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Shadman J, Panahpour H, Alipour MR, Salimi A, Shahabi P, Azar SS. Investigating the therapeutic effects of nimodipine on vasogenic cerebral edema and blood-brain barrier impairment in an ischemic stroke rat model. Neuropharmacology 2024; 257:110054. [PMID: 38950691 DOI: 10.1016/j.neuropharm.2024.110054] [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: 03/24/2024] [Revised: 06/24/2024] [Accepted: 06/26/2024] [Indexed: 07/03/2024]
Abstract
Vasogenic brain edema, a potentially life-threatening consequence following an acute ischemic stroke, is a major clinical problem. This research aims to explore the therapeutic benefits of nimodipine, a calcium channel blocker, in mitigating vasogenic cerebral edema and preserving blood-brain barrier (BBB) function in an ischemic stroke rat model. In this research, animals underwent the induction of ischemic stroke via a 60-min blockage of the middle cerebral artery and treated with a nonhypotensive dose of nimodipine (1 mg/kg/day) for a duration of five days. The wet/dry method was employed to identify cerebral edema, and the Evans blue dye extravasation technique was used to assess the permeability of the BBB. Furthermore, immunofluorescence staining was utilized to assess the protein expression levels of matrix metalloproteinase-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1). The study also examined mitochondrial function by evaluating mitochondrial swelling, succinate dehydrogenase (SDH) activity, the collapse of mitochondrial membrane potential (MMP), and the generation of reactive oxygen species (ROS). Post-stroke administration of nimodipine led to a significant decrease in cerebral edema and maintained the integrity of the BBB. The protective effects observed were associated with a reduction in cell apoptosis as well as decreased expression of MMP-9 and ICAM-1. Furthermore, nimodipine was observed to reduce mitochondrial swelling and ROS levels while simultaneously restoring MMP and SDH activity. These results suggest that nimodipine may reduce cerebral edema and BBB breakdown caused by ischemia/reperfusion. This effect is potentially mediated through the reduction of MMP-9 and ICAM-1 levels and the enhancement of mitochondrial function.
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Affiliation(s)
- Javad Shadman
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Pharmaceutical Sciences Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Hamdollah Panahpour
- Pharmaceutical Sciences Research Center, Ardabil University of Medical Sciences, Ardabil, Iran.
| | | | - Ahmad Salimi
- Department of Pharmacology and Toxicology, School of Pharmacy, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Parviz Shahabi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Saied Salimpour Azar
- Pharmaceutical Sciences Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
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2
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Milicevic KD, Barbeau BL, Lovic DD, Patel AA, Ivanova VO, Antic SD. Physiological features of parvalbumin-expressing GABAergic interneurons contributing to high-frequency oscillations in the cerebral cortex. CURRENT RESEARCH IN NEUROBIOLOGY 2023; 6:100121. [PMID: 38616956 PMCID: PMC11015061 DOI: 10.1016/j.crneur.2023.100121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 11/13/2023] [Accepted: 12/01/2023] [Indexed: 04/16/2024] Open
Abstract
Parvalbumin-expressing (PV+) inhibitory interneurons drive gamma oscillations (30-80 Hz), which underlie higher cognitive functions. In this review, we discuss two groups/aspects of fundamental properties of PV+ interneurons. In the first group (dubbed Before Axon), we list properties representing optimal synaptic integration in PV+ interneurons designed to support fast oscillations. For example: [i] Information can neither enter nor leave the neocortex without the engagement of fast PV+ -mediated inhibition; [ii] Voltage responses in PV+ interneuron dendrites integrate linearly to reduce impact of the fluctuations in the afferent drive; and [iii] Reversed somatodendritic Rm gradient accelerates the time courses of synaptic potentials arriving at the soma. In the second group (dubbed After Axon), we list morphological and biophysical properties responsible for (a) short synaptic delays, and (b) efficient postsynaptic outcomes. For example: [i] Fast-spiking ability that allows PV+ interneurons to outpace other cortical neurons (pyramidal neurons). [ii] Myelinated axon (which is only found in the PV+ subclass of interneurons) to secure fast-spiking at the initial axon segment; and [iii] Inhibitory autapses - autoinhibition, which assures brief biphasic voltage transients and supports postinhibitory rebounds. Recent advent of scientific tools, such as viral strategies to target PV cells and the ability to monitor PV cells via in vivo imaging during behavior, will aid in defining the role of PV cells in the CNS. Given the link between PV+ interneurons and cognition, in the future, it would be useful to carry out physiological recordings in the PV+ cell type selectively and characterize if and how psychiatric and neurological diseases affect initiation and propagation of electrical signals in this cortical sub-circuit. Voltage imaging may allow fast recordings of electrical signals from many PV+ interneurons simultaneously.
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Affiliation(s)
- Katarina D. Milicevic
- University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT, 06030, USA
- University of Belgrade, Faculty of Biology, Center for Laser Microscopy, Belgrade, 11000, Serbia
| | - Brianna L. Barbeau
- University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT, 06030, USA
| | - Darko D. Lovic
- University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT, 06030, USA
- University of Belgrade, Faculty of Biology, Center for Laser Microscopy, Belgrade, 11000, Serbia
| | - Aayushi A. Patel
- University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT, 06030, USA
| | - Violetta O. Ivanova
- University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT, 06030, USA
| | - Srdjan D. Antic
- University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT, 06030, USA
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3
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Sharp-wave ripple doublets induce complex dendritic spikes in parvalbumin interneurons in vivo. Nat Commun 2022; 13:6715. [PMID: 36344570 PMCID: PMC9640570 DOI: 10.1038/s41467-022-34520-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/25/2022] [Indexed: 11/09/2022] Open
Abstract
Neuronal plasticity has been shown to be causally linked to coincidence detection through dendritic spikes (dSpikes). We demonstrate the existence of SPW-R-associated, branch-specific, local dSpikes and their computational role in basal dendrites of hippocampal PV+ interneurons in awake animals. To measure the entire dendritic arbor of long thin dendrites during SPW-Rs, we used fast 3D acousto-optical imaging through an eccentric deep-brain adapter and ipsilateral local field potential recording. The regenerative calcium spike started at variable, NMDA-AMPA-dependent, hot spots and propagated in both direction with a high amplitude beyond a critical distance threshold (~150 µm) involving voltage-gated calcium channels. A supralinear dendritic summation emerged during SPW-R doublets when two successive SPW-R events coincide within a short temporal window (~150 ms), e.g., during more complex association tasks, and generated large dSpikes with an about 2.5-3-fold amplitude increase which propagated down to the soma. Our results suggest that these doublet-associated dSpikes can work as a dendritic-level temporal and spatial coincidence detector during SPW-R-related network computation in awake mice.
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4
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Jeong N, Singer AC. Learning from inhibition: Functional roles of hippocampal CA1 inhibition in spatial learning and memory. Curr Opin Neurobiol 2022; 76:102604. [PMID: 35810533 DOI: 10.1016/j.conb.2022.102604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 05/19/2022] [Accepted: 06/07/2022] [Indexed: 11/19/2022]
Abstract
Hippocampal inhibitory interneurons exert a powerful influence on learning and memory. Inhibitory interneurons are known to play a major role in many diseases that affect memory, and to strongly influence brain functions required for memory-related tasks. While previous studies involving genetic, optogenetic, and pharmacological manipulations have shown that hippocampal interneurons play essential roles in spatial and episodic learning and memory, exactly how interneurons affect local circuit computations during spatial navigation is not well understood. Given the significant anatomical, morphological, and functional heterogeneity in hippocampal interneurons, one may suspect cell-type specific roles in circuit computations. Here, we review emerging evidence of CA1 hippocampal interneurons' role in local circuit computations that support spatial learning and memory and discuss open questions about CA1 interneurons in spatial learning.
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Affiliation(s)
- Nuri Jeong
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA; Neuroscience Graduate Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, 30322, USA. https://twitter.com/nuriscientist
| | - Annabelle C Singer
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA.
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5
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Larkum ME, Wu J, Duverdin SA, Gidon A. The guide to dendritic spikes of the mammalian cortex in vitro and in vivo. Neuroscience 2022; 489:15-33. [PMID: 35182699 DOI: 10.1016/j.neuroscience.2022.02.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 02/01/2022] [Accepted: 02/10/2022] [Indexed: 12/23/2022]
Abstract
Half a century since their discovery by Llinás and colleagues, dendritic spikes have been observed in various neurons in different brain regions, from the neocortex and cerebellum to the basal ganglia. Dendrites exhibit a terrifically diverse but stereotypical repertoire of spikes, sometimes specific to subregions of the dendrite. Despite their prevalence, we only have a glimpse into their role in the behaving animal. This article aims to survey the full range of dendritic spikes found in excitatory and inhibitory neurons, compare them in vivo versus in vitro, and discuss new studies describing dendritic spikes in the human cortex. We focus on dendritic spikes in neocortical and hippocampal neurons and present a roadmap to identify and understand the broader role of dendritic spikes in single-cell computation.
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Affiliation(s)
- Matthew E Larkum
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; NeuroCure Cluster, Charité - Universitätsmedizin Berlin, Germany
| | - Jiameng Wu
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; Einstein Center for Neurosciences Berlin, Berlin, Germany
| | - Sarah A Duverdin
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; Department of Integrative Neurophysiology, Amsterdam Neuroscience, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Albert Gidon
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
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6
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Toro-Fernández LF, Zuluaga-Monares JC, Saldarriaga-Cartagena AM, Cardona-Gómez GP, Posada-Duque R. Targeting CDK5 in Astrocytes Promotes Calcium Homeostasis Under Excitotoxic Conditions. Front Cell Neurosci 2021; 15:643717. [PMID: 34790098 PMCID: PMC8591049 DOI: 10.3389/fncel.2021.643717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 10/05/2021] [Indexed: 11/22/2022] Open
Abstract
Glutamate excitotoxicity triggers overactivation of CDK5 and increases calcium influx in neural cells, which promotes dendritic retraction, spine loss, increased mitochondrial calcium from the endoplasmic reticulum, and neuronal death. Our previous studies showed that CDK5 knockdown (KD) in astrocytes improves neurovascular integrity and cognitive functions and exerts neuroprotective effects. However, how CDK5-targeted astrocytes affect calcium regulation and whether this phenomenon is associated with changes in neuronal plasticity have not yet been analyzed. In this study, CDK5 KD astrocytes transplanted in CA3 remained at the injection site without proliferation, regulated calcium in the CA1 hippocampal region after excitotoxicity by glutamate in ex vivo hippocampal slices, improving synapsin and PSD95 clustering. These CDK5 KD astrocytes induced astrocyte stellation and neuroprotection after excitotoxicity induced by glutamate in vitro. Also, these effects were supported by CDK5 inhibition (CDK5i) in vitro through intracellular stabilization of calcium levels in astrocytes. Additionally, these cells in cocultures restored calcium homeostasis in neurons, redistributing calcium from somas to dendrites, accompanied by dendrite branching, higher dendritic spines and synapsin-PSD95 clustering. In summary, induction of calcium homeostasis at the CA1 hippocampal area by CDK5 KD astrocytes transplanted in the CA3 area highlights the role of astrocytes as a cell therapy target due to CDK5-KD astrocyte-mediated synaptic clustering, calcium spreading regulation between both areas, and recovery of the intracellular astrocyte-neuron calcium imbalance and plasticity impairment generated by glutamate excitotoxicity.
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Affiliation(s)
- Luisa Fernanda Toro-Fernández
- Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, Colombia.,Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellín, Colombia
| | - Juan Camilo Zuluaga-Monares
- Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, Colombia.,Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellín, Colombia
| | - Ana María Saldarriaga-Cartagena
- Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, Colombia.,Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellín, Colombia
| | - Gloria Patricia Cardona-Gómez
- Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellín, Colombia
| | - Rafael Posada-Duque
- Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, Colombia.,Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellín, Colombia
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7
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Rodrigues NC, Silva-Cruz A, Caulino-Rocha A, Bento-Oliveira A, Alexandre Ribeiro J, Cunha-Reis D. Hippocampal CA1 theta burst-induced LTP from weaning to adulthood: Cellular and molecular mechanisms in young male rats revisited. Eur J Neurosci 2021; 54:5272-5292. [PMID: 34251729 DOI: 10.1111/ejn.15390] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 07/08/2021] [Accepted: 07/08/2021] [Indexed: 01/05/2023]
Abstract
Long-term potentiation (LTP) is a highly studied cellular process, yet determining the transduction and gamma aminobutyric acid (GABAergic) pathways that are the essential versus modulatory for LTP elicited by theta burst stimulation (TBS) in the hippocampal Cornu Ammonis 1 (CA1) area is still elusive, due to the use of different TBS intensities, patterns or different rodent/cellular models. We now characterised the developmental maturation and the transduction and GABAergic pathways required for mild TBS-induced LTP in hippocampal CA1 area in male rats. LTP induced by TBS (5x4) (five bursts of four pulses delivered at 100 Hz) lasted for up to 3 h and was increasingly larger from weaning to adulthood. Stronger TBS patterns - TBS (15x4) or three TBS (15x4) separated by 6 min induced nearly maximal LTP not being the best choice to study the value of LTP-enhancing drugs. LTP induced by TBS (5x4) in young adults was fully dependent on N-methyl D-aspartate (NMDA) receptor and calmodulin-dependent protein kinase II (CaMKII) activity but independent of protein kinase A (PKA) or protein kinase C (PKC) activity. Furthermore, it was partially dependent on GABAB receptor activation and was potentiated by GABAA receptor blockade and less by GAT-1 transporter blockade. AMPA GluA1 phosphorylation on Ser831 (CaMKII target) but not GluA1 Ser845 (PKA target) was essential for LTP expression. The phosphorylation of the Kv4.2 channel was observed at Ser438 (CaMKII target) but not at Thr602 or Thr607 (ERK/MAPK pathway target). This suggests that cellular kinases like PKA, PKC, or kinases of the ERK/MAPK family although important modulators of TBS (5x4)-induced LTP may not be essential for its expression in the CA1 area of the hippocampus.
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Affiliation(s)
| | - Armando Silva-Cruz
- Instituto de Medicina Molecular, Unidade de Neurociências, Lisbon, Portugal
| | - Ana Caulino-Rocha
- Departamento de Química e Bioquímica, Faculty of Sciences, Universidade de Lisboa, Lisbon, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Andreia Bento-Oliveira
- Departamento de Química e Bioquímica, Faculty of Sciences, Universidade de Lisboa, Lisbon, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Joaquim Alexandre Ribeiro
- Instituto de Medicina Molecular, Unidade de Neurociências, Lisbon, Portugal.,Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Diana Cunha-Reis
- Instituto de Medicina Molecular, Unidade de Neurociências, Lisbon, Portugal.,Departamento de Química e Bioquímica, Faculty of Sciences, Universidade de Lisboa, Lisbon, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
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8
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Pancotti L, Topolnik L. Cholinergic Modulation of Dendritic Signaling in Hippocampal GABAergic Inhibitory Interneurons. Neuroscience 2021; 489:44-56. [PMID: 34129910 DOI: 10.1016/j.neuroscience.2021.06.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 12/11/2022]
Abstract
Dendrites represent the "reception hub" of the neuron as they collect thousands of different inputs and send a coherent response to the cell body. A considerable portion of these signals, especially in vivo, arises from neuromodulatory sources, which affect dendritic computations and cellular activity. In this context, acetylcholine (ACh) exerts a coordinating role of different brain structures, contributing to goal-driven behaviors and sleep-wake cycles. Specifically, cholinergic neurons from the medial septum-diagonal band of Broca complex send numerous projections to glutamatergic principal cells and GABAergic inhibitory neurons in the hippocampus, differentially entraining them during network oscillations. Interneurons display abundant expression of cholinergic receptors and marked responses to stimulation by ACh. Nonetheless, the precise localization of ACh inputs is largely unknown, and evidence for cholinergic modulation of interneuronal dendritic signaling remains elusive. In this article, we review evidence that suggests modulatory effects of ACh on dendritic computations in three hippocampal interneuron subtypes: fast-spiking parvalbumin-positive (PV+) cells, somatostatin-expressing (SOM+) oriens lacunosum moleculare cells and vasoactive intestinal polypeptide-expressing (VIP+) interneuron-selective interneurons. We consider the distribution of cholinergic receptors on these interneurons, including information about their specific somatodendritic location, and discuss how the action of these receptors can modulate dendritic Ca2+ signaling and activity of interneurons. The implications of ACh-dependent Ca2+ signaling for dendritic plasticity are also discussed. We propose that cholinergic modulation can shape the dendritic integration and plasticity in interneurons in a cell type-specific manner, and the elucidation of these mechanisms will be required to understand the contribution of each cell type to large-scale network activity.
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Affiliation(s)
- Luca Pancotti
- Department of Biochemistry, Microbiology and Bio-informatics, Laval University, Canada; Neuroscience Axis, CRCHUQ, Laval University, Canada
| | - Lisa Topolnik
- Department of Biochemistry, Microbiology and Bio-informatics, Laval University, Canada; Neuroscience Axis, CRCHUQ, Laval University, Canada.
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9
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Perez-Alvarez A, Huhn F, Dürst CD, Franzelin A, Lamothe-Molina PJ, Oertner TG. Freeze-Frame Imaging of Dendritic Calcium Signals With TubuTag. Front Mol Neurosci 2021; 14:635820. [PMID: 33762909 PMCID: PMC7982875 DOI: 10.3389/fnmol.2021.635820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
The extensive dendritic arbor of neurons is thought to be actively involved in the processing of information. Dendrites contain a rich diversity of ligand- and voltage-activated ion channels as well as metabotropic receptors. In addition, they are capable of releasing calcium from intracellular stores. Under specific conditions, large neurons produce calcium spikes that are locally restricted to a dendritic section. To investigate calcium signaling in dendrites, we introduce TubuTag, a genetically encoded ratiometric calcium sensor anchored to the cytoskeleton. TubuTag integrates cytoplasmic calcium signals by irreversible photoconversion from green to red fluorescence when illuminated with violet light. We used a custom two-photon microscope with a large field of view to image pyramidal neurons in CA1 at subcellular resolution. Photoconversion was strongest in the most distal parts of the apical dendrite, suggesting a gradient in the amplitude of dendritic calcium signals. As the read-out of fluorescence can be performed several hours after photoconversion, TubuTag will help investigating dendritic signal integration and calcium homeostasis in large populations of neurons.
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Affiliation(s)
- Alberto Perez-Alvarez
- Institute for Synaptic Physiology, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Rapp OptoElectronic GmbH, Wedel, Germany
| | | | - Céline D Dürst
- Institute for Synaptic Physiology, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Rapp OptoElectronic GmbH, Wedel, Germany
| | - Andreas Franzelin
- Institute for Synaptic Physiology, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Paul J Lamothe-Molina
- Institute for Synaptic Physiology, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas G Oertner
- Institute for Synaptic Physiology, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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10
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Perez-Alvarez A, Fearey BC, O'Toole RJ, Yang W, Arganda-Carreras I, Lamothe-Molina PJ, Moeyaert B, Mohr MA, Panzera LC, Schulze C, Schreiter ER, Wiegert JS, Gee CE, Hoppa MB, Oertner TG. Freeze-frame imaging of synaptic activity using SynTagMA. Nat Commun 2020; 11:2464. [PMID: 32424147 PMCID: PMC7235013 DOI: 10.1038/s41467-020-16315-4] [Citation(s) in RCA: 13] [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: 09/09/2019] [Accepted: 04/23/2020] [Indexed: 12/16/2022] Open
Abstract
Information within the brain travels from neuron to neuron across billions of synapses. At any given moment, only a small subset of neurons and synapses are active, but finding the active synapses in brain tissue has been a technical challenge. Here we introduce SynTagMA to tag active synapses in a user-defined time window. Upon 395-405 nm illumination, this genetically encoded marker of activity converts from green to red fluorescence if, and only if, it is bound to calcium. Targeted to presynaptic terminals, preSynTagMA allows discrimination between active and silent axons. Targeted to excitatory postsynapses, postSynTagMA creates a snapshot of synapses active just before photoconversion. To analyze large datasets, we show how to identify and track the fluorescence of thousands of individual synapses in an automated fashion. Together, these tools provide an efficient method for repeatedly mapping active neurons and synapses in cell culture, slice preparations, and in vivo during behavior.
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Affiliation(s)
- Alberto Perez-Alvarez
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, D-20251, Germany
| | - Brenna C Fearey
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, D-20251, Germany
| | - Ryan J O'Toole
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - Wei Yang
- Research Group Synaptic Wiring and Information Processing, University Medical Center Hamburg-Eppendorf, Hamburg, D-20251, Germany
| | - Ignacio Arganda-Carreras
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
- Dept. of Computer Science and Artificial Intelligence, Basque Country University, San Sebastian, Spain
- Donostia International Physics Center (DIPC), San Sebastian, Spain
| | - Paul J Lamothe-Molina
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, D-20251, Germany
| | | | - Manuel A Mohr
- HHMI, Janelia Farm Research Campus, Ashburn, VA, 20147, USA
| | - Lauren C Panzera
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - Christian Schulze
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, D-20251, Germany
| | | | - J Simon Wiegert
- Research Group Synaptic Wiring and Information Processing, University Medical Center Hamburg-Eppendorf, Hamburg, D-20251, Germany
| | - Christine E Gee
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, D-20251, Germany
| | - Michael B Hoppa
- Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA
| | - Thomas G Oertner
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, D-20251, Germany.
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11
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Luo X, Guet-McCreight A, Villette V, Francavilla R, Marino B, Chamberland S, Skinner FK, Topolnik L. Synaptic Mechanisms Underlying the Network State-Dependent Recruitment of VIP-Expressing Interneurons in the CA1 Hippocampus. Cereb Cortex 2020; 30:3667-3685. [PMID: 32080739 DOI: 10.1093/cercor/bhz334] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/13/2019] [Indexed: 11/14/2022] Open
Abstract
Disinhibition is a widespread circuit mechanism for information selection and transfer. In the hippocampus, disinhibition of principal cells is provided by the interneuron-specific interneurons that express the vasoactive intestinal polypeptide (VIP-IS) and innervate selectively inhibitory interneurons. By combining optophysiological experiments with computational models, we determined the impact of synaptic inputs onto the network state-dependent recruitment of VIP-IS cells. We found that VIP-IS cells fire spikes in response to both the Schaffer collateral and the temporoammonic pathway activation. Moreover, by integrating their intrinsic and synaptic properties into computational models, we predicted recruitment of these cells between the rising phase and peak of theta oscillation and during ripples. Two-photon Ca2+-imaging in awake mice supported in part the theoretical predictions, revealing a significant speed modulation of VIP-IS cells and their preferential albeit delayed recruitment during theta-run epochs, with estimated firing at the rising phase and peak of the theta cycle. However, it also uncovered that VIP-IS cells are not activated during ripples. Thus, given the preferential theta-modulated firing of VIP-IS cells in awake hippocampus, we postulate that these cells may be important for information gating during spatial navigation and memory encoding.
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Affiliation(s)
- Xiao Luo
- Department of Biochemistry, Microbiology and Bio-informatics, Laval University, Québec, PQ, Canada.,Neuroscience Axis, CHU de Québec Research Center (CHUL), Québec, PQ, Canada
| | - Alexandre Guet-McCreight
- Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Vincent Villette
- Department of Biochemistry, Microbiology and Bio-informatics, Laval University, Québec, PQ, Canada.,Neuroscience Axis, CHU de Québec Research Center (CHUL), Québec, PQ, Canada.,Institut de Biologie de l'ÉcoleNormale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Ruggiero Francavilla
- Department of Biochemistry, Microbiology and Bio-informatics, Laval University, Québec, PQ, Canada.,Neuroscience Axis, CHU de Québec Research Center (CHUL), Québec, PQ, Canada
| | - Beatrice Marino
- Department of Biochemistry, Microbiology and Bio-informatics, Laval University, Québec, PQ, Canada.,Neuroscience Axis, CHU de Québec Research Center (CHUL), Québec, PQ, Canada
| | - Simon Chamberland
- Department of Biochemistry, Microbiology and Bio-informatics, Laval University, Québec, PQ, Canada.,Neuroscience Axis, CHU de Québec Research Center (CHUL), Québec, PQ, Canada.,New York University Neuroscience Institute, New York, NY, USA
| | - Frances K Skinner
- Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Departments of Medicine (Neurology) and Physiology, University of Toronto, Toronto, ON, Canada
| | - Lisa Topolnik
- Department of Biochemistry, Microbiology and Bio-informatics, Laval University, Québec, PQ, Canada.,Neuroscience Axis, CHU de Québec Research Center (CHUL), Québec, PQ, Canada
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12
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GRIN2D/GluN2D NMDA receptor: Unique features and its contribution to pediatric developmental and epileptic encephalopathy. Eur J Paediatr Neurol 2020; 24:89-99. [PMID: 31918992 PMCID: PMC7035963 DOI: 10.1016/j.ejpn.2019.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 12/06/2019] [Indexed: 12/14/2022]
Abstract
N-methyl-d-aspartate receptors (NMDARs), a subset of ligand-gated ionotropic glutamate receptors, are critical for learning, memory, and neuronal development. However, when NMDAR subunits are mutated, a host of neuropathological conditions can occur, including epilepsy. Recently, genetic variation within the GRIN2D gene, which encodes the GluN2D subunit of the NMDAR, has been associated with a set of early-onset neurological diseases, notably developmental and epileptic encephalopathy (DEE). Importantly, patients with GRIN2D variants are largely refractory to conventional anti-epileptic drug (AED) treatment, highlighting the need to further understand the distinctive characteristics of GluN2D in neurological and pathological functions. In this review, we first summarize GluN2D's unique spatial and temporal expression patterns, electrophysiological profiles, and contributions to both pre- and postsynaptic signaling. Next, we review thirteen unique case studies from DEE patients harboring ten different causal GRIN2D variants. These patients are highly heterogenous, manifesting multiple seizure types, electroencephalographic recordings, and neurological and developmental outcomes. Lastly, this review concludes by highlighting the difficulty in treating patients with DEE-associated GRIN2D variants, and stresses the need for selective therapeutic agents delivered within a precise time window.
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13
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Singh V, Mishra VN, Chaurasia RN, Joshi D, Pandey V. Modes of Calcium Regulation in Ischemic Neuron. Indian J Clin Biochem 2019; 34:246-253. [PMID: 31391713 PMCID: PMC6660593 DOI: 10.1007/s12291-019-00838-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022]
Abstract
Calcium (Ca2+) dysregulation is a major catalytic event. Ca2+ dysregulation leads to neuronal cell death and brain damage result in cerebral ischemia. Neurons are unable in maintaining calcium homeostasis. Ca2+ homeostasis imbalance results in increased calcium influx and impaired calcium extrusion across the plasma membrane. Ca2+ dysregulation is mediated by different cellular and biochemical mechanism, which leads to neuronal loss resulting stroke/cerebral ischemia. A better understanding of the Ca2+ dysregulation might help in the development of new treatments in order to reduce ischemic brain injury. An optimal concentration of Ca2+ does not lead to neurotoxicity in the ischemic neuron. Intracellular Ca2+ act as a trigger for acute neurotoxicity and this cause induction of long-lasting processes leading to necrotic and/or apoptotic post-ischemic delayed neuronal death or of compensatory, neuroprotective mechanisms has increased considerably. Moreover, routes of ischemic Ca2+ influx to neurons, involvement of intracellular Ca2+ stores and Ca2+ buffers, spatial and temporal relations between ischemia-induced increases in intracellular Ca2+ concentration and neurotoxicity will further increase our understanding about underlying mechanism and they can act as a target for the development of drugs. Here, in our article we are trying to provide a brief overview of various Ca2+ influx pathways involve in ischemic neuron and how ischemic neuron attempts to counterbalance this calcium overload.
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Affiliation(s)
- Vineeta Singh
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
| | - Vijaya Nath Mishra
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
| | - Rameshwar Nath Chaurasia
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
| | - Deepika Joshi
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
| | - Vibha Pandey
- Department of Neurology, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005 UP India
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