1
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Lowe SA, Wilson AD, Aughey GN, Banerjee A, Goble T, Simon-Batsford N, Sanderson A, Kratschmer P, Balogun M, Gao H, Aw SS, Jepson JEC. Modulation of a critical period for motor development in Drosophila by BK potassium channels. Curr Biol 2024; 34:3488-3505.e3. [PMID: 39053467 DOI: 10.1016/j.cub.2024.06.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/16/2024] [Accepted: 06/26/2024] [Indexed: 07/27/2024]
Abstract
Critical periods are windows of heightened plasticity occurring during neurodevelopment. Alterations in neural activity during these periods can cause long-lasting changes in the structure, connectivity, and intrinsic excitability of neurons, which may contribute to the pathology of neurodevelopmental disorders. However, endogenous regulators of critical periods remain poorly defined. Here, we study this issue using a fruit fly (Drosophila) model of an early-onset movement disorder caused by BK potassium channel gain of function (BK GOF). Deploying a genetic method to place robust expression of GOF BK channels under spatiotemporal control, we show that adult-stage neuronal expression of GOF BK channels minimally disrupts fly movement. In contrast, limiting neuronal expression of GOF BK channels to a short window during late neurodevelopment profoundly impairs locomotion and limb kinematics in resulting adult flies. During this critical period, BK GOF perturbs synaptic localization of the active zone protein Bruchpilot and reduces excitatory neurotransmission. Conversely, enhancing neural activity specifically during development rescues motor defects in BK GOF flies. Collectively, our results reveal a critical developmental period for limb control in Drosophila that is influenced by BK channels and suggest that BK GOF causes movement disorders by disrupting activity-dependent aspects of synaptic development.
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Affiliation(s)
- Simon A Lowe
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.
| | - Abigail D Wilson
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Gabriel N Aughey
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Animesh Banerjee
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A(∗)STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Talya Goble
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK; Department of Cell and Developmental Biology, University College London, London, UK
| | - Nell Simon-Batsford
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Angelina Sanderson
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK; Champalimaud Research, Champalimaud Centre for the Unknown, Lisboa, Portugal
| | - Patrick Kratschmer
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Maryam Balogun
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Hao Gao
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Sherry S Aw
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A(∗)STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - James E C Jepson
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.
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2
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Gruver KM, Jiao JWY, Fields E, Song S, Sjöström PJ, Watt AJ. Structured connectivity in the output of the cerebellar cortex. Nat Commun 2024; 15:5563. [PMID: 38982047 PMCID: PMC11233638 DOI: 10.1038/s41467-024-49339-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 05/28/2024] [Indexed: 07/11/2024] Open
Abstract
The spatial organization of a neuronal circuit is critically important for its function since the location of neurons is often associated with function. In the cerebellum, the major output of the cerebellar cortex are synapses made from Purkinje cells onto neurons in the cerebellar nuclei, yet little has been known about the spatial organization of these synapses. We explored this question using whole-cell electrophysiology and optogenetics in acute sagittal cerebellar slices to produce spatial connectivity maps of cerebellar cortical output in mice. We observed non-random connectivity where Purkinje cell inputs clustered in cerebellar transverse zones: while many nuclear neurons received inputs from a single zone, several multi-zonal connectivity motifs were also observed. Single neurons receiving input from all four zones were overrepresented in our data. These findings reveal that the output of the cerebellar cortex is spatially structured and represents a locus for multimodal integration in the cerebellum.
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Affiliation(s)
- Kim M Gruver
- Department of Biology, McGill University, Montréal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Jenny W Y Jiao
- Department of Biology, McGill University, Montréal, QC, Canada
| | - Eviatar Fields
- Department of Biology, McGill University, Montréal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada
| | - Sen Song
- Laboratory of Brain and Intelligence and Department of Biomedical Engineering, Tsinghua University, Beijing, China
| | - Per Jesper Sjöström
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
| | - Alanna J Watt
- Department of Biology, McGill University, Montréal, QC, Canada.
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3
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Nakayama H, Miyazaki T, Abe M, Yamazaki M, Kawamura Y, Choo M, Konno K, Kawata S, Uesaka N, Hashimoto K, Miyata M, Sakimura K, Watanabe M, Kano M. Direct and indirect pathways for heterosynaptic interaction underlying developmental synapse elimination in the mouse cerebellum. Commun Biol 2024; 7:806. [PMID: 38961250 PMCID: PMC11222442 DOI: 10.1038/s42003-024-06447-4] [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: 09/29/2023] [Accepted: 06/12/2024] [Indexed: 07/05/2024] Open
Abstract
Developmental synapse elimination is crucial for shaping mature neural circuits. In the neonatal mouse cerebellum, Purkinje cells (PCs) receive excitatory synaptic inputs from multiple climbing fibers (CFs) and synapses from all but one CF are eliminated by around postnatal day 20. Heterosynaptic interaction between CFs and parallel fibers (PFs), the axons of cerebellar granule cells (GCs) forming excitatory synapses onto PCs and molecular layer interneurons (MLIs), is crucial for CF synapse elimination. However, mechanisms for this heterosynaptic interaction are largely unknown. Here we show that deletion of AMPA-type glutamate receptor functions in GCs impairs CF synapse elimination mediated by metabotropic glutamate receptor 1 (mGlu1) signaling in PCs. Furthermore, CF synapse elimination is impaired by deleting NMDA-type glutamate receptors from MLIs. We propose that PF activity is crucial for CF synapse elimination by directly activating mGlu1 in PCs and indirectly enhancing the inhibition of PCs through activating NMDA receptors in MLIs.
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Affiliation(s)
- Hisako Nakayama
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Taisuke Miyazaki
- Department of Functioning and Disability, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Yoshinobu Kawamura
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Myeongjeong Choo
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kohtarou Konno
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Shinya Kawata
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Naofumi Uesaka
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Mariko Miyata
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), Tokyo, Japan.
- Advanced Comprehensive Research Organization (ACRO), Teikyo University, Tokyo, Japan.
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4
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Shamsara E, Yamakou ME, Atay FM, Jost J. Dynamics of neural fields with exponential temporal kernel. Theory Biosci 2024; 143:107-122. [PMID: 38460025 PMCID: PMC11127868 DOI: 10.1007/s12064-024-00414-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 02/09/2024] [Indexed: 03/11/2024]
Abstract
We consider the standard neural field equation with an exponential temporal kernel. We analyze the time-independent (static) and time-dependent (dynamic) bifurcations of the equilibrium solution and the emerging spatiotemporal wave patterns. We show that an exponential temporal kernel does not allow static bifurcations such as saddle-node, pitchfork, and in particular, static Turing bifurcations. However, the exponential temporal kernel possesses the important property that it takes into account the finite memory of past activities of neurons, which Green's function does not. Through a dynamic bifurcation analysis, we give explicit bifurcation conditions. Hopf bifurcations lead to temporally non-constant, but spatially constant solutions, but Turing-Hopf bifurcations generate spatially and temporally non-constant solutions, in particular, traveling waves. Bifurcation parameters are the coefficient of the exponential temporal kernel, the transmission speed of neural signals, the time delay rate of synapses, and the ratio of excitatory to inhibitory synaptic weights.
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Affiliation(s)
- Elham Shamsara
- Methods in Medical Informatics, Department of Computer Science, University of Tübingen, 72076, Tübingen, Germany
| | - Marius E Yamakou
- Department of Data Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstr. 11, 91058, Erlangen, Germany.
| | - Fatihcan M Atay
- Department of Mathematics, Bilkent University, 06800, Ankara, Turkey
| | - Jürgen Jost
- Max-Planck-Institut für Mathematik in den Naturwissenschaften, Inselstr. 22, 04103, Leipzig, Germany
- Santa Fe Institute for the Sciences of Complexity, Santa Fe, NM, 87501, USA
- ScaDS.AI, Dresden/Leipzig, Germany
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5
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Papo D, Buldú JM. Does the brain behave like a (complex) network? I. Dynamics. Phys Life Rev 2024; 48:47-98. [PMID: 38145591 DOI: 10.1016/j.plrev.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 12/10/2023] [Indexed: 12/27/2023]
Abstract
Graph theory is now becoming a standard tool in system-level neuroscience. However, endowing observed brain anatomy and dynamics with a complex network structure does not entail that the brain actually works as a network. Asking whether the brain behaves as a network means asking whether network properties count. From the viewpoint of neurophysiology and, possibly, of brain physics, the most substantial issues a network structure may be instrumental in addressing relate to the influence of network properties on brain dynamics and to whether these properties ultimately explain some aspects of brain function. Here, we address the dynamical implications of complex network, examining which aspects and scales of brain activity may be understood to genuinely behave as a network. To do so, we first define the meaning of networkness, and analyse some of its implications. We then examine ways in which brain anatomy and dynamics can be endowed with a network structure and discuss possible ways in which network structure may be shown to represent a genuine organisational principle of brain activity, rather than just a convenient description of its anatomy and dynamics.
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Affiliation(s)
- D Papo
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy; Center for Translational Neurophysiology, Fondazione Istituto Italiano di Tecnologia, Ferrara, Italy.
| | - J M Buldú
- Complex Systems Group & G.I.S.C., Universidad Rey Juan Carlos, Madrid, Spain
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6
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Wong HHW, Watt AJ, Sjöström PJ. Synapse-specific burst coding sustained by local axonal translation. Neuron 2024; 112:264-276.e6. [PMID: 37944518 DOI: 10.1016/j.neuron.2023.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/19/2023] [Accepted: 09/13/2023] [Indexed: 11/12/2023]
Abstract
Neurotransmission in the brain is unreliable, suggesting that high-frequency spike bursts rather than individual spikes carry the neural code. For instance, cortical pyramidal neurons rely on bursts in memory formation. Protein synthesis is another key factor in long-term synaptic plasticity and learning but is widely considered unnecessary for synaptic transmission. Here, however, we show that burst neurotransmission at synapses between neocortical layer 5 pyramidal cells depends on axonal protein synthesis linked to presynaptic NMDA receptors and mTOR. We localized protein synthesis to axons with laser axotomy and puromycylation live imaging. We whole-cell recorded connected neurons to reveal how translation sustained readily releasable vesicle pool size and replenishment rate. We live imaged axons and found sparsely docked RNA granules, suggesting synapse-specific regulation. In agreement, translation boosted neurotransmission onto excitatory but not inhibitory basket or Martinotti cells. Local axonal mRNA translation is thus a hitherto unappreciated principle for sustaining burst coding at specific synapse types.
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Affiliation(s)
- Hovy Ho-Wai Wong
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC H3G 1A4, Canada.
| | - Alanna J Watt
- Biology Department, McGill University, Montreal, QC H3G 0B1, Canada
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC H3G 1A4, Canada.
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7
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Mätlik K, Govek EE, Paul MR, Allis CD, Hatten ME. Histone bivalency regulates the timing of cerebellar granule cell development. Genes Dev 2023; 37:570-589. [PMID: 37491148 PMCID: PMC10499015 DOI: 10.1101/gad.350594.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 07/10/2023] [Indexed: 07/27/2023]
Abstract
Developing neurons undergo a progression of morphological and gene expression changes as they transition from neuronal progenitors to mature neurons. Here we used RNA-seq and H3K4me3 and H3K27me3 ChIP-seq to analyze how chromatin modifications control gene expression in a specific type of CNS neuron: the mouse cerebellar granule cell (GC). We found that in proliferating GC progenitors (GCPs), H3K4me3/H3K27me3 bivalency is common at neuronal genes and undergoes dynamic changes that correlate with gene expression during migration and circuit formation. Expressing a fluorescent sensor for bivalent domains revealed subnuclear bivalent foci in proliferating GCPs. Inhibiting H3K27 methyltransferases EZH1 and EZH2 in vitro and in organotypic cerebellar slices dramatically altered the expression of bivalent genes, induced the down-regulation of migration-related genes and up-regulation of synaptic genes, inhibited glial-guided migration, and accelerated terminal differentiation. Thus, histone bivalency is required to regulate the timing of the progression from progenitor cells to mature neurons.
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Affiliation(s)
- Kärt Mätlik
- Laboratory of Developmental Neurobiology, Rockefeller University, New York, New York 10065, USA
| | - Eve-Ellen Govek
- Laboratory of Developmental Neurobiology, Rockefeller University, New York, New York 10065, USA
| | - Matthew R Paul
- Bioinformatics Resource Center, Rockefeller University, New York, New York 10065, USA
| | - C David Allis
- Laboratory of Chromatin Biology and Epigenetics, Rockefeller University, New York, New York 10065, USA
| | - Mary E Hatten
- Laboratory of Developmental Neurobiology, Rockefeller University, New York, New York 10065, USA;
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8
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Olkhova EA, Smith LA, Bradshaw C, Gorman GS, Erskine D, Ng YS. Neurological Phenotypes in Mouse Models of Mitochondrial Disease and Relevance to Human Neuropathology. Int J Mol Sci 2023; 24:ijms24119698. [PMID: 37298649 DOI: 10.3390/ijms24119698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 05/24/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023] Open
Abstract
Mitochondrial diseases represent the most common inherited neurometabolic disorders, for which no effective therapy currently exists for most patients. The unmet clinical need requires a more comprehensive understanding of the disease mechanisms and the development of reliable and robust in vivo models that accurately recapitulate human disease. This review aims to summarise and discuss various mouse models harbouring transgenic impairments in genes that regulate mitochondrial function, specifically their neurological phenotype and neuropathological features. Ataxia secondary to cerebellar impairment is one of the most prevalent neurological features of mouse models of mitochondrial dysfunction, consistent with the observation that progressive cerebellar ataxia is a common neurological manifestation in patients with mitochondrial disease. The loss of Purkinje neurons is a shared neuropathological finding in human post-mortem tissues and numerous mouse models. However, none of the existing mouse models recapitulate other devastating neurological phenotypes, such as refractory focal seizures and stroke-like episodes seen in patients. Additionally, we discuss the roles of reactive astrogliosis and microglial reactivity, which may be driving the neuropathology in some of the mouse models of mitochondrial dysfunction, as well as mechanisms through which cellular death may occur, beyond apoptosis, in neurons undergoing mitochondrial bioenergy crisis.
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Affiliation(s)
- Elizaveta A Olkhova
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Laura A Smith
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Carla Bradshaw
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, UK
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
| | - Daniel Erskine
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, UK
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
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9
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Abstract
The nervous system regulates tissue stem and precursor populations throughout life. Parallel to roles in development, the nervous system is emerging as a critical regulator of cancer, from oncogenesis to malignant growth and metastatic spread. Various preclinical models in a range of malignancies have demonstrated that nervous system activity can control cancer initiation and powerfully influence cancer progression and metastasis. Just as the nervous system can regulate cancer progression, cancer also remodels and hijacks nervous system structure and function. Interactions between the nervous system and cancer occur both in the local tumour microenvironment and systemically. Neurons and glial cells communicate directly with malignant cells in the tumour microenvironment through paracrine factors and, in some cases, through neuron-to-cancer cell synapses. Additionally, indirect interactions occur at a distance through circulating signals and through influences on immune cell trafficking and function. Such cross-talk among the nervous system, immune system and cancer-both systemically and in the local tumour microenvironment-regulates pro-tumour inflammation and anti-cancer immunity. Elucidating the neuroscience of cancer, which calls for interdisciplinary collaboration among the fields of neuroscience, developmental biology, immunology and cancer biology, may advance effective therapies for many of the most difficult to treat malignancies.
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Affiliation(s)
- Rebecca Mancusi
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
| | - Michelle Monje
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA.
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA.
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10
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Mätlik K, Govek EE, Paul MR, Allis CD, Hatten ME. Histone bivalency regulates the timing of cerebellar granule cell development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526881. [PMID: 36778390 PMCID: PMC9915618 DOI: 10.1101/2023.02.02.526881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Developing neurons undergo a progression of morphological and gene expression changes as they transition from neuronal progenitors to mature, multipolar neurons. Here we use RNA-seq and H3K4me3 and H3K27me3 ChIP-seq to analyze how chromatin modifications control gene expression in a specific type of CNS neuron, the mouse cerebellar granule cell (GC). We find that in proliferating GC progenitors (GCPs), H3K4me3/H3K27me3 bivalency is common at neuronal genes and undergoes dynamic changes that correlate with gene expression during migration and circuit formation. Expressing a fluorescent sensor for bivalent H3K4me3 and H3K27me3 domains revealed subnuclear bivalent foci in proliferating GCPs. Inhibiting H3K27 methyltransferases EZH1 and EZH2 in vitro and in organotypic cerebellar slices dramatically altered the expression of bivalent genes and induced the downregulation of migration-related genes and upregulation of synaptic genes, inhibited glial-guided migration, and accelerated terminal differentiation. Thus, histone bivalency is required to regulate the timing of the progression from progenitor cells to mature neurons.
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Affiliation(s)
- Kärt Mätlik
- Laboratory of Developmental Neurobiology, Rockefeller University, 10065, New York, NY, USA
| | - Eve-Ellen Govek
- Laboratory of Developmental Neurobiology, Rockefeller University, 10065, New York, NY, USA
| | - Matthew R. Paul
- Bioinformatics Resource Center, Rockefeller University, 10065, New York, NY, USA
| | - C. David Allis
- Laboratory of Chromatin Biology and Epigenetics, Rockefeller University, 10065, New York, NY, USA
| | - Mary E. Hatten
- Laboratory of Developmental Neurobiology, Rockefeller University, 10065, New York, NY, USA
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11
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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.
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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;
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12
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Shi Y, Qin L, Wu M, Zheng J, Xie T, Shao Z. Gut neuroendocrine signaling regulates synaptic assembly in C. elegans. EMBO Rep 2022; 23:e53267. [PMID: 35748387 DOI: 10.15252/embr.202153267] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/26/2022] [Accepted: 06/01/2022] [Indexed: 11/09/2022] Open
Abstract
Synaptic connections are essential to build a functional brain. How synapses are formed during development is a fundamental question in neuroscience. Recent studies provided evidence that the gut plays an important role in neuronal development through processing signals derived from gut microbes or nutrients. Defects in gut-brain communication can lead to various neurological disorders. Although the roles of the gut in communicating signals from its internal environment to the brain are well known, it remains unclear whether the gut plays a genetically encoded role in neuronal development. Using C. elegans as a model, we uncover that a Wnt-endocrine signaling pathway in the gut regulates synaptic development in the brain. A canonical Wnt signaling pathway promotes synapse formation through regulating the expression of the neuropeptides encoding gene nlp-40 in the gut, which functions through the neuronally expressed GPCR/AEX-2 receptor during development. Wnt-NLP-40-AEX-2 signaling likely acts to modulate neuronal activity. Our study reveals a genetic role of the gut in synaptic development and identifies a novel contribution of the gut-brain axis.
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Affiliation(s)
- Yanjun Shi
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Lu Qin
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Mengting Wu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Junyu Zheng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Tao Xie
- Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhiyong Shao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
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13
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Bhattacharya S, Donoghue JA, Mahnke M, Brincat SL, Brown EN, Miller EK. Propofol Anesthesia Alters Cortical Traveling Waves. J Cogn Neurosci 2022; 34:1274-1286. [PMID: 35468201 DOI: 10.1162/jocn_a_01856] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Oscillatory dynamics in cortex seem to organize into traveling waves that serve a variety of functions. Recent studies show that propofol, a widely used anesthetic, dramatically alters cortical oscillations by increasing slow-delta oscillatory power and coherence. It is not known how this affects traveling waves. We compared traveling waves across the cortex of non-human primates before, during, and after propofol-induced loss of consciousness (LOC). After LOC, traveling waves in the slow-delta (∼1 Hz) range increased, grew more organized, and traveled in different directions relative to the awake state. Higher frequency (8-30 Hz) traveling waves, by contrast, decreased, lost structure, and switched to directions where the slow-delta waves were less frequent. The results suggest that LOC may be due, in part, to increases in the strength and direction of slow-delta traveling waves that, in turn, alter and disrupt traveling waves in the higher frequencies associated with cognition.
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Affiliation(s)
| | | | | | | | - Emery N Brown
- Massachusetts Institute of Technology, Cambridge.,Massachusetts General Hospital/Harvard Medical School, Boston
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14
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Abstract
Nervous system activity regulates development, homeostasis, and plasticity of the brain as well as other organs in the body. These mechanisms are subverted in cancer to propel malignant growth. In turn, cancers modulate neural structure and function to augment growth-promoting neural signaling in the tumor microenvironment. Approaching cancer biology from a neuroscience perspective will elucidate new therapeutic strategies for presently lethal forms of cancer. In this review, we highlight the neural signaling mechanisms recapitulated in primary brain tumors, brain metastases, and solid tumors throughout the body that regulate cancer progression. Expected final online publication date for the Annual Review of Neuroscience, Volume 45 is July 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Michael B Keough
- Department of Neurology and Neurological Sciences and Howard Hughes Medical Institute, Stanford University, Stanford, California, USA;
| | - Michelle Monje
- Department of Neurology and Neurological Sciences and Howard Hughes Medical Institute, Stanford University, Stanford, California, USA;
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15
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Structure, Function, and Genetics of the Cerebellum in Autism. JOURNAL OF PSYCHIATRY AND BRAIN SCIENCE 2022; 7:e220008. [PMID: 36425354 PMCID: PMC9683352 DOI: 10.20900/jpbs.20220008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Autism spectrum disorders are common neurodevelopmental disorders that are defined by core behavioral symptoms but have diverse genetic and environmental risk factors. Despite its etiological heterogeneity, several unifying theories of autism have been proposed, including a central role for cerebellar dysfunction. The cerebellum follows a protracted course of development that culminates in an exquisitely crafted brain structure containing over half of the neurons in the entire brain densely packed into a highly organized structure. Through its complex network of connections with cortical and subcortical brain regions, the cerebellum acts as a sensorimotor regulator and affects changes in executive and limbic processing. In this review, we summarize the structural, functional, and genetic contributions of the cerebellum to autism.
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16
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Halverson HE, Kim J, Khilkevich A, Mauk MD, Augustine GJ. Feedback inhibition underlies new computational functions of cerebellar interneurons. eLife 2022; 11:77603. [PMID: 36480240 PMCID: PMC9771357 DOI: 10.7554/elife.77603] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
The function of a feedback inhibitory circuit between cerebellar Purkinje cells and molecular layer interneurons (MLIs) was defined by combining optogenetics, neuronal activity recordings both in cerebellar slices and in vivo, and computational modeling. Purkinje cells inhibit a subset of MLIs in the inner third of the molecular layer. This inhibition is non-reciprocal, short-range (less than 200 μm) and is based on convergence of one to two Purkinje cells onto MLIs. During learning-related eyelid movements in vivo, the activity of a subset of MLIs progressively increases as Purkinje cell activity decreases, with Purkinje cells usually leading the MLIs. Computer simulations indicate that these relationships are best explained by the feedback circuit from Purkinje cells to MLIs and that this feedback circuit plays a central role in making cerebellar learning efficient.
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Affiliation(s)
- Hunter E Halverson
- Center for Learning and Memory, The University of TexasAustinUnited States
| | - Jinsook Kim
- Program in Neuroscience & Mental Health, Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingaporeSingapore,Institute of Molecular and Cell BiologySingaporeSingapore
| | - Andrei Khilkevich
- Center for Learning and Memory, The University of TexasAustinUnited States
| | - Michael D Mauk
- Center for Learning and Memory, The University of TexasAustinUnited States,Department of Neuroscience, The University of TexasAustinUnited States
| | - George J Augustine
- Program in Neuroscience & Mental Health, Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingaporeSingapore,Institute of Molecular and Cell BiologySingaporeSingapore
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17
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Traveling waves in the prefrontal cortex during working memory. PLoS Comput Biol 2022; 18:e1009827. [PMID: 35089915 PMCID: PMC8827486 DOI: 10.1371/journal.pcbi.1009827] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 02/09/2022] [Accepted: 01/11/2022] [Indexed: 11/19/2022] Open
Abstract
Neural oscillations are evident across cortex but their spatial structure is not well- explored. Are oscillations stationary or do they form "traveling waves", i.e., spatially organized patterns whose peaks and troughs move sequentially across cortex? Here, we show that oscillations in the prefrontal cortex (PFC) organized as traveling waves in the theta (4-8Hz), alpha (8-12Hz) and beta (12-30Hz) bands. Some traveling waves were planar but most rotated. The waves were modulated during performance of a working memory task. During baseline conditions, waves flowed bidirectionally along a specific axis of orientation. Waves in different frequency bands could travel in different directions. During task performance, there was an increase in waves in one direction over the other, especially in the beta band.
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18
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Guo C, Rudolph S, Neuwirth ME, Regehr WG. Purkinje cell outputs selectively inhibit a subset of unipolar brush cells in the input layer of the cerebellar cortex. eLife 2021; 10:e68802. [PMID: 34369877 PMCID: PMC8352585 DOI: 10.7554/elife.68802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/23/2021] [Indexed: 11/13/2022] Open
Abstract
Circuitry of the cerebellar cortex is regionally and functionally specialized. Unipolar brush cells (UBCs), and Purkinje cell (PC) synapses made by axon collaterals in the granular layer, are both enriched in areas that control balance and eye movement. Here, we find a link between these specializations in mice: PCs preferentially inhibit metabotropic glutamate receptor type 1 (mGluR1)-expressing UBCs that respond to mossy fiber (MF) inputs with long lasting increases in firing, but PCs do not inhibit mGluR1-lacking UBCs. PCs inhibit about 29% of mGluR1-expressing UBCs by activating GABAA receptors (GABAARs) and inhibit almost all mGluR1-expressing UBCs by activating GABAB receptors (GABABRs). PC to UBC synapses allow PC output to regulate the input layer of the cerebellar cortex in diverse ways. Based on optogenetic studies and a small number of paired recordings, GABAAR-mediated feedback is fast and unreliable. GABABR-mediated inhibition is slower and is sufficiently large to strongly influence the input-output transformations of mGluR1-expressing UBCs.
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Affiliation(s)
- Chong Guo
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Stephanie Rudolph
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Morgan E Neuwirth
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
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19
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Purkinje cell axonal swellings enhance action potential fidelity and cerebellar function. Nat Commun 2021; 12:4129. [PMID: 34226561 PMCID: PMC8257784 DOI: 10.1038/s41467-021-24390-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/11/2021] [Indexed: 11/08/2022] Open
Abstract
Axonal plasticity allows neurons to control their output, which critically determines the flow of information in the brain. Axon diameter can be regulated by activity, yet how morphological changes in an axon impact its function remains poorly understood. Axonal swellings have been found on Purkinje cell axons in the cerebellum both in healthy development and in neurodegenerative diseases, and computational models predicts that axonal swellings impair axonal function. Here we report that in young Purkinje cells, axons with swellings propagated action potentials with higher fidelity than those without, and that axonal swellings form when axonal failures are high. Furthermore, we observed that healthy young adult mice with more axonal swellings learn better on cerebellar-related tasks than mice with fewer swellings. Our findings suggest that axonal swellings underlie a form of axonal plasticity that optimizes the fidelity of action potential propagation in axons, resulting in enhanced learning.
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20
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Hirono M, Karube F, Yanagawa Y. Modulatory Effects of Monoamines and Perineuronal Nets on Output of Cerebellar Purkinje Cells. Front Neural Circuits 2021; 15:661899. [PMID: 34194302 PMCID: PMC8236809 DOI: 10.3389/fncir.2021.661899] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/12/2021] [Indexed: 12/27/2022] Open
Abstract
Classically, the cerebellum has been thought to play a significant role in motor coordination. However, a growing body of evidence for novel neural connections between the cerebellum and various brain regions indicates that the cerebellum also contributes to other brain functions implicated in reward, language, and social behavior. Cerebellar Purkinje cells (PCs) make inhibitory GABAergic synapses with their target neurons: other PCs and Lugaro/globular cells via PC axon collaterals, and neurons in the deep cerebellar nuclei (DCN) via PC primary axons. PC-Lugaro/globular cell connections form a cerebellar cortical microcircuit, which is driven by serotonin and noradrenaline. PCs' primary outputs control not only firing but also synaptic plasticity of DCN neurons following the integration of excitatory and inhibitory inputs in the cerebellar cortex. Thus, strong PC-mediated inhibition is involved in cerebellar functions as a key regulator of cerebellar neural networks. In this review, we focus on physiological characteristics of GABAergic transmission from PCs. First, we introduce monoaminergic modulation of GABAergic transmission at synapses of PC-Lugaro/globular cell as well as PC-large glutamatergic DCN neuron, and a Lugaro/globular cell-incorporated microcircuit. Second, we review the physiological roles of perineuronal nets (PNNs), which are organized components of the extracellular matrix and enwrap the cell bodies and proximal processes, in GABA release from PCs to large glutamatergic DCN neurons and in cerebellar motor learning. Recent evidence suggests that alterations in PNN density in the DCN can regulate cerebellar functions.
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Affiliation(s)
- Moritoshi Hirono
- Department of Physiology, Wakayama Medical University, Wakayama, Japan
| | - Fuyuki Karube
- Lab of Histology and Cytology, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
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21
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Hooshmandi M, Truong VT, Fields E, Thomas RE, Wong C, Sharma V, Gantois I, Soriano Roque P, Chalkiadaki K, Wu N, Chakraborty A, Tahmasebi S, Prager-Khoutorsky M, Sonenberg N, Suvrathan A, Watt AJ, Gkogkas CG, Khoutorsky A. 4E-BP2-dependent translation in cerebellar Purkinje cells controls spatial memory but not autism-like behaviors. Cell Rep 2021; 35:109036. [PMID: 33910008 DOI: 10.1016/j.celrep.2021.109036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 02/15/2021] [Accepted: 04/06/2021] [Indexed: 11/19/2022] Open
Abstract
Recent studies have demonstrated that selective activation of mammalian target of rapamycin complex 1 (mTORC1) in the cerebellum by deletion of the mTORC1 upstream repressors TSC1 or phosphatase and tensin homolog (PTEN) in Purkinje cells (PCs) causes autism-like features and cognitive deficits. However, the molecular mechanisms by which overactivated mTORC1 in the cerebellum engenders these behaviors remain unknown. The eukaryotic translation initiation factor 4E-binding protein 2 (4E-BP2) is a central translational repressor downstream of mTORC1. Here, we show that mice with selective ablation of 4E-BP2 in PCs display a reduced number of PCs, increased regularity of PC action potential firing, and deficits in motor learning. Surprisingly, although spatial memory is impaired in these mice, they exhibit normal social interaction and show no deficits in repetitive behavior. Our data suggest that, downstream of mTORC1/4E-BP2, there are distinct cerebellar mechanisms independently controlling social behavior and memory formation.
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Affiliation(s)
- Mehdi Hooshmandi
- Department of Anesthesia and Faculty of Dentistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Vinh Tai Truong
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Eviatar Fields
- Department of Biology, McGill University, Montreal, QC H3A 1A3, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B4, Canada
| | - Riya Elizabeth Thomas
- Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B4, Canada; Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, Montreal QC, H3G1A4, Canada; Department of Neurology and Neurosurgery, Department of Pediatrics, McGill University, Montreal QC, H3G1A4, Canada
| | - Calvin Wong
- Department of Anesthesia and Faculty of Dentistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Vijendra Sharma
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Ilse Gantois
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Patricia Soriano Roque
- Department of Anesthesia and Faculty of Dentistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Kleanthi Chalkiadaki
- Division of Biomedical Research, Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece
| | - Neil Wu
- Department of Anesthesia and Faculty of Dentistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Anindyo Chakraborty
- Department of Anesthesia and Faculty of Dentistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Soroush Tahmasebi
- Department of Pharmacology and Regenerative Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | | | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Aparna Suvrathan
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, Montreal QC, H3G1A4, Canada; Department of Neurology and Neurosurgery, Department of Pediatrics, McGill University, Montreal QC, H3G1A4, Canada
| | - Alanna J Watt
- Department of Biology, McGill University, Montreal, QC H3A 1A3, Canada
| | - Christos G Gkogkas
- Division of Biomedical Research, Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece.
| | - Arkady Khoutorsky
- Department of Anesthesia and Faculty of Dentistry, McGill University, Montreal, QC H3G 1Y6, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC H3A 0G1, Canada.
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22
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Zhang C, Maslar D, Minckley TF, LeJeune KD, Qin Y. Spontaneous, synchronous zinc spikes oscillate with neural excitability and calcium spikes in primary hippocampal neuron culture. J Neurochem 2021; 157:1838-1849. [PMID: 33638177 DOI: 10.1111/jnc.15334] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/23/2021] [Indexed: 12/19/2022]
Abstract
Zinc has been suggested to act as an intracellular signaling molecule due to its regulatory effects on numerous protein targets including enzymes, transcription factors, ion channels, neurotrophic factors, and postsynaptic scaffolding proteins. However, intracellular zinc concentration is tightly maintained at steady levels under natural physiological conditions. Dynamic changes in intracellular zinc concentration have only been detected in certain types of cells that are exposed to pathologic stimuli or upon receptor ligand binding. Unlike calcium, the ubiquitous signaling metal ion that can oscillate periodically and spontaneously in various cells, spontaneous zinc oscillations have never been reported. In this work, we made the novel observation that the developing neurons generated spontaneous and synchronous zinc spikes in primary hippocampal cultures using a fluorescent zinc sensor, FluoZin-3. Blocking of glutamate receptor-dependent calcium influx depleted the zinc spikes, suggesting that these zinc spikes were driven by the glutamate-mediated spontaneous neural excitability and calcium spikes that have been characterized in early developing neurons. Simultaneous imaging of calcium or pH together with zinc, we uncovered that a downward pH spike was evoked with each zinc spike and this transient cellular acidification occurred downstream of calcium spikes but upstream of zinc spikes. Our results suggest that spontaneous, synchronous zinc spikes were generated through calcium influx-induced cellular acidification, which liberates zinc from intracellular zinc binding ligands. Given that changes in zinc concentration can modulate activities of proteins essential for synapse maturation and neuronal differentiation, these zinc spikes might act as important signaling roles in neuronal development.
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Affiliation(s)
- Chen Zhang
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | - Drew Maslar
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | - Taylor F Minckley
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | - Kate D LeJeune
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, CO, USA
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23
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Redolfi N, Lodovichi C. Spontaneous Afferent Activity Carves Olfactory Circuits. Front Cell Neurosci 2021; 15:637536. [PMID: 33767612 PMCID: PMC7985084 DOI: 10.3389/fncel.2021.637536] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/08/2021] [Indexed: 12/11/2022] Open
Abstract
Electrical activity has a key role in shaping neuronal circuits during development. In most sensory modalities, early in development, internally generated spontaneous activity sculpts the initial layout of neuronal wiring. With the maturation of the sense organs, the system relies more on sensory-evoked electrical activity. Stimuli-driven neuronal discharge is required for the transformation of immature circuits in the specific patterns of neuronal connectivity that subserve normal brain function. The olfactory system (OS) differs from this organizational plan. Despite the important role of odorant receptors (ORs) in shaping olfactory topography, odor-evoked activity does not have a prominent role in refining neuronal wiring. On the contrary, afferent spontaneous discharge is required to achieve and maintain the specific diagram of connectivity that defines the topography of the olfactory bulb (OB). Here, we provide an overview of the development of olfactory topography, with a focus on the role of afferent spontaneous discharge in the formation and maintenance of the specific synaptic contacts that result in the topographic organization of the OB.
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Affiliation(s)
- Nelly Redolfi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Claudia Lodovichi
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Neuroscience Institute CNR, Padua, Italy.,Veneto Institute of Molecular Medicine, Padua, Italy.,Padova Neuroscience Center, University of Padua, Padua, Italy
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24
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Browne TJ, Hughes DI, Dayas CV, Callister RJ, Graham BA. Projection Neuron Axon Collaterals in the Dorsal Horn: Placing a New Player in Spinal Cord Pain Processing. Front Physiol 2020; 11:560802. [PMID: 33408637 PMCID: PMC7779806 DOI: 10.3389/fphys.2020.560802] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 11/26/2020] [Indexed: 11/13/2022] Open
Abstract
The pain experience depends on the relay of nociceptive signals from the spinal cord dorsal horn to higher brain centers. This function is ultimately achieved by the output of a small population of highly specialized neurons called projection neurons (PNs). Like output neurons in other central nervous system (CNS) regions, PNs are invested with a substantial axon collateral system that ramifies extensively within local circuits. These axon collaterals are widely distributed within and between spinal cord segments. Anatomical data on PN axon collaterals have existed since the time of Cajal, however, their function in spinal pain signaling remains unclear and is absent from current models of spinal pain processing. Despite these omissions, some insight on the potential role of PN axon collaterals can be drawn from axon collateral systems of principal or output neurons in other CNS regions, such as the hippocampus, amygdala, olfactory cortex, and ventral horn of the spinal cord. The connectivity and actions of axon collaterals in these systems have been well-defined and used to confirm crucial roles in memory, fear, olfaction, and movement control, respectively. We review this information here and propose a framework for characterizing PN axon collateral function in the dorsal horn. We highlight that experimental approaches traditionally used to delineate axon collateral function in other CNS regions are not easily applied to PNs because of their scarcity relative to spinal interneurons (INs), and the lack of cellular organization in the dorsal horn. Finally, we emphasize how the rapid development of techniques such as viral expression of optogenetic or chemogenetic probes can overcome these challenges and allow characterization of PN axon collateral function. Obtaining detailed information of this type is a necessary first step for incorporation of PN collateral system function into models of spinal sensory processing.
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Affiliation(s)
- Tyler J Browne
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute (HMRI), New Lambton Heights, NSW, Australia
| | - David I Hughes
- Institute of Neuroscience Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Christopher V Dayas
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute (HMRI), New Lambton Heights, NSW, Australia
| | - Robert J Callister
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute (HMRI), New Lambton Heights, NSW, Australia
| | - Brett A Graham
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute (HMRI), New Lambton Heights, NSW, Australia
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25
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Zang Y, Hong S, De Schutter E. Firing rate-dependent phase responses of Purkinje cells support transient oscillations. eLife 2020; 9:e60692. [PMID: 32895121 PMCID: PMC7478895 DOI: 10.7554/elife.60692] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 08/20/2020] [Indexed: 01/09/2023] Open
Abstract
Both spike rate and timing can transmit information in the brain. Phase response curves (PRCs) quantify how a neuron transforms input to output by spike timing. PRCs exhibit strong firing-rate adaptation, but its mechanism and relevance for network output are poorly understood. Using our Purkinje cell (PC) model, we demonstrate that the rate adaptation is caused by rate-dependent subthreshold membrane potentials efficiently regulating the activation of Na+ channels. Then, we use a realistic PC network model to examine how rate-dependent responses synchronize spikes in the scenario of reciprocal inhibition-caused high-frequency oscillations. The changes in PRC cause oscillations and spike correlations only at high firing rates. The causal role of the PRC is confirmed using a simpler coupled oscillator network model. This mechanism enables transient oscillations between fast-spiking neurons that thereby form PC assemblies. Our work demonstrates that rate adaptation of PRCs can spatio-temporally organize the PC input to cerebellar nuclei.
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Affiliation(s)
- Yunliang Zang
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate UniversityOkinawaJapan
| | - Sungho Hong
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate UniversityOkinawaJapan
| | - Erik De Schutter
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate UniversityOkinawaJapan
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26
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Functionally distinct Purkinje cell types show temporal precision in encoding locomotion. Proc Natl Acad Sci U S A 2020; 117:17330-17337. [PMID: 32632015 PMCID: PMC7382291 DOI: 10.1073/pnas.2005633117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Purkinje cells, the principal neurons of cerebellar computations, are believed to comprise a uniform neuronal population of cells, each with similar functional properties. Here, we show an undiscovered heterogeneity of adult zebrafish Purkinje cells, revealing the existence of anatomically and functionally distinct cell types. Dual patch-clamp recordings showed that the cerebellar circuit contains all Purkinje cell types that cross-communicate extensively using chemical and electrical synapses. Further activation of spinal central pattern generators (CPGs) revealed unique phase-locked activity from each Purkinje cell type during the locomotor cycle. Thus, we show intricately organized Purkinje cell networks in the adult zebrafish cerebellum that encode the locomotion rhythm differentially, and we suggest that these organizational properties may also apply to other cerebellar functions.
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27
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Cook AA, Fields E, Watt AJ. Losing the Beat: Contribution of Purkinje Cell Firing Dysfunction to Disease, and Its Reversal. Neuroscience 2020; 462:247-261. [PMID: 32554108 DOI: 10.1016/j.neuroscience.2020.06.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023]
Abstract
The cerebellum is a brain structure that is highly interconnected with other brain regions. There are many contributing factors to cerebellar-related brain disease, such as altered afferent input, local connectivity, and/or cerebellar output. Purkinje cells (PC) are the principle cells of the cerebellar cortex, and fire intrinsically; that is, they fire spontaneous action potentials at high frequencies. This review paper focuses on PC intrinsic firing activity, which is altered in multiple neurological diseases, including ataxia, Huntington Disease (HD) and autism spectrum disorder (ASD). Notably, there are several cases where interventions that restore or rescue PC intrinsic activity also improve impaired behavior in these mouse models of disease. These findings suggest that rescuing PC firing deficits themselves may be sufficient to improve impairment in cerebellar-related behavior in disease. We propose that restoring PC intrinsic firing represents a good target for drug development that might be of therapeutic use for several disorders.
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Affiliation(s)
- Anna A Cook
- Department of Biology, McGill University, Montreal, Canada
| | - Eviatar Fields
- Department of Biology, McGill University, Montreal, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Canada
| | - Alanna J Watt
- Department of Biology, McGill University, Montreal, Canada.
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28
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Gamlin CR, Zhang C, Dyer MA, Wong ROL. Distinct Developmental Mechanisms Act Independently to Shape Biased Synaptic Divergence from an Inhibitory Neuron. Curr Biol 2020; 30:1258-1268.e2. [PMID: 32109390 DOI: 10.1016/j.cub.2020.01.080] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/19/2019] [Accepted: 01/28/2020] [Indexed: 12/19/2022]
Abstract
Neurons often contact more than one postsynaptic partner type and display stereotypic patterns of synaptic divergence. Such synaptic patterns usually involve some partners receiving more synapses than others. The developmental strategies generating "biased" synaptic distributions remain largely unknown. To gain insight, we took advantage of a compact circuit in the vertebrate retina, whereby the AII amacrine cell (AII AC) provides inhibition onto cone bipolar cell (BC) axons and retinal ganglion cell (RGC) dendrites, but makes the majority of its synapses with the BCs. Using light and electron microscopy, we reconstructed the morphology and connectivity of mouse retinal AII ACs across postnatal development. We found that AII ACs do not elaborate their presynaptic structures, the lobular appendages, until BCs differentiate about a week after RGCs are present. Lobular appendages are present in mutant mice lacking BCs, implying that although synchronized with BC axonal differentiation, presynaptic differentiation of the AII ACs is not dependent on cues from BCs. With maturation, AII ACs maintain a constant number of synapses with RGCs, preferentially increase synaptogenesis with BCs, and eliminate synapses with wide-field amacrine cells. Thus, AII ACs undergo partner type-specific changes in connectivity to attain their mature pattern of synaptic divergence. Moreover, AII ACs contact non-BCs to the same extent in bipolarless retinas, indicating that AII ACs establish partner-type-specific connectivity using diverse mechanisms that operate in parallel but independently.
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Affiliation(s)
- Clare R Gamlin
- Department of Biological Structure, University of Washington, NE Pacific Street, Seattle, WA 98195, USA
| | - Chi Zhang
- Department of Biological Structure, University of Washington, NE Pacific Street, Seattle, WA 98195, USA
| | - Michael A Dyer
- Department of Developmental Neurobiology, St. Jude's Children Research Hospital, Danny Thomas Place, Memphis, TN 38105, USA
| | - Rachel O L Wong
- Department of Biological Structure, University of Washington, NE Pacific Street, Seattle, WA 98195, USA.
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29
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Pan Y, Monje M. Activity Shapes Neural Circuit Form and Function: A Historical Perspective. J Neurosci 2020; 40:944-954. [PMID: 31996470 PMCID: PMC6988998 DOI: 10.1523/jneurosci.0740-19.2019] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 12/07/2019] [Accepted: 12/10/2019] [Indexed: 12/30/2022] Open
Abstract
The brilliant and often prescient hypotheses of Ramon y Cajal have proven foundational for modern neuroscience, but his statement that "In adult centers the nerve paths are something fixed, ended, immutable … " is an exception that did not stand the test of empirical study. Mechanisms of cellular and circuit-level plasticity continue to shape and reshape many regions of the adult nervous system long after the neurodevelopmental period. Initially focused on neurons alone, the field has followed a meteoric trajectory in understanding of activity-regulated neurodevelopment and ongoing neuroplasticity with an arc toward appreciating neuron-glial interactions and the role that each neural cell type plays in shaping adaptable neural circuity. In this review, as part of a celebration of the 50th anniversary of Society for Neuroscience, we provide a historical perspective, following this arc of inquiry from neuronal to neuron-glial mechanisms by which activity and experience modulate circuit structure and function. The scope of this consideration is broad, and it will not be possible to cover the wealth of knowledge about all aspects of activity-dependent circuit development and plasticity in depth.
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Affiliation(s)
- Yuan Pan
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California 94305
| | - Michelle Monje
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California 94305
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30
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Sathyanesan A, Zhou J, Scafidi J, Heck DH, Sillitoe RV, Gallo V. Emerging connections between cerebellar development, behaviour and complex brain disorders. Nat Rev Neurosci 2019; 20:298-313. [PMID: 30923348 DOI: 10.1038/s41583-019-0152-2] [Citation(s) in RCA: 152] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The human cerebellum has a protracted developmental timeline compared with the neocortex, expanding the window of vulnerability to neurological disorders. As the cerebellum is critical for motor behaviour, it is not surprising that most neurodevelopmental disorders share motor deficits as a common sequela. However, evidence gathered since the late 1980s suggests that the cerebellum is involved in motor and non-motor function, including cognition and emotion. More recently, evidence indicates that major neurodevelopmental disorders such as intellectual disability, autism spectrum disorder, attention-deficit hyperactivity disorder and Down syndrome have potential links to abnormal cerebellar development. Out of recent findings from clinical and preclinical studies, the concept of the 'cerebellar connectome' has emerged that can be used as a framework to link the role of cerebellar development to human behaviour, disease states and the design of better therapeutic strategies.
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Affiliation(s)
- Aaron Sathyanesan
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, DC, USA.
| | - Joy Zhou
- Department of Pathology and Immunology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Joseph Scafidi
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, DC, USA.,George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Detlef H Heck
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.,Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, DC, USA. .,George Washington University School of Medicine and Health Sciences, Washington, DC, USA.
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31
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Gruver KM, Watt AJ. Optimizing Optogenetic Activation of Purkinje Cell Axons to Investigate the Purkinje Cell - DCN Synapse. Front Synaptic Neurosci 2019; 11:31. [PMID: 31824291 PMCID: PMC6883385 DOI: 10.3389/fnsyn.2019.00031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 11/04/2019] [Indexed: 11/13/2022] Open
Abstract
Optogenetics is a state-of-the-art tool for interrogating neural circuits. In the cerebellum, Purkinje cells serve as the sole output of the cerebellar cortex where they synapse on neurons in the deep cerebellar nuclei (DCN). To investigate the properties of this synaptic connection, we sought to elicit time-locked single action potentials from Purkinje cell axons. Using optical stimulation of channelrhodopsin-2 (ChR2)-expressing Purkinje cells combined with patch-clamp recordings of Purkinje cells and DCN neurons in acute cerebellar slices, we determine the photostimulation parameters required to elicit single time-locked action potentials from Purkinje cell axons. We show that axons require longer light pulses than somata do to elicit single action potentials and that Purkinje cell axons are also more susceptible to light perturbations. We then demonstrate that these empirically determined photostimulation parameters elicit time-locked synaptic currents from postsynaptic cells in the DCN. Our results highlight the importance of optimizing optogenetic stimulation conditions to interrogate synaptic connections.
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Affiliation(s)
- Kim M Gruver
- Department of Biology, McGill University, Montreal, QC, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Alanna J Watt
- Department of Biology, McGill University, Montreal, QC, Canada
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32
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Miterko LN, Baker KB, Beckinghausen J, Bradnam LV, Cheng MY, Cooperrider J, DeLong MR, Gornati SV, Hallett M, Heck DH, Hoebeek FE, Kouzani AZ, Kuo SH, Louis ED, Machado A, Manto M, McCambridge AB, Nitsche MA, Taib NOB, Popa T, Tanaka M, Timmann D, Steinberg GK, Wang EH, Wichmann T, Xie T, Sillitoe RV. Consensus Paper: Experimental Neurostimulation of the Cerebellum. CEREBELLUM (LONDON, ENGLAND) 2019; 18:1064-1097. [PMID: 31165428 PMCID: PMC6867990 DOI: 10.1007/s12311-019-01041-5] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The cerebellum is best known for its role in controlling motor behaviors. However, recent work supports the view that it also influences non-motor behaviors. The contribution of the cerebellum towards different brain functions is underscored by its involvement in a diverse and increasing number of neurological and neuropsychiatric conditions including ataxia, dystonia, essential tremor, Parkinson's disease (PD), epilepsy, stroke, multiple sclerosis, autism spectrum disorders, dyslexia, attention deficit hyperactivity disorder (ADHD), and schizophrenia. Although there are no cures for these conditions, cerebellar stimulation is quickly gaining attention for symptomatic alleviation, as cerebellar circuitry has arisen as a promising target for invasive and non-invasive neuromodulation. This consensus paper brings together experts from the fields of neurophysiology, neurology, and neurosurgery to discuss recent efforts in using the cerebellum as a therapeutic intervention. We report on the most advanced techniques for manipulating cerebellar circuits in humans and animal models and define key hurdles and questions for moving forward.
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Affiliation(s)
- Lauren N Miterko
- Department of Pathology and Immunology, Department of Neuroscience, Program in Developmental Biology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Kenneth B Baker
- Neurological Institute, Department of Neurosurgery, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Jaclyn Beckinghausen
- Department of Pathology and Immunology, Department of Neuroscience, Program in Developmental Biology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Lynley V Bradnam
- Department of Exercise Science, Faculty of Science, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Michelle Y Cheng
- Department of Neurosurgery, Stanford University School of Medicine, 1201 Welch Road, MSLS P352, Stanford, CA, 94305-5487, USA
| | - Jessica Cooperrider
- Neurological Institute, Department of Neurosurgery, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Mahlon R DeLong
- Department of Neurology, Emory University, Atlanta, GA, 30322, USA
| | - Simona V Gornati
- Department of Neuroscience, Erasmus Medical Center, 3015 AA, Rotterdam, Netherlands
| | - Mark Hallett
- Human Motor Control Section, NINDS, NIH, Building 10, Room 7D37, 10 Center Dr MSC 1428, Bethesda, MD, 20892-1428, USA
| | - Detlef H Heck
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, 855 Monroe Ave, Memphis, TN, 38163, USA
| | - Freek E Hoebeek
- Department of Neuroscience, Erasmus Medical Center, 3015 AA, Rotterdam, Netherlands
- NIDOD Department, Wilhelmina Children's Hospital, University Medical Center Utrecht Brain Center, Utrecht, Netherlands
| | - Abbas Z Kouzani
- School of Engineering, Deakin University, Geelong, VIC, 3216, Australia
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Department of Chronic Disease Epidemiology, Yale School of Public Health, Center for Neuroepidemiology and Clinical Research, Yale School of Medicine, Yale University, New Haven, CT, 06520, USA
| | - Andre Machado
- Neurological Institute, Department of Neurosurgery, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Mario Manto
- Service de Neurologie, CHU-Charleroi, 6000, Charleroi, Belgium
- Service des Neurosciences, Université de Mons, 7000, Mons, Belgium
| | - Alana B McCambridge
- Graduate School of Health, Physiotherapy, University of Technology Sydney, PO Box 123, Broadway, Sydney, NSW, 2007, Australia
| | - Michael A Nitsche
- Department of Psychology and Neurosiences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
- Department of Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany
| | | | - Traian Popa
- Human Motor Control Section, NINDS, NIH, Building 10, Room 7D37, 10 Center Dr MSC 1428, Bethesda, MD, 20892-1428, USA
- Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Ecole Polytechnique Federale de Lausanne (EPFL), Sion, Switzerland
| | - Masaki Tanaka
- Department of Physiology, Hokkaido University School of Medicine, Sapporo, 060-8638, Japan
| | - Dagmar Timmann
- Department of Neurology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Gary K Steinberg
- Department of Neurosurgery, Stanford University School of Medicine, 1201 Welch Road, MSLS P352, Stanford, CA, 94305-5487, USA
- R281 Department of Neurosurgery, Stanfod University School of Medicine, 300 Pasteur Drive, Stanford, CA, 94305, USA
| | - Eric H Wang
- Department of Neurosurgery, Stanford University School of Medicine, 1201 Welch Road, MSLS P352, Stanford, CA, 94305-5487, USA
| | - Thomas Wichmann
- Department of Neurology, Emory University, Atlanta, GA, 30322, USA
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30322, USA
| | - Tao Xie
- Department of Neurology, University of Chicago, 5841 S. Maryland Avenue, MC 2030, Chicago, IL, 60637-1470, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Department of Neuroscience, Program in Developmental Biology, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.
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33
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Sathyanesan A, Gallo V. Cerebellar contribution to locomotor behavior: A neurodevelopmental perspective. Neurobiol Learn Mem 2019; 165:106861. [PMID: 29723669 PMCID: PMC7303045 DOI: 10.1016/j.nlm.2018.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 04/06/2018] [Accepted: 04/24/2018] [Indexed: 12/30/2022]
Abstract
The developmental trajectory of the formation of cerebellar circuitry has significant implications for locomotor plasticity and adaptive learning at later stages. While there is a wealth of knowledge on the development of locomotor behavior in human infants, children, and adolescents, pre-clinical animal models have fallen behind on the study of the emergence of behavioral motifs in locomotor function across postnatal development. Since cerebellar development is protracted, it is subject to higher risk of genetic or environmental disruption, potentially leading to abnormal behavioral development. This highlights the need for more sophisticated and specific functional analyses of adaptive cerebellar behavior within the context of whole-body locomotion across the entire span of postnatal development. Here we review evidence on cerebellar contribution to adaptive locomotor behavior, highlighting methodologies employed to quantify and categorize behavior at different developmental stages, with the ultimate goal of following the course of early behavioral alterations in neurodevelopmental disorders. Since experimental paradigms used to study cerebellar behavior are lacking in both specificity and applicability to locomotor contexts, we highlight the use of the Erasmus Ladder - an advanced, computerized, fully automated system to quantify adaptive cerebellar learning in conjunction with locomotor function. Finally, we emphasize the need to develop objective, quantitative, behavioral tasks which can track changes in developmental trajectories rather than endpoint measurement at the adult stage of behavior.
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Affiliation(s)
- Aaron Sathyanesan
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, DC, USA.
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, DC, USA; George Washington University School of Medicine and Health Sciences, USA
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34
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Li L, Jayabal S, Ghorbani M, Legault LM, McGraw S, Watt AJ, Yang XJ. ATAT1 regulates forebrain development and stress-induced tubulin hyperacetylation. Cell Mol Life Sci 2019; 76:3621-3640. [PMID: 30953095 PMCID: PMC11105686 DOI: 10.1007/s00018-019-03088-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 03/18/2019] [Accepted: 03/27/2019] [Indexed: 02/02/2023]
Abstract
α-Tubulin acetyltransferase 1 (ATAT1) catalyzes acetylation of α-tubulin at lysine 40 in various organisms ranging from Tetrahymena to humans. Despite the importance in mammals suggested by studies of cultured cells, the mouse Atat1 gene is non-essential for survival, raising an intriguing question about its real functions in vivo. To address this question, we systematically analyzed a mouse strain lacking the gene. The analyses revealed that starting at postnatal day 5, the mutant mice display enlarged lateral ventricles in the forebrain, resembling ventricular dilation in human patients with ventriculomegaly. In the mice, ventricular dilation is due to hypoplasia in the septum and striatum. Behavioral tests of the mice uncovered deficits in motor coordination. Birth-dating experiments revealed that neuronal migration to the mutant septum and striatum is impaired during brain development. In the mutant embryonic fibroblasts, we found mild defects in cell proliferation and primary cilium formation. Notably, in these cells, ATAT1 is indispensable for tubulin hyperacetylation in response to high salt, high glucose, and hydrogen peroxide-induced oxidative stress. We investigated the role of ATAT1 in the hematopoietic system using multicolor flow cytometry and found that this system remains normal in the mutant mice. Although tubulin acetylation was undetectable in a majority of mutant tissues, residual levels were detected in the heart, skeletal muscle, trachea, oviduct, thymus and spleen. This study thus not only establishes the importance of ATAT1 in regulating mouse forebrain development and governing tubulin hyperacetylation during stress responses, but also suggests the existence of an additional α-tubulin acetyltransferase.
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Affiliation(s)
- Lin Li
- The Rosalind and Morris Goodman Cancer Research Center, McGill University, 1160 Pine Avenue West, Montreal, QC, H3A 1A3, Canada
- Department of Medicine, McGill University, Montreal, Canada
| | - Sriram Jayabal
- Department of Biology, McGill University, Montreal, Canada
| | - Mohammad Ghorbani
- The Rosalind and Morris Goodman Cancer Research Center, McGill University, 1160 Pine Avenue West, Montreal, QC, H3A 1A3, Canada
- Department of Medicine, McGill University, Montreal, Canada
| | - Lisa-Marie Legault
- Department of Obstetrics and Gynecology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Serge McGraw
- Department of Obstetrics and Gynecology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Alanna J Watt
- Department of Biology, McGill University, Montreal, Canada
| | - Xiang-Jiao Yang
- The Rosalind and Morris Goodman Cancer Research Center, McGill University, 1160 Pine Avenue West, Montreal, QC, H3A 1A3, Canada.
- Department of Medicine, McGill University, Montreal, Canada.
- Department of Biochemistry, McGill University, Montreal, Canada.
- McGill University Health Center, Montreal, QC, Canada.
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35
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Dohaku R, Yamaguchi M, Yamamoto N, Shimizu T, Osakada F, Hibi M. Tracing of Afferent Connections in the Zebrafish Cerebellum Using Recombinant Rabies Virus. Front Neural Circuits 2019; 13:30. [PMID: 31068795 PMCID: PMC6491863 DOI: 10.3389/fncir.2019.00030] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/10/2019] [Indexed: 12/31/2022] Open
Abstract
The cerebellum is involved in some forms of motor coordination and learning, and in cognitive and emotional functions. To elucidate the functions of the cerebellum, it is important to unravel the detailed connections of the cerebellar neurons. Although the cerebellar neural circuit structure is generally conserved among vertebrates, it is not clear whether the cerebellum receives and processes the same or similar information in different vertebrate species. Here, we performed monosynaptic retrograde tracing with recombinant rabies viruses (RV) to identify the afferent connections of the zebrafish cerebellar neurons. We used a G-deleted RV that expressed GFP. The virus was also pseudotyped with EnvA, an envelope protein of avian sarcoma and leucosis virus (ALSV-A). For the specific infection of cerebellar neurons, we expressed the RV glycoprotein (G) gene and the envelope protein TVA, which is the receptor for EnvA, in Purkinje cells (PCs) or granule cells (GCs), using the promoter for aldolase Ca (aldoca) or cerebellin 12 (cbln12), respectively. When the virus infected PCs in the aldoca line, GFP was detected in the PCs’ presynaptic neurons, including GCs and neurons in the inferior olivary nuclei (IOs), which send climbing fibers (CFs). These observations validated the RV tracing method in zebrafish. When the virus infected GCs in the cbln12 line, GFP was again detected in their presynaptic neurons, including neurons in the pretectal nuclei, the nucleus lateralis valvulae (NLV), the central gray (CG), the medial octavolateralis nucleus (MON), and the descending octaval nucleus (DON). GFP was not observed in these neurons when the virus infected PCs in the aldoca line. These precerebellar neurons generally agree with those reported for other teleost species and are at least partly conserved with those in mammals. Our results demonstrate that the RV system can be used for connectome analyses in zebrafish, and provide fundamental information about the cerebellar neural circuits, which will be valuable for elucidating the functions of cerebellar neural circuits in zebrafish.
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Affiliation(s)
- Ryuji Dohaku
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Masahiro Yamaguchi
- Laboratory of Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Naoyuki Yamamoto
- Department of Animal Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Takashi Shimizu
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.,Laboratory of Organogenesis and Organ Function, Bioscience and Biotechnology, Nagoya University, Nagoya, Japan
| | - Fumitaka Osakada
- Laboratory of Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Masahiko Hibi
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.,Laboratory of Organogenesis and Organ Function, Bioscience and Biotechnology, Nagoya University, Nagoya, Japan
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36
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Dalrymple AN, Sharples SA, Osachoff N, Lognon AP, Whelan PJ. A supervised machine learning approach to characterize spinal network function. J Neurophysiol 2019; 121:2001-2012. [PMID: 30943091 DOI: 10.1152/jn.00763.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Spontaneous activity is a common feature of immature neuronal networks throughout the central nervous system and plays an important role in network development and consolidation. In postnatal rodents, spontaneous activity in the spinal cord exhibits complex, stochastic patterns that have historically proven challenging to characterize. We developed a software tool for quickly and automatically characterizing and classifying episodes of spontaneous activity generated from developing spinal networks. We recorded spontaneous activity from in vitro lumbar ventral roots of 16 neonatal [postnatal day (P)0-P3] mice. Recordings were DC coupled and detrended, and episodes were separated for analysis. Amplitude-, duration-, and frequency-related features were extracted from each episode and organized into five classes. Paired classes and features were used to train and test supervised machine learning algorithms. Multilayer perceptrons were used to classify episodes as rhythmic or multiburst. We increased network excitability with potassium chloride and tested the utility of the tool to detect changes in features and episode class. We also demonstrate usability by having a novel experimenter use the program to classify episodes collected at a later time point (P5). Supervised machine learning-based classification of episodes accounted for changes that traditional approaches cannot detect. Our tool, named SpontaneousClassification, advances the detail in which we can study not only developing spinal networks, but also spontaneous networks in other areas of the nervous system. NEW & NOTEWORTHY Spontaneous activity is important for nervous system network development and consolidation. Our software uses machine learning to automatically and quickly characterize and classify episodes of spontaneous activity in the spinal cord of newborn mice. It detected changes in network activity following KCl-enhanced excitation. Using our software to classify spontaneous activity throughout development, in pathological models, or with neuromodulation, may offer insight into the development and organization of spinal circuits.
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Affiliation(s)
- A N Dalrymple
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton, Alberta , Canada
| | - S A Sharples
- Hotchkiss Brain Institute, University of Calgary , Calgary, Alberta , Canada.,Graduate Program in Neuroscience, University of Calgary , Calgary, Alberta , Canada
| | - N Osachoff
- Department of Comparative Biology and Experimental Medicine, University of Calgary , Calgary, Alberta , Canada
| | - A P Lognon
- Hotchkiss Brain Institute, University of Calgary , Calgary, Alberta , Canada.,Graduate Program in Neuroscience, University of Calgary , Calgary, Alberta , Canada
| | - P J Whelan
- Hotchkiss Brain Institute, University of Calgary , Calgary, Alberta , Canada.,Department of Comparative Biology and Experimental Medicine, University of Calgary , Calgary, Alberta , Canada
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37
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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.
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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.
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Brain-Derived Neurotrophic Factor Is Required for the Neuroprotective Effect of Mifepristone on Immature Purkinje Cells in Cerebellar Slice Culture. Int J Mol Sci 2019; 20:ijms20020285. [PMID: 30642045 PMCID: PMC6359295 DOI: 10.3390/ijms20020285] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 12/02/2022] Open
Abstract
Endogenous γ-aminobutyric acid (GABA)-dependent activity induces death of developing Purkinje neurons in mouse organotypic cerebellar cultures and the synthetic steroid mifepristone blocks this effect. Here, using brain-derived neurotrophic factor (BDNF) heterozygous mice, we show that BDNF plays no role in immature Purkinje cell death. However, interestingly, BDNF haploinsufficiency impairs neuronal survival induced by mifepristone and GABAA-receptors antagonist (bicuculline) treatments, indicating that the underlying neuroprotective mechanism requires the neurotrophin full expression.
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Han KS, Guo C, Chen CH, Witter L, Osorno T, Regehr WG. Ephaptic Coupling Promotes Synchronous Firing of Cerebellar Purkinje Cells. Neuron 2018; 100:564-578.e3. [PMID: 30293822 DOI: 10.1016/j.neuron.2018.09.018] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/29/2018] [Accepted: 09/10/2018] [Indexed: 11/29/2022]
Abstract
Correlated neuronal activity at various timescales plays an important role in information transfer and processing. We find that in awake-behaving mice, an unexpectedly large fraction of neighboring Purkinje cells (PCs) exhibit sub-millisecond synchrony. Correlated firing usually arises from chemical or electrical synapses, but, surprisingly, neither is required to generate PC synchrony. We therefore assessed ephaptic coupling, a mechanism in which neurons communicate via extracellular electrical signals. In the neocortex, ephaptic signals from many neurons summate to entrain spiking on slow timescales, but extracellular signals from individual cells are thought to be too small to synchronize firing. Here we find that a single PC generates sufficiently large extracellular potentials to open sodium channels in nearby PC axons. Rapid synchronization is made possible because ephaptic signals generated by PCs peak during the rising phase of action potentials. These findings show that ephaptic coupling contributes to the prevalent synchronization of nearby PCs.
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Affiliation(s)
- Kyung-Seok Han
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Chong Guo
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Christopher H Chen
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Laurens Witter
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Tomas Osorno
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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40
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Maslyukov A, Li K, Su X, Kovalchuk Y, Garaschuk O. Spontaneous calcium transients in the immature adult-born neurons of the olfactory bulb. Cell Calcium 2018; 74:43-52. [DOI: 10.1016/j.ceca.2018.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/05/2018] [Accepted: 06/05/2018] [Indexed: 02/06/2023]
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Neonatal brain injury causes cerebellar learning deficits and Purkinje cell dysfunction. Nat Commun 2018; 9:3235. [PMID: 30104642 PMCID: PMC6089917 DOI: 10.1038/s41467-018-05656-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 07/16/2018] [Indexed: 11/08/2022] Open
Abstract
Premature infants are more likely to develop locomotor disorders than term infants. In a chronic sub-lethal hypoxia (Hx) mouse model of neonatal brain injury, we recently demonstrated the presence of cellular and physiological changes in the cerebellar white matter. We also observed Hx-induced delay in Purkinje cell (PC) arborization. However, the behavioral consequences of these cellular alterations remain unexplored. Using the Erasmus Ladder to study cerebellar behavior, we report the presence of locomotor malperformance and long-term cerebellar learning deficits in Hx mice. Optogenetics experiments in Hx mice reveal a profound reduction in spontaneous and photoevoked PC firing frequency. Finally, treatment with a gamma-aminobutyric acid (GABA) reuptake inhibitor partially rescues locomotor performance and improves PC firing. Our results demonstrate a long-term miscoordination phenotype characterized by locomotor malperformance and cerebellar learning deficits in a mouse model of neonatal brain injury. Our findings also implicate the developing GABA network as a potential therapeutic target for prematurity-related locomotor deficits.
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Kanner S, Goldin M, Galron R, Ben Jacob E, Bonifazi P, Barzilai A. Astrocytes restore connectivity and synchronization in dysfunctional cerebellar networks. Proc Natl Acad Sci U S A 2018; 115:8025-8030. [PMID: 30012604 PMCID: PMC6077713 DOI: 10.1073/pnas.1718582115] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Evidence suggests that astrocytes play key roles in structural and functional organization of neuronal circuits. To understand how astrocytes influence the physiopathology of cerebellar circuits, we cultured cells from cerebella of mice that lack the ATM gene. Mutations in ATM are causative of the human cerebellar degenerative disease ataxia-telangiectasia. Cerebellar cultures grown from Atm-/- mice had disrupted network synchronization, atrophied astrocytic arborizations, reduced autophagy levels, and higher numbers of synapses per neuron than wild-type cultures. Chimeric circuitries composed of wild-type astrocytes and Atm-/- neurons were indistinguishable from wild-type cultures. Adult cerebellar characterizations confirmed disrupted astrocyte morphology, increased GABAergic synaptic markers, and reduced autophagy in Atm-/- compared with wild-type mice. These results indicate that astrocytes can impact neuronal circuits at levels ranging from synaptic expression to global dynamics.
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Affiliation(s)
- Sivan Kanner
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Miri Goldin
- School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv, Israel
- Computational Neuroimaging Laboratory, Biocruces Health Research Institute, Hospital Universitario Cruces, 48903 Baracaldo, Vizcaya, Spain
| | - Ronit Galron
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Eshel Ben Jacob
- School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Paolo Bonifazi
- School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv, Israel;
- Computational Neuroimaging Laboratory, Biocruces Health Research Institute, Hospital Universitario Cruces, 48903 Baracaldo, Vizcaya, Spain
- Ikerbasque: The Basque Foundation for Science, 48013 Bilbao, Bizkaia, Spain
| | - Ari Barzilai
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel;
- Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel
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43
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Ady V, Toscano-Márquez B, Nath M, Chang PK, Hui J, Cook A, Charron F, Larivière R, Brais B, McKinney RA, Watt AJ. Altered synaptic and firing properties of cerebellar Purkinje cells in a mouse model of ARSACS. J Physiol 2018; 596:4253-4267. [PMID: 29928778 DOI: 10.1113/jp275902] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 06/19/2018] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset neurodegenerative human disease characterized in part by ataxia and Purkinje cell loss in anterior cerebellar lobules. A knock-out mouse model has been developed that recapitulates several features of ARSACS. Using this ARSACS mouse model, we report changes in synaptic input and intrinsic firing in cerebellar Purkinje cells, as well as in their synaptic output in the deep cerebellar nuclei. Changes in firing are observed in anterior lobules that later exhibit Purkinje cell death, but not in posterior lobules that do not. Our results show that both synaptic and intrinsic alterations in Purkinje cell properties likely contribute to disease manifestation in ARSACS; these findings resemble pathophysiological changes reported in several other ataxias. ABSTRACT Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset neurodegenerative disease that includes a pronounced and progressive cerebellar dysfunction. ARSACS is caused by an autosomal recessive loss-of-function mutation in the Sacs gene that encodes the protein sacsin. To better understand the cerebellar pathophysiology in ARSACS, we studied synaptic and firing properties of Purkinje cells from a mouse model of ARSACS, Sacs-/- mice. We found that excitatory synaptic drive was reduced onto Sacs-/- Purkinje cells, and that Purkinje cell firing rate, but not regularity, was reduced at postnatal day (P)40, an age when ataxia symptoms were first reported. Firing rate deficits were limited to anterior lobules that later display Purkinje cell death, and were not observed in posterior lobules where Purkinje cells are not lost. Mild firing deficits were observed as early as P20, prior to the manifestation of motor deficits, suggesting that a critical level of cerebellar dysfunction is required for motor coordination to emerge. Finally, we observed a reduction in Purkinje cell innervation onto target neurons in the deep cerebellar nuclei (DCN) in Sacs-/- mice. Together, these findings suggest that multiple alterations in the cerebellar circuit including Purkinje cell input and output contribute to cerebellar-related disease onset in ARSACS.
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Affiliation(s)
- Visou Ady
- Department of Biology, McGill University, Montréal, Canada
| | | | - Moushumi Nath
- Department of Biology, McGill University, Montréal, Canada
| | - Philip K Chang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Canada
| | - Jeanette Hui
- Department of Biology, McGill University, Montréal, Canada
| | - Anna Cook
- Department of Biology, McGill University, Montréal, Canada
| | - François Charron
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Canada
| | - Roxanne Larivière
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, Canada
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, Canada
| | - R Anne McKinney
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Canada
| | - Alanna J Watt
- Department of Biology, McGill University, Montréal, Canada
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Persistent Sodium Current Drives Excitability of Immature Renshaw Cells in Early Embryonic Spinal Networks. J Neurosci 2018; 38:7667-7682. [PMID: 30012693 DOI: 10.1523/jneurosci.3203-17.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 06/14/2018] [Accepted: 06/29/2018] [Indexed: 12/13/2022] Open
Abstract
Spontaneous network activity (SNA) emerges in the spinal cord (SC) before the formation of peripheral sensory inputs and central descending inputs. SNA is characterized by recurrent giant depolarizing potentials (GDPs). Because GDPs in motoneurons (MNs) are mainly evoked by prolonged release of GABA, they likely necessitate sustained firing of interneurons. To address this issue we analyzed, as a model, embryonic Renshaw cell (V1R) activity at the onset of SNA (E12.5) in the embryonic mouse SC (both sexes). V1R are one of the interneurons known to contact MNs, which are generated early in the embryonic SC. Here, we show that V1R already produce GABA in E12.5 embryo, and that V1R make synaptic-like contacts with MNs and have putative extrasynaptic release sites, while paracrine release of GABA occurs at this developmental stage. In addition, we discovered that V1R are spontaneously active during SNA and can already generate several intrinsic activity patterns including repetitive-spiking and sodium-dependent plateau potential that rely on the presence of persistent sodium currents (INap). This is the first demonstration that INap is present in the embryonic SC and that this current can control intrinsic activation properties of newborn interneurons in the SC of mammalian embryos. Finally, we found that 5 μm riluzole, which is known to block INaP, altered SNA by reducing episode duration and increasing inter-episode interval. Because SNA is essential for neuronal maturation, axon pathfinding, and synaptogenesis, the presence of INaP in embryonic SC neurons may play a role in the early development of mammalian locomotor networks.SIGNIFICANCE STATEMENT The developing spinal cord (SC) exhibits spontaneous network activity (SNA) involved in the building of nascent locomotor circuits in the embryo. Many studies suggest that SNA depends on the rhythmic release of GABA, yet intracellular recordings of GABAergic neurons have never been performed at the onset of SNA in the SC. We first discovered that embryonic Renshaw cells (V1R) are GABAergic at E12.5 and spontaneously active during SNA. We uncover a new role for persistent sodium currents (INaP) in driving plateau potential in V1R and in SNA patterning in the embryonic SC. Our study thus sheds light on a role for INaP in the excitability of V1R and the developing SC.
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45
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Homeostatic Feedback Modulates the Development of Two-State Patterned Activity in a Model Serotonin Motor Circuit in Caenorhabditis elegans. J Neurosci 2018; 38:6283-6298. [PMID: 29891728 DOI: 10.1523/jneurosci.3658-17.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 06/03/2018] [Accepted: 06/06/2018] [Indexed: 01/31/2023] Open
Abstract
Neuron activity accompanies synapse formation and maintenance, but how early circuit activity contributes to behavior development is not well understood. Here, we use the Caenorhabditis elegans egg-laying motor circuit as a model to understand how coordinated cell and circuit activity develops and drives a robust two-state behavior in adults. Using calcium imaging in behaving animals, we find the serotonergic hermaphrodite-specific neurons (HSNs) and vulval muscles show rhythmic calcium transients in L4 larvae before eggs are produced. HSN activity in L4 is tonic and lacks the alternating burst-firing/quiescent pattern seen in egg-laying adults. Vulval muscle activity in L4 is initially uncoordinated but becomes synchronous as the anterior and posterior muscle arms meet at HSN synaptic release sites. However, coordinated muscle activity does not require presynaptic HSN input. Using reversible silencing experiments, we show that neuronal and vulval muscle activity in L4 is not required for the onset of adult behavior. Instead, the accumulation of eggs in the adult uterus renders the muscles sensitive to HSN input. Sterilization or acute electrical silencing of the vulval muscles inhibits presynaptic HSN activity and reversal of muscle silencing triggers a homeostatic increase in HSN activity and egg release that maintains ∼12-15 eggs in the uterus. Feedback of egg accumulation depends upon the vulval muscle postsynaptic terminus, suggesting that a retrograde signal sustains HSN synaptic activity and egg release. Our results show that egg-laying behavior in C. elegans is driven by a homeostat that scales serotonin motor neuron activity in response to postsynaptic muscle feedback.SIGNIFICANCE STATEMENT The functional importance of early, spontaneous neuron activity in synapse and circuit development is not well understood. Here, we show in the nematode Caenorhabditis elegans that the serotonergic hermaphrodite-specific neurons (HSNs) and postsynaptic vulval muscles show activity during circuit development, well before the onset of adult behavior. Surprisingly, early activity is not required for circuit development or the onset of adult behavior and the circuit remains unable to drive egg laying until fertilized embryos are deposited into the uterus. Egg accumulation potentiates vulval muscle excitability, but ultimately acts to promote burst firing in the presynaptic HSNs which results in egg laying. Our results suggest that mechanosensory feedback acts at three distinct steps to initiate, sustain, and terminate C. elegans egg-laying circuit activity and behavior.
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46
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Beckinghausen J, Sillitoe RV. Insights into cerebellar development and connectivity. Neurosci Lett 2018; 688:2-13. [PMID: 29746896 DOI: 10.1016/j.neulet.2018.05.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 05/04/2018] [Accepted: 05/06/2018] [Indexed: 02/06/2023]
Abstract
The cerebellum has a well-established role in controlling motor functions such coordination, balance, posture, and skilled learning. There is mounting evidence that it might also play a critical role in non-motor functions such as cognition and emotion. It is therefore not surprising that cerebellar defects are associated with a wide array of diseases including ataxia, dystonia, tremor, schizophrenia, dyslexia, and autism spectrum disorder. What is intriguing is that a seemingly uniform circuit that is often described as being "simple" should carry out all of these behaviors. Analyses of how cerebellar circuits develop have revealed that such descriptions massively underestimate the complexity of the cerebellum. The cerebellum is in fact highly patterned and organized around a series of parasagittal stripes and transverse zones. This topographic architecture partitions all cerebellar circuits into functional modules that are thought to enhance processing power during cerebellar dependent behaviors. What are arguably the most remarkable features of cerebellar topography are the developmental processes that produce them. This review is concerned with the genetic and cellular mechanisms that orchestrate cerebellar patterning. We place a major focus on how Purkinje cells control multiple aspects of cerebellar circuit assembly. Using this model, we discuss evidence for how "zebra-like" patterns in Purkinje cells sculpt the cerebellum, how specific genetic cues mediate the process, and how activity refines the patterns into an adult map that is capable of executing various functions. We also discuss how defective Purkinje cell patterning might impact the pathogenesis of neurological conditions.
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Affiliation(s)
- Jaclyn Beckinghausen
- Department of Pathology and Immunology, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Department of Neuroscience, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute of TX Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Department of Neuroscience, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA; Jan and Dan Duncan Neurological Research Institute of TX Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA.
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47
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Yamamoto H, Kubota S, Shimizu FA, Hirano-Iwata A, Niwano M. Effective Subnetwork Topology for Synchronizing Interconnected Networks of Coupled Phase Oscillators. Front Comput Neurosci 2018; 12:17. [PMID: 29643771 PMCID: PMC5882810 DOI: 10.3389/fncom.2018.00017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 03/06/2018] [Indexed: 11/13/2022] Open
Abstract
A system consisting of interconnected networks, or a network of networks (NoN), appears diversely in many real-world systems, including the brain. In this study, we consider NoNs consisting of heterogeneous phase oscillators and investigate how the topology of subnetworks affects the global synchrony of the network. The degree of synchrony and the effect of subnetwork topology are evaluated based on the Kuramoto order parameter and the minimum coupling strength necessary for the order parameter to exceed a threshold value, respectively. In contrast to an isolated network in which random connectivity is favorable for achieving synchrony, NoNs synchronize with weaker interconnections when the degree distribution of subnetworks is heterogeneous, suggesting the major role of the high-degree nodes. We also investigate a case in which subnetworks with different average natural frequencies are coupled to show that direct coupling of subnetworks with the largest variation is effective for synchronizing the whole system. In real-world NoNs like the brain, the balance of synchrony and asynchrony is critical for its function at various spatial resolutions. Our work provides novel insights into the topological basis of coordinated dynamics in such networks.
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Affiliation(s)
- Hideaki Yamamoto
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan
| | - Shigeru Kubota
- Graduate School of Science and Engineering, Yamagata University, Yamagata, Japan
| | - Fabio A Shimizu
- Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
| | - Ayumi Hirano-Iwata
- Research Institute of Electrical Communication, Tohoku University, Sendai, Japan.,Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
| | - Michio Niwano
- Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
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48
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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.
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Affiliation(s)
- Egidio D'Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
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49
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Wefers AK, Haberlandt C, Tekin NB, Fedorov DA, Timmermann A, van der Want JJL, Chaudhry FA, Steinhäuser C, Schilling K, Jabs R. Synaptic input as a directional cue for migrating interneuron precursors. Development 2017; 144:4125-4136. [PMID: 29061636 DOI: 10.1242/dev.154096] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 10/11/2017] [Indexed: 02/02/2023]
Abstract
During CNS development, interneuron precursors have to migrate extensively before they integrate in specific microcircuits. Known regulators of neuronal motility include classical neurotransmitters, yet the mechanisms that assure interneuron dispersal and interneuron/projection neuron matching during histogenesis remain largely elusive. We combined time-lapse video microscopy and electrophysiological analysis of the nascent cerebellum of transgenic Pax2-EGFP mice to address this issue. We found that cerebellar interneuronal precursors regularly show spontaneous postsynaptic currents, indicative of synaptic innervation, well before settling in the molecular layer. In keeping with the sensitivity of these cells to neurotransmitters, ablation of synaptic communication by blocking vesicular release in acute slices of developing cerebella slows migration. Significantly, abrogation of exocytosis primarily impedes the directional persistence of migratory interneuronal precursors. These results establish an unprecedented function of the early synaptic innervation of migrating neuronal precursors and demonstrate a role for synapses in the regulation of migration and pathfinding.
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Affiliation(s)
- Annika K Wefers
- Anatomisches Institut, Anatomie & Zellbiologie, Medizinische Fakultät, University of Bonn, 53115 Bonn, Germany.,Institut für Zelluläre Neurowissenschaften, Medizinische Fakultät, University of Bonn, 53105 Bonn, Germany
| | - Christian Haberlandt
- Institut für Zelluläre Neurowissenschaften, Medizinische Fakultät, University of Bonn, 53105 Bonn, Germany
| | - Nuriye B Tekin
- Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway
| | - Dmitry A Fedorov
- Institut für Zelluläre Neurowissenschaften, Medizinische Fakultät, University of Bonn, 53105 Bonn, Germany
| | - Aline Timmermann
- Institut für Zelluläre Neurowissenschaften, Medizinische Fakultät, University of Bonn, 53105 Bonn, Germany
| | - Johannes J L van der Want
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Farrukh A Chaudhry
- Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway
| | - Christian Steinhäuser
- Institut für Zelluläre Neurowissenschaften, Medizinische Fakultät, University of Bonn, 53105 Bonn, Germany
| | - Karl Schilling
- Anatomisches Institut, Anatomie & Zellbiologie, Medizinische Fakultät, University of Bonn, 53115 Bonn, Germany
| | - Ronald Jabs
- Institut für Zelluläre Neurowissenschaften, Medizinische Fakultät, University of Bonn, 53105 Bonn, Germany
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50
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Griguoli M, Cherubini E. Early Correlated Network Activity in the Hippocampus: Its Putative Role in Shaping Neuronal Circuits. Front Cell Neurosci 2017; 11:255. [PMID: 28878628 PMCID: PMC5572250 DOI: 10.3389/fncel.2017.00255] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/08/2017] [Indexed: 12/02/2022] Open
Abstract
Synchronized neuronal activity occurring at different developmental stages in various brain structures represents a hallmark of developmental circuits. This activity, which differs in its specific patterns among animal species may play a crucial role in de novo formation and in shaping neuronal networks. In the rodent hippocampus in vitro, the so-called giant depolarizing potentials (GDPs) constitute a primordial form of neuronal synchrony preceding more organized forms of activity such as oscillations in the theta and gamma frequency range. GDPs are generated at the network level by the interaction of the neurotransmitters glutamate and GABA which, immediately after birth, exert both a depolarizing and excitatory action on their targets. GDPs are triggered by GABAergic interneurons, which in virtue of their extensive axonal branching operate as functional hubs to synchronize large ensembles of cells. Intrinsic bursting activity, driven by a persistent sodium conductance and facilitated by the low expression of Kv7.2 and Kv7.3 channel subunits, responsible for IM, exerts a permissive role in GDP generation. Here, we discuss how GDPs are generated in a probabilistic way when neuronal excitability within a local circuit reaches a certain threshold and how GDP-associated calcium transients act as coincident detectors for enhancing synaptic strength at emerging GABAergic and glutamatergic synapses. We discuss the possible in vivo correlate of this activity. Finally, we debate recent data showing how, in several animal models of neuropsychiatric disorders including autism, a GDPs dysfunction is associated to morphological alterations of neuronal circuits and behavioral deficits reminiscent of those observed in patients.
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Affiliation(s)
- Marilena Griguoli
- European Brain Research Institute (EBRI) "Fondazione Rita Levi-Montalcini"Rome, Italy
| | - Enrico Cherubini
- European Brain Research Institute (EBRI) "Fondazione Rita Levi-Montalcini"Rome, Italy.,Department of Neuroscience, International School for Advanced StudiesTrieste, Italy
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