1
|
Lackey EP, Moreira L, Norton A, Hemelt ME, Osorno T, Nguyen TM, Macosko EZ, Lee WCA, Hull CA, Regehr WG. Specialized connectivity of molecular layer interneuron subtypes leads to disinhibition and synchronous inhibition of cerebellar Purkinje cells. Neuron 2024; 112:2333-2348.e6. [PMID: 38692278 DOI: 10.1016/j.neuron.2024.04.010] [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: 09/28/2023] [Revised: 01/12/2024] [Accepted: 04/08/2024] [Indexed: 05/03/2024]
Abstract
Molecular layer interneurons (MLIs) account for approximately 80% of the inhibitory interneurons in the cerebellar cortex and are vital to cerebellar processing. MLIs are thought to primarily inhibit Purkinje cells (PCs) and suppress the plasticity of synapses onto PCs. MLIs also inhibit, and are electrically coupled to, other MLIs, but the functional significance of these connections is not known. Here, we find that two recently recognized MLI subtypes, MLI1 and MLI2, have a highly specialized connectivity that allows them to serve distinct functional roles. MLI1s primarily inhibit PCs, are electrically coupled to each other, fire synchronously with other MLI1s on the millisecond timescale in vivo, and synchronously pause PC firing. MLI2s are not electrically coupled, primarily inhibit MLI1s and disinhibit PCs, and are well suited to gating cerebellar-dependent behavior and learning. The synchronous firing of electrically coupled MLI1s and disinhibition provided by MLI2s require a major re-evaluation of cerebellar processing.
Collapse
Affiliation(s)
| | - Luis Moreira
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Aliya Norton
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Marie E Hemelt
- Department of Neurobiology, Duke University Medical School, Durham, NC, USA
| | - Tomas Osorno
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Tri M Nguyen
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Evan Z Macosko
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA; Broad Institute of Harvard and MIT, Stanley Center for Psychiatric Research, Cambridge, MA, USA
| | - Wei-Chung Allen Lee
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA; Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Court A Hull
- Department of Neurobiology, Duke University Medical School, Durham, NC, USA
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
2
|
Pali E, D’Angelo E, Prestori F. Understanding Cerebellar Input Stage through Computational and Plasticity Rules. BIOLOGY 2024; 13:403. [PMID: 38927283 PMCID: PMC11200477 DOI: 10.3390/biology13060403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/21/2024] [Accepted: 05/27/2024] [Indexed: 06/28/2024]
Abstract
A central hypothesis concerning brain functioning is that plasticity regulates the signal transfer function by modifying the efficacy of synaptic transmission. In the cerebellum, the granular layer has been shown to control the gain of signals transmitted through the mossy fiber pathway. Until now, the impact of plasticity on incoming activity patterns has been analyzed by combining electrophysiological recordings in acute cerebellar slices and computational modeling, unraveling a broad spectrum of different forms of synaptic plasticity in the granular layer, often accompanied by forms of intrinsic excitability changes. Here, we attempt to provide a brief overview of the most prominent forms of plasticity at the excitatory synapses formed by mossy fibers onto primary neuronal components (granule cells, Golgi cells and unipolar brush cells) in the granular layer. Specifically, we highlight the current understanding of the mechanisms and their functional implications for synaptic and intrinsic plasticity, providing valuable insights into how inputs are processed and reconfigured at the cerebellar input stage.
Collapse
Affiliation(s)
- Eleonora Pali
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy; (E.P.)
| | - Egidio D’Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy; (E.P.)
- Digital Neuroscience Center, IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Francesca Prestori
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy; (E.P.)
| |
Collapse
|
3
|
Beau M, Herzfeld DJ, Naveros F, Hemelt ME, D’Agostino F, Oostland M, Sánchez-López A, Chung YY, Michael Maibach, Kyranakis S, Stabb HN, Martínez Lopera MG, Lajko A, Zedler M, Ohmae S, Hall NJ, Clark BA, Cohen D, Lisberger SG, Kostadinov D, Hull C, Häusser M, Medina JF. A deep-learning strategy to identify cell types across species from high-density extracellular recordings. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.30.577845. [PMID: 38352514 PMCID: PMC10862837 DOI: 10.1101/2024.01.30.577845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
High-density probes allow electrophysiological recordings from many neurons simultaneously across entire brain circuits but don't reveal cell type. Here, we develop a strategy to identify cell types from extracellular recordings in awake animals, revealing the computational roles of neurons with distinct functional, molecular, and anatomical properties. We combine optogenetic activation and pharmacology using the cerebellum as a testbed to generate a curated ground-truth library of electrophysiological properties for Purkinje cells, molecular layer interneurons, Golgi cells, and mossy fibers. We train a semi-supervised deep-learning classifier that predicts cell types with greater than 95% accuracy based on waveform, discharge statistics, and layer of the recorded neuron. The classifier's predictions agree with expert classification on recordings using different probes, in different laboratories, from functionally distinct cerebellar regions, and across animal species. Our classifier extends the power of modern dynamical systems analyses by revealing the unique contributions of simultaneously-recorded cell types during behavior.
Collapse
Affiliation(s)
- Maxime Beau
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - David J. Herzfeld
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Francisco Naveros
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Computer Engineering, Automation and Robotics, Research Centre for Information and Communication Technologies, University of Granada, Granada, Spain
| | - Marie E. Hemelt
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Federico D’Agostino
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Marlies Oostland
- Wolfson Institute for Biomedical Research, University College London, London, UK
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | | | - Young Yoon Chung
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Michael Maibach
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Stephen Kyranakis
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Hannah N. Stabb
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | | | - Agoston Lajko
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Marie Zedler
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Shogo Ohmae
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Nathan J. Hall
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Beverley A. Clark
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Dana Cohen
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | | | - Dimitar Kostadinov
- Wolfson Institute for Biomedical Research, University College London, London, UK
- Centre for Developmental Neurobiology, King’s College London, London, UK
| | - Court Hull
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Michael Häusser
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Javier F. Medina
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
4
|
Geminiani A, Casellato C, Boele HJ, Pedrocchi A, De Zeeuw CI, D’Angelo E. Mesoscale simulations predict the role of synergistic cerebellar plasticity during classical eyeblink conditioning. PLoS Comput Biol 2024; 20:e1011277. [PMID: 38574161 PMCID: PMC11060558 DOI: 10.1371/journal.pcbi.1011277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 04/30/2024] [Accepted: 02/12/2024] [Indexed: 04/06/2024] Open
Abstract
According to the motor learning theory by Albus and Ito, synaptic depression at the parallel fibre to Purkinje cells synapse (pf-PC) is the main substrate responsible for learning sensorimotor contingencies under climbing fibre control. However, recent experimental evidence challenges this relatively monopolistic view of cerebellar learning. Bidirectional plasticity appears crucial for learning, in which different microzones can undergo opposite changes of synaptic strength (e.g. downbound microzones-more likely depression, upbound microzones-more likely potentiation), and multiple forms of plasticity have been identified, distributed over different cerebellar circuit synapses. Here, we have simulated classical eyeblink conditioning (CEBC) using an advanced spiking cerebellar model embedding downbound and upbound modules that are subject to multiple plasticity rules. Simulations indicate that synaptic plasticity regulates the cascade of precise spiking patterns spreading throughout the cerebellar cortex and cerebellar nuclei. CEBC was supported by plasticity at the pf-PC synapses as well as at the synapses of the molecular layer interneurons (MLIs), but only the combined switch-off of both sites of plasticity compromised learning significantly. By differentially engaging climbing fibre information and related forms of synaptic plasticity, both microzones contributed to generate a well-timed conditioned response, but it was the downbound module that played the major role in this process. The outcomes of our simulations closely align with the behavioural and electrophysiological phenotypes of mutant mice suffering from cell-specific mutations that affect processing of their PC and/or MLI synapses. Our data highlight that a synergy of bidirectional plasticity rules distributed across the cerebellum can facilitate finetuning of adaptive associative behaviours at a high spatiotemporal resolution.
Collapse
Affiliation(s)
- Alice Geminiani
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Claudia Casellato
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Digital Neuroscience Center, IRCCS Mondino Foundation, Pavia, Italy
| | - Henk-Jan Boele
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
- Neuroscience Institute, Princeton University, Washington Road, Princeton, New Jersey, United States of America
| | - Alessandra Pedrocchi
- NearLab, Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Egidio D’Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Digital Neuroscience Center, IRCCS Mondino Foundation, Pavia, Italy
| |
Collapse
|
5
|
Gilbert M, Rasmussen A. Gap Junctions May Have A Computational Function In The Cerebellum: A Hypothesis. CEREBELLUM (LONDON, ENGLAND) 2024:10.1007/s12311-024-01680-3. [PMID: 38499814 DOI: 10.1007/s12311-024-01680-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/29/2024] [Indexed: 03/20/2024]
Abstract
In the cerebellum, granule cells make parallel fibre contact on (and excite) Golgi cells and Golgi cells inhibit granule cells, forming an open feedback loop. Parallel fibres excite Golgi cells synaptically, each making a single contact. Golgi cells inhibit granule cells in a structure called a glomerulus almost exclusively by GABA spillover acting through extrasynaptic GABAA receptors. Golgi cells are connected dendritically by gap junctions. It has long been suspected that feedback contributes to homeostatic regulation of parallel fibre signals activity, causing the fraction of the population that are active to be maintained at a low level. We present a detailed neurophysiological and computationally-rendered model of functionally grouped Golgi cells which can infer the density of parallel fibre signals activity and convert it into proportional modulation of inhibition of granule cells. The conversion is unlearned and not actively computed; rather, output is simply the computational effect of cell morphology and network architecture. Unexpectedly, the conversion becomes more precise at low density, suggesting that self-regulation is attracted to sparse code, because it is stable. A computational function of gap junctions may not be confined to the cerebellum.
Collapse
Affiliation(s)
- Mike Gilbert
- School of Psychology, College of Life and Environmental Sciences, University of Birmingham, B15 2TT, Birmingham, UK.
| | - Anders Rasmussen
- Department of Experimental Medical Science, Lund University, BMC F10, 22184, Lund, Sweden
| |
Collapse
|
6
|
Broersen R, Albergaria C, Carulli D, Carey MR, Canto CB, De Zeeuw CI. Synaptic mechanisms for associative learning in the cerebellar nuclei. Nat Commun 2023; 14:7459. [PMID: 37985778 PMCID: PMC10662440 DOI: 10.1038/s41467-023-43227-w] [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: 11/17/2022] [Accepted: 11/03/2023] [Indexed: 11/22/2023] Open
Abstract
Associative learning during delay eyeblink conditioning (EBC) depends on an intact cerebellum. However, the relative contribution of changes in the cerebellar nuclei to learning remains a subject of ongoing debate. In particular, little is known about the changes in synaptic inputs to cerebellar nuclei neurons that take place during EBC and how they shape the membrane potential of these neurons. Here, we probed the ability of these inputs to support associative learning in mice, and investigated structural and cell-physiological changes within the cerebellar nuclei during learning. We find that optogenetic stimulation of mossy fiber afferents to the anterior interposed nucleus (AIP) can substitute for a conditioned stimulus and is sufficient to elicit conditioned responses (CRs) that are adaptively well-timed. Further, EBC induces structural changes in mossy fiber and inhibitory inputs, but not in climbing fiber inputs, and it leads to changes in subthreshold processing of AIP neurons that correlate with conditioned eyelid movements. The changes in synaptic and spiking activity that precede the CRs allow for a decoder to distinguish trials with a CR. Our data reveal how structural and physiological modifications of synaptic inputs to cerebellar nuclei neurons can facilitate learning.
Collapse
Affiliation(s)
- Robin Broersen
- Department of Cerebellar Coordination and Cognition, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
| | - Catarina Albergaria
- Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
- University College London, Sainsbury Wellcome Centre, London, UK
| | - Daniela Carulli
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Megan R Carey
- Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal.
| | - Cathrin B Canto
- Department of Cerebellar Coordination and Cognition, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands.
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands.
| | - Chris I De Zeeuw
- Department of Cerebellar Coordination and Cognition, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands.
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands.
| |
Collapse
|
7
|
Lackey EP, Moreira L, Norton A, Hemelt ME, Osorno T, Nguyen TM, Macosko EZ, Lee WCA, Hull CA, Regehr WG. Cerebellar circuits for disinhibition and synchronous inhibition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.15.557934. [PMID: 37745401 PMCID: PMC10516046 DOI: 10.1101/2023.09.15.557934] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
The cerebellar cortex contributes to diverse behaviors by transforming mossy fiber inputs into predictions in the form of Purkinje cell (PC) outputs, and then refining those predictions1. Molecular layer interneurons (MLIs) account for approximately 80% of the inhibitory interneurons in the cerebellar cortex2, and are vital to cerebellar processing1,3. MLIs are thought to primarily inhibit PCs and suppress the plasticity of excitatory synapses onto PCs. MLIs also inhibit, and are electrically coupled to, other MLIs4-7, but the functional significance of these connections is not known1,3. Behavioral studies suggest that cerebellar-dependent learning is gated by disinhibition of PCs, but the source of such disinhibition has not been identified8. Here we find that two recently recognized MLI subtypes2, MLI1 and MLI2, have highly specialized connectivity that allows them to serve very different functional roles. MLI1s primarily inhibit PCs, are electrically coupled to each other, fire synchronously with other MLI1s on the millisecond time scale in vivo, and synchronously pause PC firing. MLI2s are not electrically coupled, they primarily inhibit MLI1s and disinhibit PCs, and are well suited to gating cerebellar-dependent learning8. These findings require a major reevaluation of processing within the cerebellum in which disinhibition, a powerful circuit motif present in the cerebral cortex and elsewhere9-17, greatly increases the computational power and flexibility of the cerebellum. They also suggest that millisecond time scale synchronous firing of electrically-coupled MLI1s helps regulate the output of the cerebellar cortex by synchronously pausing PC firing, which has been shown to evoke precisely-timed firing in PC targets18.
Collapse
Affiliation(s)
- Elizabeth P Lackey
- Department of Neurobiology, Harvard Medical School, Boston MA, United States
| | - Luis Moreira
- Department of Neurobiology, Harvard Medical School, Boston MA, United States
| | - Aliya Norton
- Department of Neurobiology, Harvard Medical School, Boston MA, United States
| | - Marie E Hemelt
- Department of Neurobiology, Duke University Medical School, Durham, United States
| | - Tomas Osorno
- Department of Neurobiology, Harvard Medical School, Boston MA, United States
| | - Tri M Nguyen
- Department of Neurobiology, Harvard Medical School, Boston MA, United States
| | - Evan Z Macosko
- Department of Neurobiology, Harvard Medical School, Boston MA, United States
- Broad Institute of Harvard and MIT, Stanley Center for Psychiatric Research, Cambridge, MA, USA
| | - Wei-Chung Allen Lee
- Department of Neurobiology, Harvard Medical School, Boston MA, United States
- Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Court A Hull
- Department of Neurobiology, Duke University Medical School, Durham, United States
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston MA, United States
| |
Collapse
|
8
|
Model simulations unveil the structure-function-dynamics relationship of the cerebellar cortical microcircuit. Commun Biol 2022; 5:1240. [PMCID: PMC9663576 DOI: 10.1038/s42003-022-04213-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/02/2022] [Indexed: 11/16/2022] Open
Abstract
AbstractThe cerebellar network is renowned for its regular architecture that has inspired foundational computational theories. However, the relationship between circuit structure, function and dynamics remains elusive. To tackle the issue, we developed an advanced computational modeling framework that allows us to reconstruct and simulate the structure and function of the mouse cerebellar cortex using morphologically realistic multi-compartmental neuron models. The cerebellar connectome is generated through appropriate connection rules, unifying a collection of scattered experimental data into a coherent construct and providing a new model-based ground-truth about circuit organization. Naturalistic background and sensory-burst stimulation are used for functional validation against recordings in vivo, monitoring the impact of cellular mechanisms on signal propagation, inhibitory control, and long-term synaptic plasticity. Our simulations show how mossy fibers entrain the local neuronal microcircuit, boosting the formation of columns of activity travelling from the granular to the molecular layer providing a new resource for the investigation of local microcircuit computation and of the neural correlates of behavior.
Collapse
|
9
|
Masoli S, Rizza MF, Tognolina M, Prestori F, D’Angelo E. Computational models of neurotransmission at cerebellar synapses unveil the impact on network computation. Front Comput Neurosci 2022; 16:1006989. [PMID: 36387305 PMCID: PMC9649760 DOI: 10.3389/fncom.2022.1006989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/10/2022] [Indexed: 11/25/2022] Open
Abstract
The neuroscientific field benefits from the conjoint evolution of experimental and computational techniques, allowing for the reconstruction and simulation of complex models of neurons and synapses. Chemical synapses are characterized by presynaptic vesicle cycling, neurotransmitter diffusion, and postsynaptic receptor activation, which eventually lead to postsynaptic currents and subsequent membrane potential changes. These mechanisms have been accurately modeled for different synapses and receptor types (AMPA, NMDA, and GABA) of the cerebellar cortical network, allowing simulation of their impact on computation. Of special relevance is short-term synaptic plasticity, which generates spatiotemporal filtering in local microcircuits and controls burst transmission and information flow through the network. Here, we present how data-driven computational models recapitulate the properties of neurotransmission at cerebellar synapses. The simulation of microcircuit models is starting to reveal how diverse synaptic mechanisms shape the spatiotemporal profiles of circuit activity and computation.
Collapse
Affiliation(s)
- Stefano Masoli
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | | | | | - Francesca Prestori
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- *Correspondence: Francesca Prestori,
| | - Egidio D’Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- IRCCS Mondino Foundation, Brain Connectivity Center, Pavia, Italy
- Egidio D’Angelo,
| |
Collapse
|
10
|
Nettekoven C, Mitchell L, Clarke WT, Emir U, Campbell J, Johansen-Berg H, Jenkinson N, Stagg CJ. Cerebellar GABA Change during Visuomotor Adaptation Relates to Adaptation Performance and Cerebellar Network Connectivity: A Magnetic Resonance Spectroscopic Imaging Study. J Neurosci 2022; 42:7721-7732. [PMID: 36414012 PMCID: PMC9581563 DOI: 10.1523/jneurosci.0096-22.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/09/2022] [Accepted: 06/16/2022] [Indexed: 12/15/2022] Open
Abstract
Motor adaptation is crucial for performing accurate movements in a changing environment and relies on the cerebellum. Although cerebellar involvement has been well characterized, the neurochemical changes in the cerebellum underpinning human motor adaptation remain unknown. We used a novel magnetic resonance spectroscopic imaging (MRSI) technique to measure changes in the inhibitory neurotransmitter GABA in the human cerebellum during visuomotor adaptation. Participants (n = 17, six female) used their right hand to adapt to a rotated cursor in the scanner, compared with a control task requiring no adaptation. We spatially resolved adaptation-driven GABA changes at the cerebellar nuclei and cerebellar cortex in the left and the right cerebellar hemisphere independently and found that simple right-hand movements increase GABA in the right cerebellar nuclei and decreases GABA in the left. When isolating adaptation-driven GABA changes, we found that GABA in the left cerebellar nuclei and the right cerebellar nuclei diverged, although GABA change from baseline at the right cerebellar nuclei was not different from zero at the group level. Early adaptation-driven GABA fluctuations in the right cerebellar nuclei correlated with adaptation performance. Participants showing greater GABA decrease adapted better, suggesting early GABA change is behaviorally relevant. Early GABA change also correlated with functional connectivity change in a cerebellar network. Participants showing greater decreases in GABA showed greater strength increases in cerebellar network connectivity. Results were specific to GABA, to adaptation, and to the cerebellar network. This study provides first evidence for plastic changes in cerebellar neurochemistry during motor adaptation. Characterizing these naturally occurring neurochemical changes may provide a basis for developing therapeutic interventions to facilitate human motor adaptation.SIGNIFICANCE STATEMENT Despite motor adaptation being fundamental to maintaining accurate movements, its neurochemical basis remains poorly understood, perhaps because measuring neurochemicals in the human cerebellum is technically challenging. Using a novel magnetic resonance spectroscopic imaging method, this study provides evidence for GABA changes in the left compared with the right cerebellar nuclei driven by both simple movement and motor adaptation. Although right cerebellar GABA changes were not significantly different from zero at the group level, the adaptation-driven GABA fluctuations in the right cerebellar nuclei correlated with adaptation performance and with functional connectivity change in a cerebellar network. These results show the first evidence for plastic changes in cerebellar neurochemistry during a cerebellar learning task. This provides the basis for developing therapeutic interventions that facilitate these naturally occurring changes to amplify cerebellar-dependent learning.
Collapse
Affiliation(s)
- Caroline Nettekoven
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU UK
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3TH UK
- Department of Psychiatry, University of Oxford, Oxford OX3 7JX UK
| | - Leah Mitchell
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU UK
| | - William T Clarke
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU UK
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3TH UK
| | - Uzay Emir
- School of Health Sciences, Purdue University, Purdue, Indiana 47907
| | - Jon Campbell
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU UK
| | - Heidi Johansen-Berg
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU UK
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK
| | - Ned Jenkinson
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham B15 2TT UK
| | - Charlotte J Stagg
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU UK
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK
| |
Collapse
|
11
|
Abstract
The cerebellar cortex is an important system for relating neural circuits and learning. Its promise reflects the longstanding idea that it contains simple, repeated circuit modules with only a few cell types and a single plasticity mechanism that mediates learning according to classical Marr-Albus models. However, emerging data have revealed surprising diversity in neuron types, synaptic connections, and plasticity mechanisms, both locally and regionally within the cerebellar cortex. In light of these findings, it is not surprising that attempts to generate a holistic model of cerebellar learning across different behaviors have not been successful. While the cerebellum remains an ideal system for linking neuronal function with behavior, it is necessary to update the cerebellar circuit framework to achieve its great promise. In this review, we highlight recent advances in our understanding of cerebellar-cortical cell types, synaptic connections, signaling mechanisms, and forms of plasticity that enrich cerebellar processing.
Collapse
Affiliation(s)
- Court Hull
- Department of Neurobiology, Duke University School of Medicine, Durham, North Carolina, USA;
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA;
| |
Collapse
|
12
|
Guarque-Chabrera J, Gil-Miravet I, Olucha-Bordonau F, Melchor-Eixea I, Miquel M. When the front fails, the rear wins. Cerebellar correlates of prefrontal dysfunction in cocaine-induced memory in male rats. Prog Neuropsychopharmacol Biol Psychiatry 2022; 112:110429. [PMID: 34416354 DOI: 10.1016/j.pnpbp.2021.110429] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/04/2021] [Accepted: 08/11/2021] [Indexed: 01/03/2023]
Abstract
Reciprocal pathways connecting the cerebellum to the prefrontal cortex provide a biological and functional substrate to modulate cognitive functions. Dysfunction of both medial prefrontal cortex (mPFC) and cerebellum underlie the phenotypes of several neuropsychiatric disorders that exhibit comorbidity with substance use disorder (SUD). In people with SUD, cue-action-reward associations appears to be particularly strong and salient, acting as powerful motivational triggers for craving and relapse. Studies of cue reactivity in human with SUD have shown cerebellar activations when drug-related cues are presented. Our preclinical research showed that cocaine-induced conditioned preference increases neural activity and upregulates perineuronal nets (PNNs) around Golgi interneurons in the posterior cerebellar cortex. In the present investigation, we aimed at evaluating cerebellar signatures of conditioned preference for cocaine when drug learning is established under mPFC impairment. We used lidocaine to temporarily inactivate in male rats either the Prelimbic (PL) or the Infralimbic (IL) cortices during cocaine-induced conditioning. The inactivation of the IL, but not the PL, encouraged the acquisition of preference for cocaine-related cues, increased posterior cerebellar cortex activity, and upregulated the expression of PNNs around Golgi interneurons. Moreover, IL impairment not only increased vGluT2- and vGAT-related activity around Golgi cells but also regulated PNNs differently on subpopulations of Golgi cells, increasing the number of neurogranin+ PNN-expressing Golgi cells. Our findings suggest that IL dysfunction may facilitate the acquisition of cocaine-induced memory and cerebellar drug-related learning hallmarks. Overall, IL perturbation during cocaine-induced Pavlovian learning increased cerebellar activity and drug effects. Importantly, cerebellum involvement requires a contingent experience with the drug, and it is not the effect of a mere inactivation of IL cortex.
Collapse
Affiliation(s)
- Julian Guarque-Chabrera
- Área de Psicobiología, Universitat Jaume I, Castellón de la Plana, Comunitat Valenciana 12071, Spain.
| | - Isis Gil-Miravet
- Área de Psicobiología, Universitat Jaume I, Castellón de la Plana, Comunitat Valenciana 12071, Spain.
| | | | - Ignasi Melchor-Eixea
- Área de Psicobiología, Universitat Jaume I, Castellón de la Plana, Comunitat Valenciana 12071, Spain.
| | - Marta Miquel
- Área de Psicobiología, Universitat Jaume I, Castellón de la Plana, Comunitat Valenciana 12071, Spain.
| |
Collapse
|
13
|
Transcranial direct current stimulation of cerebellum alters spiking precision in cerebellar cortex: A modeling study of cellular responses. PLoS Comput Biol 2021; 17:e1009609. [PMID: 34882680 PMCID: PMC8691604 DOI: 10.1371/journal.pcbi.1009609] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 12/21/2021] [Accepted: 11/02/2021] [Indexed: 01/13/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) of the cerebellum has rapidly raised interest but the effects of tDCS on cerebellar neurons remain unclear. Assessing the cellular response to tDCS is challenging because of the uneven, highly stratified cytoarchitecture of the cerebellum, within which cellular morphologies, physiological properties, and function vary largely across several types of neurons. In this study, we combine MRI-based segmentation of the cerebellum and a finite element model of the tDCS-induced electric field (EF) inside the cerebellum to determine the field imposed on the cerebellar neurons throughout the region. We then pair the EF with multicompartment models of the Purkinje cell (PC), deep cerebellar neuron (DCN), and granule cell (GrC) and quantify the acute response of these neurons under various orientations, physiological conditions, and sequences of presynaptic stimuli. We show that cerebellar tDCS significantly modulates the postsynaptic spiking precision of the PC, which is expressed as a change in the spike count and timing in response to presynaptic stimuli. tDCS has modest effects, instead, on the PC tonic firing at rest and on the postsynaptic activity of DCN and GrC. In Purkinje cells, anodal tDCS shortens the repolarization phase following complex spikes (-14.7 ± 6.5% of baseline value, mean ± S.D.; max: -22.7%) and promotes burstiness with longer bursts compared to resting conditions. Cathodal tDCS, instead, promotes irregular spiking by enhancing somatic excitability and significantly prolongs the repolarization after complex spikes compared to baseline (+37.0 ± 28.9%, mean ± S.D.; max: +84.3%). tDCS-induced changes to the repolarization phase and firing pattern exceed 10% of the baseline values in Purkinje cells covering up to 20% of the cerebellar cortex, with the effects being distributed along the EF direction and concentrated in the area under the electrode over the cerebellum. Altogether, the acute effects of tDCS on cerebellum mainly focus on Purkinje cells and modulate the precision of the response to synaptic stimuli, thus having the largest impact when the cerebellar cortex is active. Since the spatiotemporal precision of the PC spiking is critical to learning and coordination, our results suggest cerebellar tDCS as a viable therapeutic option for disorders involving cerebellar hyperactivity such as ataxia. Transcranial direct current stimulation (tDCS) of the cerebellum is gaining momentum as a neuromodulation tool for the treatment of neurological diseases like movement disorders. Nonetheless, the response of cells in the cerebellum to tDCS is unclear and hardly generalizes from our understanding of tDCS of the cerebral cortex. We use computational models to investigate the response of several types of cerebellar neurons to the electric field induced by tDCS and show that, differently from the cerebral cortex, tDCS has significant acute effects on the cerebellar cortex. These effects (i) primarily alter the way Purkinje cells encode synaptic stimuli from the molecular layer and (ii) can help hyperactive cells regain postsynaptic spiking precision. Since the spatiotemporal precision of the Purkinje cell spiking is critical to learning and coordination, the study shows how tDCS can operate at the cellular level to treat movement disorders like tremor and ataxia.
Collapse
|
14
|
Gurnani H, Silver RA. Multidimensional population activity in an electrically coupled inhibitory circuit in the cerebellar cortex. Neuron 2021; 109:1739-1753.e8. [PMID: 33848473 PMCID: PMC8153252 DOI: 10.1016/j.neuron.2021.03.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 01/20/2021] [Accepted: 03/20/2021] [Indexed: 01/05/2023]
Abstract
Inhibitory neurons orchestrate the activity of excitatory neurons and play key roles in circuit function. Although individual interneurons have been studied extensively, little is known about their properties at the population level. Using random-access 3D two-photon microscopy, we imaged local populations of cerebellar Golgi cells (GoCs), which deliver inhibition to granule cells. We show that population activity is organized into multiple modes during spontaneous behaviors. A slow, network-wide common modulation of GoC activity correlates with the level of whisking and locomotion, while faster (<1 s) differential population activity, arising from spatially mixed heterogeneous GoC responses, encodes more precise information. A biologically detailed GoC circuit model reproduced the common population mode and the dimensionality observed experimentally, but these properties disappeared when electrical coupling was removed. Our results establish that local GoC circuits exhibit multidimensional activity patterns that could be used for inhibition-mediated adaptive gain control and spatiotemporal patterning of downstream granule cells.
Collapse
Affiliation(s)
- Harsha Gurnani
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, UK
| | - R Angus Silver
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, UK.
| |
Collapse
|
15
|
Calcium Channel-Dependent Induction of Long-Term Synaptic Plasticity at Excitatory Golgi Cell Synapses of Cerebellum. J Neurosci 2021; 41:3307-3319. [PMID: 33500277 DOI: 10.1523/jneurosci.3013-19.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 12/15/2020] [Accepted: 12/18/2020] [Indexed: 11/21/2022] Open
Abstract
Golgi cells, together with granule cells and mossy fibers, form a neuronal microcircuit regulating information transfer at the cerebellum input stage. Despite theoretical predictions, little was known about long-term synaptic plasticity at Golgi cell synapses. Here, we have used whole-cell patch-clamp recordings and calcium imaging to investigate long-term synaptic plasticity at excitatory synapses impinging on Golgi cells. In acute mouse cerebellar slices, mossy fiber theta-burst stimulation (TBS) could induce either long-term potentiation (LTP) or long-term depression (LTD) at mossy fiber-Golgi cell and granule cell-Golgi cell synapses. This synaptic plasticity showed a peculiar voltage dependence, with LTD or LTP being favored when TBS induction occurred at depolarized or hyperpolarized potentials, respectively. LTP required, in addition to NMDA channels, activation of T-type Ca2+ channels, while LTD required uniquely activation of L-type Ca2+ channels. Notably, the voltage dependence of plasticity at the mossy fiber-Golgi cell synapses was inverted with respect to pure NMDA receptor-dependent plasticity at the neighboring mossy fiber-granule cell synapse, implying that the mossy fiber presynaptic terminal can activate different induction mechanisms depending on the target cell. In aggregate, this result shows that Golgi cells show cell-specific forms of long-term plasticity at their excitatory synapses, that could play a crucial role in sculpting the response patterns of the cerebellar granular layer.SIGNIFICANCE STATEMENT This article shows for the first time a novel form of Ca2+ channel-dependent synaptic plasticity at the excitatory synapses impinging on cerebellar Golgi cells. This plasticity is bidirectional and inverted with respect to NMDA receptor-dependent paradigms, with long-term depression (LTD) and long-term potentiation (LTP) being favored at depolarized and hyperpolarized potentials, respectively. Furthermore, LTP and LTD induction requires differential involvement of T-type and L-type voltage-gated Ca2+ channels rather than the NMDA receptors alone. These results, along with recent computational predictions, support the idea that Golgi cell plasticity could play a crucial role in controlling information flow through the granular layer along with cerebellar learning and memory.
Collapse
|
16
|
Rhee JK, Park H, Kim T, Yamamoto Y, Tanaka-Yamamoto K. Projection-dependent heterogeneity of cerebellar granule cell calcium responses. Mol Brain 2021; 14:63. [PMID: 33789707 PMCID: PMC8011397 DOI: 10.1186/s13041-021-00773-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 03/18/2021] [Indexed: 11/13/2022] Open
Abstract
Cerebellar granule cells (GCs) relay mossy fiber (MF) inputs to Purkinje cell dendrites via their axons, the parallel fibers (PFs), which are individually located at a given sublayer of the molecular layer (ML). Although a certain degree of heterogeneity among GCs has been recently reported, variability of GC responses to MF inputs has never been associated with their most notable structural variability, location of their projecting PFs in the ML. Here, we utilize an adeno-associated virus (AAV)-mediated labeling technique that enables us to categorize GCs according to the location of their PFs, and compare the Ca2+ responses to MF stimulations between three groups of GCs, consisting of either GCs having PFs at the deep (D-GCs), middle (M-GCs), or superficial (S-GCs) sublayer. Our structural analysis revealed that there was no correlation between position of GC soma in the GC layer and location of its PF in the ML, confirming that our AAV-mediated labeling was important to test the projection-dependent variability of the Ca2+ responses in GCs. We then found that the Ca2+ responses of D-GCs differed from those of M-GCs. Pharmacological experiments implied that the different Ca2+ responses were mainly attributable to varied distributions of GABAA receptors (GABAARs) at the synaptic and extrasynaptic regions of GC dendrites. In addition to GABAAR distributions, amounts of extrasynaptic NMDA receptors appear to be also varied, because Ca2+ responses were different between D-GCs and M-GCs when glutamate spillover was enhanced. Whereas the Ca2+ responses of S-GCs were mostly equivalent to those of D-GCs and M-GCs, the blockade of GABA uptake resulted in larger Ca2+ responses in S-GCs compared with D-GCs and M-GCs, implying existence of mechanisms leading to more excitability in S-GCs with increased GABA release. Thus, this study reveals MF stimulation-mediated non-uniform Ca2+ responses in the cerebellar GCs associated with the location of their PFs in the ML, and raises a possibility that combination of inherent functional variability of GCs and their specific axonal projection contributes to the information processing through the GCs.
Collapse
Affiliation(s)
- Jun Kyu Rhee
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, 02792, Republic of Korea
| | - Heeyoun Park
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Taegon Kim
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
| | - Yukio Yamamoto
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
| | - Keiko Tanaka-Yamamoto
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
| |
Collapse
|
17
|
De Zeeuw CI, Lisberger SG, Raymond JL. Diversity and dynamism in the cerebellum. Nat Neurosci 2021; 24:160-167. [PMID: 33288911 DOI: 10.1038/s41593-020-00754-9] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 11/09/2020] [Indexed: 02/01/2023]
Abstract
The past several years have brought revelations and paradigm shifts in research on the cerebellum. Historically viewed as a simple sensorimotor controller with homogeneous architecture, the cerebellum is increasingly implicated in cognitive functions. It possesses an impressive diversity of molecular, cellular and circuit mechanisms, embedded in a dynamic, recurrent circuit architecture. Recent insights about the diversity and dynamism of the cerebellum provide a roadmap for the next decade of cerebellar research, challenging some old concepts, reinvigorating others and defining major new research directions.
Collapse
Affiliation(s)
- Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience, Royal Academy of Sciences (KNAW), Amsterdam, The Netherlands
| | | | | |
Collapse
|
18
|
Masoli S, Ottaviani A, Casali S, D’Angelo E. Cerebellar Golgi cell models predict dendritic processing and mechanisms of synaptic plasticity. PLoS Comput Biol 2020; 16:e1007937. [PMID: 33378395 PMCID: PMC7837495 DOI: 10.1371/journal.pcbi.1007937] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 01/26/2021] [Accepted: 11/13/2020] [Indexed: 02/06/2023] Open
Abstract
The Golgi cells are the main inhibitory interneurons of the cerebellar granular layer. Although recent works have highlighted the complexity of their dendritic organization and synaptic inputs, the mechanisms through which these neurons integrate complex input patterns remained unknown. Here we have used 8 detailed morphological reconstructions to develop multicompartmental models of Golgi cells, in which Na, Ca, and K channels were distributed along dendrites, soma, axonal initial segment and axon. The models faithfully reproduced a rich pattern of electrophysiological and pharmacological properties and predicted the operating mechanisms of these neurons. Basal dendrites turned out to be more tightly electrically coupled to the axon initial segment than apical dendrites. During synaptic transmission, parallel fibers caused slow Ca-dependent depolarizations in apical dendrites that boosted the axon initial segment encoder and Na-spike backpropagation into basal dendrites, while inhibitory synapses effectively shunted backpropagating currents. This oriented dendritic processing set up a coincidence detector controlling voltage-dependent NMDA receptor unblock in basal dendrites, which, by regulating local calcium influx, may provide the basis for spike-timing dependent plasticity anticipated by theory.
Collapse
Affiliation(s)
- Stefano Masoli
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | | | - Stefano Casali
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Egidio D’Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Brain Connectivity Center, IRCCS Mondino Foundation, Pavia, Italy
| |
Collapse
|
19
|
Cellular-resolution mapping uncovers spatial adaptive filtering at the rat cerebellum input stage. Commun Biol 2020; 3:635. [PMID: 33128000 PMCID: PMC7599228 DOI: 10.1038/s42003-020-01360-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 10/08/2020] [Indexed: 01/08/2023] Open
Abstract
Long-term synaptic plasticity is thought to provide the substrate for adaptive computation in brain circuits but very little is known about its spatiotemporal organization. Here, we combined multi-spot two-photon laser microscopy in rat cerebellar slices with realistic modeling to map the distribution of plasticity in multi-neuronal units of the cerebellar granular layer. The units, composed by ~300 neurons activated by ~50 mossy fiber glomeruli, showed long-term potentiation concentrated in the core and long-term depression in the periphery. This plasticity was effectively accounted for by an NMDA receptor and calcium-dependent induction rule and was regulated by the inhibitory Golgi cell loops. Long-term synaptic plasticity created effective spatial filters tuning the time-delay and gain of spike retransmission at the cerebellum input stage and provided a plausible basis for the spatiotemporal recoding of input spike patterns anticipated by the motor learning theory. Casali, Tognolina et al. use two-photon laser microscopy to spatially map long-term synaptic plasticity in rat cerebellar granular cells following stimulation of mossy fibers. Their data allow them to apply realistic modeling to test hypotheses about the synaptic spiking dynamics and reveal the importance of synaptic inhibition to defining these microcircuits.
Collapse
|
20
|
Ohtsuki G, Shishikura M, Ozaki A. Synergistic excitability plasticity in cerebellar functioning. FEBS J 2020; 287:4557-4593. [PMID: 32367676 DOI: 10.1111/febs.15355] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 04/22/2020] [Accepted: 04/30/2020] [Indexed: 12/27/2022]
Abstract
The cerebellum, a universal processor for sensory acquisition and internal models, and its association with synaptic and nonsynaptic plasticity have been envisioned as the biological correlates of learning, perception, and even thought. Indeed, the cerebellum is no longer considered merely as the locus of motor coordination and its learning. Here, we introduce the mechanisms underlying the induction of multiple types of plasticity in cerebellar circuit and give an overview focusing on the plasticity of nonsynaptic intrinsic excitability. The discovery of long-term potentiation of synaptic responsiveness in hippocampal neurons led investigations into changes of their intrinsic excitability. This activity-dependent potentiation of neuronal excitability is distinct from that of synaptic efficacy. Systematic examination of excitability plasticity has indicated that the modulation of various types of Ca2+ - and voltage-dependent K+ channels underlies the phenomenon, which is also triggered by immune activity. Intrinsic plasticity is expressed specifically on dendrites and modifies the integrative processing and filtering effect. In Purkinje cells, modulation of the discordance of synaptic current on soma and dendrite suggested a novel type of cellular learning mechanism. This property enables a plausible synergy between synaptic efficacy and intrinsic excitability, by amplifying electrical conductivity and influencing the polarity of bidirectional synaptic plasticity. Furthermore, the induction of intrinsic plasticity in the cerebellum correlates with motor performance and cognitive processes, through functional connections from the cerebellar nuclei to neocortex and associated regions: for example, thalamus and midbrain. Taken together, recent advances in neuroscience have begun to shed light on the complex functioning of nonsynaptic excitability and the synergy.
Collapse
Affiliation(s)
- Gen Ohtsuki
- The Hakubi Center for Advanced Research, Kyoto University, Japan.,Department of Biophysics, Kyoto University Graduate School of Science, Japan.,Department of Drug Discovery Medicine, Kyoto University Graduate School of Medicine, Japan
| | - Mari Shishikura
- Department of Biophysics, Kyoto University Graduate School of Science, Japan
| | - Akitoshi Ozaki
- Department of Biophysics, Kyoto University Graduate School of Science, Japan
| |
Collapse
|
21
|
Zhang LB, Zhang J, Sun MJ, Chen H, Yan J, Luo FL, Yao ZX, Wu YM, Hu B. Neuronal Activity in the Cerebellum During the Sleep-Wakefulness Transition in Mice. Neurosci Bull 2020; 36:919-931. [PMID: 32430873 DOI: 10.1007/s12264-020-00511-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 02/09/2020] [Indexed: 12/12/2022] Open
Abstract
Cerebellar malfunction can lead to sleep disturbance such as excessive daytime sleepiness, suggesting that the cerebellum may be involved in regulating sleep and/or wakefulness. However, understanding the features of cerebellar regulation in sleep and wakefulness states requires a detailed characterization of neuronal activity within this area. By performing multiple-unit recordings in mice, we showed that Purkinje cells (PCs) in the cerebellar cortex exhibited increased firing activity prior to the transition from sleep to wakefulness. Notably, the increased PC activity resulted from the inputs of low-frequency non-PC units in the cerebellar cortex. Moreover, the increased PC activity was accompanied by decreased activity in neurons of the deep cerebellar nuclei at the non-rapid eye-movement sleep-wakefulness transition. Our results provide in vivo electrophysiological evidence that the cerebellum has the potential to actively regulate the sleep-wakefulness transition.
Collapse
Affiliation(s)
- Li-Bin Zhang
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China.,State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital/Research Institute of Surgery, Army Medical University, Chongqing, 400042, China
| | - Jie Zhang
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China
| | - Meng-Jia Sun
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China.,Squadron 10, Battalion 3, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China
| | - Hao Chen
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China
| | - Jie Yan
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China
| | - Fen-Lan Luo
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China
| | - Zhong-Xiang Yao
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China
| | - Ya-Min Wu
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital/Research Institute of Surgery, Army Medical University, Chongqing, 400042, China.
| | - Bo Hu
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China.
| |
Collapse
|
22
|
Wang Y, Wang Y, Xu C, Wang S, Tan N, Chen C, Chen L, Wu X, Fei F, Cheng H, Lin W, Qi Y, Chen B, Liang J, Zhao J, Xu Z, Guo Y, Zhang S, Li X, Zhou Y, Duan S, Chen Z. Direct Septum-Hippocampus Cholinergic Circuit Attenuates Seizure Through Driving Somatostatin Inhibition. Biol Psychiatry 2020; 87:843-856. [PMID: 31987494 DOI: 10.1016/j.biopsych.2019.11.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/24/2019] [Accepted: 11/12/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND Previous studies indicated the involvement of cholinergic neurons in seizure; however, the specific role of the medial septum (MS)-hippocampus cholinergic circuit in temporal lobe epilepsy (TLE) has not yet been completely elucidated. METHODS In the current study, we used magnetic resonance imaging and diffusion tensor imaging to characterize the pathological change of the MS-hippocampus circuit in 42 patients with TLE compared with 22 healthy volunteers. Using optogenetics and chemogenetics, combined with in vivo or in vitro electrophysiology and retrograde rabies virus tracing, we revealed a direct MS-hippocampus cholinergic circuit that potently attenuates seizure through driving somatostatin inhibition in animal TLE models. RESULTS We found that patients with TLE with hippocampal sclerosis showed a decrease of neuronal fiber connectivity of the MS-hippocampus compared with healthy people. In the mouse TLE model, MS cholinergic neurons ceased firing during hippocampal seizures. Optogenetic and chemogenetic activation of MS cholinergic neurons (but not glutamatergic or GABAergic [gamma-aminobutyric acidergic] neurons) significantly attenuated hippocampal seizures, while specific inhibition promoted hippocampal seizures. Electrophysiology combined with modified rabies virus tracing studies showed that direct (but not indirect) MS-hippocampal cholinergic projections mediated the antiseizure effect by preferentially targeting hippocampal GABAergic neurons. Furthermore, chemogenetic inhibition of hippocampal somatostatin-positive (rather than parvalbumin-positive) subtype of GABAergic neurons reversed the antiseizure effect of the MS-hippocampus cholinergic circuit, which was mimicked by activating somatostatin-positive neurons. CONCLUSIONS These findings underscore the notable antiseizure role of the direct cholinergic MS-hippocampus circuit in TLE through driving the downstream somatostatin effector. This may provide a better understanding of the changes of the seizure circuit and the precise spatiotemporal control of epilepsy.
Collapse
Affiliation(s)
- Ying Wang
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China.
| | - Cenglin Xu
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shuang Wang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Na Tan
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Cong Chen
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Liying Chen
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xiaohua Wu
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Fan Fei
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Heming Cheng
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Wenkai Lin
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yingbei Qi
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Bin Chen
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Jiao Liang
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Junli Zhao
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Zhenghao Xu
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Guo
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shihong Zhang
- Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoming Li
- Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yudong Zhou
- Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shumin Duan
- Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| |
Collapse
|
23
|
Yamaura H, Igarashi J, Yamazaki T. Simulation of a Human-Scale Cerebellar Network Model on the K Computer. Front Neuroinform 2020; 14:16. [PMID: 32317955 PMCID: PMC7146068 DOI: 10.3389/fninf.2020.00016] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 03/18/2020] [Indexed: 12/15/2022] Open
Abstract
Computer simulation of the human brain at an individual neuron resolution is an ultimate goal of computational neuroscience. The Japanese flagship supercomputer, K, provides unprecedented computational capability toward this goal. The cerebellum contains 80% of the neurons in the whole brain. Therefore, computer simulation of the human-scale cerebellum will be a challenge for modern supercomputers. In this study, we built a human-scale spiking network model of the cerebellum, composed of 68 billion spiking neurons, on the K computer. As a benchmark, we performed a computer simulation of a cerebellum-dependent eye movement task known as the optokinetic response. We succeeded in reproducing plausible neuronal activity patterns that are observed experimentally in animals. The model was built on dedicated neural network simulation software called MONET (Millefeuille-like Organization NEural neTwork), which calculates layered sheet types of neural networks with parallelization by tile partitioning. To examine the scalability of the MONET simulator, we repeatedly performed simulations while changing the number of compute nodes from 1,024 to 82,944 and measured the computational time. We observed a good weak-scaling property for our cerebellar network model. Using all 82,944 nodes, we succeeded in simulating a human-scale cerebellum for the first time, although the simulation was 578 times slower than the wall clock time. These results suggest that the K computer is already capable of creating a simulation of a human-scale cerebellar model with the aid of the MONET simulator.
Collapse
Affiliation(s)
- Hiroshi Yamaura
- Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan
| | - Jun Igarashi
- Head Office for Information Systems and Cybersecurity, RIKEN, Saitama, Japan
| | - Tadashi Yamazaki
- Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan
| |
Collapse
|
24
|
Prestori F, Mapelli L, D'Angelo E. Diverse Neuron Properties and Complex Network Dynamics in the Cerebellar Cortical Inhibitory Circuit. Front Mol Neurosci 2019; 12:267. [PMID: 31787879 PMCID: PMC6854908 DOI: 10.3389/fnmol.2019.00267] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 10/17/2019] [Indexed: 12/12/2022] Open
Abstract
Neuronal inhibition can be defined as a spatiotemporal restriction or suppression of local microcircuit activity. The importance of inhibition relies in its fundamental role in shaping signal processing in single neurons and neuronal circuits. In this context, the activity of inhibitory interneurons proved the key to endow networks with complex computational and dynamic properties. In the last 50 years, the prevailing view on the functional role of cerebellar cortical inhibitory circuits was that excitatory and inhibitory inputs sum spatially and temporally in order to determine the motor output through Purkinje cells (PCs). Consequently, cerebellar inhibition has traditionally been conceived in terms of restricting or blocking excitation. This assumption has been challenged, in particular in the cerebellar cortex where all neurons except granule cells (and unipolar brush cells in specific lobules) are inhibitory and fire spontaneously at high rates. Recently, a combination of electrophysiological recordings in vitro and in vivo, imaging, optogenetics and computational modeling, has revealed that inhibitory interneurons play a much more complex role in regulating cerebellar microcircuit functions: inhibition shapes neuronal response dynamics in the whole circuit and eventually regulate the PC output. This review elaborates current knowledge on cerebellar inhibitory interneurons [Golgi cells, Lugaro cells (LCs), basket cells (BCs) and stellate cells (SCs)], starting from their ontogenesis and moving up to their morphological, physiological and plastic properties, and integrates this knowledge with that on the more renown granule cells and PCs. We will focus on the circuit loops in which these interneurons are involved and on the way they generate feed-forward, feedback and lateral inhibition along with complex spatio-temporal response dynamics. In this perspective, inhibitory interneurons emerge as the real controllers of cerebellar functioning.
Collapse
Affiliation(s)
- Francesca Prestori
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Lisa Mapelli
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Egidio D'Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.,IRCCS Mondino Foundation, Pavia, Italy
| |
Collapse
|
25
|
Abstract
Supervised learning plays a key role in the operation of many biological and artificial neural networks. Analysis of the computations underlying supervised learning is facilitated by the relatively simple and uniform architecture of the cerebellum, a brain area that supports numerous motor, sensory, and cognitive functions. We highlight recent discoveries indicating that the cerebellum implements supervised learning using the following organizational principles: ( a) extensive preprocessing of input representations (i.e., feature engineering), ( b) massively recurrent circuit architecture, ( c) linear input-output computations, ( d) sophisticated instructive signals that can be regulated and are predictive, ( e) adaptive mechanisms of plasticity with multiple timescales, and ( f) task-specific hardware specializations. The principles emerging from studies of the cerebellum have striking parallels with those in other brain areas and in artificial neural networks, as well as some notable differences, which can inform future research on supervised learning and inspire next-generation machine-based algorithms.
Collapse
Affiliation(s)
- Jennifer L Raymond
- Department of Neurobiology, Stanford University School of Medicine, Stanford, California 94305, USA;
| | - Javier F Medina
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA;
| |
Collapse
|
26
|
Casali S, Marenzi E, Medini C, Casellato C, D'Angelo E. Reconstruction and Simulation of a Scaffold Model of the Cerebellar Network. Front Neuroinform 2019; 13:37. [PMID: 31156416 PMCID: PMC6530631 DOI: 10.3389/fninf.2019.00037] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/29/2019] [Indexed: 02/05/2023] Open
Abstract
Reconstructing neuronal microcircuits through computational models is fundamental to simulate local neuronal dynamics. Here a scaffold model of the cerebellum has been developed in order to flexibly place neurons in space, connect them synaptically, and endow neurons and synapses with biologically-grounded mechanisms. The scaffold model can keep neuronal morphology separated from network connectivity, which can in turn be obtained from convergence/divergence ratios and axonal/dendritic field 3D geometries. We first tested the scaffold on the cerebellar microcircuit, which presents a challenging 3D organization, at the same time providing appropriate datasets to validate emerging network behaviors. The scaffold was designed to integrate the cerebellar cortex with deep cerebellar nuclei (DCN), including different neuronal types: Golgi cells, granule cells, Purkinje cells, stellate cells, basket cells, and DCN principal cells. Mossy fiber inputs were conveyed through the glomeruli. An anisotropic volume (0.077 mm3) of mouse cerebellum was reconstructed, in which point-neuron models were tuned toward the specific discharge properties of neurons and were connected by exponentially decaying excitatory and inhibitory synapses. Simulations using both pyNEST and pyNEURON showed the emergence of organized spatio-temporal patterns of neuronal activity similar to those revealed experimentally in response to background noise and burst stimulation of mossy fiber bundles. Different configurations of granular and molecular layer connectivity consistently modified neuronal activation patterns, revealing the importance of structural constraints for cerebellar network functioning. The scaffold provided thus an effective workflow accounting for the complex architecture of the cerebellar network. In principle, the scaffold can incorporate cellular mechanisms at multiple levels of detail and be tuned to test different structural and functional hypotheses. A future implementation using detailed 3D multi-compartment neuron models and dynamic synapses will be needed to investigate the impact of single neuron properties on network computation.
Collapse
Affiliation(s)
- Stefano Casali
- Neurophysiology Unit, Neurocomputational Laboratory, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Elisa Marenzi
- Neurophysiology Unit, Neurocomputational Laboratory, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Chaitanya Medini
- Neurophysiology Unit, Neurocomputational Laboratory, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Claudia Casellato
- Neurophysiology Unit, Neurocomputational Laboratory, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Egidio D'Angelo
- Neurophysiology Unit, Neurocomputational Laboratory, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| |
Collapse
|
27
|
Xia Y, Zhang Y, Shen M, Xu H, Li Z, He N. Golgi protein 73 and its diagnostic value in liver diseases. Cell Prolif 2019; 52:e12538. [PMID: 30341783 PMCID: PMC6496820 DOI: 10.1111/cpr.12538] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/29/2018] [Accepted: 09/04/2018] [Indexed: 02/06/2023] Open
Abstract
Golgi protein 73 (GP73, also referred to as Golph 2) with 400 amino acids is a 73 kDa transmembrane glycoprotein typically found in the cis-Golg complex. It is primarily expressed in epithelial cells, which has been found upregulated in hepatocytes in patients suffering from both viral and non-viral liver diseases. GP73 has drawn increasing attention for its potential application in the diagnosis of liver diseases such as hepatitis, liver cirrhosis and liver cancer. Herein, we reviewed the discovery history of GP73 and summarized studies by many groups around the world, aiming at understanding its structure, expression, function, detection methods and the relationship between GP73 and liver diseases in various settings.
Collapse
Affiliation(s)
- Yanyan Xia
- Department of Clinical LaboratoryThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Yuanying Zhang
- Department of Molecular BiologyJiangsu Cancer HospitalNanjingChina
| | - Mengjiao Shen
- Department of Clinical LaboratoryThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Hongpan Xu
- Department of Clinical LaboratoryThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjingChina
| | - Zhiyang Li
- Center of Laboratory MedicineThe Second Affiliated Hospital of Nanjing Medical UniversityNanjingChina
| | - Nongyue He
- State Key Laboratory of BioelectronicsSoutheast UniversityNanjingChina
| |
Collapse
|
28
|
Cayco-Gajic NA, Silver RA. Re-evaluating Circuit Mechanisms Underlying Pattern Separation. Neuron 2019; 101:584-602. [PMID: 30790539 PMCID: PMC7028396 DOI: 10.1016/j.neuron.2019.01.044] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/07/2019] [Accepted: 01/18/2019] [Indexed: 11/22/2022]
Abstract
When animals interact with complex environments, their neural circuits must separate overlapping patterns of activity that represent sensory and motor information. Pattern separation is thought to be a key function of several brain regions, including the cerebellar cortex, insect mushroom body, and dentate gyrus. However, recent findings have questioned long-held ideas on how these circuits perform this fundamental computation. Here, we re-evaluate the functional and structural mechanisms underlying pattern separation. We argue that the dimensionality of the space available for population codes representing sensory and motor information provides a common framework for understanding pattern separation. We then discuss how these three circuits use different strategies to separate activity patterns and facilitate associative learning in the presence of trial-to-trial variability.
Collapse
Affiliation(s)
- N Alex Cayco-Gajic
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - R Angus Silver
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
| |
Collapse
|
29
|
Brown AM, Arancillo M, Lin T, Catt DR, Zhou J, Lackey EP, Stay TL, Zuo Z, White JJ, Sillitoe RV. Molecular layer interneurons shape the spike activity of cerebellar Purkinje cells. Sci Rep 2019; 9:1742. [PMID: 30742002 PMCID: PMC6370775 DOI: 10.1038/s41598-018-38264-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 12/14/2018] [Indexed: 12/03/2022] Open
Abstract
Purkinje cells receive synaptic input from several classes of interneurons. Here, we address the roles of inhibitory molecular layer interneurons in establishing Purkinje cell function in vivo. Using conditional genetics approaches in mice, we compare how the lack of stellate cell versus basket cell GABAergic neurotransmission sculpts the firing properties of Purkinje cells. We take advantage of an inducible Ascl1CreER allele to spatially and temporally target the deletion of the vesicular GABA transporter, Vgat, in developing neurons. Selective depletion of basket cell GABAergic neurotransmission increases the frequency of Purkinje cell simple spike firing and decreases the frequency of complex spike firing in adult behaving mice. In contrast, lack of stellate cell communication increases the regularity of Purkinje cell simple spike firing while increasing the frequency of complex spike firing. Our data uncover complementary roles for molecular layer interneurons in shaping the rate and pattern of Purkinje cell activity in vivo.
Collapse
Affiliation(s)
- Amanda M Brown
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Department of Neuroscience, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Marife Arancillo
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Tao Lin
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Daniel R Catt
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Joy Zhou
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Elizabeth P Lackey
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Department of Neuroscience, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Trace L Stay
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Department of Neuroscience, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Zhongyuan Zuo
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Joshua J White
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Department of Neuroscience, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA.
- Department of Neuroscience, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA.
- Program in Developmental Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA.
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, Texas, 77030, USA.
| |
Collapse
|
30
|
Pathway-Specific Drive of Cerebellar Golgi Cells Reveals Integrative Rules of Cortical Inhibition. J Neurosci 2018; 39:1169-1181. [PMID: 30587539 DOI: 10.1523/jneurosci.1448-18.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 11/27/2018] [Accepted: 12/13/2018] [Indexed: 11/21/2022] Open
Abstract
Cerebellar granule cells (GrCs) constitute over half of all neurons in the vertebrate brain and are proposed to decorrelate convergent mossy fiber (MF) inputs in service of learning. Interneurons within the GrC layer, Golgi cells (GoCs), are the primary inhibitors of this vast population and therefore play a major role in influencing the computations performed within the layer. Despite this central function for GoCs, few studies have directly examined how GoCs integrate inputs from specific afferents, which vary in density to regulate GrC population activity. We used a variety of methods in mice of either sex to study feedforward inhibition recruited by identified MFs, focusing on features that would influence integration by GrCs. Comprehensive 3D reconstruction and quantification of GoC axonal boutons revealed tightly clustered boutons that focus feedforward inhibition in the neighborhood of GoC somata. Acute whole-cell patch-clamp recordings from GrCs in brain slices showed that, despite high GoC bouton density, fast phasic inhibition was very sparse relative to slow spillover mediated inhibition. Dynamic-clamp simulating inhibition combined with optogenetic MF activation at moderate rates supported a predominant role of slow spillover mediated inhibition in reducing GrC activity. Whole-cell recordings from GoCs revealed a role for the density of active MFs in preferentially driving them. Thus, our data provide empirical confirmation of predicted rules by which MFs activate GoCs to regulate GrC activity levels.SIGNIFICANCE STATEMENT A unifying framework in neural circuit analysis is identifying circuit motifs that subserve common computations. Wide-field inhibitory interneurons globally inhibit neighbors and have been studied extensively in the insect olfactory system and proposed to serve pattern separation functions. Cerebellar Golgi cells (GoCs), a type of mammalian wide-field inhibitory interneuron observed in the granule cell layer, are well suited to perform normalization or pattern separation functions, but the relationship between spatial characteristics of input patterns to GoC-mediated inhibition has received limited attention. This study provides unprecedented quantitative structural details of GoCs and identifies a role for population input activity levels in recruiting inhibition using in vitro electrophysiology and optogenetics.
Collapse
|
31
|
Fleming E, Hull C. Serotonin regulates dynamics of cerebellar granule cell activity by modulating tonic inhibition. J Neurophysiol 2018; 121:105-114. [PMID: 30281395 DOI: 10.1152/jn.00492.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Understanding how afferent information is integrated by cortical structures requires identifying the factors shaping excitation and inhibition within their input layers. The input layer of the cerebellar cortex integrates diverse sensorimotor information to enable learned associations that refine the dynamics of movement. Specifically, mossy fiber afferents relay sensorimotor input into the cerebellum to excite granule cells, whose activity is regulated by inhibitory Golgi cells. To test how this integration can be modulated, we have used an acute brain slice preparation from young adult rats and found that encoding of mossy fiber input in the cerebellar granule cell layer can be regulated by serotonin (5-hydroxytryptamine, 5-HT) via a specific action on Golgi cells. We find that 5-HT depolarizes Golgi cells, likely by activating 5-HT2A receptors, but does not directly act on either granule cells or mossy fibers. As a result of Golgi cell depolarization, 5-HT significantly increases tonic inhibition onto both granule cells and Golgi cells. 5-HT-mediated Golgi cell depolarization is not sufficient, however, to alter the probability or timing of mossy fiber-evoked feed-forward inhibition onto granule cells. Together, increased granule cell tonic inhibition paired with normal feed-forward inhibition acts to reduce granule cell spike probability without altering spike timing. Hence, these data provide a circuit mechanism by which 5-HT can reduce granule cell activity without altering temporal representations of mossy fiber input. Such changes in network integration could enable flexible, state-specific suppression of cerebellar sensorimotor input that should not be learned or enable reversal learning for unwanted associations. NEW & NOTEWORTHY Serotonin (5-hydroxytryptamine, 5-HT) regulates synaptic integration at the input stage of cerebellar processing by increasing tonic inhibition of granule cells. This circuit mechanism reduces the probability of granule cell spiking without altering spike timing, thus suppressing cerebellar input without altering its temporal representation in the granule cell layer.
Collapse
Affiliation(s)
- Elizabeth Fleming
- Department of Neurobiology, Duke University Medical School , Durham, North Carolina
| | - Court Hull
- Department of Neurobiology, Duke University Medical School , Durham, North Carolina
| |
Collapse
|
32
|
Medial Auditory Thalamus Is Necessary for Expression of Auditory Trace Eyelid Conditioning. J Neurosci 2018; 38:8831-8844. [PMID: 30120206 DOI: 10.1523/jneurosci.1009-18.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 08/06/2018] [Accepted: 08/09/2018] [Indexed: 12/13/2022] Open
Abstract
Transforming a brief sensory event into a persistent neural response represents a mechanism for linking temporally disparate stimuli together to support learning. The cerebellum requires this type of persistent input during trace conditioning to engage associative plasticity and acquire adaptively timed conditioned responses (CRs). An initial step toward identifying the sites and mechanisms generating and transmitting persistent signals to the cerebellum is to identify the input pathway. The medial auditory thalamic nuclei (MATN) are the necessary and sufficient source of auditory input to the cerebellum for delay conditioning in rodents and a possible input to forebrain sites generating persistent signals. Using pharmacological and computational approaches, we test (1) whether the necessity of MATN during auditory eyelid conditioning is conserved across species, (2) whether the MATN are necessary for the expression of trace eyelid CRs, and if so, (3)whether this relates to the generation of persistent signals. We find that contralateral inactivation of MATN with muscimol largely abolished trace and delay CRs in male rabbits. Residual CRs were decreased in amplitude, but CR timing was unaffected. Results from large-scale cerebellar simulations are consistent with previous experimental demonstrations that silencing only CS-duration inputs does not abolish trace CRs, and instead affects their timing. Together, these results suggest that the MATN are a necessary component of both the direct auditory stimulus pathway to the cerebellum and the pathway generating task-essential persistent signals.SIGNIFICANCE STATEMENT Persistent activity is required for working memory-dependent tasks, such as trace conditioning, and represents a mechanism by which sensory information can be used over time for learning and cognition. This neuronal response entails the transformation of a discrete sensory-evoked response into a signal that extends beyond the stimulus event. Understanding the generation and transmission of this stimulus transformation requires identifying the input sources necessary for task-essential persistent signals. We report that the medial auditory thalamic nuclei are required for the expression of auditory trace conditioning and suggest that these nuclei are a component of the pathway-generating persistent signals. Our study provides a foundation for testing circuit-level mechanisms underlying persistent activity in a cerebellar learning model with identified inputs and well defined behavioral outputs.
Collapse
|
33
|
Tantra M, Guo L, Kim J, Zainolabidin N, Eulenburg V, Augustine GJ, Chen AI. Conditional deletion of Cadherin 13 perturbs Golgi cells and disrupts social and cognitive behaviors. GENES, BRAIN, AND BEHAVIOR 2018; 17:e12466. [PMID: 29446202 PMCID: PMC6635760 DOI: 10.1111/gbb.12466] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 02/02/2018] [Accepted: 02/05/2018] [Indexed: 12/21/2022]
Abstract
Inhibitory interneurons mediate the gating of synaptic transmission and modulate the activities of neural circuits. Disruption of the function of inhibitory networks in the forebrain is linked to impairment of social and cognitive behaviors, but the involvement of inhibitory interneurons in the cerebellum has not been assessed. We found that Cadherin 13 (Cdh13), a gene implicated in autism spectrum disorder and attention-deficit hyperactivity disorder, is specifically expressed in Golgi cells within the cerebellar cortex. To assess the function of Cdh13 and utilize the manipulation of Cdh13 expression in Golgi cells as an entry point to examine cerebellar-mediated function, we generated mice carrying Cdh13-floxed alleles and conditionally deleted Cdh13 with GlyT2::Cre mice. Loss of Cdh13 results in a decrease in the expression/localization of GAD67 and reduces spontaneous inhibitory postsynaptic current (IPSC) in cerebellar Golgi cells without disrupting spontaneous excitatory postsynaptic current (EPSC). At the behavioral level, loss of Cdh13 in the cerebellum, piriform cortex and endopiriform claustrum have no impact on gross motor coordination or general locomotor behaviors, but leads to deficits in cognitive and social abilities. Mice lacking Cdh13 exhibit reduced cognitive flexibility and loss of preference for contact region concomitant with increased reciprocal social interactions. Together, our findings show that Cdh13 is critical for inhibitory function of Golgi cells, and that GlyT2::Cre-mediated deletion of Cdh13 in non-executive centers of the brain, such as the cerebellum, may contribute to cognitive and social behavioral deficits linked to neurological disorders.
Collapse
Affiliation(s)
- M. Tantra
- School of Biological SciencesNanyang Technological University (NTU)Singapore
- School of Life SciencesUniversity of WarwickCoventryUK
| | - L. Guo
- School of Biological SciencesNanyang Technological University (NTU)Singapore
- School of Life SciencesUniversity of WarwickCoventryUK
| | - J. Kim
- Lee Kong Chian School of MedicineNanyang Technological University (NTU)Singapore
| | - N. Zainolabidin
- School of Biological SciencesNanyang Technological University (NTU)Singapore
- School of Life SciencesUniversity of WarwickCoventryUK
| | - V. Eulenburg
- Institute of BiochemistryFriedrich‐Alexander University Erlangen‐NurembergErlangenGermany
| | - G. J. Augustine
- Lee Kong Chian School of MedicineNanyang Technological University (NTU)Singapore
- Institute of Molecular and Cell BiologySingapore
| | - A. I. Chen
- School of Biological SciencesNanyang Technological University (NTU)Singapore
- School of Life SciencesUniversity of WarwickCoventryUK
- Institute of Molecular and Cell BiologySingapore
| |
Collapse
|
34
|
Park D, Bae S, Yoon TH, Ko J. Molecular Mechanisms of Synaptic Specificity: Spotlight on Hippocampal and Cerebellar Synapse Organizers. Mol Cells 2018; 41:373-380. [PMID: 29665671 PMCID: PMC5974614 DOI: 10.14348/molcells.2018.0081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 03/30/2018] [Accepted: 04/02/2018] [Indexed: 12/13/2022] Open
Abstract
Synapses and neural circuits form with exquisite specificity during brain development to allow the precise and appropriate flow of neural information. Although this property of synapses and neural circuits has been extensively investigated for more than a century, molecular mechanisms underlying this property are only recently being unveiled. Recent studies highlight several classes of cell-surface proteins as organizing hubs in building structural and functional architectures of specific synapses and neural circuits. In the present mini-review, we discuss recent findings on various synapse organizers that confer the distinct properties of specific synapse types and neural circuit architectures in mammalian brains, with a particular focus on the hippocampus and cerebellum.
Collapse
Affiliation(s)
- Dongseok Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| | - Sungwon Bae
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| | - Taek Han Yoon
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| |
Collapse
|
35
|
Locomotor activity modulates associative learning in mouse cerebellum. Nat Neurosci 2018; 21:725-735. [PMID: 29662214 PMCID: PMC5923878 DOI: 10.1038/s41593-018-0129-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/01/2018] [Indexed: 11/26/2022]
Abstract
Changes in behavioral state can profoundly influence brain function. Here we show that behavioral state modulates performance in delay eyeblink conditioning, a cerebellum-dependent form of associative learning. Increased locomotor speed in head-fixed mice drove earlier onset of learning and trial-by-trial enhancement of learned responses that were dissociable from changes in arousal and independent of sensory modality. Eyelid responses evoked by optogenetic stimulation of mossy fiber inputs to the cerebellum, but not at sites downstream, were positively modulated by ongoing locomotion. Substituting prolonged, low-intensity optogenetic mossy fiber stimulation for locomotion was sufficient to enhance conditioned responses. Our results suggest that locomotor activity modulates delay eyeblink conditioning through increased activation of the mossy fiber pathway within the cerebellum. Taken together, these results provide evidence for a novel role for behavioral state modulation in associative learning and suggest a potential mechanism through which engaging in movement can improve an individual’s ability to learn.
Collapse
|
36
|
Robinson JC, Chapman CA, Courtemanche R. Gap Junction Modulation of Low-Frequency Oscillations in the Cerebellar Granule Cell Layer. THE CEREBELLUM 2018; 16:802-811. [PMID: 28421552 DOI: 10.1007/s12311-017-0858-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Local field potential (LFP) oscillations in the granule cell layer (GCL) of the cerebellar cortex have been identified previously in the awake rat and monkey during immobility. These low-frequency oscillations are thought to be generated through local circuit interactions between Golgi cells and granule cells within the GCL. Golgi cells display rhythmic firing and pacemaking properties, and also are electrically coupled through gap junctions within the GCL. Here, we tested if gap junctions in the rat cerebellar cortex contribute to the generation of LFP oscillations in the GCL. We recorded LFP oscillations under urethane anesthesia, and examined the effects of local infusion of gap junction blockers on 5-15 Hz oscillations. Local infusion of the gap junction blockers carbenoxolone and mefloquine resulted in significant decreases in the power of oscillations over a 30-min period, but the power of oscillations was unchanged in control experiments following vehicle injections. In addition, infusion of gap junction blockers had no significant effect on multi-unit activity, suggesting that the attenuation of low-frequency oscillations was likely due to reductions in electrical coupling rather than a decreased excitability within the granule cell layer. Our results indicate that electrical coupling among the Golgi cell networks in the cerebellar cortex contributes to the local circuit mechanisms that promote the occurrence of GCL LFP slow oscillations in the anesthetized rat.
Collapse
Affiliation(s)
- Jennifer Claire Robinson
- Department of Exercise Science, and the FRQS Groupe de Recherche en Neurobiologie Comportementale (CSBN), Concordia University, SP-165-03, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada
| | - C Andrew Chapman
- Department of Psychology, and the FRQS Groupe de Recherche en Neurobiologie Comportementale (CSBN), Concordia University, Montreal, Canada
| | - Richard Courtemanche
- Department of Exercise Science, and the FRQS Groupe de Recherche en Neurobiologie Comportementale (CSBN), Concordia University, SP-165-03, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada.
| |
Collapse
|
37
|
Abstract
The cerebellum is a central brain structure deeply integrated into major loops with the cerebral cortex, brainstem, and spinal cord. The cerebellum shows a complex regional organization consisting of modules with sagittal orientation. The cerebellum takes part in motor control and its lesions cause a movement incoordination syndrome called ataxia. Recent observations also imply involvement of the cerebellum in cognition and executive control, with an impact on pathologies like dyslexia and autism. The cerebellum operates as a forward controller learning to predict the precise timing of correlated events. The physiologic mechanisms of cerebellar functioning are still the object of intense research. The signals entering the cerebellum through the mossy fibers are processed in the granular layer and transmitted to Purkinje cells, while a collateral pathway activates the deep cerebellar nuclei (DCN). Purkinje cells in turn inhibit DCN, so that the cerebellar cortex operates as a side loop controlling the DCN. Learning is now known to occur through synaptic plasticity at multiple synapses in the granular layer, molecular layer, and DCN, extending the original concept of the Motor Learning Theory that predicted a single form of plasticity at the synapse between parallel fibers and Purkinje cells under the supervision of climbing fibers deriving from the inferior olive. Coordination derives from the precise regulation of timing and gain in the different cerebellar modules. The investigation of cerebellar dynamics using advanced physiologic recordings and computational models is now providing new clues on how the cerebellar network performs its internal computations.
Collapse
Affiliation(s)
- Egidio D'Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
| |
Collapse
|
38
|
Nietz AK, Vaden JH, Coddington LT, Overstreet-Wadiche L, Wadiche JI. Non-synaptic signaling from cerebellar climbing fibers modulates Golgi cell activity. eLife 2017; 6. [PMID: 29028183 PMCID: PMC5640426 DOI: 10.7554/elife.29215] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/02/2017] [Indexed: 01/30/2023] Open
Abstract
Golgi cells are the principal inhibitory neurons at the input stage of the cerebellum, providing feedforward and feedback inhibition through mossy fiber and parallel fiber synapses. In vivo studies have shown that Golgi cell activity is regulated by climbing fiber stimulation, yet there is little functional or anatomical evidence for synapses between climbing fibers and Golgi cells. Here, we show that glutamate released from climbing fibers activates ionotropic and metabotropic receptors on Golgi cells through spillover-mediated transmission. The interplay of excitatory and inhibitory conductances provides flexible control over Golgi cell spiking, allowing either excitation or a biphasic sequence of excitation and inhibition following single climbing fiber stimulation. Together with prior studies of spillover transmission to molecular layer interneurons, these results reveal that climbing fibers exert control over inhibition at both the input and output layers of the cerebellar cortex.
Collapse
Affiliation(s)
- Angela K Nietz
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, United States
| | - Jada H Vaden
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, United States
| | - Luke T Coddington
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, United States
| | | | - Jacques I Wadiche
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, United States
| |
Collapse
|
39
|
Sudhakar SK, Hong S, Raikov I, Publio R, Lang C, Close T, Guo D, Negrello M, De Schutter E. Spatiotemporal network coding of physiological mossy fiber inputs by the cerebellar granular layer. PLoS Comput Biol 2017; 13:e1005754. [PMID: 28934196 PMCID: PMC5626500 DOI: 10.1371/journal.pcbi.1005754] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 10/03/2017] [Accepted: 08/31/2017] [Indexed: 11/18/2022] Open
Abstract
The granular layer, which mainly consists of granule and Golgi cells, is the first stage of the cerebellar cortex and processes spatiotemporal information transmitted by mossy fiber inputs with a wide variety of firing patterns. To study its dynamics at multiple time scales in response to inputs approximating real spatiotemporal patterns, we constructed a large-scale 3D network model of the granular layer. Patterned mossy fiber activity induces rhythmic Golgi cell activity that is synchronized by shared parallel fiber input and by gap junctions. This leads to long distance synchrony of Golgi cells along the transverse axis, powerfully regulating granule cell firing by imposing inhibition during a specific time window. The essential network mechanisms, including tunable Golgi cell oscillations, on-beam inhibition and NMDA receptors causing first winner keeps winning of granule cells, illustrate how fundamental properties of the granule layer operate in tandem to produce (1) well timed and spatially bound output, (2) a wide dynamic range of granule cell firing and (3) transient and coherent gating oscillations. These results substantially enrich our understanding of granule cell layer processing, which seems to promote spatial group selection of granule cell activity as a function of timing of mossy fiber input. The cerebellum is an organ of peculiar geometrical properties, and has been attributed the function of applying spatiotemporal transforms to sensorimotor data since Eccles. In this work we have analyzed the spatiotemporal response properties of the first part of the cerebellar circuit, the granule layer. On the basis of a biophysically plausible and large-scale model of the cerebellum, constrained by a wealth of anatomical data, we study the network dynamics and firing properties of individual cell populations in response to 'realistic' input patterns. We make specific predictions about the spatiotemporal features of granule layer processing regarding the effects of the gap junction coupled network of Golgi cells on a spatially restricted input, in an effect we denominate first-takes-all. Furthermore, we calculate that the granule cell layer has a wide dynamic range, indicating that this is a system that can transmit large variations of input intensities.
Collapse
Affiliation(s)
- Shyam Kumar Sudhakar
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
- Laboratory of Theoretical Neurobiology and Neuro-engineering, University of Antwerp, Wilrijk, Belgium
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sungho Hong
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
| | - Ivan Raikov
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
| | - Rodrigo Publio
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
| | - Claus Lang
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
- Bernstein Center of Computational Neuroscience Berlin, Berlin, Germany
| | - Thomas Close
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
| | - Daqing Guo
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
| | - Mario Negrello
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
- Laboratory of Theoretical Neurobiology and Neuro-engineering, University of Antwerp, Wilrijk, Belgium
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Erik De Schutter
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
- Laboratory of Theoretical Neurobiology and Neuro-engineering, University of Antwerp, Wilrijk, Belgium
- * E-mail:
| |
Collapse
|
40
|
Nagy JI, Rash JE. Cx36, Cx43 and Cx45 in mouse and rat cerebellar cortex: species-specific expression, compensation in Cx36 null mice and co-localization in neurons vs. glia. Eur J Neurosci 2017; 46:1790-1804. [PMID: 28561933 DOI: 10.1111/ejn.13614] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/13/2017] [Accepted: 05/24/2017] [Indexed: 12/13/2022]
Abstract
Electrical synapses formed by connexin36 (Cx36)-containing gap junctions between interneurons in the cerebellar cortex have been well characterized, including those formed between basket cells and between Golgi cells, and there is gene reporter-based evidence for the expression of connexin45 (Cx45) in the cerebellar molecular layer. Here, we used immunofluorescence approaches to further investigate expression patterns of Cx36 and Cx45 in this layer and to examine localization relationships of these connexins with each other and with glial connexin43 (Cx43). In mice, strain differences were found, such that punctate labelling for Cx36 was differentially distributed in the molecular layer of C57BL/6 vs. CD1 mice. In mice with EGFP reporter representing Cx36 expression, Cx36-puncta were localized to processes of stellate cells and other cerebellar interneurons. Punctate labelling of Cx45 was faint in the molecular layer of wild-type mice and was increased in intensity in mice with Cx36 gene ablation. The vast majority of Cx36-puncta co-localized with Cx45-puncta, which in turn was associated with the scaffolding protein zonula occludens-1. In rats, Cx45-puncta were also co-localized with Cx36-puncta and additionally occurred along Bergmann glial processes adjacent to Cx43-puncta. The results indicate strain and species differences in Cx36 as well as Cx45 expression, possible compensatory processes after loss of Cx36 expression and localization of Cx45 to both neuronal and Bergmann glial gap junctions. Further, expression of both Cx43 and Cx45 in Bergmann glia of rat may contribute to the complex properties of junctional coupling between these cells and perhaps to their reported coupling with Purkinje cells.
Collapse
Affiliation(s)
- J I Nagy
- Department of Physiology and Pathophysiology, Faculty of Medicine, University of Manitoba, 745 Bannatyne Ave, Winnipeg, MB, R3E 0J9, Canada
| | - J E Rash
- Department of Biomedical Sciences, and Program in Molecular, Cellular and Integrative Neurosciences, Colorado State University, Fort Collins, CO, USA
| |
Collapse
|
41
|
Hull C. Measuring Feedforward Inhibition and Its Impact on Local Circuit Function. Cold Spring Harb Protoc 2017; 2017:2017/5/pdb.prot095828. [PMID: 28461661 DOI: 10.1101/pdb.prot095828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This protocol describes a series of approaches to measure feedforward inhibition in acute brain slices from the cerebellar cortex. Using whole-cell voltage and current clamp recordings from Purkinje cells in conjunction with electrical stimulation of the parallel fibers, these methods demonstrate how to measure the relationship between excitation and inhibition in a feedforward circuit. This protocol also describes how to measure the impact of feedforward inhibition on Purkinje cell excitability, with an emphasis on spike timing.
Collapse
Affiliation(s)
- Court Hull
- Department of Neurobiology, Duke University, Durham, North Carolina 27710
| |
Collapse
|
42
|
Interactive roles of the cerebellum and striatum in sub-second and supra-second timing: Support for an initiation, continuation, adjustment, and termination (ICAT) model of temporal processing. Neurosci Biobehav Rev 2016; 71:739-755. [PMID: 27773690 DOI: 10.1016/j.neubiorev.2016.10.015] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/06/2016] [Accepted: 10/19/2016] [Indexed: 12/29/2022]
|
43
|
Purkinje Cells Directly Inhibit Granule Cells in Specialized Regions of the Cerebellar Cortex. Neuron 2016; 91:1330-1341. [PMID: 27593180 DOI: 10.1016/j.neuron.2016.08.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/02/2016] [Accepted: 08/11/2016] [Indexed: 01/19/2023]
Abstract
Inhibition of granule cells plays a key role in gating the flow of signals into the cerebellum, and it is thought that Golgi cells are the only interneurons that inhibit granule cells. Here we show that Purkinje cells, the sole output neurons of the cerebellar cortex, also directly inhibit granule cells via their axon collaterals. Anatomical and optogenetic studies indicate that this non-canonical feedback is region specific: it is most prominent in lobules that regulate eye movement and process vestibular information. Collaterals provide fast, slow, and tonic inhibition to granule cells, and thus allow Purkinje cells to regulate granule cell excitability on multiple timescales. We propose that this feedback mechanism could regulate excitability of the input layer, contribute to sparse coding, and mediate temporal integration.
Collapse
|
44
|
Yaeger DB, Trussell LO. Auditory Golgi cells are interconnected predominantly by electrical synapses. J Neurophysiol 2016; 116:540-51. [PMID: 27121584 PMCID: PMC4978786 DOI: 10.1152/jn.01108.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 04/26/2016] [Indexed: 11/22/2022] Open
Abstract
The mossy fiber-granule cell-parallel fiber system conveys proprioceptive and corollary discharge information to principal cells in cerebellum-like systems. In the dorsal cochlear nucleus (DCN), Golgi cells inhibit granule cells and thus regulate information transfer along the mossy fiber-granule cell-parallel fiber pathway. Whereas excitatory synaptic inputs to Golgi cells are well understood, inhibitory and electrical synaptic inputs to Golgi cells have not been examined. Using paired recordings in a mouse brain slice preparation, we find that Golgi cells of the cochlear nucleus reliably form electrical synapses onto one another. Golgi cells were only rarely electrically coupled to superficial stellate cells, which form a separate network of electrically coupled interneurons in the DCN. Spikelets had a biphasic effect on the excitability of postjunctional Golgi cells, with a brief excitatory phase and a prolonged inhibitory phase due to the propagation of the prejunctional afterhyperpolarization through gap junctions. Golgi cells and stellate cells made weak inhibitory chemical synapses onto Golgi cells with low probability. Electrical synapses are therefore the predominant form of synaptic communication between auditory Golgi cells. We propose that electrical synapses between Golgi cells may function to regulate the synchrony of Golgi cell firing when electrically coupled Golgi cells receive temporally correlated excitatory synaptic input.
Collapse
Affiliation(s)
- Daniel B Yaeger
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon; and
| | - Laurence O Trussell
- Vollum Institute and Oregon Hearing Research Center, Oregon Health and Science University, Portland, Oregon
| |
Collapse
|
45
|
Barmack NH, Yakhnitsa V. Climbing fibers mediate vestibular modulation of both "complex" and "simple spikes" in Purkinje cells. THE CEREBELLUM 2016; 14:597-612. [PMID: 26424151 DOI: 10.1007/s12311-015-0725-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Climbing and mossy fibers comprise two distinct afferent paths to the cerebellum. Climbing fibers directly evoke a large multispiked action potential in Purkinje cells termed a "complex spike" (CS). By logical exclusion, the other class of Purkinje cell action potential, termed "simple spike" (SS), has often been attributed to activity conveyed by mossy fibers and relayed to Purkinje cells through granule cells. Here, we investigate the relative importance of climbing and mossy fiber pathways in modulating neuronal activity by recording extracellularly from Purkinje cells, as well as from mossy fiber terminals and interneurons in folia 8-10. Sinusoidal roll-tilt vestibular stimulation vigorously modulates the discharge of climbing and mossy fiber afferents, Purkinje cells, and interneurons in folia 9-10 in anesthetized mice. Roll-tilt onto the side ipsilateral to the recording site increases the discharge of both climbing fibers (CSs) and mossy fibers. However, the discharges of SSs decrease during ipsilateral roll-tilt. Unilateral microlesions of the beta nucleus (β-nucleus) of the inferior olive blocks vestibular modulation of both CSs and SSs in contralateral Purkinje cells. The blockage of SSs occurs even though primary and secondary vestibular mossy fibers remain intact. When mossy fiber afferents are damaged by a unilateral labyrinthectomy (UL), vestibular modulation of SSs in Purkinje cells ipsilateral to the UL remains intact. Two inhibitory interneurons, Golgi and stellate cells, could potentially contribute to climbing fiber-induced modulation of SSs. However, during sinusoidal roll-tilt, only stellate cells discharge appropriately out of phase with the discharge of SSs. Golgi cells discharge in phase with SSs. When the vestibularly modulated discharge is blocked by a microlesion of the inferior olive, the modulated discharge of CSs and SSs is also blocked. When the vestibular mossy fiber pathway is destroyed, vestibular modulation of ipsilateral CSs and SSs persists. We conclude that climbing fibers are primarily responsible for the vestibularly modulated discharge of both CSs and SSs. Modulation of the discharge of SSs is likely caused by climbing fiber-evoked stellate cell inhibition.
Collapse
Affiliation(s)
- N H Barmack
- Department of Physiology and Pharmacology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA.
| | - V Yakhnitsa
- Department of Physiology and Pharmacology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| |
Collapse
|
46
|
D'Angelo E, Antonietti A, Casali S, Casellato C, Garrido JA, Luque NR, Mapelli L, Masoli S, Pedrocchi A, Prestori F, Rizza MF, Ros E. Modeling the Cerebellar Microcircuit: New Strategies for a Long-Standing Issue. Front Cell Neurosci 2016; 10:176. [PMID: 27458345 PMCID: PMC4937064 DOI: 10.3389/fncel.2016.00176] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 06/23/2016] [Indexed: 11/13/2022] Open
Abstract
The cerebellar microcircuit has been the work bench for theoretical and computational modeling since the beginning of neuroscientific research. The regular neural architecture of the cerebellum inspired different solutions to the long-standing issue of how its circuitry could control motor learning and coordination. Originally, the cerebellar network was modeled using a statistical-topological approach that was later extended by considering the geometrical organization of local microcircuits. However, with the advancement in anatomical and physiological investigations, new discoveries have revealed an unexpected richness of connections, neuronal dynamics and plasticity, calling for a change in modeling strategies, so as to include the multitude of elementary aspects of the network into an integrated and easily updatable computational framework. Recently, biophysically accurate “realistic” models using a bottom-up strategy accounted for both detailed connectivity and neuronal non-linear membrane dynamics. In this perspective review, we will consider the state of the art and discuss how these initial efforts could be further improved. Moreover, we will consider how embodied neurorobotic models including spiking cerebellar networks could help explaining the role and interplay of distributed forms of plasticity. We envisage that realistic modeling, combined with closed-loop simulations, will help to capture the essence of cerebellar computations and could eventually be applied to neurological diseases and neurorobotic control systems.
Collapse
Affiliation(s)
- Egidio D'Angelo
- Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy; Brain Connectivity Center, C. Mondino National Neurological InstitutePavia, Italy
| | - Alberto Antonietti
- NearLab - NeuroEngineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano Milano, Italy
| | - Stefano Casali
- Department of Brain and Behavioral Sciences, University of Pavia Pavia, Italy
| | - Claudia Casellato
- NearLab - NeuroEngineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano Milano, Italy
| | - Jesus A Garrido
- Department of Computer Architecture and Technology, University of Granada Granada, Spain
| | - Niceto Rafael Luque
- Department of Computer Architecture and Technology, University of Granada Granada, Spain
| | - Lisa Mapelli
- Department of Brain and Behavioral Sciences, University of Pavia Pavia, Italy
| | - Stefano Masoli
- Department of Brain and Behavioral Sciences, University of Pavia Pavia, Italy
| | - Alessandra Pedrocchi
- NearLab - NeuroEngineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano Milano, Italy
| | - Francesca Prestori
- Department of Brain and Behavioral Sciences, University of Pavia Pavia, Italy
| | - Martina Francesca Rizza
- Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy; Dipartimento di Informatica, Sistemistica e Comunicazione, Università degli Studi di Milano-BicoccaMilan, Italy
| | - Eduardo Ros
- Department of Computer Architecture and Technology, University of Granada Granada, Spain
| |
Collapse
|
47
|
Gharravi AM. Staining of cerebellar cortex granular layer interneurons with natural dye of Madder. CEREBELLUM & ATAXIAS 2016; 3:12. [PMID: 27257507 PMCID: PMC4890242 DOI: 10.1186/s40673-016-0050-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 04/26/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND The objective of the present study was an investigation of root Rubia Tinctorum (Madder) as a natural dye to identification of granular layer interneurons of the rat cerebellum. METHODS Seven to ten micrometre sections were collected from the cerebellum and stained only with Madder for 2, 24 and 48 h. Other sections were stained with Madder then with hematoxyllin, cresyl violet, eosin, light green. Microscopic identification of cells was performed based on cell morphology, reaction and binding of with the dye. All data were expressed as mean ± SD in and significance was set at p ≤0.05. RESULTS Madder with alum as mordant resulted a deep red staining of interneurons. Unipolar brush cells (UBCs) were observed with a cell body diameter intermediate between granule and Golgi cells in the superficial layer of the granular layer. Golgi cells were identified almost as large as Purkinje cells with irregular rounded or polygonal morphology. Lugaro cells were observed as spindle-shaped cells adjacent to Purkinje layer. CONCLUSION Results of the present study showed that mader could stain granular layer interneurons in cerebellum cortex of rat.
Collapse
|
48
|
Only a Minority of the Inhibitory Inputs to Cerebellar Golgi Cells Originates from Local GABAergic Cells. eNeuro 2016; 3:eN-NWR-0055-16. [PMID: 27257627 PMCID: PMC4876488 DOI: 10.1523/eneuro.0055-16.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/28/2016] [Accepted: 05/08/2016] [Indexed: 11/21/2022] Open
Abstract
Cerebellar Golgi cells (GoCs) efficiently control the spiking activity of granule cells through GABAA receptor-mediated tonic and phasic inhibition. Recent experiments provided compelling evidence for the extensive interconnection of GoCs through electrical synapses, but their chemical inhibitory synaptic inputs are debated. Here, we investigated the GABAergic synaptic inputs of GoCs using in vitro electrophysiology and quantitative light microscopy (LM) and electron microscopy (EM). We characterized GABAA receptor-mediated IPSCs in GoCs and Lugaro cells (LuCs), and found that IPSCs in GoCs have lower frequencies, smaller amplitudes, and much slower decay kinetics. Pharmacological and LM immunolocalization experiments revealed that GoCs express α3, whereas LuCs express α1 subunit-containing GABAA receptors. The selective expression and clustered distribution of the α3 subunit in GoCs allowed the quantitative analysis of GABAergic synapses on their dendrites in the molecular layer (ML). EM and LM experiments in rats, and wild-type and GlyT2-GFP transgenic mice revealed that only one third of axon terminals establishing GABAergic synapses on GoC dendrites contain GlyT2, ruling out LuCs, globular cells, and any noncortical glycinergic inputs as major inhibitory sources. We also show that axon terminals of stellate/basket cells very rarely innervate GlyT2-GFP-expressing GoCs, indicating that only a minority of the inhibitory inputs to GoCs in the ML originates from local interneurons, and the majority of their inhibitory inputs exclusively releases GABA.
Collapse
|
49
|
Conditional Spike Transmission Mediated by Electrical Coupling Ensures Millisecond Precision-Correlated Activity among Interneurons In Vivo. Neuron 2016; 90:810-23. [PMID: 27161527 PMCID: PMC4882376 DOI: 10.1016/j.neuron.2016.04.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 02/18/2016] [Accepted: 04/01/2016] [Indexed: 11/23/2022]
Abstract
Many GABAergic interneurons are electrically coupled and in vitro can display correlated activity with millisecond precision. However, the mechanisms underlying correlated activity between interneurons in vivo are unknown. Using dual patch-clamp recordings in vivo, we reveal that in the presence of spontaneous background synaptic activity, electrically coupled cerebellar Golgi cells exhibit robust millisecond precision-correlated activity which is enhanced by sensory stimulation. This precisely correlated activity results from the cooperative action of two mechanisms. First, electrical coupling ensures slow subthreshold membrane potential correlations by equalizing membrane potential fluctuations, such that coupled neurons tend to approach action potential threshold together. Second, fast spike-triggered spikelets transmitted through gap junctions conditionally trigger postjunctional spikes, depending on both neurons being close to threshold. Electrical coupling therefore controls the temporal precision and degree of both spontaneous and sensory-evoked correlated activity between interneurons, by the cooperative effects of shared synaptic depolarization and spikelet transmission. Double patch-clamp recordings from Golgi cells reveal millisecond synchrony in vivo Millisecond synchrony requires gap junctions and is enhanced by sensory stimuli Gap junctions drive synchrony via slow Vm equalization and fast spikelet transmission Modeling shows these findings can be generalized to any electrically coupled neurons
Collapse
|
50
|
Cattani A, Solinas S, Canuto C. A Hybrid Model for the Computationally-Efficient Simulation of the Cerebellar Granular Layer. Front Comput Neurosci 2016; 10:30. [PMID: 27148027 PMCID: PMC4837690 DOI: 10.3389/fncom.2016.00030] [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: 12/04/2015] [Accepted: 03/24/2016] [Indexed: 11/13/2022] Open
Abstract
The aim of the present paper is to efficiently describe the membrane potential dynamics of neural populations formed by species having a high density difference in specific brain areas. We propose a hybrid model whose main ingredients are a conductance-based model (ODE system) and its continuous counterpart (PDE system) obtained through a limit process in which the number of neurons confined in a bounded region of the brain tissue is sent to infinity. Specifically, in the discrete model, each cell is described by a set of time-dependent variables, whereas in the continuum model, cells are grouped into populations that are described by a set of continuous variables. Communications between populations, which translate into interactions among the discrete and the continuous models, are the essence of the hybrid model we present here. The cerebellum and cerebellum-like structures show in their granular layer a large difference in the relative density of neuronal species making them a natural testing ground for our hybrid model. By reconstructing the ensemble activity of the cerebellar granular layer network and by comparing our results to a more realistic computational network, we demonstrate that our description of the network activity, even though it is not biophysically detailed, is still capable of reproducing salient features of neural network dynamics. Our modeling approach yields a significant computational cost reduction by increasing the simulation speed at least 270 times. The hybrid model reproduces interesting dynamics such as local microcircuit synchronization, traveling waves, center-surround, and time-windowing.
Collapse
Affiliation(s)
- Anna Cattani
- Laboratory of Neural Computation, Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia Rovereto, Italy
| | - Sergio Solinas
- Department of Brain and Behavioural Science, University of Pavia Pavia, Italy
| | - Claudio Canuto
- Department of Mathematical Sciences, Polytechnic University of Turin Torino, Italy
| |
Collapse
|