneous populations of CB1cannabinoid receptor-expressing interneurons in the CA3 region of the hippocampus show homogeneous input-output characteristics. Hippocampus 2014; 24:1506-23. [DOI: 10.1002/hipo.22330] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2014] [Indexed: 12/28/2022]
Affiliation(s)
- Gergely G. Szabó
- Lendület Laboratory of Network Neurophysiology; Department of Cellular and Network Neurobiology; Institute of Experimental Medicine; Hungarian Academy of Sciences; Budapest Hungary
| | - Orsolya I. Papp
- Lendület Laboratory of Network Neurophysiology; Department of Cellular and Network Neurobiology; Institute of Experimental Medicine; Hungarian Academy of Sciences; Budapest Hungary
| | - Zoltán Máté
- Division of Medical Gene Technology; Institute of Experimental Medicine, Hungarian Academy of Sciences; Budapest Hungary
| | - Gábor Szabó
- Division of Medical Gene Technology; Institute of Experimental Medicine, Hungarian Academy of Sciences; Budapest Hungary
| | - Norbert Hájos
- Lendület Laboratory of Network Neurophysiology; Department of Cellular and Network Neurobiology; Institute of Experimental Medicine; Hungarian Academy of Sciences; Budapest Hungary
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Interneuronal GABAA receptors inside and outside of synapses. Curr Opin Neurobiol 2013; 26:57-63. [PMID: 24650505 DOI: 10.1016/j.conb.2013.12.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 11/17/2013] [Accepted: 12/03/2013] [Indexed: 01/04/2023]
Abstract
About 20% of the total number of neurons in the brain are interneurons (INs) that utilize GABA as their neurotransmitter. The receptors for GABA have been well studied in principal cells, but INs also express GABA receptors, in particular the GABAA type (GABAARs), which may also be activated in an autocrine manner by the transmitter released by the INs themselves. As more and more neurological and psychiatric disorders are being discovered to be linked to malfunction or deficits of INs, this review will cover how INs communicate with each other through the activation of synaptic and extrasynaptic GABAARs. The properties of GABAARs specific to INs may differ significantly from those found on principal cells to open the prospect of developing IN-specific drugs.
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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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Kisfali M, Lrincz T, Vizi ES. Comparison of Ca2+ transients and [Ca2+]i in the dendrites and boutons of non-fast-spiking GABAergic hippocampal interneurons using two-photon laser microscopy and high- and low-affinity dyes. J Physiol 2013; 591:5541-53. [PMID: 23981718 DOI: 10.1113/jphysiol.2013.258863] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Using two-photon laser microscopy, high- and low-affinity dyes and patch clamp electrophysiology, we successfully measured somatic stimulation-evoked Ca(2+) transients simultaneously in the dendrites and axonal boutons of the same non-fast-spiking GABAergic interneurons in acute slice preparations obtained from hippocampal area CA1. The advantage of the acute preparation is that both neuronal connections and anatomy are maintained. Calculated as unperturbed values, the amplitudes of Ca(2+) transients and changes in [Ca(2+)]i in response to somatic single or burst stimulation were much higher in boutons (428 nM/AP) than in dendrites (49 nM/AP), leading to the conclusion that the much greater influx of Ca(2+) observed in terminals might be due to a higher density of N-type voltage-sensitive Ca(2+) channels compared to the L-type channels present in dendrites. Whereas the decay of Ca(2+) transients recorded in dendrites was primarily mono-exponential, the decay in boutons was bi-exponential, as indicated by an initial fast phase, followed by a much slower reduction in fluorescence intensity. The extrusion of Ca(2+) was much faster in boutons than in dendrites. To avoid saturation effects and the flawed conversion of fluorescence measures of [Ca(2+)]i, we assessed the limits of [Ca(2+)] measurements (which ranged between 6 and 82% of the applied dye saturation) when high- and low-affinity dyes were applied at different concentrations. When two APs were delivered at a high frequency (>3 Hz) of stimulation, the low-affinity indicators OGB-6F (KD = 3.0 μM) and OGB-5N (KD = 20 μM) were able to accurately reflect the changes in ΔF/F produced by the consecutive APs. There was no difference in the endogenous buffer capacity (κE), which can shape Ca(2+) signals, calculated in dendrites (κE = 354) or boutons (κE = 458).
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Affiliation(s)
- Máté Kisfali
- E. S. Vizi: Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony str. 43, Budapest, 1083 Hungary.
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Dubruc F, Dupret D, Caillard O. Self-tuning of inhibition by endocannabinoids shapes spike-time precision in CA1 pyramidal neurons. J Neurophysiol 2013; 110:1930-44. [PMID: 23904493 DOI: 10.1152/jn.00099.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the hippocampus, activity-dependent changes of synaptic transmission and spike-timing coordination are thought to mediate information processing for the purpose of memory formation. Here, we investigated the self-tuning of intrinsic excitability and spiking reliability by CA1 hippocampal pyramidal cells via changes of their GABAergic inhibitory inputs and endocannabinoid (eCB) signaling. Firing patterns of CA1 place cells, when replayed in vitro, induced an eCB-dependent transient reduction of spontaneous GABAergic activity, sharing the main features of depolarization-induced suppression of inhibition (DSI), and conditioned a transient improvement of spike-time precision during consecutive burst discharges. When evaluating the consequences of DSI on excitatory postsynaptic potential (EPSP)-spike coupling, we found that transient reductions of uncorrelated (spontaneous) or correlated (feedforward) inhibition improved EPSP-spike coupling probability. The relationship between EPSP-spike-timing reliability and inhibition was, however, more complex: transient reduction of correlated (feedforward) inhibition disrupted or improved spike-timing reliability according to the initial spike-coupling probability. Thus eCB-mediated tuning of pyramidal cell spike-time precision is governed not only by the initial level of global inhibition, but also by the ratio between spontaneous and feedforward GABAergic activities. These results reveal that eCB-mediated self-tuning of spike timing by the discharge of pyramidal cells can constitute an important contribution to place-cell assemblies and memory formation in the hippocampus.
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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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Cox DJ, Racca C. Differential dendritic targeting of AMPA receptor subunit mRNAs in adult rat hippocampal principal neurons and interneurons. J Comp Neurol 2013; 521:1954-2007. [DOI: 10.1002/cne.23292] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 12/13/2012] [Accepted: 12/14/2012] [Indexed: 12/19/2022]
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Zachariou M, Alexander SPH, Coombes S, Christodoulou C. A biophysical model of endocannabinoid-mediated short term depression in hippocampal inhibition. PLoS One 2013; 8:e58926. [PMID: 23527052 PMCID: PMC3601106 DOI: 10.1371/journal.pone.0058926] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 02/08/2013] [Indexed: 12/22/2022] Open
Abstract
Memories are believed to be represented in the synaptic pathways of vastly interconnected networks of neurons. The plasticity of synapses, that is, their strengthening and weakening depending on neuronal activity, is believed to be the basis of learning and establishing memories. An increasing number of studies indicate that endocannabinoids have a widespread action on brain function through modulation of synap–tic transmission and plasticity. Recent experimental studies have characterised the role of endocannabinoids in mediating both short- and long-term synaptic plasticity in various brain regions including the hippocampus, a brain region strongly associated with cognitive functions, such as learning and memory. Here, we present a biophysically plausible model of cannabinoid retrograde signalling at the synaptic level and investigate how this signalling mediates depolarisation induced suppression of inhibition (DSI), a prominent form of short-term synaptic depression in inhibitory transmission in hippocampus. The model successfully captures many of the key characteristics of DSI in the hippocampus, as observed experimentally, with a minimal yet sufficient mathematical description of the major signalling molecules and cascades involved. More specifically, this model serves as a framework to test hypotheses on the factors determining the variability of DSI and investigate under which conditions it can be evoked. The model reveals the frequency and duration bands in which the post-synaptic cell can be sufficiently stimulated to elicit DSI. Moreover, the model provides key insights on how the state of the inhibitory cell modulates DSI according to its firing rate and relative timing to the post-synaptic activation. Thus, it provides concrete suggestions to further investigate experimentally how DSI modulates and is modulated by neuronal activity in the brain. Importantly, this model serves as a stepping stone for future deciphering of the role of endocannabinoids in synaptic transmission as a feedback mechanism both at synaptic and network level.
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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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Nagy GA, Botond G, Borhegyi Z, Plummer NW, Freund TF, Hájos N. DAG-sensitive and Ca(2+) permeable TRPC6 channels are expressed in dentate granule cells and interneurons in the hippocampal formation. Hippocampus 2012. [PMID: 23193081 DOI: 10.1002/hipo.22081] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Members of the transient receptor potential (TRP) cation channel family play important roles in several neuronal functions. To understand the precise role of these channels in information processing, their presence on neuronal elements must be revealed. In this study, we investigated the localization of TRPC6 channels in the adult hippocampal formation. Immunostainings with a specific antibody, which was validated in Trpc6 knockout mice, showed that in the dentate gyrus, TRPC6 channels are strongly expressed in granule cells. Immunogold staining revealing the subcellular localization of TRPC6 channels clarified that these proteins were predominantly present on the membrane surface of the dendritic shafts of dentate granule cells, and also in their axons, often associated with intracellular membrane cisternae. In addition, TRPC6 channels could be observed in the dendrites of some interneurons. Double immunofluorescent staining showed that TRPC6 channels were present in the dendrites of hilar interneurons and hippocampal interneurons with horizontal dendrites in the stratum oriens expressing mGlu1a receptors, whereas parvalbumin immunoreactivity was revealed in TRPC6-expressing dendrites with radial appearance in the stratum radiatum. Electron microscopy showed that the immunogold particles depicting TRPC6 channels were located on the surface membranes of the interneuron dendrites. Our results suggest that TRPC6 channels are in a key position to alter the information entry into the trisynaptic loop of the hippocampal formation from the entorhinal cortex, and to control the function of both feed-forward and feed-back inhibitory circuits in this brain region. © 2012 Wiley Periodicals, Inc.
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Affiliation(s)
- Gergő A Nagy
- Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary
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Banerjee J, Alkondon M, Pereira EFR, Albuquerque EX. Regulation of GABAergic inputs to CA1 pyramidal neurons by nicotinic receptors and kynurenic acid. J Pharmacol Exp Ther 2012; 341:500-9. [PMID: 22344459 DOI: 10.1124/jpet.111.189860] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Impaired α7 nicotinic acetylcholine receptor (nAChR) function and GABAergic transmission in the hippocampus and elevated brain levels of kynurenic acid (KYNA), an astrocyte-derived metabolite of the kynurenine pathway, are key features of schizophrenia. KYNA acts as a noncompetitive antagonist with respect to agonists at both α7 nAChRs and N-methyl-D-aspartate receptors. Here, we tested the hypothesis that in hippocampal slices tonically active α7 nAChRs control GABAergic transmission to CA1 pyramidal neurons and are sensitive to inhibition by rising levels of KYNA. The α7 nAChR-selective antagonist α-bungarotoxin (α-BGT; 100 nM) and methyllycaconitine (MLA; 10 nM), an antagonist at α7 and other nAChRs, reduced by 51.3 ± 1.3 and 65.2 ± 1.5%, respectively, the frequency of GABAergic postsynaptic currents (PSCs) recorded from CA1 pyramidal neurons. MLA had no effect on miniature GABAergic PSCs. Thus, GABAergic synaptic activity in CA1 pyramidal neurons is maintained, in part, by tonically active α7 nAChRs located on the preterminal region of axons and/or the somatodendritic region of interneurons that synapse onto the neurons under study. L-Kynurenine (20 or 200 μM) or KYNA (20-200 μM) suppressed concentration-dependently the frequency of GABAergic PSCs; the inhibitory effect of 20 μM L-kynurenine had an onset time of approximately 35 min and could not be detected in the presence of 100 nM α-BGT. These results suggest that KYNA levels generated from 20 μM kynurenine inhibit tonically active α7 nAChR-dependent GABAergic transmission to the pyramidal neurons. Disruption of nAChR-dependent GABAergic transmission by mildly elevated levels of KYNA can be an important determinant of the cognitive deficits presented by patients with schizophrenia.
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Affiliation(s)
- Jyotirmoy Banerjee
- Division of Translational Toxicology, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA
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Terminal field and firing selectivity of cholecystokinin-expressing interneurons in the hippocampal CA3 area. J Neurosci 2012; 31:18073-93. [PMID: 22159120 DOI: 10.1523/jneurosci.3573-11.2011] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Hippocampal oscillations reflect coordinated neuronal activity on many timescales. Distinct types of GABAergic interneuron participate in the coordination of pyramidal cells over different oscillatory cycle phases. In the CA3 area, which generates sharp waves and gamma oscillations, the contribution of identified GABAergic neurons remains to be defined. We have examined the firing of a family of cholecystokinin-expressing interneurons during network oscillations in urethane-anesthetized rats and compared them with firing of CA3 pyramidal cells. The position of the terminals of individual visualized interneurons was highly diverse, selective, and often spatially coaligned with either the entorhinal or the associational inputs to area CA3. The spike timing in relation to theta and gamma oscillations and sharp waves was correlated with the innervated pyramidal cell domain. Basket and dendritic-layer-innervating interneurons receive entorhinal and associational inputs and preferentially fire on the ascending theta phase, when pyramidal cell assemblies emerge. Perforant-path-associated cells, driven by recurrent collaterals of pyramidal cells fire on theta troughs, when established pyramidal cell assemblies are most active. In the CA3 area, slow and fast gamma oscillations occurred on opposite theta oscillation phases. Perforant-path-associated and some COUP-TFII-positive interneurons are strongly coupled to both fast and slow gamma oscillations, but basket and dendritic-layer-innervating cells are weakly coupled to fast gamma oscillations only. During sharp waves, different interneuron types are activated, inhibited, or remain unaffected. We suggest that specialization in pyramidal cell domain and glutamatergic input-specific operations, reflected in the position of GABAergic terminals, is the evolutionary drive underlying the diversity of cholecystokinin-expressing interneurons.
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Regulation of neuronal input transformations by tunable dendritic inhibition. Nat Neurosci 2012; 15:423-30, S1-3. [PMID: 22246433 DOI: 10.1038/nn.3024] [Citation(s) in RCA: 314] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 12/07/2011] [Indexed: 11/08/2022]
Abstract
Transforming synaptic input into action potential output is a fundamental function of neurons. The pattern of action potential output from principal cells of the mammalian hippocampus encodes spatial and nonspatial information, but the cellular and circuit mechanisms by which neurons transform their synaptic input into a given output are unknown. Using a combination of optical activation and cell type-specific pharmacogenetic silencing in vitro, we found that dendritic inhibition is the primary regulator of input-output transformations in mouse hippocampal CA1 pyramidal cells, and acts by gating the dendritic electrogenesis driving burst spiking. Dendrite-targeting interneurons are themselves modulated by interneurons targeting pyramidal cell somata, providing a synaptic substrate for tuning pyramidal cell output through interactions in the local inhibitory network. These results provide evidence for a division of labor in cortical circuits, where distinct computational functions are implemented by subtypes of local inhibitory neurons.
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Anxiogenic effect of CCK8s in the ventral hippocampus of rats: possible involvement of GABAA receptors. Pharmacol Rep 2012; 64:45-53. [DOI: 10.1016/s1734-1140(12)70729-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 09/15/2011] [Indexed: 11/17/2022]
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