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Wang Z, Hu Q, Tian C, Wang R, Jiao Q, Chen F, Wu T, Wang J, Zhu Y, Liu A, Zhang W, Li J, Shen H. Prophylactic Effects of n-Acethylcysteine on Inflammation-induced Depression-like Behaviors in Mice. Neuroscience 2024; 549:42-54. [PMID: 38729599 DOI: 10.1016/j.neuroscience.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 04/16/2024] [Accepted: 05/04/2024] [Indexed: 05/12/2024]
Abstract
Depression, affecting individuals worldwide, is a prevalent mental disease, with an increasing incidence. Numerous studies have been conducted on depression, yet its pathogenesis remains elusive. Recent advancements in research indicate that disturbances in synaptic transmission, synaptic plasticity, and reduced neurotrophic factor expression significantly contribute to depression's pathogenesis. In our study, we utilized adult male C57BL/6J mice. Lipopolysaccharide (LPS) can induce both chronic and acute depression-like symptoms in mice, a widely used model for studying depression associated with inflammation. N-acetylcysteine (NAC) exhibits anti-inflammatory and ameliorative effects on depressive symptoms. This study sought to determine whether NAC use could mitigate inflammatory depressive behavior through the enhancement of synaptic transmission, synaptic plasticity, and increasing levels of brain-derived neurotrophic factor (BDNF). In this study, we discovered that in mice modeled with depression-like symptoms, the expression levels of dendrites, BDNF, and miniature excitatory postsynaptic potential (mEPSC) in glutamatergic neurons, as well as the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid glutamate receptors (AMPARs) GluA1 and GluA2 subunits, were significantly decreased. These findings suggest an impairment in the synaptic transmission of glutamatergic neurons. Following treatment with NAC, the previously mentioned levels improved, indicating an enhancement in both synaptic transmission and synaptic plasticity. Our results suggest that NAC exerts a protective effect on mouse models of inflammatory depression, potentially through the enhancement of synaptic transmission and plasticity, as well as the restoration of neurotrophic factor expression. These findings offer vital animal experimental evidence supporting NAC's role in mitigating inflammatory depressive behaviors.
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Affiliation(s)
- Zhenhuan Wang
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Qi Hu
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China; Comprehensive Development Service Center, Tianjin Baodi District Health Commission, Tianjin, China
| | - Chao Tian
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Ruipeng Wang
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Qingyan Jiao
- Department of Sleep Medicine, Tianjin Anding Hospital, Tianjin, China
| | - Feng Chen
- Institute for Translational Neuroscience, the Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Tongrui Wu
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Jialiang Wang
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Yuxuan Zhu
- Laboratory of Neurobiology, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Aili Liu
- Laboratory of Neurobiology, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Wei Zhang
- Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin, China.
| | - Jie Li
- Institute of Mental Health, Tianjin Anding Hospital, Tianjin, China.
| | - Hui Shen
- Laboratory of Neurobiology, Department of Cell Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China.
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2
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van Onselen R, Downing TG. Uptake of β-N-methylamino-L-alanine (BMAA) into glutamate-specific synaptic vesicles: Exploring the validity of the excitotoxicity mechanism of BMAA. Neurosci Lett 2024; 821:137593. [PMID: 38103629 DOI: 10.1016/j.neulet.2023.137593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/01/2023] [Accepted: 12/07/2023] [Indexed: 12/19/2023]
Abstract
The first mechanism of toxicity proposed for the cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) was excitotoxicity, and this was supported by numerous in vitro studies in which overactivation of both ionotropic and metabotropic glutamate receptors was reported. However, the excitotoxicity of BMAA is weak in comparison with other known excitotoxins and on par with that of glutamate, implying that to achieve sufficient synaptic concentrations of BMAA to cause classical in vivo excitotoxicity, BMAA must either accumulate in synapses to allow persistent glutamate receptor activation or it must be released in sufficiently high concentrations into synapses to cause the overexcitation. Since it has been shown that BMAA can be readily removed from synapses, release of high concentrations of BMAA into synapses must be shown to confirm its role as an excitotoxin in in vivo systems. This study therefore sought to evaluate the uptake of BMAA into synaptic vesicles and to determine if BMAA affects the uptake of glutamate into synaptic vesicles. There was no evidence to support uptake of BMAA into glutamate-specific synaptic vesicles but there was some indication that BMAA may affect the uptake of glutamate into synaptic vesicles. The uptake of BMAA into synaptic vesicles isolated from areas other than the cerebral cortex should be investigated before definite conclusions can be drawn about the role of BMAA as an excitotoxin.
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Affiliation(s)
- Rianita van Onselen
- Biomedical Research and Innovation Platform, South African Medical Research Council, Cape Town, South Africa; Department of Biochemistry and Microbiology, Nelson Mandela University, Gqeberha, South Africa
| | - Tim G Downing
- Department of Biochemistry and Microbiology, Nelson Mandela University, Gqeberha, South Africa.
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Velasco CD, Santarella-Mellwig R, Schorb M, Gao L, Thorn-Seshold O, Llobet A. Microtubule depolymerization contributes to spontaneous neurotransmitter release in vitro. Commun Biol 2023; 6:488. [PMID: 37147475 PMCID: PMC10163034 DOI: 10.1038/s42003-023-04779-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 03/29/2023] [Indexed: 05/07/2023] Open
Abstract
Microtubules are key to multiple neuronal functions involving the transport of organelles, however, their relationship to neurotransmitter release is still unresolved. Here, we show that microtubules present in the presynaptic compartment of cholinergic autaptic synapses are dynamic. To investigate how the balance between microtubule growth and shrinkage affects neurotransmission we induced synchronous microtubule depolymerization by photoactivation of the chemical inhibitor SBTub3. The consequence was an increase in spontaneous neurotransmitter release. An analogous effect was obtained by dialyzing the cytosol with Kif18A, a plus-end-directed kinesin with microtubule depolymerizing activity. Kif18A also inhibited the refilling of the readily releasable pool of synaptic vesicles during high frequency stimulation. The action of Kif18A was associated to one order of magnitude increases in the numbers of exo-endocytic pits and endosomes present in the presynaptic terminal. An enhancement of spontaneous neurotransmitter release was also observed when neurons were dialyzed with stathmin-1, a protein with a widespread presence in the nervous system that induces microtubule depolymerization. Taken together, these results support that microtubules restrict spontaneous neurotransmitter release as well as promote the replenishment of the readily releasable pool of synaptic vesicles.
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Affiliation(s)
- Cecilia D Velasco
- Laboratory of Neurobiology, Department of Pathology and Experimental Therapy, Institute of Neurosciences, University of Barcelona, 08907, L'Hospitalet de Llobregat, Barcelona, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), 08907, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Rachel Santarella-Mellwig
- Electron Microscopy Core Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Martin Schorb
- Electron Microscopy Core Facility, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Li Gao
- Department of Pharmacy, Ludwig-Maximilians University of Munich, Munich, 81377, Germany
| | - Oliver Thorn-Seshold
- Department of Pharmacy, Ludwig-Maximilians University of Munich, Munich, 81377, Germany
| | - Artur Llobet
- Laboratory of Neurobiology, Department of Pathology and Experimental Therapy, Institute of Neurosciences, University of Barcelona, 08907, L'Hospitalet de Llobregat, Barcelona, Spain.
- Bellvitge Biomedical Research Institute (IDIBELL), 08907, L'Hospitalet de Llobregat, Barcelona, Spain.
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Sun W, Chen X, Mei Y, Li X, Yang Y, An L. Co-exposure of melamine and cyanuric acid as a risk factor for oxidative stress and energy metabolism: Adverse effects on hippocampal neuronal and synaptic function induced by excessive ROS production. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 247:114230. [PMID: 36306617 DOI: 10.1016/j.ecoenv.2022.114230] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/16/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Melamine (MEL) and cyanuric acid (CA) alone have relatively low toxicity, but together they may cause serious damage to multiple organs, including the central nervous system, however, the underlying mechanism is unknown. This study aimed to determine and compare the neurotoxic effects of MEL (20 μg/mL), CA (20 μg/mL) and their combination (10 μg/mL MEL and 10 μg/mL CA) on cultured hippocampal neurons. The cell viability, apoptosis, anti-oxidative and energy metabolic indices were detected following 24 h of incubations. The miniature excitatory postsynaptic currents (mEPSCs), miniature inhibitory postsynaptic currents (mIPSCs) and synaptic plasticity in the hippocampal CA1 neurons were recorded. Moreover, ROS scavenger NAC was co-infused to investigate the potential mechanism. We found the complex of MEL and CA but not their alone caused severe cell death and disturbed energy production through activation caspase-3-mediated apoptosis. Meanwhile, the combination significantly reduced the amplitude, decay time and frequency of mEPSCs but not mIPSCs, indicating the pre- and post-synaptic inhibitory actions on neuronal activity. Paired-pulsed ratio (PPR) and long-term potentiation (LTP) at the Schaffer collateral-CA1 synapses were critically depressed. However, the co-application of NAC could effectively mitigate the cellular apoptosis, energy metabolism dysfunction and the impairments in neuronal and synaptic function. Our findings provide the first evidence that the combination of MEL and CA can exert more prominently neurotoxic effects than their alone and certify that one of the potential mechanisms for neuronal and synaptic dysfunction is the ROS-mediated signaling pathway.
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Affiliation(s)
- Wei Sun
- Department of Pediatric, The First Affiliated Hospital, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550001, China; Behavioral Neuroscience Laboratory, The First Affiliated Hospital, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550001, China
| | - Xiao Chen
- Behavioral Neuroscience Laboratory, The First Affiliated Hospital, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550001, China; Graduate School of Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Yazi Mei
- Graduate School of Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Xiaoliang Li
- Department of Neurology, Jinan Geriatric/Rehabilitation Hospital, Jinan 250013, China
| | - Yang Yang
- Department of Pediatric, The First Affiliated Hospital, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550001, China
| | - Lei An
- Department of Pediatric, The First Affiliated Hospital, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550001, China; Behavioral Neuroscience Laboratory, The First Affiliated Hospital, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550001, China; Department of Neurology, Jinan Geriatric/Rehabilitation Hospital, Jinan 250013, China; Department of Neurology, The First Affiliated Hospital, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550001, China.
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Rostamipour K, Talandashti R, Mehrnejad F. Atomistic insight into the luminal allosteric regulation of vesicular glutamate transporter 2 by chloride and protons: An
all‐atom
molecular dynamics simulation study. Proteins 2022; 90:2045-2057. [DOI: 10.1002/prot.26396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/27/2022] [Accepted: 06/28/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Kiana Rostamipour
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies University of Tehran Tehran Iran
| | - Reza Talandashti
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies University of Tehran Tehran Iran
| | - Faramarz Mehrnejad
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies University of Tehran Tehran Iran
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6
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Hori T, Eguchi K, Wang HY, Miyasaka T, Guillaud L, Taoufiq Z, Mahapatra S, Yamada H, Takei K, Takahashi T. Microtubule assembly by soluble tau impairs vesicle endocytosis and excitatory neurotransmission via dynamin sequestration in Alzheimer's disease mice synapse model. eLife 2022; 11:73542. [PMID: 35471147 PMCID: PMC9071263 DOI: 10.7554/elife.73542] [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: 09/02/2021] [Accepted: 04/20/2022] [Indexed: 11/27/2022] Open
Abstract
Elevation of soluble wild-type (WT) tau occurs in synaptic compartments in Alzheimer’s disease. We addressed whether tau elevation affects synaptic transmission at the calyx of Held in slices from mice brainstem. Whole-cell loading of WT human tau (h-tau) in presynaptic terminals at 10–20 µM caused microtubule (MT) assembly and activity-dependent rundown of excitatory neurotransmission. Capacitance measurements revealed that the primary target of WT h-tau is vesicle endocytosis. Blocking MT assembly using nocodazole prevented tau-induced impairments of endocytosis and neurotransmission. Immunofluorescence imaging analyses revealed that MT assembly by WT h-tau loading was associated with an increased MT-bound fraction of the endocytic protein dynamin. A synthetic dodecapeptide corresponding to dynamin 1-pleckstrin-homology domain inhibited MT-dynamin interaction and rescued tau-induced impairments of endocytosis and neurotransmission. We conclude that elevation of presynaptic WT tau induces de novo assembly of MTs, thereby sequestering free dynamins. As a result, endocytosis and subsequent vesicle replenishment are impaired, causing activity-dependent rundown of neurotransmission.
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Affiliation(s)
- Tetsuya Hori
- Cellular and Molecular Synaptic Function Unit, Okinawa Institute of Science and Technology - Graduate University, Okinawa, Japan
| | - Kohgaku Eguchi
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Han-Ying Wang
- Cellular and Molecular Synaptic Function Unit, Okinawa Institute of Science and Technology - Graduate University, Okinawa, Japan
| | - Tomohiro Miyasaka
- Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Laurent Guillaud
- Cellular and Molecular Synaptic Function Unit, Okinawa Institute of Science and Technology - Graduate University, Okinawa, Japan
| | - Zacharie Taoufiq
- Cellular and Molecular Synaptic Function Unit,, Okinawa Institute of Science and Technology - Graduate University, Okinawa, Japan
| | - Satyajit Mahapatra
- Cellular and Molecular Synaptic Function Unit,, Okinawa Institute of Science and Technology - Graduate University, Okinawa, Japan
| | - Hiroshi Yamada
- Department of Neuroscience, Okayama University, Okayama, Japan
| | - Kohji Takei
- Department of Neuroscience, Okayama University, Okayama, Japan
| | - Tomoyuki Takahashi
- Cellular and Molecular Synaptic Function Unit, Okinawa Institute of Science and Technology - Graduate University, Okinawa, Japan
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7
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Hori T, Takamori S. Physiological Perspectives on Molecular Mechanisms and Regulation of Vesicular Glutamate Transport: Lessons From Calyx of Held Synapses. Front Cell Neurosci 2022; 15:811892. [PMID: 35095427 PMCID: PMC8793065 DOI: 10.3389/fncel.2021.811892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/07/2021] [Indexed: 12/02/2022] Open
Abstract
Accumulation of glutamate, the primary excitatory neurotransmitter in the mammalian central nervous system, into presynaptic synaptic vesicles (SVs) depends upon three vesicular glutamate transporters (VGLUTs). Since VGLUTs are driven by a proton electrochemical gradient across the SV membrane generated by vacuolar-type H+-ATPases (V-ATPases), the rate of glutamate transport into SVs, as well as the amount of glutamate in SVs at equilibrium, are influenced by activities of both VGLUTs and V-ATPase. Despite emerging evidence that suggests various factors influencing glutamate transport by VGLUTs in vitro, little has been reported in physiological or pathological contexts to date. Historically, this was partially due to a lack of appropriate methods to monitor glutamate loading into SVs in living synapses. Furthermore, whether or not glutamate refilling of SVs can be rate-limiting for synaptic transmission is not well understood, primarily due to a lack of knowledge concerning the time required for vesicle reuse and refilling during repetitive stimulation. In this review, we first introduce a unique electrophysiological method to monitor glutamate refilling by VGLUTs in a giant model synapse from the calyx of Held in rodent brainstem slices, and we discuss the advantages and limitations of the method. We then introduce the current understanding of factors that potentially alter the amount and rate of glutamate refilling of SVs in this synapse, and discuss open questions from physiological viewpoints.
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Affiliation(s)
- Tetsuya Hori
- Cellular and Molecular Synaptic Function Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
- *Correspondence: Tetsuya Hori Shigeo Takamori
| | - Shigeo Takamori
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan
- *Correspondence: Tetsuya Hori Shigeo Takamori
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8
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Takahashi T. Presynaptic Black Box Opened by Pioneers at Biophysics Department in University College London. Neuroscience 2020; 439:10-21. [DOI: 10.1016/j.neuroscience.2019.04.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 11/15/2022]
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9
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Activity and Cytosolic Na + Regulate Synaptic Vesicle Endocytosis. J Neurosci 2020; 40:6112-6120. [PMID: 32605936 DOI: 10.1523/jneurosci.0119-20.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 06/18/2020] [Accepted: 06/24/2020] [Indexed: 11/21/2022] Open
Abstract
Retrieval of synaptic vesicles via endocytosis is essential for maintaining sustained synaptic transmission, especially for neurons that fire action potentials at high frequencies. However, how neuronal activity regulates synaptic vesicle recycling is largely unknown. Here we report that Na+ substantially accumulated in the mouse calyx of Held terminals of either sex during repetitive high-frequency spiking. Elevated presynaptic Na+ accelerated both slow and rapid forms of endocytosis and facilitated endocytosis overshoot, but did not affect the readily releasable pool size, Ca2+ influx, or exocytosis. To examine whether this facilitation of endocytosis is related to the Na+-dependent vesicular content change, we dialyzed glutamate into the presynaptic cytosol or blocked the vesicular glutamate uptake with bafilomycin and found that the rate of endocytosis was not affected by regulating the vesicular glutamate content. Endocytosis is critically dependent on intracellular Ca2+, and the activity of Na+/Ca2+ exchanger (NCX) may be altered when the Na+ gradient is changed. However, neither NCX inhibitor nor change of extracellular Na+ concentration affected the endocytosis rate. Moreover, two-photon Ca2+ imaging showed that presynaptic Na+ did not affect the action potential-evoked intracellular Ca2+ transient and decay. Therefore, we revealed a novel mechanism of cytosolic Na+ in accelerating vesicle endocytosis. During high-frequency synaptic transmission, when large numbers of synaptic vesicles were fused, the rapid buildup of presynaptic cytosolic Na+ promoted vesicle recycling and sustained synaptic transmission.SIGNIFICANCE STATEMENT High-frequency firing neurons are widely distributed in the CNS. A large number of synaptic vesicles are released during high-frequency synaptic transmission; accordingly, synaptic vesicles need to be recycled rapidly to replenish the vesicle pool. Synaptic vesicle exocytosis and endocytosis are tightly coupled, and their coupling is essential for synaptic function and structural stability. We showed here that intracellular Na+ concentration at the calyx of Held terminal increased rapidly during spike activity and the increased Na+ accelerated endocytosis. Thus, when large numbers of synaptic vesicles are released during high-frequency synaptic transmission, Na+ accumulated in terminals and facilitated vesicle recycling. These findings represent a novel cellular mechanism that supports reliable synaptic transmission at high frequency in the CNS.
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10
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Li F, Eriksen J, Finer-Moore J, Chang R, Nguyen P, Bowen A, Myasnikov A, Yu Z, Bulkley D, Cheng Y, Edwards RH, Stroud RM. Ion transport and regulation in a synaptic vesicle glutamate transporter. Science 2020; 368:893-897. [PMID: 32439795 DOI: 10.1126/science.aba9202] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/27/2020] [Indexed: 12/28/2022]
Abstract
Synaptic vesicles accumulate neurotransmitters, enabling the quantal release by exocytosis that underlies synaptic transmission. Specific neurotransmitter transporters are responsible for this activity and therefore are essential for brain function. The vesicular glutamate transporters (VGLUTs) concentrate the principal excitatory neurotransmitter glutamate into synaptic vesicles, driven by membrane potential. However, the mechanism by which they do so remains poorly understood owing to a lack of structural information. We report the cryo-electron microscopy structure of rat VGLUT2 at 3.8-angstrom resolution and propose structure-based mechanisms for substrate recognition and allosteric activation by low pH and chloride. A potential permeation pathway for chloride intersects with the glutamate binding site. These results demonstrate how the activity of VGLUTs can be coordinated with large shifts in proton and chloride concentrations during the synaptic vesicle cycle to ensure normal synaptic transmission.
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Affiliation(s)
- Fei Li
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.,Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA
| | - Jacob Eriksen
- Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA
| | - Janet Finer-Moore
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Roger Chang
- Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA.,Graduate Program in Biomedical Sciences, UCSF, San Francisco, CA, USA
| | - Phuong Nguyen
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Alisa Bowen
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Alexander Myasnikov
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Zanlin Yu
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - David Bulkley
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.,Howard Hughes Medical Institute, UCSF, San Francisco, CA, USA
| | - Robert H Edwards
- Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA.
| | - Robert M Stroud
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.
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11
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Yamashita M, Kawaguchi SY, Hori T, Takahashi T. Vesicular GABA Uptake Can Be Rate Limiting for Recovery of IPSCs from Synaptic Depression. Cell Rep 2019; 22:3134-3141. [PMID: 29562170 DOI: 10.1016/j.celrep.2018.02.080] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 01/05/2018] [Accepted: 02/21/2018] [Indexed: 11/16/2022] Open
Abstract
Synaptic efficacy plays crucial roles in neuronal circuit operation and synaptic plasticity. Presynaptic determinants of synaptic efficacy are neurotransmitter content in synaptic vesicles and the number of vesicles undergoing exocytosis at a time. Bursts of presynaptic firings depress synaptic efficacy, mainly due to depletion of releasable vesicles, whereas recovery from strong depression is initiated by endocytic vesicle retrieval followed by refilling of vesicles with neurotransmitter. We washed out presynaptic cytosolic GABA to induce a rundown of IPSCs at cerebellar inhibitory cell pairs in slices from rats and then allowed fast recovery by elevating GABA concentration using photo-uncaging. The time course of this recovery coincided with that of IPSCs from activity-dependent depression induced by a train of high-frequency stimulation. We conclude that vesicular GABA uptake can be a limiting step for the recovery of inhibitory neurotransmission from synaptic depression.
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Affiliation(s)
- Manami Yamashita
- Laboratory of Molecular Synaptic Function, Graduate School of Brain Science, Doshisha University, Kyoto 610-0394, Japan; Department of Physiology, Faculty of Medicine, Osaka Medical College, Osaka 569-8686, Japan
| | - Shin-Ya Kawaguchi
- Society-Academia Collaboration for Innovation, Kyoto University, Kyoto 606-8501, Japan
| | - Tetsuya Hori
- Department of Neurophysiology, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto 610-0394, Japan.
| | - Tomoyuki Takahashi
- Cellular and Molecular Synaptic Function Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa 904-0495, Japan.
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12
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Singh M, Miura P, Renden R. Age-related defects in short-term plasticity are reversed by acetyl-L-carnitine at the mouse calyx of Held. Neurobiol Aging 2018; 67:108-119. [PMID: 29656010 PMCID: PMC5955853 DOI: 10.1016/j.neurobiolaging.2018.03.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 03/13/2018] [Accepted: 03/13/2018] [Indexed: 12/19/2022]
Abstract
Hearing acuity and sound localization are affected by aging and may contribute to cognitive dementias. Although loss of sensorineural conduction is well documented to occur with age, little is known regarding short-term synaptic plasticity in central auditory nuclei. Age-related changes in synaptic transmission properties were evaluated at the mouse calyx of Held, a sign-inverting relay synapse in the circuit for sound localization, in juvenile adults (1 month old) and late middle-aged (18-21 months old) mice. Synaptic timing and short-term plasticity were severely disrupted in older mice. Surprisingly, acetyl-l-carnitine (ALCAR), an anti-inflammatory agent that facilitates mitochondrial function, fully reversed synaptic transmission delays and defects in short-term plasticity in aged mice to reflect transmission similar to that seen in juvenile adults. These findings support ALCAR supplementation as an adjuvant to improve short-term plasticity and potentially central nervous system performance in animals compromised by age and/or neurodegenerative disease.
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Affiliation(s)
- Mahendra Singh
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Pedro Miura
- Department of Biology, University of Nevada, Reno, Reno, NV, USA
| | - Robert Renden
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA.
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