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Booker SA, Sumera A, Kind PC, Wyllie DJA. Contribution of NMDA Receptors to Synaptic Function in Rat Hippocampal Interneurons. eNeuro 2021; 8:ENEURO.0552-20.2021. [PMID: 34326063 PMCID: PMC8362681 DOI: 10.1523/eneuro.0552-20.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 06/15/2021] [Accepted: 07/03/2021] [Indexed: 12/12/2022] Open
Abstract
The ability of neurons to produce behaviorally relevant activity in the absence of pathology relies on the fine balance of synaptic inhibition to excitation. In the hippocampal CA1 microcircuit, this balance is maintained by a diverse population of inhibitory interneurons that receive largely similar glutamatergic afferents as their target pyramidal cells, with EPSCs generated by both AMPA receptors (AMPARs) and NMDA receptors (NMDARs). In this study, we take advantage of a recently generated GluN2A-null rat model to assess the contribution of GluN2A subunits to glutamatergic synaptic currents in three subclasses of interneuron found in the CA1 region of the hippocampus. For both parvalbumin-positive and somatostatin-positive interneurons, the GluN2A subunit is expressed at glutamatergic synapses and contributes to the EPSC. In contrast, in cholecystokinin (CCK)-positive interneurons, the contribution of GluN2A to the EPSC is negligible. Furthermore, synaptic potentiation at glutamatergic synapses on CCK-positive interneurons does not require the activation of GluN2A-containing NMDARs but does rely on the activation of NMDARs containing GluN2B and GluN2D subunits.
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Affiliation(s)
- Sam A. Booker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Anna Sumera
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Peter C. Kind
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore 560065, India
| | - David J. A. Wyllie
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Patrick Wild Centre, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore 560065, India
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Oliveira LS, Sumera A, Booker SA. Repeated whole-cell patch-clamp recording from CA1 pyramidal cells in rodent hippocampal slices followed by axon initial segment labeling. STAR Protoc 2021; 2:100336. [PMID: 33644771 PMCID: PMC7887436 DOI: 10.1016/j.xpro.2021.100336] [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] [Indexed: 11/10/2022] Open
Abstract
This protocol allows repeated whole-cell patch-clamp recordings from individual rodent CA1 hippocampal neurons, followed by immunohistological labeling of the axon initial segment. This overcomes the need to maintain whole-cell recordings over the timescales required for homeostatic modification to cellular excitability, allowing for correlative analysis of the structure and function of neurons. Moreover, this protocol allows for paired analysis of physiological properties assessed before and after pharmacological treatment, thus providing increased statistical power, despite the relatively low-throughput nature of the recordings. For complete details on the use and execution of this protocol, please refer to Booker et al. (2020a). Protocol allows repeated whole-cell patch-clamp recording in ex vivo hippocampal neurons Produces within neuron controls, increasing statistical power through paired analysis Allows for axon initial segment labeling following whole-cell patch-clamp recordings Facilitates comparison of neuron structure and function following long-term pharmacology
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Affiliation(s)
- Laura S Oliveira
- Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.,Patrick Wild Centre for Research into Autism, Fragile X Syndome, and Intellectual Disability, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.,Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Anna Sumera
- Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.,Patrick Wild Centre for Research into Autism, Fragile X Syndome, and Intellectual Disability, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.,Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Sam A Booker
- Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.,Patrick Wild Centre for Research into Autism, Fragile X Syndome, and Intellectual Disability, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.,Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
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Zoupi L, Booker SA, Eigel D, Werner C, Kind PC, Spires-Jones TL, Newland B, Williams AC. Selective vulnerability of inhibitory networks in multiple sclerosis. Acta Neuropathol 2021; 141:415-429. [PMID: 33449171 PMCID: PMC7882577 DOI: 10.1007/s00401-020-02258-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/01/2023]
Abstract
In multiple sclerosis (MS), a chronic demyelinating disease of the central nervous system, neurodegeneration is detected early in the disease course and is associated with the long-term disability of patients. Neurodegeneration is linked to both inflammation and demyelination, but its exact cause remains unknown. This gap in knowledge contributes to the current lack of treatments for the neurodegenerative phase of MS. Here we ask if neurodegeneration in MS affects specific neuronal components and if it is the result of demyelination. Neuropathological examination of secondary progressive MS motor cortices revealed a selective vulnerability of inhibitory interneurons in MS. The generation of a rodent model of focal subpial cortical demyelination reproduces this selective neurodegeneration providing a new preclinical model for the study of neuroprotective treatments.
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Affiliation(s)
- Lida Zoupi
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Sam A Booker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD, UK
- Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Dimitri Eigel
- Leibniz-Institut Für Polymerforschung Dresden E.V, Max Bergmann Center of Biomaterials Dresden, Hohe Straße 6, 01069, Dresden, Germany
| | - Carsten Werner
- Leibniz-Institut Für Polymerforschung Dresden E.V, Max Bergmann Center of Biomaterials Dresden, Hohe Straße 6, 01069, Dresden, Germany
| | - Peter C Kind
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD, UK
- Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Tara L Spires-Jones
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, EH8 9JZ, UK
| | - Ben Newland
- Leibniz-Institut Für Polymerforschung Dresden E.V, Max Bergmann Center of Biomaterials Dresden, Hohe Straße 6, 01069, Dresden, Germany
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK
| | - Anna C Williams
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, EH16 4UU, UK.
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Booker SA, Simões de Oliveira L, Anstey NJ, Kozic Z, Dando OR, Jackson AD, Baxter PS, Isom LL, Sherman DL, Hardingham GE, Brophy PJ, Wyllie DJ, Kind PC. Input-Output Relationship of CA1 Pyramidal Neurons Reveals Intact Homeostatic Mechanisms in a Mouse Model of Fragile X Syndrome. Cell Rep 2020; 32:107988. [PMID: 32783927 PMCID: PMC7435362 DOI: 10.1016/j.celrep.2020.107988] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 04/01/2020] [Accepted: 07/14/2020] [Indexed: 12/13/2022] Open
Abstract
Cellular hyperexcitability is a salient feature of fragile X syndrome animal models. The cellular basis of hyperexcitability and how it responds to changing activity states is not fully understood. Here, we show increased axon initial segment length in CA1 of the Fmr1-/y mouse hippocampus, with increased cellular excitability. This change in length does not result from reduced AIS plasticity, as prolonged depolarization induces changes in AIS length independent of genotype. However, depolarization does reduce cellular excitability, the magnitude of which is greater in Fmr1-/y neurons. Finally, we observe reduced functional inputs from the entorhinal cortex, with no genotypic difference in the firing rates of CA1 pyramidal neurons. This suggests that AIS-dependent hyperexcitability in Fmr1-/y mice may result from adaptive or homeostatic regulation induced by reduced functional synaptic connectivity. Thus, while AIS length and intrinsic excitability contribute to cellular hyperexcitability, they may reflect a homeostatic mechanism for reduced synaptic input onto CA1 neurons.
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Affiliation(s)
- Sam A. Booker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK,Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK,Corresponding author
| | - Laura Simões de Oliveira
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK,Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK
| | - Natasha J. Anstey
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK,Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK,Centre for Brain Development and Repair, InStem, GKVK Campus, Bangalore 560065, India
| | - Zrinko Kozic
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Owen R. Dando
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK,Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK,Dementia Research Institute, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK,Centre for Brain Development and Repair, InStem, GKVK Campus, Bangalore 560065, India
| | - Adam D. Jackson
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK,Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK,Centre for Brain Development and Repair, InStem, GKVK Campus, Bangalore 560065, India
| | - Paul S. Baxter
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Dementia Research Institute, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Lori L. Isom
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109-5632, USA
| | - Diane L. Sherman
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Giles E. Hardingham
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Dementia Research Institute, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Peter J. Brophy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - David J.A. Wyllie
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK,Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK,Centre for Brain Development and Repair, InStem, GKVK Campus, Bangalore 560065, India
| | - Peter C. Kind
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK,Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK,Centre for Brain Development and Repair, InStem, GKVK Campus, Bangalore 560065, India,Corresponding author
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Mitchell R, Campbell G, Mikolajczak M, McGill K, Mahad D, Fleetwood-Walker SM. A Targeted Mutation Disrupting Mitochondrial Complex IV Function in Primary Afferent Neurons Leads to Pain Hypersensitivity Through P2Y 1 Receptor Activation. Mol Neurobiol 2019; 56:5917-5933. [PMID: 30689196 DOI: 10.1007/s12035-018-1455-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/14/2018] [Indexed: 01/20/2023]
Abstract
As mitochondrial dysfunction is evident in neurodegenerative disorders that are accompanied by pain, we generated inducible mutant mice with disruption of mitochondrial respiratory chain complex IV, by COX10 deletion limited to sensory afferent neurons through the use of an Advillin Cre-reporter. COX10 deletion results in a selective energy-deficiency phenotype with minimal production of reactive oxygen species. Mutant mice showed reduced activity of mitochondrial respiratory chain complex IV in many sensory neurons, increased ADP/ATP ratios in dorsal root ganglia and dorsal spinal cord synaptoneurosomes, as well as impaired mitochondrial membrane potential, in these synaptoneurosome preparations. These changes were accompanied by marked pain hypersensitivity in mechanical and thermal (hot and cold) tests without altered motor function. To address the underlying basis, we measured Ca2+ fluorescence responses of dorsal spinal cord synaptoneurosomes to activation of the GluK1 (kainate) receptor, which we showed to be widely expressed in small but not large nociceptive afferents, and is minimally expressed elsewhere in the spinal cord. Synaptoneurosomes from mutant mice showed greatly increased responses to GluK1 agonist. To explore whether altered nucleotide levels may play a part in this hypersensitivity, we pharmacologically interrogated potential roles of AMP-kinase and ADP-sensitive purinergic receptors. The ADP-sensitive P2Y1 receptor was clearly implicated. Its expression in small nociceptive afferents was increased in mutants, whose in vivo pain hypersensitivity, in mechanical, thermal and cold tests, was reversed by a selective P2Y1 antagonist. Energy depletion and ADP elevation in sensory afferents, due to mitochondrial respiratory chain complex IV deficiency, appear sufficient to induce pain hypersensitivity, by ADP activation of P2Y1 receptors.
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MESH Headings
- Adenosine Diphosphate/metabolism
- Adenosine Monophosphate/metabolism
- Alkyl and Aryl Transferases/metabolism
- Animals
- Behavior, Animal
- Calcium/metabolism
- Cells, Cultured
- Electron Transport Complex IV/genetics
- Electron Transport Complex IV/metabolism
- Fluorescence
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/metabolism
- Hypersensitivity/complications
- Hypersensitivity/pathology
- Membrane Proteins/metabolism
- Mice, Inbred C57BL
- Mice, Transgenic
- Mitochondria/drug effects
- Mitochondria/metabolism
- Mutation/genetics
- Neurons, Afferent/drug effects
- Neurons, Afferent/metabolism
- Neurons, Afferent/pathology
- Nociception/drug effects
- Pain/complications
- Pain/pathology
- Phenotype
- Purinergic P2Y Receptor Antagonists/pharmacology
- Receptors, Kainic Acid/metabolism
- Receptors, Purinergic P2Y1/metabolism
- Spinal Cord/pathology
- Synapses/drug effects
- Synapses/metabolism
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Affiliation(s)
- Rory Mitchell
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Graham Campbell
- Centre for Clinical Brain Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, University of Edinburgh, Chancellor's Building, Little France, Edinburgh, Edinburgh, EH16 4SB, UK
| | - Marta Mikolajczak
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Katie McGill
- Centre for Clinical Brain Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, University of Edinburgh, Chancellor's Building, Little France, Edinburgh, Edinburgh, EH16 4SB, UK
| | - Don Mahad
- Centre for Clinical Brain Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, University of Edinburgh, Chancellor's Building, Little France, Edinburgh, Edinburgh, EH16 4SB, UK
| | - Sue M Fleetwood-Walker
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.
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