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McFarlan AR, Guo C, Gomez I, Weinerman C, Liang TA, Sjöström PJ. The spike-timing-dependent plasticity of VIP interneurons in motor cortex. Front Cell Neurosci 2024; 18:1389094. [PMID: 38706517 PMCID: PMC11066220 DOI: 10.3389/fncel.2024.1389094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 04/09/2024] [Indexed: 05/07/2024] Open
Abstract
The plasticity of inhibitory interneurons (INs) plays an important role in the organization and maintenance of cortical microcircuits. Given the many different IN types, there is an even greater diversity in synapse-type-specific plasticity learning rules at excitatory to excitatory (E→I), I→E, and I→I synapses. I→I synapses play a key disinhibitory role in cortical circuits. Because they typically target other INs, vasoactive intestinal peptide (VIP) INs are often featured in I→I→E disinhibition, which upregulates activity in nearby excitatory neurons. VIP IN dysregulation may thus lead to neuropathologies such as epilepsy. In spite of the important activity regulatory role of VIP INs, their long-term plasticity has not been described. Therefore, we characterized the phenomenology of spike-timing-dependent plasticity (STDP) at inputs and outputs of genetically defined VIP INs. Using a combination of whole-cell recording, 2-photon microscopy, and optogenetics, we explored I→I STDP at layer 2/3 (L2/3) VIP IN outputs onto L5 Martinotti cells (MCs) and basket cells (BCs). We found that VIP IN→MC synapses underwent causal long-term depression (LTD) that was presynaptically expressed. VIP IN→BC connections, however, did not undergo any detectable plasticity. Conversely, using extracellular stimulation, we explored E→I STDP at inputs to VIP INs which revealed long-term potentiation (LTP) for both causal and acausal timings. Taken together, our results demonstrate that VIP INs possess synapse-type-specific learning rules at their inputs and outputs. This suggests the possibility of harnessing VIP IN long-term plasticity to control activity-related neuropathologies such as epilepsy.
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Affiliation(s)
- Amanda R. McFarlan
- Centre for Research in Neuroscience, BRaIN Program, Department of Neurology and Neurosurgery, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Connie Guo
- Centre for Research in Neuroscience, BRaIN Program, Department of Neurology and Neurosurgery, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Isabella Gomez
- Centre for Research in Neuroscience, BRaIN Program, Department of Neurology and Neurosurgery, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
| | - Chaim Weinerman
- Centre for Research in Neuroscience, BRaIN Program, Department of Neurology and Neurosurgery, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
| | - Tasha A. Liang
- Centre for Research in Neuroscience, BRaIN Program, Department of Neurology and Neurosurgery, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
| | - P. Jesper Sjöström
- Centre for Research in Neuroscience, BRaIN Program, Department of Neurology and Neurosurgery, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
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2
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Miyazaki Y, Otsuka T, Yamagata Y, Endo T, Sanbo M, Sano H, Kobayashi K, Inahashi H, Kornau HC, Schmitz D, Prüss H, Meijer D, Hirabayashi M, Fukata Y, Fukata M. Oligodendrocyte-derived LGI3 and its receptor ADAM23 organize juxtaparanodal Kv1 channel clustering for short-term synaptic plasticity. Cell Rep 2024; 43:113634. [PMID: 38194969 PMCID: PMC10828548 DOI: 10.1016/j.celrep.2023.113634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/31/2023] [Accepted: 12/14/2023] [Indexed: 01/11/2024] Open
Abstract
Neurodevelopmental disorders, such as intellectual disability (ID), epilepsy, and autism, involve altered synaptic transmission and plasticity. Functional characterization of their associated genes is vital for understanding physio-pathological brain functions. LGI3 is a recently recognized ID-associated gene encoding a secretory protein related to an epilepsy-gene product, LGI1. Here, we find that LGI3 is uniquely secreted from oligodendrocytes in the brain and enriched at juxtaparanodes of myelinated axons, forming nanoscale subclusters. Proteomic analysis using epitope-tagged Lgi3 knockin mice shows that LGI3 uses ADAM23 as a receptor and selectively co-assembles with Kv1 channels. A lack of Lgi3 in mice disrupts juxtaparanodal clustering of ADAM23 and Kv1 channels and suppresses Kv1-channel-mediated short-term synaptic plasticity. Collectively, this study identifies an extracellular organizer of juxtaparanodal Kv1 channel clustering for finely tuned synaptic transmission. Given the defective secretion of the LGI3 missense variant, we propose a molecular pathway, the juxtaparanodal LGI3-ADAM23-Kv1 channel, for understanding neurodevelopmental disorders.
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Affiliation(s)
- Yuri Miyazaki
- Division of Neuropharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Takeshi Otsuka
- Section of Cellular Electrophysiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan
| | - Yoko Yamagata
- Section of Multilayer Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
| | | | - Makoto Sanbo
- Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Hiromi Sano
- Division of Behavioral Neuropharmacology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Kenta Kobayashi
- Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan; Section of Viral Vector Development, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
| | - Hiroki Inahashi
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Hans-Christian Kornau
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Neuroscience Research Center (NWFZ), Cluster NeuroCure, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Dietmar Schmitz
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Neuroscience Research Center (NWFZ), Cluster NeuroCure, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Harald Prüss
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Helmholtz Innovation Lab BaoBab (Brain Antibody-omics and B-cell Lab), Berlin, Germany; Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Dies Meijer
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK; Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
| | - Masumi Hirabayashi
- Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan; Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Division of Molecular and Cellular Pharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
| | - Masaki Fukata
- Division of Neuropharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan.
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3
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Wong HHW, Watt AJ, Sjöström PJ. Synapse-specific burst coding sustained by local axonal translation. Neuron 2024; 112:264-276.e6. [PMID: 37944518 DOI: 10.1016/j.neuron.2023.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/19/2023] [Accepted: 09/13/2023] [Indexed: 11/12/2023]
Abstract
Neurotransmission in the brain is unreliable, suggesting that high-frequency spike bursts rather than individual spikes carry the neural code. For instance, cortical pyramidal neurons rely on bursts in memory formation. Protein synthesis is another key factor in long-term synaptic plasticity and learning but is widely considered unnecessary for synaptic transmission. Here, however, we show that burst neurotransmission at synapses between neocortical layer 5 pyramidal cells depends on axonal protein synthesis linked to presynaptic NMDA receptors and mTOR. We localized protein synthesis to axons with laser axotomy and puromycylation live imaging. We whole-cell recorded connected neurons to reveal how translation sustained readily releasable vesicle pool size and replenishment rate. We live imaged axons and found sparsely docked RNA granules, suggesting synapse-specific regulation. In agreement, translation boosted neurotransmission onto excitatory but not inhibitory basket or Martinotti cells. Local axonal mRNA translation is thus a hitherto unappreciated principle for sustaining burst coding at specific synapse types.
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Affiliation(s)
- Hovy Ho-Wai Wong
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC H3G 1A4, Canada.
| | - Alanna J Watt
- Biology Department, McGill University, Montreal, QC H3G 0B1, Canada
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC H3G 1A4, Canada.
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4
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Chien VSC, Wang P, Maess B, Fishman Y, Knösche TR. Laminar neural dynamics of auditory evoked responses: Computational modeling of local field potentials in auditory cortex of non-human primates. Neuroimage 2023; 281:120364. [PMID: 37683810 DOI: 10.1016/j.neuroimage.2023.120364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 08/15/2023] [Accepted: 09/04/2023] [Indexed: 09/10/2023] Open
Abstract
Evoked neural responses to sensory stimuli have been extensively investigated in humans and animal models both to enhance our understanding of brain function and to aid in clinical diagnosis of neurological and neuropsychiatric conditions. Recording and imaging techniques such as electroencephalography (EEG), magnetoencephalography (MEG), local field potentials (LFPs), and calcium imaging provide complementary information about different aspects of brain activity at different spatial and temporal scales. Modeling and simulations provide a way to integrate these different types of information to clarify underlying neural mechanisms. In this study, we aimed to shed light on the neural dynamics underlying auditory evoked responses by fitting a rate-based model to LFPs recorded via multi-contact electrodes which simultaneously sampled neural activity across cortical laminae. Recordings included neural population responses to best-frequency (BF) and non-BF tones at four representative sites in primary auditory cortex (A1) of awake monkeys. The model considered major neural populations of excitatory, parvalbumin-expressing (PV), and somatostatin-expressing (SOM) neurons across layers 2/3, 4, and 5/6. Unknown parameters, including the connection strength between the populations, were fitted to the data. Our results revealed similar population dynamics, fitted model parameters, predicted equivalent current dipoles (ECD), tuning curves, and lateral inhibition profiles across recording sites and animals, in spite of quite different extracellular current distributions. We found that PV firing rates were higher in BF than in non-BF responses, mainly due to different strengths of tonotopic thalamic input, whereas SOM firing rates were higher in non-BF than in BF responses due to lateral inhibition. In conclusion, we demonstrate the feasibility of the model-fitting approach in identifying the contributions of cell-type specific population activity to stimulus-evoked LFPs across cortical laminae, providing a foundation for further investigations into the dynamics of neural circuits underlying cortical sensory processing.
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Affiliation(s)
- Vincent S C Chien
- Max Planck Institute for Human Cognitive and Brain Sciences, Germany; Institute of Computer Science of the Czech Academy of Sciences, Czech Republic
| | - Peng Wang
- Max Planck Institute for Human Cognitive and Brain Sciences, Germany; Institute of Psychology, University of Greifswald, Germany; Institute of Psychology, University of Regensburg, Germany
| | - Burkhard Maess
- Max Planck Institute for Human Cognitive and Brain Sciences, Germany
| | - Yonatan Fishman
- Departments of Neurology and Neuroscience, Albert Einstein College of Medicine, USA
| | - Thomas R Knösche
- Max Planck Institute for Human Cognitive and Brain Sciences, Germany.
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5
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Swanson OK, Yevoo PE, Richard D, Maffei A. Altered Thalamocortical Signaling in a Mouse Model of Parkinson's Disease. J Neurosci 2023; 43:6021-6034. [PMID: 37527923 PMCID: PMC10451150 DOI: 10.1523/jneurosci.2871-20.2023] [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: 11/12/2020] [Revised: 06/05/2023] [Accepted: 06/10/2023] [Indexed: 08/03/2023] Open
Abstract
Activation of the primary motor cortex (M1) is important for the execution of skilled movements and motor learning, and its dysfunction contributes to the pathophysiology of Parkinson's disease (PD). A well-accepted idea in PD research, albeit not tested experimentally, is that the loss of midbrain dopamine leads to decreased activation of M1 by the motor thalamus. Here, we report that midbrain dopamine loss altered motor thalamus input in a laminar- and cell type-specific fashion and induced laminar-specific changes in intracortical synaptic transmission. Frequency-dependent changes in synaptic dynamics were also observed. Our results demonstrate that loss of midbrain dopaminergic neurons alters thalamocortical activation of M1 in both male and female mice, and provide novel insights into circuit mechanisms for motor cortex dysfunction in a mouse model of PD.SIGNIFICANCE STATEMENT Loss of midbrain dopamine neurons increases inhibition from the basal ganglia to the motor thalamus, suggesting that it may ultimately lead to reduced activation of primary motor cortex (M1). In contrast with this line of thinking, analysis of M1 activity in patients and animal models of Parkinson's disease report hyperactivation of this region. Our results are the first report that midbrain dopamine loss alters the input-output function of M1 through laminar and cell type specific effects. These findings support and expand on the idea that loss of midbrain dopamine reduces motor cortex activation and provide experimental evidence that reconciles reduced thalamocortical input with reports of altered activation of motor cortex in patients with Parkinson's disease.
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Affiliation(s)
- Olivia K Swanson
- Department of Neurobiology and Behavior, State University of New York-Stony Brook, Stony Brook, New York 11794
- Graduate Program in Neuroscience, State University of New York-Stony Brook, Stony Brook, New York 11794
| | - Priscilla E Yevoo
- Department of Neurobiology and Behavior, State University of New York-Stony Brook, Stony Brook, New York 11794
- Graduate Program in Neuroscience, State University of New York-Stony Brook, Stony Brook, New York 11794
| | - Dave Richard
- Department of Neurobiology and Behavior, State University of New York-Stony Brook, Stony Brook, New York 11794
| | - Arianna Maffei
- Department of Neurobiology and Behavior, State University of New York-Stony Brook, Stony Brook, New York 11794
- Graduate Program in Neuroscience, State University of New York-Stony Brook, Stony Brook, New York 11794
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6
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Kim MH, Radaelli C, Thomsen ER, Monet D, Chartrand T, Jorstad NL, Mahoney JT, Taormina MJ, Long B, Baker K, Bakken TE, Campagnola L, Casper T, Clark M, Dee N, D'Orazi F, Gamlin C, Kalmbach BE, Kebede S, Lee BR, Ng L, Trinh J, Cobbs C, Gwinn RP, Keene CD, Ko AL, Ojemann JG, Silbergeld DL, Sorensen SA, Berg J, Smith KA, Nicovich PR, Jarsky T, Zeng H, Ting JT, Levi BP, Lein E. Target cell-specific synaptic dynamics of excitatory to inhibitory neuron connections in supragranular layers of human neocortex. eLife 2023; 12:e81863. [PMID: 37249212 PMCID: PMC10332811 DOI: 10.7554/elife.81863] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 05/29/2023] [Indexed: 05/31/2023] Open
Abstract
Rodent studies have demonstrated that synaptic dynamics from excitatory to inhibitory neuron types are often dependent on the target cell type. However, these target cell-specific properties have not been well investigated in human cortex, where there are major technical challenges in reliably obtaining healthy tissue, conducting multiple patch-clamp recordings on inhibitory cell types, and identifying those cell types. Here, we take advantage of newly developed methods for human neurosurgical tissue analysis with multiple patch-clamp recordings, post-hoc fluorescent in situ hybridization (FISH), machine learning-based cell type classification and prospective GABAergic AAV-based labeling to investigate synaptic properties between pyramidal neurons and PVALB- vs. SST-positive interneurons. We find that there are robust molecular differences in synapse-associated genes between these neuron types, and that individual presynaptic pyramidal neurons evoke postsynaptic responses with heterogeneous synaptic dynamics in different postsynaptic cell types. Using molecular identification with FISH and classifiers based on transcriptomically identified PVALB neurons analyzed by Patch-seq, we find that PVALB neurons typically show depressing synaptic characteristics, whereas other interneuron types including SST-positive neurons show facilitating characteristics. Together, these data support the existence of target cell-specific synaptic properties in human cortex that are similar to rodent, thereby indicating evolutionary conservation of local circuit connectivity motifs from excitatory to inhibitory neurons and their synaptic dynamics.
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Affiliation(s)
- Mean-Hwan Kim
- Allen Institute for Brain ScienceSeattleUnited States
| | | | | | - Deja Monet
- Allen Institute for Brain ScienceSeattleUnited States
| | | | | | | | | | - Brian Long
- Allen Institute for Brain ScienceSeattleUnited States
| | | | | | | | - Tamara Casper
- Allen Institute for Brain ScienceSeattleUnited States
| | - Michael Clark
- Allen Institute for Brain ScienceSeattleUnited States
| | - Nick Dee
- Allen Institute for Brain ScienceSeattleUnited States
| | | | - Clare Gamlin
- Allen Institute for Brain ScienceSeattleUnited States
| | - Brian E Kalmbach
- Allen Institute for Brain ScienceSeattleUnited States
- Department of Physiology & Biophysics, School of Medicine, University of WashingtonSeattleUnited States
| | - Sara Kebede
- Allen Institute for Brain ScienceSeattleUnited States
| | - Brian R Lee
- Allen Institute for Brain ScienceSeattleUnited States
| | - Lindsay Ng
- Allen Institute for Brain ScienceSeattleUnited States
| | - Jessica Trinh
- Allen Institute for Brain ScienceSeattleUnited States
| | | | | | - C Dirk Keene
- Department of Laboratory Medicine & Pathology, School of Medicine, University of WashingtonSeattleUnited States
| | - Andrew L Ko
- Department of Neurological Surgery, School of Medicine, University of WashingtonSeattleUnited States
| | - Jeffrey G Ojemann
- Department of Neurological Surgery, School of Medicine, University of WashingtonSeattleUnited States
| | - Daniel L Silbergeld
- Department of Neurological Surgery, School of Medicine, University of WashingtonSeattleUnited States
| | | | - Jim Berg
- Allen Institute for Brain ScienceSeattleUnited States
| | | | | | - Tim Jarsky
- Allen Institute for Brain ScienceSeattleUnited States
| | - Hongkui Zeng
- Allen Institute for Brain ScienceSeattleUnited States
| | - Jonathan T Ting
- Allen Institute for Brain ScienceSeattleUnited States
- Department of Physiology & Biophysics, School of Medicine, University of WashingtonSeattleUnited States
| | - Boaz P Levi
- Allen Institute for Brain ScienceSeattleUnited States
| | - Ed Lein
- Allen Institute for Brain ScienceSeattleUnited States
- Department of Laboratory Medicine & Pathology, School of Medicine, University of WashingtonSeattleUnited States
- Department of Neurological Surgery, School of Medicine, University of WashingtonSeattleUnited States
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7
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Canales A, Scheuer KS, Zhao X, Jackson MB. Unitary synaptic responses of parvalbumin interneurons evoked by excitatory neurons in the mouse barrel cortex. Cereb Cortex 2023; 33:5108-5121. [PMID: 36227216 PMCID: PMC10151880 DOI: 10.1093/cercor/bhac403] [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: 04/20/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/13/2022] Open
Abstract
The mammalian cortex integrates and processes information to transform sensory inputs into perceptions and motor outputs. These operations are performed by networks of excitatory and inhibitory neurons distributed through the cortical layers. Parvalbumin interneurons (PVIs) are the most abundant type of inhibitory cortical neuron. With axons projecting within and between layers, PVIs supply feedforward and feedback inhibition to control and modulate circuit function. Distinct populations of excitatory neurons recruit different PVI populations, but the specializations of these synapses are poorly understood. Here, we targeted a genetically encoded hybrid voltage sensor to PVIs and used fluorescence imaging in mouse somatosensory cortex slices to record their voltage changes. Stimulating a single visually identified excitatory neuron with small-tipped theta-glass electrodes depolarized multiple PVIs, and a common threshold suggested that stimulation elicited unitary synaptic potentials in response to a single excitatory neuron. Excitatory neurons depolarized PVIs in multiple layers, with the most residing in the layer of the stimulated neuron. Spiny stellate cells depolarized PVIs more strongly than pyramidal cells by up to 77%, suggesting a greater role for stellate cells in recruiting PVI inhibition and controlling cortical computations. Response half-width also varied between different excitatory inputs. These results demonstrate functional differences between excitatory synapses on PVIs.
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Affiliation(s)
- Alejandra Canales
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, United States
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States
| | - Katherine S Scheuer
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, United States
| | - Xinyu Zhao
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, United States
| | - Meyer B Jackson
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, United States
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8
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McFarlan AR, Chou CYC, Watanabe A, Cherepacha N, Haddad M, Owens H, Sjöström PJ. The plasticitome of cortical interneurons. Nat Rev Neurosci 2023; 24:80-97. [PMID: 36585520 DOI: 10.1038/s41583-022-00663-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2022] [Indexed: 12/31/2022]
Abstract
Hebb postulated that, to store information in the brain, assemblies of excitatory neurons coding for a percept are bound together via associative long-term synaptic plasticity. In this view, it is unclear what role, if any, is carried out by inhibitory interneurons. Indeed, some have argued that inhibitory interneurons are not plastic. Yet numerous recent studies have demonstrated that, similar to excitatory neurons, inhibitory interneurons also undergo long-term plasticity. Here, we discuss the many diverse forms of long-term plasticity that are found at inputs to and outputs from several types of cortical inhibitory interneuron, including their plasticity of intrinsic excitability and their homeostatic plasticity. We explain key plasticity terminology, highlight key interneuron plasticity mechanisms, extract overarching principles and point out implications for healthy brain functionality as well as for neuropathology. We introduce the concept of the plasticitome - the synaptic plasticity counterpart to the genome or the connectome - as well as nomenclature and definitions for dealing with this rich diversity of plasticity. We argue that the great diversity of interneuron plasticity rules is best understood at the circuit level, for example as a way of elucidating how the credit-assignment problem is solved in deep biological neural networks.
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Affiliation(s)
- Amanda R McFarlan
- Centre for Research in Neuroscience, Department of Medicine, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Integrated Program in Neuroscience, McGill University, Montréal, Québec, Canada
| | - Christina Y C Chou
- Centre for Research in Neuroscience, Department of Medicine, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Integrated Program in Neuroscience, McGill University, Montréal, Québec, Canada
| | - Airi Watanabe
- Centre for Research in Neuroscience, Department of Medicine, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Integrated Program in Neuroscience, McGill University, Montréal, Québec, Canada
| | - Nicole Cherepacha
- Centre for Research in Neuroscience, Department of Medicine, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Maria Haddad
- Centre for Research in Neuroscience, Department of Medicine, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Integrated Program in Neuroscience, McGill University, Montréal, Québec, Canada
| | - Hannah Owens
- Centre for Research in Neuroscience, Department of Medicine, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Integrated Program in Neuroscience, McGill University, Montréal, Québec, Canada
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Department of Medicine, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.
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9
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Bhattacharya D, Bartley AF, Li Q, Dobrunz LE. Bicuculline restores frequency-dependent hippocampal I/E ratio and circuit function in PGC-1ɑ null mice. Neurosci Res 2022; 184:9-18. [PMID: 35842011 PMCID: PMC10865982 DOI: 10.1016/j.neures.2022.07.003] [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: 06/03/2022] [Revised: 06/22/2022] [Accepted: 07/12/2022] [Indexed: 10/31/2022]
Abstract
Altered inhibition/excitation (I/E) balance contributes to various brain disorders. Dysfunctional GABAergic interneurons enhance or reduce inhibition, resulting in I/E imbalances. Differences in short-term plasticity between excitation and inhibition cause frequency-dependence of the I/E ratio, which can be altered by GABAergic dysfunction. However, it is unknown whether I/E imbalances can be rescued pharmacologically using a single dose when the imbalance magnitude is frequency-dependent. Loss of PGC-1α (peroxisome proliferator activated receptor γ coactivator 1α) causes transcriptional dysregulation in hippocampal GABAergic interneurons. PGC-1α-/- slices have enhanced baseline inhibition onto CA1 pyramidal cells, causing increased I/E ratio and impaired circuit function. High frequency stimulation reduces the I/E ratio and recovers circuit function in PGC-1α-/- slices. Here we tested if using a low dose of bicuculline that can restore baseline I/E ratio can also rescue the frequency-dependent I/E imbalances in these mice. Remarkably, bicuculline did not reduce the I/E ratio below that of wild type during high frequency stimulation. Interestingly, bicuculline enhanced the paired-pulse ratio (PPR) of disynaptic inhibition without changing the monosynaptic inhibition PPR, suggesting that bicuculline modifies interneuron recruitment and not GABA release. Bicuculline improved CA1 output in PGC-1α-/- slices, enhancing EPSP-spike coupling to wild type levels at high and low frequencies. Our results show that it is possible to rescue frequency-dependent I/E imbalances in an animal model of transcriptional dysregulation with a single treatment.
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Affiliation(s)
- Dwipayan Bhattacharya
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, United States
| | - Aundrea F Bartley
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, United States
| | - Qin Li
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, United States
| | - Lynn E Dobrunz
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, United States.
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10
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Simonova NA, Volgushev MA, Malyshev AY. Enhanced Non-Associative Long-Term Potentiation in Immature Granule Cells in the Dentate Gyrus of Adult Rats. Front Synaptic Neurosci 2022; 14:889947. [PMID: 35711669 PMCID: PMC9192440 DOI: 10.3389/fnsyn.2022.889947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 04/15/2022] [Indexed: 11/20/2022] Open
Abstract
The dentate gyrus is one of the few sites of neurogenesis in the adult brain. Integration of new-generated granule cells into the hippocampal circuitry provides a substrate for structural plasticity, fundamental for normal function of adult hippocampus. However, mechanisms of synaptic plasticity that mediate integration of new-generated granule cells into the existing circuitry remain poorly understood. Especially mechanisms of plasticity at GABA-ergic synapses remain elusive. Here, we show that postsynaptic spiking without presynaptic activation can induce heterosynaptic, non-associative plasticity at GABA-ergic inputs to both immature and mature granule cells. In both immature and mature neurons, plastic changes were bidirectional and individual inputs could express long-term potentiation (LTP) or long-term depression (LTD), or do not change. However, properties of non-associative plasticity dramatically change with maturation of newly generated granule cells: while in immature cells there was a clear predominance of non-associative LTP and net potentiation across the inputs, in mature neurons, potentiation and depression were balanced with no net change on average. We conclude that GABA-ergic inputs to granule cells are plastic, and that the rules for induction of non-associative plasticity change with maturation. We propose that potentiation-biased non-associative plasticity of GABA-ergic transmission might help to counter-balance an increase of excitatory drive that is facilitated by enhanced LTP at glutamatergic synapses in maturating granule cells. Such mechanism might help to build a strong GABA-ergic input to surviving active new cells, necessary for normal function of mature granule cells, which operate under a tight inhibitory control and generate sparse spiking activity.
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Affiliation(s)
- Natalia A. Simonova
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
| | - Maxim A. Volgushev
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
- *Correspondence: Maxim A. Volgushev
| | - Alexey Y. Malyshev
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
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11
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Khalife MR, Scott RC, Hernan AE. Mechanisms for Cognitive Impairment in Epilepsy: Moving Beyond Seizures. Front Neurol 2022; 13:878991. [PMID: 35645970 PMCID: PMC9135108 DOI: 10.3389/fneur.2022.878991] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
There has been a major emphasis on defining the role of seizures in the causation of cognitive impairments like memory deficits in epilepsy. Here we focus on an alternative hypothesis behind these deficits, emphasizing the mechanisms of information processing underlying healthy cognition characterized as rate, temporal and population coding. We discuss the role of the underlying etiology of epilepsy in altering neural networks thereby leading to both the propensity for seizures and the associated cognitive impairments. In addition, we address potential treatments that can recover the network function in the context of a diseased brain, thereby improving both seizure and cognitive outcomes simultaneously. This review shows the importance of moving beyond seizures and approaching the deficits from a system-level perspective with the guidance of network neuroscience.
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Affiliation(s)
- Mohamed R. Khalife
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
| | - Rod C. Scott
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
- Institute of Child Health, Neurosciences Unit University College London, London, United Kingdom
| | - Amanda E. Hernan
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
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12
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Campagnola L, Seeman SC, Chartrand T, Kim L, Hoggarth A, Gamlin C, Ito S, Trinh J, Davoudian P, Radaelli C, Kim MH, Hage T, Braun T, Alfiler L, Andrade J, Bohn P, Dalley R, Henry A, Kebede S, Mukora A, Sandman D, Williams G, Larsen R, Teeter C, Daigle TL, Berry K, Dotson N, Enstrom R, Gorham M, Hupp M, Lee SD, Ngo K, Nicovich PR, Potekhina L, Ransford S, Gary A, Goldy J, McMillen D, Pham T, Tieu M, Siverts L, Walker M, Farrell C, Schroedter M, Slaughterbeck C, Cobb C, Ellenbogen R, Gwinn RP, Keene CD, Ko AL, Ojemann JG, Silbergeld DL, Carey D, Casper T, Crichton K, Clark M, Dee N, Ellingwood L, Gloe J, Kroll M, Sulc J, Tung H, Wadhwani K, Brouner K, Egdorf T, Maxwell M, McGraw M, Pom CA, Ruiz A, Bomben J, Feng D, Hejazinia N, Shi S, Szafer A, Wakeman W, Phillips J, Bernard A, Esposito L, D’Orazi FD, Sunkin S, Smith K, Tasic B, Arkhipov A, Sorensen S, Lein E, Koch C, Murphy G, Zeng H, Jarsky T. Local connectivity and synaptic dynamics in mouse and human neocortex. Science 2022; 375:eabj5861. [PMID: 35271334 PMCID: PMC9970277 DOI: 10.1126/science.abj5861] [Citation(s) in RCA: 91] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We present a unique, extensive, and open synaptic physiology analysis platform and dataset. Through its application, we reveal principles that relate cell type to synaptic properties and intralaminar circuit organization in the mouse and human cortex. The dynamics of excitatory synapses align with the postsynaptic cell subclass, whereas inhibitory synapse dynamics partly align with presynaptic cell subclass but with considerable overlap. Synaptic properties are heterogeneous in most subclass-to-subclass connections. The two main axes of heterogeneity are strength and variability. Cell subclasses divide along the variability axis, whereas the strength axis accounts for substantial heterogeneity within the subclass. In the human cortex, excitatory-to-excitatory synaptic dynamics are distinct from those in the mouse cortex and vary with depth across layers 2 and 3.
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Affiliation(s)
| | | | | | - Lisa Kim
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Clare Gamlin
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Shinya Ito
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | | | - Travis Hage
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - Phillip Bohn
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Alex Henry
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Sara Kebede
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Alice Mukora
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | | | | | - Kyla Berry
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Nadia Dotson
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Madie Hupp
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Kiet Ngo
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - Amanda Gary
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Jeff Goldy
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Michael Tieu
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | | | | | - Charles Cobb
- The Ben and Catherine Ivy Center for Advanced Brain Tumor Treatment, Swedish Neuroscience Institute, Seattle, WA, USA
| | - Richard Ellenbogen
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - Ryder P Gwinn
- Epilepsy Surgery and Functional Neurosurgery, Swedish Neuroscience Institute, Seattle, WA, USA
| | - C. Dirk Keene
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Andrew L Ko
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA,Regional Epilepsy Center at Harborview Medical Center, Seattle, WA, USA
| | - Jeffrey G Ojemann
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA,Regional Epilepsy Center at Harborview Medical Center, Seattle, WA, USA
| | - Daniel L Silbergeld
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - Daniel Carey
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - Nick Dee
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Jessica Gloe
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Josef Sulc
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Herman Tung
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Tom Egdorf
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Medea McGraw
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - David Feng
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Shu Shi
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Aaron Szafer
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Amy Bernard
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Susan Sunkin
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | | | - Ed Lein
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Gabe Murphy
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Tim Jarsky
- Allen Institute for Brain Science, Seattle, WA, USA,Corresponding author:
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13
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Hage TA, Bosma-Moody A, Baker CA, Kratz MB, Campagnola L, Jarsky T, Zeng H, Murphy GJ. Synaptic connectivity to L2/3 of primary visual cortex measured by two-photon optogenetic stimulation. eLife 2022; 11:71103. [PMID: 35060903 PMCID: PMC8824465 DOI: 10.7554/elife.71103] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/19/2022] [Indexed: 12/04/2022] Open
Abstract
Understanding cortical microcircuits requires thorough measurement of physiological properties of synaptic connections formed within and between diverse subclasses of neurons. Towards this goal, we combined spatially precise optogenetic stimulation with multicellular recording to deeply characterize intralaminar and translaminar monosynaptic connections to supragranular (L2/3) neurons in the mouse visual cortex. The reliability and specificity of multiphoton optogenetic stimulation were measured across multiple Cre lines, and measurements of connectivity were verified by comparison to paired recordings and targeted patching of optically identified presynaptic cells. With a focus on translaminar pathways, excitatory and inhibitory synaptic connections from genetically defined presynaptic populations were characterized by their relative abundance, spatial profiles, strength, and short-term dynamics. Consistent with the canonical cortical microcircuit, layer 4 excitatory neurons and interneurons within L2/3 represented the most common sources of input to L2/3 pyramidal cells. More surprisingly, we also observed strong excitatory connections from layer 5 intratelencephalic neurons and potent translaminar inhibition from multiple interneuron subclasses. The hybrid approach revealed convergence to and divergence from excitatory and inhibitory neurons within and across cortical layers. Divergent excitatory connections often spanned hundreds of microns of horizontal space. In contrast, divergent inhibitory connections were more frequently measured from postsynaptic targets near each other.
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Affiliation(s)
- Travis A Hage
- Electrophysiology, Allen Institute for Brain Science
| | | | | | - Megan B Kratz
- Electrophysiology, Allen Institute for Brain Science
| | | | - Tim Jarsky
- Synaptic Physiology, Allen Institute for Brain Science
| | - Hongkui Zeng
- Synaptic Physiology, Allen Institute for Brain Science
| | - Gabe J Murphy
- Synaptic Physiology, Allen Institute for Brain Science
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14
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Short-Term Synaptic Plasticity: Microscopic Modelling and (Some) Computational Implications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1359:105-121. [DOI: 10.1007/978-3-030-89439-9_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Synaptic Dynamics Convey Differential Sensitivity to Input Pattern Changes in Two Muscles Innervated by the Same Motor Neurons. eNeuro 2021; 8:ENEURO.0351-21.2021. [PMID: 34764189 PMCID: PMC8609967 DOI: 10.1523/eneuro.0351-21.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/21/2021] [Accepted: 09/30/2021] [Indexed: 11/21/2022] Open
Abstract
Postsynaptic responses depend on input patterns as well as short-term synaptic plasticity, summation, and postsynaptic membrane properties, but the interactions of those dynamics with realistic input patterns are not well understood. We recorded the responses of the two pyloric dilator (PD) muscles, cpv2a and cpv2b, that are innervated by and receive identical periodic bursting input from the same two motor neurons in the lobster Homarus americanus. Cpv2a and cpv2b showed quantitative differences in membrane nonlinearities and synaptic summation. At a short timescale, responses in both muscles were dominated by facilitation, albeit with different frequency and time dependence. Realistic burst stimulations revealed more substantial differences. Across bursts, cpv2a showed transient depression, whereas cpv2b showed transient facilitation. Steady-state responses to bursting input also differed substantially. Neither muscle had a monotonic dependence on frequency, but cpv2b showed particularly pronounced bandpass filtering. Cpv2a was sensitive to changes in both burst frequency and intra-burst spike frequency, whereas, despite its much slower responses, cpv2b was largely insensitive to changes in burst frequency. Cpv2a was sensitive to both burst duration and number of spikes per burst, whereas cpv2b was sensitive only to the former parameter. Neither muscle showed consistent sensitivity to changes in the overall spike interval structure, but cpv2b was surprisingly sensitive to changes in the first intervals in each burst, a parameter known to be regulated by dopamine (DA) modulation of spike propagation of the presynaptic axon. These findings highlight how seemingly minor circuit output changes mediated by neuromodulation could be read out differentially at the two synapses.
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16
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Sjöström PJ. Grand Challenge at the Frontiers of Synaptic Neuroscience. Front Synaptic Neurosci 2021; 13:748937. [PMID: 34759809 PMCID: PMC8575031 DOI: 10.3389/fnsyn.2021.748937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/22/2021] [Indexed: 11/24/2022] Open
Affiliation(s)
- P. Jesper Sjöström
- Department of Medicine, Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
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17
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Short-Term Synaptic Plasticity Makes Neurons Sensitive to the Distribution of Presynaptic Population Firing Rates. eNeuro 2021; 8:ENEURO.0297-20.2021. [PMID: 33579731 PMCID: PMC8035045 DOI: 10.1523/eneuro.0297-20.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 01/14/2021] [Accepted: 01/19/2021] [Indexed: 12/25/2022] Open
Abstract
The ability to discriminate spikes that encode a particular stimulus from spikes produced by background activity is essential for reliable information processing in the brain. We describe how synaptic short-term plasticity (STP) modulates the output of presynaptic populations as a function of the distribution of the spiking activity and find a strong relationship between STP features and sparseness of the population code, which could solve this problem. Furthermore, we show that feedforward excitation followed by inhibition (FF-EI), combined with target-dependent STP, promote substantial increase in the signal gain even for considerable deviations from the optimal conditions, granting robustness to this mechanism. A simulated neuron driven by a spiking FF-EI network is reliably modulated as predicted by a rate analysis and inherits the ability to differentiate sparse signals from dense background activity changes of the same magnitude, even at very low signal-to-noise conditions. We propose that the STP-based distribution discrimination is likely a latent function in several regions such as the cerebellum and the hippocampus.
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18
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Wong HHW, Rannio S, Jones V, Thomazeau A, Sjöström PJ. NMDA receptors in axons: there's no coincidence. J Physiol 2020; 599:367-387. [PMID: 33141440 DOI: 10.1113/jp280059] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/27/2020] [Indexed: 12/16/2022] Open
Abstract
In the textbook view, N-methyl-d-aspartate (NMDA) receptors are postsynaptically located detectors of coincident activity in Hebbian learning. However, controversial presynaptically located NMDA receptors (preNMDARs) have for decades been repeatedly reported in the literature. These preNMDARs have typically been implicated in the regulation of short-term and long-term plasticity, but precisely how they signal and what their functional roles are have been poorly understood. The functional roles of preNMDARs across several brain regions and different forms of plasticity can differ vastly, with recent discoveries showing key involvement of unusual subunit composition. Increasing evidence shows preNMDAR can signal through both ionotropic action by fluxing calcium and in metabotropic mode even in the presence of magnesium blockade. We argue that these unusual properties may explain why controversy has surrounded this receptor type. In addition, the expression of preNMDARs at some synapse types but not others can underlie synapse-type-specific plasticity. Last but not least, preNMDARs are emerging therapeutic targets in disease states such as neuropathic pain. We conclude that axonally located preNMDARs are required for specific purposes and do not end up there by accident.
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Affiliation(s)
- Hovy Ho-Wai Wong
- Department of Medicine, Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Ave, Montreal, Quebec, H3G 1A4, Canada
| | - Sabine Rannio
- Department of Medicine, Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Ave, Montreal, Quebec, H3G 1A4, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Victoria Jones
- Department of Medicine, Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Ave, Montreal, Quebec, H3G 1A4, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Aurore Thomazeau
- Department of Medicine, Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Ave, Montreal, Quebec, H3G 1A4, Canada
| | - P Jesper Sjöström
- Department of Medicine, Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Ave, Montreal, Quebec, H3G 1A4, Canada
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19
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Chavushyan V, Soghomonyan A, Karapetyan G, Simonyan K, Yenkoyan K. Disruption of Cholinergic Circuits as an Area for Targeted Drug Treatment of Alzheimer's Disease: In Vivo Assessment of Short-Term Plasticity in Rat Brain. Pharmaceuticals (Basel) 2020; 13:ph13100297. [PMID: 33050228 PMCID: PMC7600922 DOI: 10.3390/ph13100297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 12/26/2022] Open
Abstract
The search for new therapeutics for the treatment of Alzheimer’s disease (AD) is still in progress. Aberrant pathways of synaptic transmission in basal forebrain cholinergic neural circuits are thought to be associated with the progression of AD. However, the effect of amyloid-beta (Aβ) on short-term plasticity (STP) of cholinergic circuits in the nucleus basalis magnocellularis (NBM) is largely unknown. STP assessment in rat brain cholinergic circuitry may indicate a new target for AD cholinergic therapeutics. Thus, we aimed to study in vivo electrophysiological patterns of synaptic activity in NBM-hippocampus and NBM-basolateral amygdala circuits associated with AD-like neurodegeneration. The extracellular single-unit recordings of responses from the hippocampal and basolateral amygdala neurons to high-frequency stimulation (HFS) of the NBM were performed after intracerebroventricular injection of Aβ 25–35. We found that after Aβ 25–35 exposure the number of hippocampal neurons exhibiting inhibitory responses to HFS of NBM is decreased. The reverse tendency was seen in the basolateral amygdala inhibitory neural populations, whereas the number of amygdala neurons with excitatory responses decreased. The low intensity of inhibitory and excitatory responses during HFS and post-stimulus period is probably due to the anomalous basal synaptic transmission and excitability of hippocampal and amygdala neurons. These functional changes were accompanied by structural alteration of hippocampal, amygdala, and NBM neurons. We have thus demonstrated that Aβ 25–35 induces STP disruption in NBM-hippocampus and NBM-basolateral amygdala circuits as manifested by unbalanced excitatory/inhibitory responses and their frequency. The results of this study may contribute to a better understanding of synaptic integrity. We believe that advancing our understanding of in vivo mechanisms of synaptic plasticity disruption in specific neural circuits could lead to effective drug searches for AD treatment.
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Affiliation(s)
- Vergine Chavushyan
- Laboratory of Neuroscience, Yerevan State Medical University after M. Heratsi, Yerevan 0025, Armenia; (V.C.); (A.S.); (G.K.)
- Laboratory of Neuroendocrine Relations, L. Orbeli Institute of Physiology of NAS, Yerevan 0028, Armenia;
| | - Ani Soghomonyan
- Laboratory of Neuroscience, Yerevan State Medical University after M. Heratsi, Yerevan 0025, Armenia; (V.C.); (A.S.); (G.K.)
- Department of Biochemistry, Yerevan State Medical University after M. Heratsi, Yerevan 0025, Armenia
| | - Gohar Karapetyan
- Laboratory of Neuroscience, Yerevan State Medical University after M. Heratsi, Yerevan 0025, Armenia; (V.C.); (A.S.); (G.K.)
- Department of Biochemistry, Yerevan State Medical University after M. Heratsi, Yerevan 0025, Armenia
| | - Karen Simonyan
- Laboratory of Neuroendocrine Relations, L. Orbeli Institute of Physiology of NAS, Yerevan 0028, Armenia;
| | - Konstantin Yenkoyan
- Laboratory of Neuroscience, Yerevan State Medical University after M. Heratsi, Yerevan 0025, Armenia; (V.C.); (A.S.); (G.K.)
- Department of Biochemistry, Yerevan State Medical University after M. Heratsi, Yerevan 0025, Armenia
- Correspondence: or ; Tel.: +374-11-621-074
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20
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Embryonic proteoglycans regulate monoamines in the rat frontal cortex and hippocampus in Alzheimer's disease-like pathology. Neurochem Int 2020; 140:104838. [PMID: 32853753 DOI: 10.1016/j.neuint.2020.104838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 08/05/2020] [Accepted: 08/14/2020] [Indexed: 11/20/2022]
Abstract
Using the rat Alzheimer's disease (AD)-like model we have analyzed the hippocampal short-term potentiation, levels of monoamines, and morphological changes in the hippocampal and cortical neurons after the administration of proteoglycans of embryonic origin (PEG). Results showed that the levels of monoamines and especially norepinephrine in the target AD brain structures were found elevated, except serotonin, which was unaffected in the hippocampus, but decreased in the frontal cortex. These changes were accompanied by the substantial structural damage of cortical and hippocampal neurons. PEG was able to reverse most of these changes. In addition, PEG administration had regime-dependent effects on a short-term potentiation pattern of hippocampal neurons. The elevated levels of key elements of brain monoaminergic system in the model of AD support the hypothesis of the important role of monoamines in the excessive synaptic excitation resulting in cognitive dysfunction in AD brain. The neuroprotective effect of PEG, as manifested by the recovery of the monoaminergic system, suggests this bioactive substance as a perspective therapeutic agent for the treatment of AD.
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21
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Berke B, Le L, Keshishian H. Target-dependent retrograde signaling mediates synaptic plasticity at the Drosophila neuromuscular junction. Dev Neurobiol 2020; 79:895-912. [PMID: 31950660 DOI: 10.1002/dneu.22731] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 12/26/2022]
Abstract
Neurons that innervate multiple targets often establish synapses with target-specific strengths, and local forms of synaptic plasticity. We have examined the molecular-genetic mechanisms that allow a single Drosophila motoneuron, the ventral Common Exciter (vCE), to establish connections with target-specific properties at its various synaptic partners. By driving transgenes in a subset of vCE's targets, we found that individual target cells are able to independently control the properties of vCE's innervating branch and synapses. This is achieved by means of a trans-synaptic growth factor secreted by the target cell. At the larval neuromuscular junction, postsynaptic glutamate receptor activity stimulates the release of the BMP4/5/6 homolog Glass bottom boat (Gbb). As larvae mature and motoneuron terminals grow, Gbb activates the R-Smad transcriptional regulator phosphorylated Mad (pMad) to facilitate presynaptic development. We found that manipulations affecting glutamate receptors or Gbb within subsets of target muscles led to local effects either specific to the manipulated muscle or by a limited gradient within the presynaptic branches. While presynaptic development depends on pMad transcriptional activity within the motoneuron nucleus, we find that the Gbb growth factor may also act locally within presynaptic terminals. Local Gbb signaling and presynaptic pMad accumulation within boutons may therefore participate in a "synaptic tagging" mechanism, to influence synaptic growth and plasticity in Drosophila.
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Affiliation(s)
- Brett Berke
- Molecular, Cellular, and Developmental Biology Department, Yale University, New Haven, CT, USA
| | - Linh Le
- University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Haig Keshishian
- Molecular, Cellular, and Developmental Biology Department, Yale University, New Haven, CT, USA
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22
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Regulation of Recurrent Inhibition by Asynchronous Glutamate Release in Neocortex. Neuron 2020; 105:522-533.e4. [DOI: 10.1016/j.neuron.2019.10.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 06/11/2019] [Accepted: 10/28/2019] [Indexed: 01/06/2023]
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23
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Dorgans K, Demais V, Bailly Y, Poulain B, Isope P, Doussau F. Short-term plasticity at cerebellar granule cell to molecular layer interneuron synapses expands information processing. eLife 2019; 8:41586. [PMID: 31081751 PMCID: PMC6533085 DOI: 10.7554/elife.41586] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 05/11/2019] [Indexed: 12/14/2022] Open
Abstract
Information processing by cerebellar molecular layer interneurons (MLIs) plays a crucial role in motor behavior. MLI recruitment is tightly controlled by the profile of short-term plasticity (STP) at granule cell (GC)-MLI synapses. While GCs are the most numerous neurons in the brain, STP diversity at GC-MLI synapses is poorly documented. Here, we studied how single MLIs are recruited by their distinct GC inputs during burst firing. Using slice recordings at individual GC-MLI synapses of mice, we revealed four classes of connections segregated by their STP profile. Each class differentially drives MLI recruitment. We show that GC synaptic diversity is underlain by heterogeneous expression of synapsin II, a key actor of STP and that GC terminals devoid of synapsin II are associated with slow MLI recruitment. Our study reveals that molecular, structural and functional diversity across GC terminals provides a mechanism to expand the coding range of MLIs.
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Affiliation(s)
- Kevin Dorgans
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France
| | - Valérie Demais
- Plateforme Imagerie in vitro, CNRS UPS 3156, Strasbourg, France
| | - Yannick Bailly
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France.,Plateforme Imagerie in vitro, CNRS UPS 3156, Strasbourg, France
| | - Bernard Poulain
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France
| | - Philippe Isope
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France
| | - Frédéric Doussau
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France
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Khalil R, Karim AA, Khedr E, Moftah M, Moustafa AA. Dynamic Communications Between GABA A Switch, Local Connectivity, and Synapses During Cortical Development: A Computational Study. Front Cell Neurosci 2018; 12:468. [PMID: 30618625 PMCID: PMC6304749 DOI: 10.3389/fncel.2018.00468] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 11/16/2018] [Indexed: 11/13/2022] Open
Abstract
Several factors regulate cortical development, such as changes in local connectivity and the influences of dynamical synapses. In this study, we simulated various factors affecting the regulation of neural network activity during cortical development. Previous studies have shown that during early cortical development, the reversal potential of GABAA shifts from depolarizing to hyperpolarizing. Here we provide the first integrative computational model to simulate the combined effects of these factors in a unified framework (building on our prior work: Khalil et al., 2017a,b). In the current study, we extend our model to monitor firing activity in response to the excitatory action of GABAA. Precisely, we created a Spiking Neural Network model that included certain biophysical parameters for lateral connectivity (distance between adjacent neurons) and nearby local connectivity (complex connections involving those between neuronal groups). We simulated different network scenarios (for immature and mature conditions) based on these biophysical parameters. Then, we implemented two forms of Short-term synaptic plasticity (depression and facilitation). Each form has two distinct kinds according to its synaptic time constant value. Finally, in both sets of networks, we compared firing rate activity responses before and after simulating dynamical synapses. Based on simulation results, we found that the modulation effect of dynamical synapses for evaluating and shaping the firing activity of the neural network is strongly dependent on the physiological state of GABAA. Moreover, the STP mechanism acts differently in every network scenario, mirroring the crucial modulating roles of these critical parameters during cortical development. Clinical implications for pathological alterations of GABAergic signaling in neurological and psychiatric disorders are discussed.
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Affiliation(s)
- Radwa Khalil
- Department of Psychology and Methods, Jacobs University Bremen, Bremen, Germany
| | - Ahmed A Karim
- Department of Psychology and Methods, Jacobs University Bremen, Bremen, Germany.,University Clinic of Psychiatry and Psychotherapy, Tübingen, Germany
| | - Eman Khedr
- Department of Neuropsychiatry, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Marie Moftah
- Zoology Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Ahmed A Moustafa
- MARCS Institute for Brain and Behaviour, Western Sydney University, Sydney, NSW, Australia.,Department of Social Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
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25
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Lalanne T, Oyrer J, Farrant M, Sjöström PJ. Synapse Type-Dependent Expression of Calcium-Permeable AMPA Receptors. Front Synaptic Neurosci 2018; 10:34. [PMID: 30369875 PMCID: PMC6194349 DOI: 10.3389/fnsyn.2018.00034] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 09/24/2018] [Indexed: 12/13/2022] Open
Abstract
Calcium-permeable (CP) AMPA-type glutamate receptors (AMPARs) are known to mediate synaptic plasticity in several different interneuron (IN) types. Recent evidence suggests that CP-AMPARs are synapse-specifically expressed at excitatory connections onto a subset of IN types in hippocampus and neocortex. For example, CP-AMPARs are found at connections from pyramidal cells (PCs) to basket cells (BCs), but not to Martinotti cells (MCs). This synapse type-specific expression of CP-AMPARs suggests that synaptic dynamics as well as learning rules are differentially implemented in local circuits and has important implications not just in health but also in disease states such as epilepsy.
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Affiliation(s)
- Txomin Lalanne
- Department of Biomedicine, Institute of Physiology, University of Basel, Basel, Switzerland
| | - Julia Oyrer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, Montreal General Hospital, The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
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26
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Llera-Montero M, Sacramento J, Costa RP. Computational roles of plastic probabilistic synapses. Curr Opin Neurobiol 2018; 54:90-97. [PMID: 30308457 DOI: 10.1016/j.conb.2018.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/02/2018] [Accepted: 09/06/2018] [Indexed: 11/18/2022]
Abstract
The probabilistic nature of synaptic transmission has remained enigmatic. However, recent developments have started to shed light on why the brain may rely on probabilistic synapses. Here, we start out by reviewing experimental evidence on the specificity and plasticity of synaptic response statistics. Next, we overview different computational perspectives on the function of plastic probabilistic synapses for constrained, statistical and deep learning. We highlight that all of these views require some form of optimisation of probabilistic synapses, which has recently gained support from theoretical analysis of long-term synaptic plasticity experiments. Finally, we contrast these different computational views and propose avenues for future research. Overall, we argue that the time is ripe for a better understanding of the computational functions of probabilistic synapses.
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Affiliation(s)
- Milton Llera-Montero
- Computational Neuroscience Unit, Department of Computer Science, School of Computer Science, Electrical and Electronic Engineering, and Engineering Mathematics, Faculty of Engineering, University of Bristol, United Kingdom; Bristol Neuroscience, University of Bristol, United Kingdom; School of Psychological Science, Faculty of Life Sciences, University of Bristol, United Kingdom
| | | | - Rui Ponte Costa
- Computational Neuroscience Unit, Department of Computer Science, School of Computer Science, Electrical and Electronic Engineering, and Engineering Mathematics, Faculty of Engineering, University of Bristol, United Kingdom; Bristol Neuroscience, University of Bristol, United Kingdom; Department of Physiology, University of Bern, Switzerland; Centre for Neural Circuits and Behaviour, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom.
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27
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Sun HY, Li Q, Bartley AF, Dobrunz LE. Target-cell-specific Short-term Plasticity Reduces the Excitatory Drive onto CA1 Interneurons Relative to Pyramidal Cells During Physiologically-derived Spike Trains. Neuroscience 2018; 388:430-447. [PMID: 30099117 PMCID: PMC6201261 DOI: 10.1016/j.neuroscience.2018.07.051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 06/27/2018] [Accepted: 07/30/2018] [Indexed: 11/25/2022]
Abstract
Short-term plasticity enables synaptic strength to be dynamically regulated by input timing. Excitatory synapses arising from the same axon can have profoundly different presynaptic forms of short-term plasticity onto inhibitory and excitatory neurons. We previously showed that Schaffer collateral synapses onto most hippocampal CA1 stratum radiatum interneurons have less paired-pulse facilitation than synapses onto CA1 pyramidal cells, but little difference in steady-state short-term depression. However, less is known about how synapses onto interneurons respond to temporally complex patterns that occur in vivo. Here we compared Schaffer collateral synapses onto stratum radiatum interneurons and pyramidal cells in acute hippocampal slices in response to physiologically-derived spike trains. We find that synapses onto interneurons have less short-term facilitation than synapses onto pyramidal cells, and a subset expresses only short-term depression. Mathematical modeling predicts this target cell-specific short-term plasticity occurs through differences in initial release probability. All three groups have more short-term facilitation during physiologically-derived train stimulation than during constant-frequency stimulation at the same frequency, indicating that variability in stimulus timing is important. These target-cell specific differences in short-term plasticity reduce the strength of excitatory input onto interneurons relative to pyramidal cells, and of depression interneurons relative to facilitation interneurons, during high frequency portions of the train. This occurs to a similar extent at 25 °C and at 33 °C, and is even greater at physiological extracellular calcium. Target-cell specific differences in short-term plasticity enable synapses to have different temporal filtering characteristics, which may help to dynamically regulate the balance of inhibition and excitation in CA1.
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Affiliation(s)
- Hua Yu Sun
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Qin Li
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Aundrea F Bartley
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lynn E Dobrunz
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA.
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28
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Bouvier G, Larsen RS, Rodríguez-Moreno A, Paulsen O, Sjöström PJ. Towards resolving the presynaptic NMDA receptor debate. Curr Opin Neurobiol 2018; 51:1-7. [DOI: 10.1016/j.conb.2017.12.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/15/2017] [Accepted: 12/31/2017] [Indexed: 12/13/2022]
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29
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Wallrafen R, Dresbach T. The Presynaptic Protein Mover Is Differentially Expressed Across Brain Areas and Synapse Types. Front Neuroanat 2018; 12:58. [PMID: 30057527 PMCID: PMC6053503 DOI: 10.3389/fnana.2018.00058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/21/2018] [Indexed: 01/12/2023] Open
Abstract
The assembly and function of presynaptic nerve terminals relies on evolutionarily conserved proteins. A small number of presynaptic proteins occurs only in vertebrates. These proteins may add specialized functions to certain synapses, thus increasing synaptic heterogeneity. Here, we show that the vertebrate-specific synaptic vesicle (SV) protein mover is differentially distributed in the forebrain and cerebellum of the adult mouse. Using a quantitative immunofluorescence approach, we compare the expression of mover to the expression of the general SV marker synaptophysin in 16 brain areas. We find that mover is particularly abundant in the septal nuclei (SNu), ventral pallidum (VPa), amygdala and hippocampus. Within the hippocampus, mover is predominantly associated with excitatory synapses. Its levels are low in layers that receive afferent input from the entorhinal cortex, and high in layers harboring intra-hippocampal circuits. In contrast, mover levels are high in all nuclei of the amygdala, and mover is associated with inhibitory synapses in the medioposterior amygdala. Our data reveal a striking heterogeneity in the abundance of mover on three levels, i.e., between brain areas, within individual brain areas and between synapse types. This distribution suggests a role for mover in providing specialization to subsets of synapses, thereby contributing to the functional diversity of brain areas.
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Affiliation(s)
| | - Thomas Dresbach
- Synaptogenesis Group, Institute of Anatomy and Embryology, University Medical Center Goettingen, Goettingen, Germany
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30
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Luo H, Hasegawa K, Liu M, Song WJ. Comparison of the Upper Marginal Neurons of Cortical Layer 2 with Layer 2/3 Pyramidal Neurons in Mouse Temporal Cortex. Front Neuroanat 2017; 11:115. [PMID: 29311847 PMCID: PMC5742574 DOI: 10.3389/fnana.2017.00115] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 11/27/2017] [Indexed: 11/13/2022] Open
Abstract
Layer 2/3 (L2/3) excitatory neurons in the neocortex make major contributions to corticocortical connections and therefore function to integrate information across cortical areas and hemispheres. Recent evidence suggests that excitatory neurons in L2/3 can have different properties. Sparse evidence from previous studies suggests that L2 neurons located at the border between L1 and L2 (referred to as L2 marginal neurons, L2MNs), have a morphology distinct from a typical pyramidal neuron. However, whether the membrane properties and input/output properties of L2MNs are different from those of typical pyramidal neurons in L2/3 is unknown. Here we addressed these questions in a slice preparation of mouse temporal cortex. We found that L2MNs were homogeneous in intrinsic membrane properties but appeared diverse in morphology. In agreement with previous studies, L2MNs either had oblique apical dendrites or had no obvious apical dendrites. The tufts of both apical and basal dendrites of these neurons invaded L1 extensively. All L2MNs showed a regular firing pattern with moderate adaptation. Compared with typical L2/3 pyramidal neurons that showed regular spiking (RS) activity (neurons), L2MNs showed a higher firing rate, larger sag ratio, and higher input resistance. No difference in the amplitude of excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs, respectively), evoked by stimulation of L1, was found between the two types of neurons, but the IPSPs in L2MNs had a slower time course than those in L2/3 RS cells. In paired recordings, unitary EPSPs showed no significant differences between synapses formed by L2MNs and those formed by L2/3 RS neurons. However, short-term synaptic depression (STSD) examined with a L2MN as the presynaptic neuron was greater when another L2MN was the postsynaptic neuron than when a L2/3 RS neuron was the postsynaptic neuron. The distinct morphological features of L2MNs found here have developmental implications, and the differences in electrophysiological properties between L2MNs and other L2/3 pyramidal neurons suggest that they play different functional roles in cortical networks.
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Affiliation(s)
- Huan Luo
- Department of Sensory and Cognitive Physiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.,Program for Leading Graduate Schools HIGO Program, Kumamoto University, Kumamoto, Japan
| | - Kayoko Hasegawa
- Department of Sensory and Cognitive Physiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Mingsheng Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Wen-Jie Song
- Department of Sensory and Cognitive Physiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.,Program for Leading Graduate Schools HIGO Program, Kumamoto University, Kumamoto, Japan
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31
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Costa RP, Mizusaki BEP, Sjöström PJ, van Rossum MCW. Functional consequences of pre- and postsynaptic expression of synaptic plasticity. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0153. [PMID: 28093547 PMCID: PMC5247585 DOI: 10.1098/rstb.2016.0153] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2016] [Indexed: 01/23/2023] Open
Abstract
Growing experimental evidence shows that both homeostatic and Hebbian synaptic plasticity can be expressed presynaptically as well as postsynaptically. In this review, we start by discussing this evidence and methods used to determine expression loci. Next, we discuss the functional consequences of this diversity in pre- and postsynaptic expression of both homeostatic and Hebbian synaptic plasticity. In particular, we explore the functional consequences of a biologically tuned model of pre- and postsynaptically expressed spike-timing-dependent plasticity complemented with postsynaptic homeostatic control. The pre- and postsynaptic expression in this model predicts (i) more reliable receptive fields and sensory perception, (ii) rapid recovery of forgotten information (memory savings), and (iii) reduced response latencies, compared with a model with postsynaptic expression only. Finally, we discuss open questions that will require a considerable research effort to better elucidate how the specific locus of expression of homeostatic and Hebbian plasticity alters synaptic and network computations.This article is part of the themed issue 'Integrating Hebbian and homeostatic plasticity'.
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Affiliation(s)
- Rui Ponte Costa
- Institute for Adaptive and Neural Computation, School of Informatics University of Edinburgh, Edinburgh, UK.,Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Beatriz E P Mizusaki
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Program for Brain Repair and Integrative Neuroscience, The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Program for Brain Repair and Integrative Neuroscience, The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Mark C W van Rossum
- Institute for Adaptive and Neural Computation, School of Informatics University of Edinburgh, Edinburgh, UK
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32
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Differential Regulation of Evoked and Spontaneous Release by Presynaptic NMDA Receptors. Neuron 2017; 96:839-855.e5. [DOI: 10.1016/j.neuron.2017.09.030] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/03/2017] [Accepted: 09/19/2017] [Indexed: 01/04/2023]
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33
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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: 490] [Impact Index Per Article: 70.0] [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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34
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McDonnell MD, Graham BP. Phase changes in neuronal postsynaptic spiking due to short term plasticity. PLoS Comput Biol 2017; 13:e1005634. [PMID: 28937977 PMCID: PMC5627952 DOI: 10.1371/journal.pcbi.1005634] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 10/04/2017] [Accepted: 06/08/2017] [Indexed: 02/03/2023] Open
Abstract
In the brain, the postsynaptic response of a neuron to time-varying inputs is determined by the interaction of presynaptic spike times with the short-term dynamics of each synapse. For a neuron driven by stochastic synapses, synaptic depression results in a quite different postsynaptic response to a large population input depending on how correlated in time the spikes across individual synapses are. Here we show using both simulations and mathematical analysis that not only the rate but the phase of the postsynaptic response to a rhythmic population input varies as a function of synaptic dynamics and synaptic configuration. Resultant phase leads may compensate for transmission delays and be predictive of rhythmic changes. This could be particularly important for sensory processing and motor rhythm generation in the nervous system. The synapses that connect neurons in the brain are far from being simple relay points that pass a signal from one neuron to another. There is now much evidence that long term changes in the strength of such connections, which determines the amplitude of the received signal, underpin learning and memory in the brain. However, signal amplitudes also fluctuate on fast time scales of milliseconds to seconds due to a variety of particular presynaptic mechanisms that regulate the release of neurotransmitter from the presynaptic terminal. Understanding the signal filtering properties of this short-term plasticity (STP) is a challenge and requires theoretical models. Aspects such as rate filtering and information transfer have been studied. Here we explore the effects of STP on the phase of a receiving neuron’s response to oscillating input and show that short-term depression can result in a frequency-dependent phase lead. This may be particularly important in the processing of rhythmic visual and auditory signals and producing rhythmic motor outputs.
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Affiliation(s)
- Mark D. McDonnell
- Computational Learning Systems Laboratory, School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, Australia
- * E-mail: (MDM); (BPG)
| | - Bruce P. Graham
- Computing Science & Mathematics, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
- * E-mail: (MDM); (BPG)
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35
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Blitz DM, Pritchard AE, Latimer JK, Wakefield AT. Muscles innervated by a single motor neuron exhibit divergent synaptic properties on multiple time scales. ACTA ACUST UNITED AC 2017; 220:1233-1244. [PMID: 28104799 DOI: 10.1242/jeb.148908] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/10/2017] [Indexed: 11/20/2022]
Abstract
Adaptive changes in the output of neural circuits underlying rhythmic behaviors are relayed to muscles via motor neuron activity. Presynaptic and postsynaptic properties of neuromuscular junctions can impact the transformation from motor neuron activity to muscle response. Further, synaptic plasticity occurring on the time scale of inter-spike intervals can differ between multiple muscles innervated by the same motor neuron. In rhythmic behaviors, motor neuron bursts can elicit additional synaptic plasticity. However, it is unknown whether plasticity regulated by the longer time scale of inter-burst intervals also differs between synapses from the same neuron, and whether any such distinctions occur across a physiological activity range. To address these issues, we measured electrical responses in muscles innervated by a chewing circuit neuron, the lateral gastric (LG) motor neuron, in a well-characterized small motor system, the stomatogastric nervous system (STNS) of the Jonah crab, Cancer borealisIn vitro and in vivo, sensory, hormonal and modulatory inputs elicit LG bursting consisting of inter-spike intervals of 50-250 ms and inter-burst intervals of 2-24 s. Muscles expressed similar facilitation measured with paired stimuli except at the shortest inter-spike interval. However, distinct decay time constants resulted in differences in temporal summation. In response to bursting activity, augmentation occurred to different extents and saturated at different inter-burst intervals. Further, augmentation interacted with facilitation, resulting in distinct intra-burst facilitation between muscles. Thus, responses of multiple target muscles diverge across a physiological activity range as a result of distinct synaptic properties sensitive to multiple time scales.
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Affiliation(s)
- Dawn M Blitz
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - Amy E Pritchard
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - John K Latimer
- Department of Biology, Miami University, Oxford, OH 45056, USA
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36
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Barroso-Flores J, Herrera-Valdez MA, Galarraga E, Bargas J. Models of Short-Term Synaptic Plasticity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1015:41-57. [PMID: 29080020 DOI: 10.1007/978-3-319-62817-2_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We focus on dynamical descriptions of short-term synaptic plasticity. Instead of focusing on the molecular machinery that has been reviewed recently by several authors, we concentrate on the dynamics and functional significance of synaptic plasticity, and review some mathematical models that reproduce different properties of the dynamics of short term synaptic plasticity that have been observed experimentally. The complexity and shortcomings of these models point to the need of simple, yet physiologically meaningful models. We propose a simplified model to be tested in synapses displaying different types of short-term plasticity.
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Affiliation(s)
- Janet Barroso-Flores
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, DF, 04510, Mexico.
| | - Marco A Herrera-Valdez
- Departamento de Matemáticas, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, DF, 04510, Mexico.
| | - Elvira Galarraga
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, DF, 04510, Mexico
| | - José Bargas
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, DF, 04510, Mexico
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Gillary G, Niebur E. The Edge of Stability: Response Times and Delta Oscillations in Balanced Networks. PLoS Comput Biol 2016; 12:e1005121. [PMID: 27689361 PMCID: PMC5045166 DOI: 10.1371/journal.pcbi.1005121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/26/2016] [Indexed: 11/27/2022] Open
Abstract
The standard architecture of neocortex is a network with excitation and inhibition in closely maintained balance. These networks respond fast and with high precision to their inputs and they allow selective amplification of patterned signals. The stability of such networks is known to depend on balancing the strengths of positive and negative feedback. We here show that a second condition is required for stability which depends on the relative strengths and time courses of fast (AMPA) and slow (NMDA) currents in the excitatory projections. This condition also determines the response time of the network. We show that networks which respond quickly to an input are necessarily close to an oscillatory instability which resonates in the delta range. This instability explains the existence of neocortical delta oscillations and the emergence of absence epilepsy. Although cortical delta oscillations are a network-level phenomenon, we show that in non-pathological networks, individual neurons receive sufficient information to keep the network in the fast-response regime without sliding into the instability. Many networks in the brain are finely balanced, with equal contributions from excitation and inhibition. Deviations from this balance, if for instance the total amount of excitation exceeds that of inhibition, lead to potentially devastating instabilities. Unlike previous work we consider the interaction between fast and slow excitatory connections. We show that not only the amount of excitation needs to be controlled to achieve network stability but also the ratio of slow to fast excitation. Furthermore, optimally fast network performance requires that networks approach instability. However, networks very close to this instability develop oscillations in the delta range (1–4Hz) which potentially cause absence epilepsy. We show that a normal (non-pathological) network can auto-regulate its activity to avoid the instability.
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Affiliation(s)
- Grant Gillary
- Zanvyl Krieger Mind/Brain Institute, Baltimore, Maryland, United States of America
- Solomon Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Ernst Niebur
- Zanvyl Krieger Mind/Brain Institute, Baltimore, Maryland, United States of America
- Solomon Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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Tao C, Nichols TE, Hua X, Ching CRK, Rolls ET, Thompson PM, Feng J. Generalized reduced rank latent factor regression for high dimensional tensor fields, and neuroimaging-genetic applications. Neuroimage 2016; 144:35-57. [PMID: 27666385 DOI: 10.1016/j.neuroimage.2016.08.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 08/01/2016] [Accepted: 08/14/2016] [Indexed: 11/18/2022] Open
Abstract
We propose a generalized reduced rank latent factor regression model (GRRLF) for the analysis of tensor field responses and high dimensional covariates. The model is motivated by the need from imaging-genetic studies to identify genetic variants that are associated with brain imaging phenotypes, often in the form of high dimensional tensor fields. GRRLF identifies from the structure in the data the effective dimensionality of the data, and then jointly performs dimension reduction of the covariates, dynamic identification of latent factors, and nonparametric estimation of both covariate and latent response fields. After accounting for the latent and covariate effects, GRLLF performs a nonparametric test on the remaining factor of interest. GRRLF provides a better factorization of the signals compared with common solutions, and is less susceptible to overfitting because it exploits the effective dimensionality. The generality and the flexibility of GRRLF also allow various statistical models to be handled in a unified framework and solutions can be efficiently computed. Within the field of neuroimaging, it improves the sensitivity for weak signals and is a promising alternative to existing approaches. The operation of the framework is demonstrated with both synthetic datasets and a real-world neuroimaging example in which the effects of a set of genes on the structure of the brain at the voxel level were measured, and the results compared favorably with those from existing approaches.
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Affiliation(s)
- Chenyang Tao
- Centre for Computational Systems Biology and School of Mathematical Sciences, Fudan University, Shanghai, PR China; Department of Computer Science, Warwick University, Coventry, UK
| | | | - Xue Hua
- Imaging Genetics Center, Institute for Neuroimaging & Informatics, University of Southern California, Los Angeles, CA, USA
| | - Christopher R K Ching
- Imaging Genetics Center, Institute for Neuroimaging & Informatics, University of Southern California, Los Angeles, CA, USA; Interdepartmental Neuroscience Graduate Program, UCLA School of Medicine, Los Angeles, CA, USA
| | - Edmund T Rolls
- Department of Computer Science, Warwick University, Coventry, UK; Oxford Centre for Computational Neuroscience, Oxford, UK
| | - Paul M Thompson
- Imaging Genetics Center, Institute for Neuroimaging & Informatics, University of Southern California, Los Angeles, CA, USA; Departments of Neurology, Psychiatry, Radiology, Engineering, Pediatrics, and Ophthalmology, USC, Los Angeles, CA, USA
| | - Jianfeng Feng
- Centre for Computational Systems Biology and School of Mathematical Sciences, Fudan University, Shanghai, PR China; Department of Computer Science, Warwick University, Coventry, UK; School of Life Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200433, PR China.
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Kwon SK, Sando R, Lewis TL, Hirabayashi Y, Maximov A, Polleux F. LKB1 Regulates Mitochondria-Dependent Presynaptic Calcium Clearance and Neurotransmitter Release Properties at Excitatory Synapses along Cortical Axons. PLoS Biol 2016; 14:e1002516. [PMID: 27429220 PMCID: PMC4948842 DOI: 10.1371/journal.pbio.1002516] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 06/21/2016] [Indexed: 12/24/2022] Open
Abstract
Individual synapses vary significantly in their neurotransmitter release properties, which underlie complex information processing in neural circuits. Presynaptic Ca2+ homeostasis plays a critical role in specifying neurotransmitter release properties, but the mechanisms regulating synapse-specific Ca2+ homeostasis in the mammalian brain are still poorly understood. Using electrophysiology and genetically encoded Ca2+ sensors targeted to the mitochondrial matrix or to presynaptic boutons of cortical pyramidal neurons, we demonstrate that the presence or absence of mitochondria at presynaptic boutons dictates neurotransmitter release properties through Mitochondrial Calcium Uniporter (MCU)-dependent Ca2+ clearance. We demonstrate that the serine/threonine kinase LKB1 regulates MCU expression, mitochondria-dependent Ca2+ clearance, and thereby, presynaptic release properties. Re-establishment of MCU-dependent mitochondrial Ca2+ uptake at glutamatergic synapses rescues the altered neurotransmitter release properties characterizing LKB1-null cortical axons. Our results provide novel insights into the cellular and molecular mechanisms whereby mitochondria control neurotransmitter release properties in a bouton-specific way through presynaptic Ca2+ clearance.
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Affiliation(s)
- Seok-Kyu Kwon
- Columbia University Medical Center, Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, New York, New York, United States of America
| | - Richard Sando
- The Scripps Research Institute, Dorris Neuroscience Center, La Jolla, California, United States of America
| | - Tommy L. Lewis
- Columbia University Medical Center, Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, New York, New York, United States of America
| | - Yusuke Hirabayashi
- Columbia University Medical Center, Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, New York, New York, United States of America
| | - Anton Maximov
- The Scripps Research Institute, Dorris Neuroscience Center, La Jolla, California, United States of America
| | - Franck Polleux
- Columbia University Medical Center, Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, New York, New York, United States of America
- * E-mail:
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Abrahamsson T, Lalanne T, Watt AJ, Sjöström PJ. In Vitro Investigation of Synaptic Plasticity. Cold Spring Harb Protoc 2016; 2016:2016/6/pdb.top087262. [PMID: 27250951 PMCID: PMC5280069 DOI: 10.1101/pdb.top087262] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A classical in vitro model for investigation of information storage in the brain is based on the acute hippocampal slice. Here, repeated high-frequency stimulation of excitatory Schaeffer collaterals making synapses onto pyramidal cells in the hippocampal CA1 region leads to strengthening of evoked field-recording responses-long-term potentiation (LTP)-in keeping with Hebb's postulate. This model remains tremendously influential for its reliability, specificity, and relative ease of use. More recent plasticity studies have explored various other brain regions including the neocortex, which often requires more laborious whole-cell recordings of synaptically connected pairs of neurons, to ensure that the identities of recorded cells are known. In addition, with this experimental approach, the spiking activity can be controlled with millisecond precision, which is necessary for the study of spike-timing-dependent plasticity (STDP). Here, we provide protocols for in vitro study of hippocampal CA1 LTP using field recordings, and of STDP in synaptically connected pairs of layer-5 pyramidal cells in acute slices of rodent neocortex.
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Affiliation(s)
- Therese Abrahamsson
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montréal, Québec H3G 1A4, Canada
| | - Txomin Lalanne
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montréal, Québec H3G 1A4, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Alanna J. Watt
- Department of Biology, Bellini Life Sciences Building, McGill University, Montréal, Québec H3G 0B1, Canada
| | - P. Jesper Sjöström
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montréal, Québec H3G 1A4, Canada
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Quantifying Repetitive Transmission at Chemical Synapses: A Generative-Model Approach. eNeuro 2016; 3:eN-MNT-0113-15. [PMID: 27200414 PMCID: PMC4867027 DOI: 10.1523/eneuro.0113-15.2016] [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: 09/24/2015] [Revised: 03/28/2016] [Accepted: 04/02/2016] [Indexed: 12/13/2022] Open
Abstract
The dependence of the synaptic responses on the history of activation and their large variability are both distinctive features of repetitive transmission at chemical synapses. Quantitative investigations have mostly focused on trial-averaged responses to characterize dynamic aspects of the transmission—thus disregarding variability—or on the fluctuations of the responses in steady conditions to characterize variability—thus disregarding dynamics. We present a statistically principled framework to quantify the dynamics of the probability distribution of synaptic responses under arbitrary patterns of activation. This is achieved by constructing a generative model of repetitive transmission, which includes an explicit description of the sources of stochasticity present in the process. The underlying parameters are then selected via an expectation-maximization algorithm that is exact for a large class of models of synaptic transmission, so as to maximize the likelihood of the observed responses. The method exploits the information contained in the correlation between responses to produce highly accurate estimates of both quantal and dynamic parameters from the same recordings. The method also provides important conceptual and technical advances over existing state-of-the-art techniques. In particular, the repetition of the same stimulation in identical conditions becomes unnecessary. This paves the way to the design of optimal protocols to estimate synaptic parameters, to the quantitative comparison of synaptic models over benchmark datasets, and, most importantly, to the study of repetitive transmission under physiologically relevant patterns of synaptic activation.
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Shah D, Praet J, Latif Hernandez A, Höfling C, Anckaerts C, Bard F, Morawski M, Detrez JR, Prinsen E, Villa A, De Vos WH, Maggi A, D'Hooge R, Balschun D, Rossner S, Verhoye M, Van der Linden A. Early pathologic amyloid induces hypersynchrony of BOLD resting-state networks in transgenic mice and provides an early therapeutic window before amyloid plaque deposition. Alzheimers Dement 2016; 12:964-976. [PMID: 27107518 DOI: 10.1016/j.jalz.2016.03.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/16/2016] [Accepted: 03/19/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION In Alzheimer's disease (AD), pathologic amyloid-beta (Aβ) is synaptotoxic and impairs neuronal function at the microscale, influencing brain networks at the macroscale before Aβ deposition. The latter can be detected noninvasively, in vivo, using resting-state functional MRI (rsfMRI), a technique used to assess brain functional connectivity (FC). METHODS RsfMRI was performed longitudinally in TG2576 and PDAPP mice, starting before Aβ deposition to determine the earliest FC changes. Additionally, the role of pathologic Aβ on early FC alterations was investigated by treating TG2576 mice with the 3D6 anti-Aβ-antibody. RESULTS Both transgenic models showed hypersynchronized FC before Aβ deposition and hyposynchronized FC at later stages. Early anti-Aβ treatment in TG2576 mice prevented hypersynchronous FC and the associated synaptic impairments and excitatory/inhibitory disbalances. DISCUSSION Hypersynchrony of FC may be used as a new noninvasive read out of early AD and can be recovered by anti-Aβ treatment, encouraging preventive treatment strategies in familial AD.
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Affiliation(s)
- Disha Shah
- Bio-Imaging Lab, Department of Biomedical Sciences, University of Antwerp, Wilrijk, Antwerp, Belgium.
| | - Jelle Praet
- Bio-Imaging Lab, Department of Biomedical Sciences, University of Antwerp, Wilrijk, Antwerp, Belgium
| | - Amira Latif Hernandez
- Laboratory of Biological Psychology, Department of Psychology, KU Leuven, Leuven, Belgium
| | - Corinna Höfling
- Paul Flechsig Institute for Brain Research, Leipzig, Germany
| | - Cynthia Anckaerts
- Bio-Imaging Lab, Department of Biomedical Sciences, University of Antwerp, Wilrijk, Antwerp, Belgium
| | | | - Markus Morawski
- Paul Flechsig Institute for Brain Research, Leipzig, Germany
| | - Jan R Detrez
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Els Prinsen
- Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Alessandro Villa
- Center of Excellence on Neurodegenerative Diseases, Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Winnok H De Vos
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium; Cell Systems and Imaging, Department Molecular Biotechnology, University of Ghent, Ghent, Belgium
| | - Adriana Maggi
- Center of Excellence on Neurodegenerative Diseases, Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Rudi D'Hooge
- Laboratory of Biological Psychology, Department of Psychology, KU Leuven, Leuven, Belgium
| | - Detlef Balschun
- Laboratory of Biological Psychology, Department of Psychology, KU Leuven, Leuven, Belgium
| | - Steffen Rossner
- Paul Flechsig Institute for Brain Research, Leipzig, Germany
| | - Marleen Verhoye
- Bio-Imaging Lab, Department of Biomedical Sciences, University of Antwerp, Wilrijk, Antwerp, Belgium
| | - Annemie Van der Linden
- Bio-Imaging Lab, Department of Biomedical Sciences, University of Antwerp, Wilrijk, Antwerp, Belgium
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Hou WH, Kuo N, Fang GW, Huang HS, Wu KP, Zimmer A, Cheng JK, Lien CC. Wiring Specificity and Synaptic Diversity in the Mouse Lateral Central Amygdala. J Neurosci 2016; 36:4549-63. [PMID: 27098697 PMCID: PMC6601824 DOI: 10.1523/jneurosci.3309-15.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 02/15/2016] [Accepted: 03/07/2016] [Indexed: 01/24/2023] Open
Abstract
The central amygdala (CeA) nucleus, a subcortical structure composed of mostly GABA-releasing (GABAergic) neurons, controls fear expression via projections to downstream targets in the hypothalamus and brainstem. The CeA consists of the lateral (CeL) and medial (CeM) subdivisions. The CeL strongly gates information transfer to the CeM, the main output station of the amygdala, but little is known about the functional organization of local circuits in this region. Using cluster analysis, we identified two major electrophysiologically distinct CeL neuron classes in mouse amygdala slices, the early-spiking (ES) and late-spiking (LS) neurons. These two classes displayed distinct autaptic transmission. Compared with LS neurons, ES neurons had strong and depressing autapses, which enhanced spike-timing precision. With multiple patch-clamp recordings, we found that CeL neurons made chemical, but not electrical, synapses. Analysis of individual connections revealed cannabinoid type 1 receptor-mediated suppression of the ES, but not of the LS cell output synapse. More interestingly, the efficacy of the ES→LS or LS→ES synapse was ~2-fold greater than that of the LS→LS or ES→ES synapse. When tested at 20 Hz, synapses between different neurons, but not within the same class, were markedly depressing and were more powerful to sculpt activity of postsynaptic neurons. Moreover, neurons of different classes also form synapses with higher degree of connectivity. We demonstrate that ES and LS neurons represent two functionally distinct cell classes in the CeL and interactions between presynaptic and postsynaptic neurons dictate synaptic properties between neurons. SIGNIFICANCE STATEMENT The central lateral amygdala (CeL) is a key node in fear circuits, but the functional organization of local circuits in this region is largely unknown. The CeL consists of mostly GABAergic inhibitory neurons with different functional and molecular features. Here, we report that the presynaptic cell class determines functional properties of autapses and cannabinoid-mediated modulation of synaptic transmission between neurons, whereas presynaptic versus postsynaptic cell classes dictate the connectivity, efficacy, and dynamics of GABAergic synapses between any two neurons. The wiring specificity and synaptic diversity have a great impact on neuronal output in amygdala inhibitory networks. Such synaptic organizing principles advance our understanding of the significance of physiologically defined neuronal phenotypes in amygdala inhibitory networks.
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Affiliation(s)
| | | | - Ge-Wei Fang
- Institute of Biomedical Informatics, National Yang-Ming University, Taipei 112, Taiwan
| | - Hsien-Sung Huang
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Kun-Pin Wu
- Institute of Biomedical Informatics, National Yang-Ming University, Taipei 112, Taiwan
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Jen-Kun Cheng
- Department of Medicine, MacKay Medical College, New Taipei City 252, Taiwan, and Department of Anesthesiology, MacKay Memorial Hospital, Taipei 104, Taiwan
| | - Cheng-Chang Lien
- Institute of Neuroscience, Institute of Brain Science, Brain Research Center, and
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Ferrati G, Martini FJ, Maravall M. Presynaptic Adenosine Receptor-Mediated Regulation of Diverse Thalamocortical Short-Term Plasticity in the Mouse Whisker Pathway. Front Neural Circuits 2016; 10:9. [PMID: 26941610 PMCID: PMC4763074 DOI: 10.3389/fncir.2016.00009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/05/2016] [Indexed: 12/27/2022] Open
Abstract
Short-term synaptic plasticity (STP) sets the sensitivity of a synapse to incoming activity and determines the temporal patterns that it best transmits. In “driver” thalamocortical (TC) synaptic populations, STP is dominated by depression during stimulation from rest. However, during ongoing stimulation, lemniscal TC connections onto layer 4 neurons in mouse barrel cortex express variable STP. Each synapse responds to input trains with a distinct pattern of depression or facilitation around its mean steady-state response. As a result, in common with other synaptic populations, lemniscal TC synapses express diverse rather than uniform dynamics, allowing for a rich representation of temporally varying stimuli. Here, we show that this STP diversity is regulated presynaptically. Presynaptic adenosine receptors of the A1R type, but not kainate receptors (KARs), modulate STP behavior. Blocking the receptors does not eliminate diversity, indicating that diversity is related to heterogeneous expression of multiple mechanisms in the pathway from presynaptic calcium influx to neurotransmitter release.
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Affiliation(s)
- Giovanni Ferrati
- Instituto de Neurociencias de Alicante UMH-CSIC Sant Joan d'Alacant, Spain
| | | | - Miguel Maravall
- Instituto de Neurociencias de Alicante UMH-CSICSant Joan d'Alacant, Spain; School of Life Sciences, Sussex Neuroscience, University of SussexBrighton, UK
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45
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Superactivation of AMPA receptors by auxiliary proteins. Nat Commun 2016; 7:10178. [PMID: 26744192 PMCID: PMC4729862 DOI: 10.1038/ncomms10178] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/11/2015] [Indexed: 12/15/2022] Open
Abstract
Glutamate receptors form complexes in the brain with auxiliary proteins, which control their activity during fast synaptic transmission through a seemingly bewildering array of effects. Here we devise a way to isolate the activation of complexes using polyamines, which enables us to show that transmembrane AMPA receptor regulatory proteins (TARPs) exert their effects principally on the channel opening reaction. A thermodynamic argument suggests that because TARPs promote channel opening, receptor activation promotes AMPAR-TARP complexes into a superactive state with high open probability. A simple model based on this idea predicts all known effects of TARPs on AMPA receptor function. This model also predicts unexpected phenomena including massive potentiation in the absence of desensitization and supramaximal recovery that we subsequently detected in electrophysiological recordings. This transient positive feedback mechanism has implications for information processing in the brain, because it should allow activity-dependent facilitation of excitatory synaptic transmission through a postsynaptic mechanism. Transmembrane AMPA receptor regulatory proteins (TARPs) exert a number of effects on fast glutamatergic synaptic transmission. Here, the authors model the interactions of two such proteins, Stargazin and γ-8, and propose a simple kinetic mechanism by which TARPs modulate channel opening reaction.
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46
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Ahn J, MacLeod KM. Target-specific regulation of presynaptic release properties at auditory nerve terminals in the avian cochlear nucleus. J Neurophysiol 2016; 115:1679-90. [PMID: 26719087 DOI: 10.1152/jn.00752.2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/23/2015] [Indexed: 02/04/2023] Open
Abstract
Short-term synaptic plasticity (STP) acts as a time- and firing rate-dependent filter that mediates the transmission of information across synapses. In the auditory brain stem, the divergent pathways that encode acoustic timing and intensity information express differential STP. To investigate what factors determine the plasticity expressed at different terminals, we tested whether presynaptic release probability differed in the auditory nerve projections to the two divisions of the avian cochlear nucleus, nucleus angularis (NA) and nucleus magnocellularis (NM). Estimates of release probability were made with an open-channel blocker ofN-methyl-d-aspartate (NMDA) receptors. Activity-dependent blockade of NMDA receptor-mediated excitatory postsynaptic currents (EPSCs) with application of 20 μM (+)-MK801 maleate was more rapid in NM than in NA, indicating that release probability was significantly higher at terminals in NM. Paired-pulse ratio (PPR) was tightly correlated with the blockade rate at terminals in NA, suggesting that PPR was a reasonable proxy for relative release probability at these synapses. To test whether release probability was similar across convergent inputs onto NA neurons, PPRs of different nerve inputs onto the same postsynaptic NA target neuron were measured. The PPRs, as well as the plasticity during short trains, were tightly correlated across multiple inputs, further suggesting that release probability is coordinated at auditory nerve terminals in a target-specific manner. This highly specific regulation of STP in the auditory brain stem provides evidence that the synaptic dynamics are tuned to differentially transmit the auditory information in nerve activity into parallel ascending pathways.
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Affiliation(s)
- J Ahn
- Department of Biology, University of Maryland, College Park, Maryland
| | - K M MacLeod
- Department of Biology, University of Maryland, College Park, Maryland; Neuroscience and Cognitive Science Program, University of Maryland, College Park, Maryland; and Center for the Comparative and Evolutionary Biology of Hearing, University of Maryland, College Park, Maryland
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47
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Lalanne T, Oyrer J, Mancino A, Gregor E, Chung A, Huynh L, Burwell S, Maheux J, Farrant M, Sjöström PJ. Synapse-specific expression of calcium-permeable AMPA receptors in neocortical layer 5. J Physiol 2015; 594:837-61. [PMID: 26537662 PMCID: PMC4753277 DOI: 10.1113/jp271394] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/01/2015] [Indexed: 01/26/2023] Open
Abstract
Key points In the hippocampus, calcium‐permeable AMPA receptors have been found in a restricted subset of neuronal types that inhibit other neurons, although their localization in the neocortex is less well understood. In the present study, we looked for calcium‐permeable AMPA receptors in two distinct populations of neocortical inhibitory neurons: basket cells and Martinotti cells. We found them in the former but not in the latter. Furthermore, in basket cells, these receptors were associated with particularly fast responses. Computer modelling predicted (and experiments verified) that fast calcium‐permeable AMPA receptors enable basket cells to respond rapidly, such that they promptly inhibit neighbouring cells and shut down activity. The results obtained in the present study help our understanding of pathologies such as stroke and epilepsy that have been associated with disordered regulation of calcium‐permeable AMPA receptors.
Abstract AMPA‐type glutamate receptors (AMPARs) lacking an edited GluA2 subunit are calcium‐permeable (CP) and contribute to synaptic plasticity in several hippocampal interneuron types, although their precise role in the neocortex is not well described. We explored the presence of CP‐AMPARs at pyramidal cell (PC) inputs to Martinotti cells (MCs) and basket cells (BCs) in layer 5 of the developing mouse visual cortex (postnatal days 12–21). GluA2 immunolabelling was stronger in MCs than in BCs. A differential presence of CP‐AMPARs at PC‐BC and PC‐MC synapses was confirmed electrophysiologically, based on measures of spermine‐dependent rectification and CP‐AMPAR blockade by 1‐naphtyl acetyl spermine using recordings from synaptically connected cell pairs, NPEC‐AMPA uncaging and miniature current recordings. In addition, CP‐AMPAR expression in BCs was correlated with rapidly decaying synaptic currents. Computer modelling predicted that this reduces spike latencies and sharpens suprathreshold responses in BCs, which we verified experimentally using the dynamic clamp technique. Thus, the synapse‐specific expression of CP‐AMPARs may critically influence both plasticity and information processing in neocortical microcircuits. In the hippocampus, calcium‐permeable AMPA receptors have been found in a restricted subset of neuronal types that inhibit other neurons, although their localization in the neocortex is less well understood. In the present study, we looked for calcium‐permeable AMPA receptors in two distinct populations of neocortical inhibitory neurons: basket cells and Martinotti cells. We found them in the former but not in the latter. Furthermore, in basket cells, these receptors were associated with particularly fast responses. Computer modelling predicted (and experiments verified) that fast calcium‐permeable AMPA receptors enable basket cells to respond rapidly, such that they promptly inhibit neighbouring cells and shut down activity. The results obtained in the present study help our understanding of pathologies such as stroke and epilepsy that have been associated with disordered regulation of calcium‐permeable AMPA receptors.
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Affiliation(s)
- Txomin Lalanne
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Julia Oyrer
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Adamo Mancino
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Erica Gregor
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Andrew Chung
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Louis Huynh
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Sasha Burwell
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Jérôme Maheux
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada.,Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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48
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Larsen RS, Sjöström PJ. Synapse-type-specific plasticity in local circuits. Curr Opin Neurobiol 2015; 35:127-35. [PMID: 26310110 PMCID: PMC5280068 DOI: 10.1016/j.conb.2015.08.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 07/16/2015] [Accepted: 08/04/2015] [Indexed: 02/03/2023]
Abstract
Neuroscientists spent decades debating whether synaptic plasticity was presynaptically or postsynaptically expressed. It was eventually concluded that plasticity depends on many factors, including cell type. More recently, it has become increasingly clear that plasticity is regulated at an even finer grained level; it is specific to the synapse type, a concept we denote synapse-type-specific plasticity (STSP). Here, we review recent developments in the field of STSP, discussing both long-term and short-term variants and with particular emphasis on neocortical function. As there are dozens of neocortical cell types, there is a multiplicity of forms of STSP, the vast majority of which have never been explored. We argue that to understand the brain and synaptic diseases, we have to grapple with STSP.
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Affiliation(s)
- Rylan S Larsen
- Allen Institute for Brain Science, Seattle, WA 98103, USA
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montréal, Québec H3G 1A4, Canada.
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Hackett TA, Clause AR, Takahata T, Hackett NJ, Polley DB. Differential maturation of vesicular glutamate and GABA transporter expression in the mouse auditory forebrain during the first weeks of hearing. Brain Struct Funct 2015; 221:2619-73. [PMID: 26159773 DOI: 10.1007/s00429-015-1062-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 05/07/2015] [Indexed: 02/04/2023]
Abstract
Vesicular transporter proteins are an essential component of the presynaptic machinery that regulates neurotransmitter storage and release. They also provide a key point of control for homeostatic signaling pathways that maintain balanced excitation and inhibition following changes in activity levels, including the onset of sensory experience. To advance understanding of their roles in the developing auditory forebrain, we tracked the expression of the vesicular transporters of glutamate (VGluT1, VGluT2) and GABA (VGAT) in primary auditory cortex (A1) and medial geniculate body (MGB) of developing mice (P7, P11, P14, P21, adult) before and after ear canal opening (~P11-P13). RNA sequencing, in situ hybridization, and immunohistochemistry were combined to track changes in transporter expression and document regional patterns of transcript and protein localization. Overall, vesicular transporter expression changed the most between P7 and P21. The expression patterns and maturational trajectories of each marker varied by brain region, cortical layer, and MGB subdivision. VGluT1 expression was highest in A1, moderate in MGB, and increased with age in both regions. VGluT2 mRNA levels were low in A1 at all ages, but high in MGB, where adult levels were reached by P14. VGluT2 immunoreactivity was prominent in both regions. VGluT1 (+) and VGluT2 (+) transcripts were co-expressed in MGB and A1 somata, but co-localization of immunoreactive puncta was not detected. In A1, VGAT mRNA levels were relatively stable from P7 to adult, while immunoreactivity increased steadily. VGAT (+) transcripts were rare in MGB neurons, whereas VGAT immunoreactivity was robust at all ages. Morphological changes in immunoreactive puncta were found in two regions after ear canal opening. In the ventral MGB, a decrease in VGluT2 puncta density was accompanied by an increase in puncta size. In A1, perisomatic VGAT and VGluT1 terminals became prominent around the neuronal somata. Overall, the observed changes in gene and protein expression, regional architecture, and morphology relate to-and to some extent may enable-the emergence of mature sound-evoked activity patterns. In that regard, the findings of this study expand our understanding of the presynaptic mechanisms that regulate critical period formation associated with experience-dependent refinement of sound processing in auditory forebrain circuits.
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Affiliation(s)
- Troy A Hackett
- Department of Hearing and Speech Sciences, Vanderbilt University School of Medicine, 465 21st Avenue South, MRB-3 Suite 7110, Nashville, TN, 37232, USA.
| | - Amanda R Clause
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
| | - Toru Takahata
- Department of Hearing and Speech Sciences, Vanderbilt University School of Medicine, 465 21st Avenue South, MRB-3 Suite 7110, Nashville, TN, 37232, USA
| | | | - Daniel B Polley
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
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Diverse Short-Term Dynamics of Inhibitory Synapses Converging on Striatal Projection Neurons: Differential Changes in a Rodent Model of Parkinson's Disease. Neural Plast 2015; 2015:573543. [PMID: 26167304 PMCID: PMC4475734 DOI: 10.1155/2015/573543] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 05/20/2015] [Indexed: 02/08/2023] Open
Abstract
Most neurons in the striatum are projection neurons (SPNs) which make synapses with each other within distances of approximately 100 µm. About 5% of striatal neurons are GABAergic interneurons whose axons expand hundreds of microns. Short-term synaptic plasticity (STSP) between fast-spiking (FS) interneurons and SPNs and between SPNs has been described with electrophysiological and optogenetic techniques. It is difficult to obtain pair recordings from some classes of interneurons and due to limitations of actual techniques, no other types of STSP have been described on SPNs. Diverse STSPs may reflect differences in presynaptic release machineries. Therefore, we focused the present work on answering two questions: Are there different identifiable classes of STSP between GABAergic synapses on SPNs? And, if so, are synapses exhibiting different classes of STSP differentially affected by dopamine depletion? Whole-cell voltage-clamp recordings on SPNs revealed three classes of STSPs: depressing, facilitating, and biphasic (facilitating-depressing), in response to stimulation trains at 20 Hz, in a constant ionic environment. We then used the 6-hydroxydopamine (6-OHDA) rodent model of Parkinson's disease to show that synapses with different STSPs are differentially affected by dopamine depletion. We propose a general model of STSP that fits all the dynamics found in our recordings.
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