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Hussan MT, Sakai A, Matsui H. Glutamatergic pathways in the brains of turtles: A comparative perspective among reptiles, birds, and mammals. Front Neuroanat 2022; 16:937504. [PMID: 36059432 PMCID: PMC9428285 DOI: 10.3389/fnana.2022.937504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/22/2022] [Indexed: 11/13/2022] Open
Abstract
Glutamate acts as the main excitatory neurotransmitter in the brain and plays a vital role in physiological and pathological neuronal functions. In mammals, glutamate can cause detrimental excitotoxic effects under anoxic conditions. In contrast, Trachemys scripta, a freshwater turtle, is one of the most anoxia-tolerant animals, being able to survive up to months without oxygen. Therefore, turtles have been investigated to assess the molecular mechanisms of neuroprotective strategies used by them in anoxic conditions, such as maintaining low levels of glutamate, increasing adenosine and GABA, upregulating heat shock proteins, and downregulating KATP channels. These mechanisms of anoxia tolerance of the turtle brain may be applied to finding therapeutics for human glutamatergic neurological disorders such as brain injury or cerebral stroke due to ischemia. Despite the importance of glutamate as a neurotransmitter and of the turtle as an ideal research model, the glutamatergic circuits in the turtle brain remain less described whereas they have been well studied in mammalian and avian brains. In reptiles, particularly in the turtle brain, glutamatergic neurons have been identified by examining the expression of vesicular glutamate transporters (VGLUTs). In certain areas of the brain, some ionotropic glutamate receptors (GluRs) have been immunohistochemically studied, implying that there are glutamatergic target areas. Based on the expression patterns of these glutamate-related molecules and fiber connection data of the turtle brain that is available in the literature, many candidate glutamatergic circuits could be clarified, such as the olfactory circuit, hippocampal–septal pathway, corticostriatal pathway, visual pathway, auditory pathway, and granule cell–Purkinje cell pathway. This review summarizes the probable glutamatergic pathways and the distribution of glutamatergic neurons in the pallium of the turtle brain and compares them with those of avian and mammalian brains. The integrated knowledge of glutamatergic pathways serves as the fundamental basis for further functional studies in the turtle brain, which would provide insights on physiological and pathological mechanisms of glutamate regulation as well as neural circuits in different species.
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Affiliation(s)
- Mohammad Tufazzal Hussan
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan
- Department of Anatomy and Histology, Patuakhali Science and Technology University, Barishal, Bangladesh
- *Correspondence: Mohammad Tufazzal Hussan,
| | - Akiko Sakai
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan
| | - Hideaki Matsui
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan
- Hideaki Matsui,
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2
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He A, Zhang C, Ke X, Yi Y, Yu Q, Zhang T, Yu H, Du H, Li H, Tian Q, Zhu LQ, Lu Y. VGLUT3 neurons in median raphe control the efficacy of spatial memory retrieval via ETV4 regulation of VGLUT3 transcription. SCIENCE CHINA. LIFE SCIENCES 2022; 65:1590-1607. [PMID: 35089530 DOI: 10.1007/s11427-021-2047-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
The raphe nucleus is critical for feeding, rewarding and memory. However, how the heterogenous raphe neurons are molecularly and structurally organized to engage their divergent functions remains unknown. Here, we genetically target a subset of neurons expressing VGLUT3. VGLUT3 neurons control the efficacy of spatial memory retrieval by synapsing directly with parvalbumin-expressing GABA interneurons (PGIs) in the dentate gyrus. In a mouse model of Alzheimer's disease (AD mice), VGLUT3→PGIs synaptic transmission is impaired by ETV4 inhibition of VGLUT3 transcription. ETV4 binds to a promoter region of VGLUT3 and activates VGLUT3 transcription in VGLUT3 neurons. Strengthening VGLUT3→PGIs synaptic transmission by ETV4 activation of VGLUT3 transcription upscales the efficacy of spatial memory retrieval in AD mice. This study reports a novel circuit and molecular mechanism underlying the efficacy of spatial memory retrieval via ETV4 inhibition of VGLUT3 transcription and hence provides a promising target for therapeutic intervention of the disease progression.
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Affiliation(s)
- Aodi He
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Chen Zhang
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiao Ke
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yao Yi
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Quntao Yu
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Tongmei Zhang
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hongyan Yu
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Huiyun Du
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hao Li
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
- Department of Pathophysiology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qing Tian
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
- Department of Pathophysiology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ling-Qiang Zhu
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China
- Department of Pathophysiology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Youming Lu
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Wuhan Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Department of Pathophysiology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, 430030, China.
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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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Noise Exposure Alters Glutamatergic and GABAergic Synaptic Connectivity in the Hippocampus and Its Relevance to Tinnitus. Neural Plast 2021; 2021:8833087. [PMID: 33510780 PMCID: PMC7822664 DOI: 10.1155/2021/8833087] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 12/16/2020] [Accepted: 12/30/2020] [Indexed: 01/08/2023] Open
Abstract
Accumulating evidence implicates a role for brain structures outside the ascending auditory pathway in tinnitus, the phantom perception of sound. In addition to other factors such as age-dependent hearing loss, high-level sound exposure is a prominent cause of tinnitus. Here, we examined how noise exposure altered the distribution of excitatory and inhibitory synaptic inputs in the guinea pig hippocampus and determined whether these changes were associated with tinnitus. In experiment one, guinea pigs were overexposed to unilateral narrow-band noise (98 dB SPL, 2 h). Two weeks later, the density of excitatory (VGLUT-1/2) and inhibitory (VGAT) synaptic terminals in CA1, CA3, and dentate gyrus hippocampal subregions was assessed by immunohistochemistry. Overall, VGLUT-1 density primarily increased, while VGAT density decreased significantly in many regions. Then, to assess whether the noise-induced alterations were persistent and related to tinnitus, experiment two utilized a noise-exposure paradigm shown to induce tinnitus and assessed tinnitus development which was assessed using gap-prepulse inhibition of the acoustic startle (GPIAS). Twelve weeks after sound overexposure, changes in excitatory synaptic terminal density had largely recovered regardless of tinnitus status, but the recovery of GABAergic terminal density was dramatically different in animals expressing tinnitus relative to animals resistant to tinnitus. In resistant animals, inhibitory synapse density recovered to preexposure levels, but in animals expressing tinnitus, inhibitory synapse density remained chronically diminished. Taken together, our results suggest that noise exposure induces striking changes in the balance of excitatory and inhibitory synaptic inputs throughout the hippocampus and reveal a potential role for rebounding inhibition in the hippocampus as a protective factor leading to tinnitus resilience.
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Cheret C, Ganzella M, Preobraschenski J, Jahn R, Ahnert-Hilger G. Vesicular Glutamate Transporters (SLCA17 A6, 7, 8) Control Synaptic Phosphate Levels. Cell Rep 2021; 34:108623. [PMID: 33440152 PMCID: PMC7809625 DOI: 10.1016/j.celrep.2020.108623] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/28/2020] [Accepted: 12/17/2020] [Indexed: 10/27/2022] Open
Abstract
Vesicular glutamate transporters (VGLUTs) fill synaptic vesicles with glutamate. VGLUTs were originally identified as sodium-dependent transporters of inorganic phosphate (Pi), but the physiological relevance of this activity remains unclear. Heterologous expression of all three VGLUTs greatly augments intracellular Pi levels. Using neuronal models, we show that translocation of VGLUTs to the plasma membrane during exocytosis results in highly increased Pi uptake. VGLUT-mediated Pi influx is counteracted by Pi efflux. Synaptosomes prepared from perinatal VGLUT2-/- mice that are virtually free of VGLUTs show drastically reduced cytosolic Pi levels and fail to import Pi. Glutamate partially competes with sodium (Na+)/Pi (NaPi)-uptake mediated by VGLUTs but does not appear to be transported. A nanobody that blocks glutamate transport by binding to the cytoplasmic domain of VGLUT1 abolishes Pi transport when co-expressed with VGLUT1. We conclude that VGLUTs have a dual function that is essential for both vesicular glutamate loading and Pi restoration in neurons.
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Affiliation(s)
- Cyril Cheret
- Institute for Integrative Neuroanatomy, Charité, Medical University of Berlin, 10115 Berlin, Germany
| | - Marcelo Ganzella
- Laboratory of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, and University of Göttingen, 37077 Göttingen, Germany
| | - Julia Preobraschenski
- Laboratory of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, and University of Göttingen, 37077 Göttingen, Germany
| | - Reinhard Jahn
- Laboratory of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, and University of Göttingen, 37077 Göttingen, Germany.
| | - Gudrun Ahnert-Hilger
- Institute for Integrative Neuroanatomy, Charité, Medical University of Berlin, 10115 Berlin, Germany; Laboratory of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, and University of Göttingen, 37077 Göttingen, Germany.
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6
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Bhat S, El-Kasaby A, Freissmuth M, Sucic S. Functional and Biochemical Consequences of Disease Variants in Neurotransmitter Transporters: A Special Emphasis on Folding and Trafficking Deficits. Pharmacol Ther 2020; 222:107785. [PMID: 33310157 PMCID: PMC7612411 DOI: 10.1016/j.pharmthera.2020.107785] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/02/2020] [Indexed: 01/30/2023]
Abstract
Neurotransmitters, such as γ-aminobutyric acid, glutamate, acetyl choline, glycine and the monoamines, facilitate the crosstalk within the central nervous system. The designated neurotransmitter transporters (NTTs) both release and take up neurotransmitters to and from the synaptic cleft. NTT dysfunction can lead to severe pathophysiological consequences, e.g. epilepsy, intellectual disability, or Parkinson’s disease. Genetic point mutations in NTTs have recently been associated with the onset of various neurological disorders. Some of these mutations trigger folding defects in the NTT proteins. Correct folding is a prerequisite for the export of NTTs from the endoplasmic reticulum (ER) and the subsequent trafficking to their pertinent site of action, typically at the plasma membrane. Recent studies have uncovered some of the key features in the molecular machinery responsible for transporter protein folding, e.g., the role of heat shock proteins in fine-tuning the ER quality control mechanisms in cells. The therapeutic significance of understanding these events is apparent from the rising number of reports, which directly link different pathological conditions to NTT misfolding. For instance, folding-deficient variants of the human transporters for dopamine or GABA lead to infantile parkinsonism/dystonia and epilepsy, respectively. From a therapeutic point of view, some folding-deficient NTTs are amenable to functional rescue by small molecules, known as chemical and pharmacological chaperones.
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Affiliation(s)
- Shreyas Bhat
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Ali El-Kasaby
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Sonja Sucic
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria.
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7
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Li ZH, Zhang CK, Qiao Y, Ge SN, Zhang T, Li JL. Coexpression of VGLUT1 and VGLUT2 in precerebellar neurons in the lateral reticular nucleus of the rat. Brain Res Bull 2020; 162:94-106. [PMID: 32562720 DOI: 10.1016/j.brainresbull.2020.06.008] [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: 08/25/2019] [Revised: 05/19/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022]
Abstract
Vesicular glutamate transporter (VGLUT) 1 and VGLUT2 have been reported to distribute complementally in most brain regions and have been assumed to define distinct functional elements. Previous studies have shown the expression of VGLUT1 mRNA and VGLUT2 mRNA in the lateral reticular nucleus (LRN), a key precerebellar nucleus sending mossy fibers to the cerebellum. In the present study, we firstly examined the coexpression of VGLUT1 and VGLUT2 mRNA in the LRN of the rat by dual-fluorescence in situ hybridization. About 81.89 % of glutamatergic LRN neurons coexpressed VGLUT1 and VGLUT2 mRNA, and the others expressed either VGLUT1 or VGLUT2 mRNA. We then injected the retrograde tracer Fluogold (FG) into the vermal cortex of cerebellum, and observed that 95.01 % and 86.80 % of FG-labeled LRN neurons expressed VGLUT1 or VGLUT2 mRNA respectively. We further injected the anterograde tracer biotinylated dextran amine (BDA) into the LRN, and found about 82.6 % of BDA labeled axon terminals in the granular layer of cerebellar cortex showed both VGLUT1- and VGLUT2-immunoreactivities. Afterwards, we observed under electron microscopy that anterogradely labeled axon terminals showing immunoreactivity for VGLUT1 or VGLUT2 made asymmetric synapses with dendritic profiles of cerebellar neurons. Finally, we selectively down-regulated the expression of VGLUT1 mRNA or VGLUT2 mRNA by using viral vector mediated siRNA transfection and detected that the fine movements of the forelimb of rats were disturbed. These results indicated that LRN neurons coexpressing VGLUT1 and VGLUT2 project to the cerebellar cortex and these neurons might be critical in mediating the forelimb movements.
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Affiliation(s)
- Zhi-Hong Li
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, No.169 of West Changle Road, Xincheng District, Xi'an, 710032, China; Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, No.1 of Xinyi Road, Baqiao District, Xi'an, 710038, China
| | - Chun-Kui Zhang
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, No.169 of West Changle Road, Xincheng District, Xi'an, 710032, China
| | - Yu Qiao
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, No.169 of West Changle Road, Xincheng District, Xi'an, 710032, China
| | - Shun-Nan Ge
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, No.169 of West Changle Road, Xincheng District, Xi'an, 710032, China; Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, No.1 of Xinyi Road, Baqiao District, Xi'an, 710038, China
| | - Ting Zhang
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, No.169 of West Changle Road, Xincheng District, Xi'an, 710032, China
| | - Jin-Lian Li
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, No.169 of West Changle Road, Xincheng District, Xi'an, 710032, China; Department of Anatomy, School of Medicine, Northwest University, No.229 of North Taibai Road, Beilin District, Xi'an, 710069, China.
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Pietrancosta N, Djibo M, Daumas S, El Mestikawy S, Erickson JD. Molecular, Structural, Functional, and Pharmacological Sites for Vesicular Glutamate Transporter Regulation. Mol Neurobiol 2020; 57:3118-3142. [PMID: 32474835 PMCID: PMC7261050 DOI: 10.1007/s12035-020-01912-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/30/2020] [Indexed: 12/11/2022]
Abstract
Vesicular glutamate transporters (VGLUTs) control quantal size of glutamatergic transmission and have been the center of numerous studies over the past two decades. VGLUTs contain two independent transport modes that facilitate glutamate packaging into synaptic vesicles and phosphate (Pi) ion transport into the synaptic terminal. While a transmembrane proton electrical gradient established by a vacuolar-type ATPase powers vesicular glutamate transport, recent studies indicate that binding sites and flux properties for chloride, potassium, and protons within VGLUTs themselves regulate VGLUT activity as well. These intrinsic ionic binding and flux properties of VGLUTs can therefore be modulated by neurophysiological conditions to affect levels of glutamate available for release from synapses. Despite their extraordinary importance, specific and high-affinity pharmacological compounds that interact with these sites and regulate VGLUT function, distinguish between the various modes of transport, and the different isoforms themselves, are lacking. In this review, we provide an overview of the physiologic sites for VGLUT regulation that could modulate glutamate release in an over-active synapse or in a disease state.
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Affiliation(s)
- Nicolas Pietrancosta
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France. .,Laboratoire des Biomolécules, Sorbonne Université, CNRS, ENS, LBM, 75005, Paris, France.
| | - Mahamadou Djibo
- Sorbonne Paris Cité, Université Paris Descartes, LCBPT, UMR 8601, 75006, Paris, France
| | - Stephanie Daumas
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France
| | - Salah El Mestikawy
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France. .,Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 boulevard Lasalle, Verdun, Montreal, QC, Canada.
| | - Jeffrey D Erickson
- Neuroscience Center, Louisiana State University, New Orleans, LA, 70112, USA. .,Department of Pharmacology, Louisiana State University, New Orleans, LA, 70112, USA.
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Eriksen J, Li F, Edwards RH. The mechanism and regulation of vesicular glutamate transport: Coordination with the synaptic vesicle cycle. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183259. [PMID: 32147354 DOI: 10.1016/j.bbamem.2020.183259] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/02/2020] [Accepted: 03/02/2020] [Indexed: 01/30/2023]
Abstract
The transport of classical neurotransmitters into synaptic vesicles generally relies on a H+ electrochemical gradient (∆μH+). Synaptic vesicle uptake of glutamate depends primarily on the electrical component ∆ψ as the driving force, rather than the chemical component ∆pH. However, the vesicular glutamate transporters (VGLUTs) belong to the solute carrier 17 (SLC17) family, which includes closely related members that function as H+ cotransporters. Recent work has also shown that the VGLUTs undergo allosteric regulation by H+ and Cl-, and exhibit an associated Cl- conductance. These properties appear to coordinate VGLUT activity with the large ionic shifts that accompany the rapid recycling of synaptic vesicles driven by neural activity. Recent structural information also suggests common mechanisms that underlie the apparently divergent function of SLC17 family members, and that confer allosteric regulation.
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Affiliation(s)
- Jacob Eriksen
- Department of Physiology, UCSF School of Medicine, United States of America; Department of Neurology, UCSF School of Medicine, United States of America
| | - Fei Li
- Department of Physiology, UCSF School of Medicine, United States of America; Department of Neurology, UCSF School of Medicine, United States of America
| | - Robert H Edwards
- Department of Physiology, UCSF School of Medicine, United States of America; Department of Neurology, UCSF School of Medicine, United States of America.
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Abstract
Neurons that synthesize and release 5-hydroxytryptamine (5-HT; serotonin) express a core set of genes that establish and maintain this neurotransmitter phenotype and distinguish these neurons from other brain cells. Beyond a shared 5-HTergic phenotype, these neurons display divergent cellular properties in relation to anatomy, morphology, hodology, electrophysiology and gene expression, including differential expression of molecules supporting co-transmission of additional neurotransmitters. This diversity suggests that functionally heterogeneous subtypes of 5-HT neurons exist, but linking subsets of these neurons to particular functions has been technically challenging. We discuss recent data from molecular genetic, genomic and functional methods that, when coupled with classical findings, yield a reframing of the 5-HT neuronal system as a conglomeration of diverse subsystems with potential to inspire novel, more targeted therapies for clinically distinct 5-HT-related disorders.
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TAKAHASHI H, YOKOI N, SEINO S. Glutamate as intracellular and extracellular signals in pancreatic islet functions. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2019; 95:246-260. [PMID: 31189778 PMCID: PMC6751295 DOI: 10.2183/pjab.95.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/08/2019] [Indexed: 05/25/2023]
Abstract
l-Glutamate is one of the most abundant amino acids in the body and is a constituent of proteins and a substrate in metabolism. It is well known that glutamate serves as a primary excitatory neurotransmitter and a critical neuromodulator in the brain. Recent studies have shown that in addition to its pivotal role in neural functions, glutamate plays many important roles in a variety of cellular functions, including those as intracellular and extracellular signals. In pancreatic islets, glutamate is now known to be required for the normal regulation of insulin secretion, such as incretin-induced insulin secretion. In this review, we primarily discuss the physiological and pathophysiological roles of glutamate as intracellular and extracellular signals in the functions of pancreatic islets.
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Affiliation(s)
- Harumi TAKAHASHI
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Norihide YOKOI
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Susumu SEINO
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
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12
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Trudeau LE, El Mestikawy S. Glutamate Cotransmission in Cholinergic, GABAergic and Monoamine Systems: Contrasts and Commonalities. Front Neural Circuits 2018; 12:113. [PMID: 30618649 PMCID: PMC6305298 DOI: 10.3389/fncir.2018.00113] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/03/2018] [Indexed: 11/13/2022] Open
Abstract
Multiple discoveries made since the identification of vesicular glutamate transporters (VGLUTs) two decades ago revealed that many neuronal populations in the brain use glutamate in addition to their "primary" neurotransmitter. Such a mode of cotransmission has been detected in dopamine (DA), acetylcholine (ACh), serotonin (5-HT), norepinephrine (NE) and surprisingly even in GABA neurons. Interestingly, work performed by multiple groups during the past decade suggests that the use of glutamate as a cotransmitter takes different forms in these different populations of neurons. In the present review, we will provide an overview of glutamate cotransmission in these different classes of neurons, highlighting puzzling differences in: (1) the proportion of such neurons expressing a VGLUT in different brain regions and at different stages of development; (2) the sub-cellular localization of the VGLUT; (3) the localization of the VGLUT in relation to the neurons' other vesicular transporter; and (4) the functional role of glutamate cotransmission.
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Affiliation(s)
- Louis-Eric Trudeau
- CNS Research Group, Department of Pharmacology and Physiology, Department of Neurosciences, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Salah El Mestikawy
- Department of Psychiatry, Faculty of Medicine, Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada.,Sorbonne Universités, Université Pierre et Marie Curie UM 119-CNRS UMR 8246-INSERM U1130, Neurosciences Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Paris, France
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13
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Atoji Y, Sarkar S. Prox1 mRNA expression in the medial cortex of the turtle (Pseudemys scripta elegans). Neurosci Lett 2018; 687:285-289. [PMID: 30218766 DOI: 10.1016/j.neulet.2018.09.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 09/11/2018] [Indexed: 11/18/2022]
Abstract
The medial cortex of the cerebrum in reptiles is thought to be homologous to the mammalian dentate gyrus, based on cytoarchitectures, fiber connections, and neurochemical profiles. To support this hypothesis, we examined the mRNA expression of vesicular glutamate transporter 1 (vGluT1), a glutamatergic gene marker, and Prox1, a selective gene marker for granule cells of the dentate gyrus, in the turtle medial cortex (zone 2). Reverse transcription-polymerase chain reaction revealed the presence of both mRNAs in the turtle cerebrum. In situ hybridization of zone 2, which is a layer of densely packed neurons in Nissl stains, intensely expressed vGluT1 and Prox1. In zone 3, which is a loosely packed layer, vGluT1 was intensely expressed, whereas Prox1 signals gradated from strong to negative toward zone 4. These findings demonstrate that zone 2 contains glutamatergic neurons and expresses Prox1 mRNA and suggest that zone 2 in the turtle cerebrum is homologous to the mammalian dentate gyrus.
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Affiliation(s)
- Yasuro Atoji
- Laboratory of Veterinary anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan.
| | - Sonjoy Sarkar
- Laboratory of Veterinary anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
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14
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Zhang FX, Ge SN, Dong YL, Shi J, Feng YP, Li Y, Li YQ, Li JL. Vesicular glutamate transporter isoforms: The essential players in the somatosensory systems. Prog Neurobiol 2018; 171:72-89. [PMID: 30273635 DOI: 10.1016/j.pneurobio.2018.09.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 08/28/2018] [Accepted: 09/23/2018] [Indexed: 02/08/2023]
Abstract
In nervous system, glutamate transmission is crucial for centripetal conveyance and cortical perception of sensory signals of different modalities, which necessitates vesicular glutamate transporters 1-3 (VGLUT 1-3), the three homologous membrane-bound protein isoforms, to load glutamate into the presysnaptic vesicles. These VGLUTs, especially VGLUT1 and VGLUT2, selectively label and define functionally distinct neuronal subpopulations at each relay level of the neural hierarchies comprising spinal and trigeminal sensory systems. In this review, by scrutinizing each structure of the organism's fundamental hierarchies including dorsal root/trigeminal ganglia, spinal dorsal horn/trigeminal sensory nuclear complex, somatosensory thalamic nuclei and primary somatosensory cortex, we summarize and characterize in detail within each relay the neuronal clusters expressing distinct VGLUT protein/transcript isoforms, with respect to their regional distribution features (complementary distribution in some structures), axonal terminations/peripheral innervations and physiological functions. Equally important, the distribution pattern and characteristics of VGLUT1/VGLUT2 axon terminals within these structures are also epitomized. Finally, the correlation of a particular VGLUT isoform and its physiological role, disclosed thus far largely via studying the peripheral receptors, is generalized by referring to reports on global and conditioned VGLUT-knockout mice. Also, researches on VGLUTs relating to future direction are tentatively proposed, such as unveiling the elusive differences between distinct VGLUTs in mechanism and/or pharmacokinetics at ionic/molecular level, and developing VGLUT-based pain killers.
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Affiliation(s)
- Fu-Xing Zhang
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Shun-Nan Ge
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China; Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, PR China
| | - Yu-Lin Dong
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Juan Shi
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Yu-Peng Feng
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Yang Li
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, PR China
| | - Yun-Qing Li
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China; Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, PR China.
| | - Jin-Lian Li
- Department of Anatomy and K.K. Leung Brain Research Centre, School of Basic Medicine, The Fourth Military Medical University, Xi'an 710032, PR China.
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15
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Chang R, Eriksen J, Edwards RH. The dual role of chloride in synaptic vesicle glutamate transport. eLife 2018; 7:e34896. [PMID: 30040066 PMCID: PMC6057745 DOI: 10.7554/elife.34896] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 06/07/2018] [Indexed: 01/23/2023] Open
Abstract
The transport of glutamate into synaptic vesicles exhibits an unusual form of regulation by Cl- as well as an associated Cl- conductance. To distinguish direct effects of Cl- on the transporter from indirect effects via the driving force Δψ, we used whole endosome recording and report the first currents due to glutamate flux by the vesicular glutamate transporters (VGLUTs). Chloride allosterically activates the VGLUTs from both sides of the membrane, and we find that neutralization of an arginine in transmembrane domain four suffices for the lumenal activation. The dose dependence suggests that Cl- permeates through a channel and glutamate through a transporter. Competition between the anions nonetheless indicates that they use a similar permeation pathway. By controlling both ionic gradients and Δψ, endosome recording isolates different steps in the process of synaptic vesicle filling, suggesting distinct roles for Cl- in both allosteric activation and permeation.
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Affiliation(s)
- Roger Chang
- Department of PhysiologyUCSF School of MedicineSan FranciscoUnited States
- Department of NeurologyUCSF School of MedicineSan FranciscoUnited States
- Graduate Program in Biomedical SciencesUCSF School of MedicineSan FranciscoUnited States
| | - Jacob Eriksen
- Department of PhysiologyUCSF School of MedicineSan FranciscoUnited States
- Department of NeurologyUCSF School of MedicineSan FranciscoUnited States
| | - Robert H Edwards
- Department of PhysiologyUCSF School of MedicineSan FranciscoUnited States
- Department of NeurologyUCSF School of MedicineSan FranciscoUnited States
- Graduate Program in Biomedical SciencesUCSF School of MedicineSan FranciscoUnited States
- Kavli Institute for Fundamental NeuroscienceUCSF School of MedicineSan FranciscoUnited States
- Weill Institute for NeurosciencesUCSF School of MedicineSan FranciscoUnited States
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16
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Sarkar S, Atoji Y. Distribution of vesicular glutamate transporters in the brain of the turtle (Pseudemys scripta elegans). J Comp Neurol 2018; 526:1690-1702. [PMID: 29603220 DOI: 10.1002/cne.24439] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/20/2018] [Accepted: 03/20/2018] [Indexed: 12/18/2022]
Abstract
The distribution of glutamatergic neurons has been extensively studied in mammalian and avian brains, but its distribution in a reptilian brain remains unknown. In the present study, the distribution of subpopulations of glutamatergic neurons in the turtle brain was examined by in situ hybridization using probes for vesicular glutamate transporter (VGLUT) 1-3. Strong VGLUT1 expression was observed in the telencephalic pallium; the mitral cells of the olfactory bulb, the medial, dorsomedial, dorsal, and lateral parts of the cerebral cortex, pallial thickening, and dorsal ventricular ridge; and also, in granule cells of the cerebellar cortex. Moderate to weak expression was found in the lateral and medial amygdaloid nuclei, the periventricular cellular layer of the optic tectum, and in some brainstem nuclei. VGLUT2 was weakly expressed in the telencephalon but was intensely expressed in the dorsal thalamic nuclei, magnocellular part of the isthmic nucleus, brainstem nuclei, and the rostral cervical segment of the spinal cord. The cerebellar cortex was devoid of VGLUT2 expression. The central amygdaloid nucleus did not express VGLUT1 or VGLUT2. VGLUT3 was localized in the parvocellular part of the isthmic nucleus, superior and inferior raphe nuclei, and cochlear nucleus. Our results indicate that the distribution of VGLUTs in the turtle brain is similar to that in the mammalian brain rather than that in the avian brain.
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Affiliation(s)
- Sonjoy Sarkar
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yasuro Atoji
- Laboratory of Veterinary anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
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17
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Preobraschenski J, Cheret C, Ganzella M, Zander JF, Richter K, Schenck S, Jahn R, Ahnert-Hilger G. Dual and Direction-Selective Mechanisms of Phosphate Transport by the Vesicular Glutamate Transporter. Cell Rep 2018; 23:535-545. [DOI: 10.1016/j.celrep.2018.03.055] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 02/13/2018] [Accepted: 03/14/2018] [Indexed: 11/30/2022] Open
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18
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Johnson CS, Bains JS, Watts AG. Neurotransmitter diversity in pre-synaptic terminals located in the parvicellular neuroendocrine paraventricular nucleus of the rat and mouse hypothalamus. J Comp Neurol 2018; 526:1287-1306. [PMID: 29424419 DOI: 10.1002/cne.24407] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Revised: 01/24/2018] [Accepted: 01/25/2018] [Indexed: 02/02/2023]
Abstract
Virtually all rodent neuroendocrine corticotropin-releasing-hormone (CRH) neurons are in the dorsal medial parvicellular (mpd) part of the paraventricular nucleus of the hypothalamus (PVH). They form the final common pathway for adrenocortical stress responses. Their activity is controlled by sets of GABA-, glutamate-, and catecholamine-containing inputs arranged in an interactive pre-motor network. Defining the nature and arrangement of these inputs can help clarify how stressor type and intensity information is conveyed to neuroendocrine neurons. Here we use immunohistochemistry with high-resolution 3-dimensional image analyses to examine the arrangement of single- and co-occurring GABA, glutamate, and catecholamine markers in synaptophysin-defined pre-synaptic terminals in the PVHmpd of unstressed rats and Crh-IRES-Cre;Ai14 transgenic mice: respectively, vesicular glutamate transporter 2 (VGluT2), vesicular GABA transporter (VGAT), dopamine β-hydroxylase (DBH), and phenylethanolamine n-methyltransferase (PNMT). Just over half of all PVHmpd pre-synaptic terminals contain VGAT, with slightly less containing VGluT2. The vast majority of terminal appositions with mouse CRH neurons occur non-somatically. However, there are significantly more somatic VGAT than VGluT2 appositions. In the rat PVHmpd, about five times as many pre-synaptic terminals contain PNMT than DBH only. However, because epinephrine release has never been detected in the PVH, PNMT terminals may functionally be noradrenergic not adrenergic. PNMT and VGluT2 co-occur in some pre-synaptic terminals indicating the potential for co-transmission of glutamate and norepinephrine. Collectively, these results provide a structural basis for how GABA/glutamate/catecholamine interactions enable adrenocortical responses to fast-onset interosensory stimuli, and more broadly, how combinations of PVH neurotransmitters and neuromodulators interact dynamically to control adrenocortical activity.
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Affiliation(s)
- Caroline S Johnson
- The Department of Biological Sciences, USC Dornsife College of Letters, Arts, and Sciences, and Neuroscience, Graduate Program, University of Southern California, Los Angeles, California
| | - Jaideep S Bains
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Alberta, Canada
| | - Alan G Watts
- The Department of Biological Sciences, USC Dornsife College of Letters, Arts, and Sciences, and Neuroscience, Graduate Program, University of Southern California, Los Angeles, California
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19
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Mao H, Hamodeh S, Sultan F. Quantitative Comparison Of Vesicular Glutamate Transporters in rat Deep Cerebellar Nuclei. Neuroscience 2018; 376:152-161. [PMID: 29462701 DOI: 10.1016/j.neuroscience.2018.02.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/07/2018] [Accepted: 02/10/2018] [Indexed: 12/23/2022]
Abstract
The excitatory synapses of the rat deep cerebellar nuclei (DCN) were quantitatively analyzed by vesicular glutamate transporter 1 and 2 (vGluT1 and vGluT2) immunolabeling. We calculated the number and sizes of the labeled boutons and compared them between lateral/dentate nucleus (LN/DN), posterior interposed nucleus (PIN), anterior interposed nucleus (AIN), and medial nucleus (MN). The density of vGluT1+ boutons differs significantly within these nuclei. In contrast, the vGluT2+ bouton density is more similar between different nuclei. The phylogenetically newer DCN (LN/DN and PIN) have a 39% higher density of vGluT1+ boutons than the phylogenetically older DCN (AIN and MN). The volume of vGluT1+ boutons does not differ between the DCN, however the average volume of vGluT2+ boutons is larger in MN. In summary, our current results confirm and extend our previous findings showing that the increase in dendritic and axonal wiring in phylogenetically newer DCN is associated with an increase in vGluT1+ bouton density.
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Affiliation(s)
- Haian Mao
- Department of Cognitive Neurology, HIH for Clinical Brain Research, Otfried-Müller-Str. 27, 72076 Tübingen, Germany
| | - Salah Hamodeh
- Department of Cognitive Neurology, HIH for Clinical Brain Research, Otfried-Müller-Str. 27, 72076 Tübingen, Germany
| | - Fahad Sultan
- Department of Cognitive Neurology, HIH for Clinical Brain Research, Otfried-Müller-Str. 27, 72076 Tübingen, Germany; Department of Integrative Medical Biology, Umeå University, Linnéus väg 9, 901 87 Umeå, Sweden.
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20
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Richter K, Schmutz I, Darna M, Zander JF, Chavan R, Albrecht U, Ahnert-Hilger G. VGLUT1 Binding to Endophilin or Intersectin1 and Dynamin Phosphorylation in a Diurnal Context. Neuroscience 2018; 371:29-37. [DOI: 10.1016/j.neuroscience.2017.11.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/15/2017] [Accepted: 11/17/2017] [Indexed: 10/18/2022]
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21
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Martineau M, Guzman RE, Fahlke C, Klingauf J. VGLUT1 functions as a glutamate/proton exchanger with chloride channel activity in hippocampal glutamatergic synapses. Nat Commun 2017; 8:2279. [PMID: 29273736 PMCID: PMC5741633 DOI: 10.1038/s41467-017-02367-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 11/24/2017] [Indexed: 12/18/2022] Open
Abstract
Glutamate is the major excitatory transmitter in the vertebrate nervous system. To maintain synaptic efficacy, recycling synaptic vesicles (SV) are refilled with glutamate by vesicular glutamate transporters (VGLUTs). The dynamics and mechanism of glutamate uptake in intact neurons are still largely unknown. Here, we show by live-cell imaging with pH- and chloride-sensitive fluorescent probes in cultured hippocampal neurons of wild-type and VGLUT1-deficient mice that in SVs VGLUT functions as a glutamate/proton exchanger associated with a channel-like chloride conductance. After endocytosis most internalized Cl− is substituted by glutamate in an electrically, and presumably osmotically, neutral manner, and this process is driven by both the Cl− gradient itself and the proton motive force provided by the vacuolar H+-ATPase. Our results shed light on the transport mechanism of VGLUT under physiological conditions and provide a framework for how modulation of glutamate transport via Cl− and pH can change synaptic strength. During neurotransmission synaptic vesicles are filled with glutamate by vesicular glutamate transporters (VGLUTs). Here, authors image intact neurons and show that in synaptic vesicles VGLUT functions as a glutamate/proton exchanger associated with a channel-like chloride conductance.
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Affiliation(s)
- Magalie Martineau
- Department of Cellular Biophysics, Institute for Medical Physics and Biophysics, University of Muenster, 48149, Muenster, Germany. .,University of Bordeaux and Centre National de la Recherche Scientifique, Interdisciplinary Institute for Neuroscience, UMR 5297, F-33000, Bordeaux, France.
| | - Raul E Guzman
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Christoph Fahlke
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Jürgen Klingauf
- Department of Cellular Biophysics, Institute for Medical Physics and Biophysics, University of Muenster, 48149, Muenster, Germany. .,IZKF Münster and Cluster of Excellence EXC 1003, Cells in Motion (CiM), 48149, Muenster, Germany.
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22
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Ohgomori T, Yamasaki R, Kira JI, Jinno S. Upregulation of Vesicular Glutamate Transporter 2 and STAT3 Activation in the Spinal Cord of Mice Receiving 3,3'-Iminodipropionitrile. Neurotox Res 2017; 33:768-780. [PMID: 28965218 DOI: 10.1007/s12640-017-9822-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 09/14/2017] [Accepted: 09/20/2017] [Indexed: 12/12/2022]
Abstract
Chronic administration of 3,3'-iminodipropionitrile (IDPN) causes axonal impairment. Although controversy still remains, it has been suggested that IDPN intoxication mimics the axonopathy of amyotrophic lateral sclerosis (ALS). Interestingly, recent studies including our own showed that signal transducer and activator of transcription 3 (STAT3) in spinal α-motoneurons was activated in both IDPN-treated mice and SOD1 G93A mice, a genetic model of familial ALS. Because activation of STAT3 occurs in response to various stimuli, such as axonal injury, ischemia, and excessive glutamate, here we focused on a potential link between phosphorylated STAT3 (pSTAT3, an active form) and vesicular glutamate transporter 2 (VGluT2, a regulator of glutamate storage and release) in IDPN-treated mice and SOD1 G93A mice. Impairment of axonal transport was confirmed by western blot analysis: the expression levels of phosphorylated neurofilament H were elevated in both models. As shown in SOD1 G93A mice, the expression frequencies of VGluT2 in synaptophysin-positive (SYP)+ presynaptic terminals around spinal α-motoneurons were significantly higher in IDPN-treated mice than in vehicle controls. The coverages of spinal α-motoneurons by VGluT2+ presynaptic terminals were more elevated around pSTAT3+ cells than around pSTAT3- cells in IDPN-treated mice and SOD1 G93A mice. Considering that excessive glutamate is shown to be involved in axonal impairment and STAT3 activation, the present results suggest that IDPN-induced upregulation of VGluT2 may result in an increase in glutamate, which might cause axonopathy and induction of pSTAT3. The link between upregulation of VGluT2 and activation of STAT3 via glutamate may represent a common pathological feature of IDPN-treated mice and SOD1 G93A mice.
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Affiliation(s)
- Tomohiro Ohgomori
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Ryo Yamasaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Jun-Ichi Kira
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Shozo Jinno
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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Horváth HR, Fazekas CL, Balázsfi D, Jain SK, Haller J, Zelena D. Contribution of Vesicular Glutamate Transporters to Stress Response and Related Psychopathologies: Studies in VGluT3 Knockout Mice. Cell Mol Neurobiol 2017; 38:37-52. [PMID: 28776199 DOI: 10.1007/s10571-017-0528-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/28/2017] [Indexed: 10/19/2022]
Abstract
Maintenance of the homeostasis in a constantly changing environment is a fundamental process of life. Disturbances of the homeostatic balance is defined as stress response and is induced by wide variety of challenges called stressors. Being the main excitatory neurotransmitter of the central nervous system glutamate is important in the adaptation process of stress regulating both the catecholaminergic system and the hypothalamic-pituitary-adrenocortical axis. Data are accumulating about the role of different glutamatergic receptors at all levels of these axes, but little is known about the contribution of different vesicular glutamate transporters (VGluT1-3) characterizing the glutamatergic neurons. Here we summarize basic knowledge about VGluTs, their role in physiological regulation of stress adaptation, as well as their contribution to stress-related psychopathology. Most of our knowledge comes from the VGluT3 knockout mice, as VGluT1 and 2 knockouts are not viable. VGluT3 was discovered later than, and is not as widespread as the VGluT1 and 2. It may co-localize with other transmitters, and participate in retrograde signaling; as such its role might be unique. Previous reports using VGluT3 knockout mice showed enhanced anxiety and innate fear compared to wild type. Moreover, these knockout animals had enhanced resting corticotropin-releasing hormone mRNA levels in the hypothalamus and disturbed glucocorticoid stress responses. In conclusion, VGluT3 participates in stress adaptation regulation. The neuroendocrine changes observed in VGluT3 knockout mice may contribute to their anxious, fearful phenotype.
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Affiliation(s)
- Hanga Réka Horváth
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 43, Szigony utca, Szigony 43, 1083, Budapest, Hungary
| | - Csilla Lea Fazekas
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 43, Szigony utca, Szigony 43, 1083, Budapest, Hungary
| | - Diána Balázsfi
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 43, Szigony utca, Szigony 43, 1083, Budapest, Hungary.,János Szentágothai School of Neurosciences, Semmelweis University, 26, Üllői út, 1085, Budapest, Hungary
| | | | - József Haller
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 43, Szigony utca, Szigony 43, 1083, Budapest, Hungary
| | - Dóra Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 43, Szigony utca, Szigony 43, 1083, Budapest, Hungary. .,Centre for Neuroscience, Szentágothai Research Centre, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary.
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24
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Ohgomori T, Yamasaki R, Takeuchi H, Kadomatsu K, Kira JI, Jinno S. Differential involvement of vesicular and glial glutamate transporters around spinal α-motoneurons in the pathogenesis of SOD1 G93A mouse model of amyotrophic lateral sclerosis. Neuroscience 2017; 356:114-124. [PMID: 28526579 DOI: 10.1016/j.neuroscience.2017.05.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/31/2017] [Accepted: 05/08/2017] [Indexed: 12/14/2022]
Abstract
From a view point of the glutamate excitotoxicity theory, several studies have suggested that abnormal glutamate homeostasis via dysfunction of glial glutamate transporter-1 (GLT-1) may underlie neurodegeneration in amyotrophic lateral sclerosis (ALS). However, the detailed role of GLT-1 in the pathogenies of ALS remains controversial. To assess this issue, here we elucidated structural alterations associated with dysregulation of glutamate homeostasis using SOD1G93A mice, a genetic model of familial ALS. We first examined the viability of α-motoneurons in the lumbar spinal cord of SOD1G93A mice. Measurement of the soma size and density indicated that α-motoneurons might be intact at 9weeks of age (presymptomatic stage), then soma shrinkage began at 15weeks of age (progressive stage), and finally neuronal density declined at 21weeks of age (end stage). Next, we carried out the line profile analysis, and found that the coverage of α-motoneurons by GLT-1-positive (GLT-1+) astrocytic processes was decreased only at 21weeks of age, while the reduction of coverage of α-motoneurons by synaptophysin-positive (SYP+) presynaptic terminals began at 15weeks of age. Interestingly, the coverage of α-motoneurons by VGluT2+ presynaptic terminals was transiently increased at 9weeks of age, and then gradually decreased towards 21weeks of age. On the other hand, there were no time-dependent alterations in the coverage of α-motoneurons by GABAergic presynaptic terminals. These findings suggest that VGluT2 and GLT-1 may be differentially involved in the pathogenesis of ALS via abnormal glutamate homeostasis at the presymptomatic stage and end stage of disease, respectively.
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Affiliation(s)
- Tomohiro Ohgomori
- Department of Anatomy and Neuroscience, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Ryo Yamasaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Hideyuki Takeuchi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan; Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kenji Kadomatsu
- Department of Biochemistry, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Jun-Ichi Kira
- Department of Neurology, Neurological Institute, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Shozo Jinno
- Department of Anatomy and Neuroscience, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan.
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26
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Weingarten CP, Doraiswamy PM, Fisher MPA. A New Spin on Neural Processing: Quantum Cognition. Front Hum Neurosci 2016; 10:541. [PMID: 27833543 PMCID: PMC5080346 DOI: 10.3389/fnhum.2016.00541] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/12/2016] [Indexed: 11/20/2022] Open
Affiliation(s)
- Carol P Weingarten
- Department of Psychiatry and Behavioral Sciences, Duke University Medical CenterDurham, NC, USA; Brain Imaging and Analysis Center, Duke University Medical CenterDurham, NC, USA
| | - P Murali Doraiswamy
- Department of Psychiatry and Behavioral Sciences, Duke University Medical CenterDurham, NC, USA; Duke Institute for Brain Sciences, Duke UniversityDurham, NC, USA
| | - Matthew P A Fisher
- Department of Physics, University of California, Santa Barbara Santa Barbara, CA USA
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Wang HS, Yu G, Wang ZT, Yi SP, Su RB, Gong ZH. Changes in VGLUT1 and VGLUT2 expression in rat dorsal root ganglia and spinal cord following spared nerve injury. Neurochem Int 2016; 99:9-15. [PMID: 27210824 DOI: 10.1016/j.neuint.2016.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 05/05/2016] [Accepted: 05/17/2016] [Indexed: 10/21/2022]
Abstract
Disturbance of glutamate homeostasis is a well-characterized mechanism of neuropathic pain. Vesicular glutamate transporters (VGLUTs) determine glutamate accumulation in synaptic vesicles and their roles in neuropathic pain have been suggested by gene-knockout studies. Here, we investigated the spatio-temporal changes in VGLUT expression during the development of neuropathic pain in wild-type rats. Spared nerve injury (SNI) induced mechanical allodynia from postoperative day 1 to at least day 14. Expression of VGLUT1 and VGLUT2 in dorsal root ganglia and spinal cord was examined by western blot analyses on different postoperative days. We observed that VGLUT2 were selectively upregulated in crude vesicle fractions from the ipsilateral lumbar enlargement on postoperative days 7 and 14, while VGLUT1 was transiently downregulated in ipsilateral DRG (day 4) and contralateral lumbar enlargement (day 1). Upregulation of VGLUT2 was not accompanied by alterations in vesicular expression of synaptotagmin or glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Thus, VGLUTs expression, especially VGLUT2, is regulated following peripheral nerve injury. Temporal regulation of VGLUT2 expression in spinal cord may represent a novel presynaptic mechanism contributing to injury-induced glutamate imbalance and associated neuropathic pain.
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Affiliation(s)
- Hong-Sheng Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Gang Yu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Zhi-Tong Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Shou-Pu Yi
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Rui-Bin Su
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Ze-Hui Gong
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
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28
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Seal RP. Do the distinct synaptic properties of VGLUTs shape pain? Neurochem Int 2016; 98:82-8. [PMID: 27180049 DOI: 10.1016/j.neuint.2016.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 04/26/2016] [Accepted: 04/28/2016] [Indexed: 11/25/2022]
Abstract
The somatosensory system transmits touch, temperature, itch and pain. Three vesicular glutamate transporter isoforms mediate the release of glutamate throughout the mammalian nervous system with largely non-overlapping distributions and unique roles at the synapse. This review discusses the contribution of each of these essential transporters to circuits underlying pain and other somatosensory behaviors throughout postnatal development and in the adult. A better understanding of the individual contributions of the VGLUT isoforms could provide new avenues for therapeutic intervention.
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Affiliation(s)
- Rebecca P Seal
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
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29
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Takamori S. Presynaptic Molecular Determinants of Quantal Size. Front Synaptic Neurosci 2016; 8:2. [PMID: 26903855 PMCID: PMC4744840 DOI: 10.3389/fnsyn.2016.00002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/25/2016] [Indexed: 01/22/2023] Open
Abstract
The quantal hypothesis for the release of neurotransmitters at the chemical synapse has gained wide acceptance since it was first worked out at the motor endplate in frog skeletal muscle in the 1950’s. Considering the morphological identification of synaptic vesicles (SVs) at the nerve terminals that appeared to be homogeneous in size, the hypothesis proposed that signal transduction at synapses is mediated by the release of neurotransmitters packed in SVs that are individually uniform in size; the amount of transmitter in a synaptic vesicle is called a quantum. Although quantal size—the amplitude of the postsynaptic response elicited by the release of neurotransmitters from a single vesicle—clearly depends on the number and sensitivity of the postsynaptic receptors, accumulating evidence has also indicated that the amount of neurotransmitters stored in SVs can be altered by various presynaptic factors. Here, I provide an overview of the concepts and underlying presynaptic molecular underpinnings that may regulate quantal size.
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Affiliation(s)
- Shigeo Takamori
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University Kyoto, Japan
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30
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31
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Vesicular glutamate transporters as anion channels? Pflugers Arch 2015; 468:513-8. [DOI: 10.1007/s00424-015-1760-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/05/2015] [Accepted: 11/12/2015] [Indexed: 01/13/2023]
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32
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Pundir AS, Singh UA, Ahuja N, Makhija S, Dikshit PC, Radotra B, Kumar P, Shankar SK, Mahadevan A, Roy TS, Iyengar S. Growth and refinement of excitatory synapses in the human auditory cortex. Brain Struct Funct 2015; 221:3641-74. [PMID: 26438332 DOI: 10.1007/s00429-015-1124-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 09/25/2015] [Indexed: 02/03/2023]
Abstract
We had earlier demonstrated a neurofilament-rich plexus of axons in the presumptive human auditory cortex during fetal development which became adult-like during infancy. To elucidate the origin of these axons, we studied the expression of the vesicular glutamate transporters (VGLUT) 1 and 2 in the human auditory cortex at different stages of development. While VGLUT-1 expression predominates in intrinsic and cortico-cortical synapses, VGLUT-2 expression predominates in thalamocortical synapses. Levels of VGLUT-2 mRNA were higher in the auditory cortex before birth compared to postnatal development. In contrast, levels of VGLUT-1 mRNA were low before birth and increased during postnatal development to peak during childhood and then began to decrease in adolescence. Both VGLUT-1 and VGLUT-2 proteins were present in the human auditory cortex as early as 15GW. Further, immunohistochemistry revealed that the supra- and infragranular layers were more immunoreactive for VGLUT-1 compared to that in Layer IV at 34GW and this pattern was maintained until adulthood. As for VGLUT-1 mRNA, VGLUT-1 synapses increased in density between prenatal development and childhood in the human auditory cortex after which they appeared to undergo attrition or pruning. The adult pattern of VGLUT-2 immunoreactivity (a dense band of VGLUT-2-positive terminals in Layer IV) also began to appear in the presumptive Heschl's gyrus at 34GW. The density of VGLUT-2-positive puncta in Layer IV increased between prenatal development and adolescence, followed by a decrease in adulthood, suggesting that thalamic axons which innervate the human auditory cortex undergo pruning comparatively late in development.
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Affiliation(s)
- Arvind Singh Pundir
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India
| | - Utkarsha A Singh
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India
| | - Nikhil Ahuja
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India
| | - Sonal Makhija
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India
| | - P C Dikshit
- Department of Forensic Medicine, Maulana Azad Medical College, Bahadur Shah Zafar Marg, New Delhi, 110002, India
| | - Bishan Radotra
- Department of Histopathology, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh, 160012, India
| | - Praveen Kumar
- Department of Obstetrics and Gynecology, Base Hospital, Delhi Cantonment, Delhi, 110010, India
| | - S K Shankar
- Department of Neuropathology, National Institute of Mental Health and Allied Sciences, Hosur Road, Bangalore, 560029, India
| | - Anita Mahadevan
- Department of Neuropathology, National Institute of Mental Health and Allied Sciences, Hosur Road, Bangalore, 560029, India
| | - T S Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110002, India
| | - Soumya Iyengar
- Division of Systems Neuroscience, National Brain Research Centre (Deemed University), NH-8, Manesar, Gurgaon, Haryana, 122051, India.
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33
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Changes in VGLUT2 expression and function in pain-related supraspinal regions correlate with the pathogenesis of neuropathic pain in a mouse spared nerve injury model. Brain Res 2015; 1624:515-524. [PMID: 26300222 DOI: 10.1016/j.brainres.2015.08.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 08/11/2015] [Accepted: 08/13/2015] [Indexed: 01/05/2023]
Abstract
Vesicular glutamate transporters (VGLUTs) control the storage and release of glutamate, which plays a critical role in pain processing. The VGLUT2 isoform has been found to be densely distributed in the nociceptive pathways in supraspinal regions, and VGLUT2-deficient mice exhibit an attenuation of neuropathic pain; these results suggest a possible involvement of VGLUT2 in neuropathic pain. To further examine this, we investigated the temporal changes in VGLUT2 expression in different brain regions as well as changes in glutamate release from thalamic synaptosomes in spared nerve injury (SNI) mice. We also investigated the effects of a VGLUT inhibitor, Chicago Sky Blue 6B (CSB6B), on pain behavior, c-Fos expression, and depolarization-evoked glutamate release in SNI mice. Our results showed a significant elevation of VGLUT2 expression up to postoperative day 1 in the thalamus, periaqueductal gray, and amygdala, followed by a return to control levels. Consistent with the changes in VGLUT2 expression, SNI enhanced depolarization-induced glutamate release from thalamic synaptosomes, while CSB6B treatment produced a concentration-dependent inhibition of glutamate release. Moreover, intracerebroventricular administration of CSB6B, at a dose that did not affect motor function, attenuated mechanical allodynia and c-Fos up-regulation in pain-related brain areas during the early stages of neuropathic pain development. These results demonstrate that changes in the expression of supraspinal VGLUT2 may be a new mechanism relevant to the induction of neuropathic pain after nerve injury that acts through an aggravation of glutamate imbalance.
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34
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Atoji Y. Expression of ionotropic glutamate receptors, AMPA, kainite and NMDA, in the pigeon retina. Exp Eye Res 2015; 136:72-7. [DOI: 10.1016/j.exer.2015.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/22/2015] [Accepted: 05/12/2015] [Indexed: 11/30/2022]
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35
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Hackett JT, Ueda T. Glutamate Release. Neurochem Res 2015; 40:2443-60. [PMID: 26012367 DOI: 10.1007/s11064-015-1622-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 05/17/2015] [Accepted: 05/20/2015] [Indexed: 12/18/2022]
Abstract
Our aim was to review the processes of glutamate release from both biochemical and neurophysiological points of view. A large body of evidence now indicates that glutamate is specifically accumulated into synaptic vesicles, which provides strong support for the concept that glutamate is released from synaptic vesicles and is the major excitatory neurotransmitter. Evidence suggests the notion that synaptic vesicles, in order to sustain the neurotransmitter pool of glutamate, are endowed with an efficient mechanism for vesicular filling of glutamate. Glutamate-loaded vesicles undergo removal of Synapsin I by CaM kinase II-mediated phosphorylation, transforming to the release-ready pool. Vesicle docking to and fusion with the presynaptic plasma membrane are thought to be mediated by the SNARE complex. The Ca(2+)-dependent step in exocytosis is proposed to be mediated by synaptotagmin.
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Affiliation(s)
- John T Hackett
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, 22908-0736, USA
| | - Tetsufumi Ueda
- Molecular and Behavioral Neuroscience Institute, The University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA. .,Department of Pharmacology, Medical School, The University of Michigan, Ann Arbor, MI, 48109, USA. .,Department of Psychiatry, Medical School, The University of Michigan, Ann Arbor, MI, 48109, USA.
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36
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Vigneault É, Poirel O, Riad M, Prud'homme J, Dumas S, Turecki G, Fasano C, Mechawar N, El Mestikawy S. Distribution of vesicular glutamate transporters in the human brain. Front Neuroanat 2015; 9:23. [PMID: 25798091 PMCID: PMC4350397 DOI: 10.3389/fnana.2015.00023] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 02/12/2015] [Indexed: 11/19/2022] Open
Abstract
Glutamate is the major excitatory transmitter in the brain. Vesicular glutamate transporters (VGLUT1-3) are responsible for uploading glutamate into synaptic vesicles. VGLUT1 and VGLUT2 are considered as specific markers of canonical glutamatergic neurons, while VGLUT3 is found in neurons previously shown to use other neurotransmitters than glutamate. Although there exists a rich literature on the localization of these glutamatergic markers in the rodent brain, little is currently known about the distribution of VGLUT1-3 in the human brain. In the present study, using subtype specific probes and antisera, we examined the localization of the three vesicular glutamate transporters in the human brain by in situ hybridization, immunoautoradiography and immunohistochemistry. We found that the VGLUT1 transcript was highly expressed in the cerebral cortex, hippocampus and cerebellum, whereas VGLUT2 mRNA was mainly found in the thalamus and brainstem. VGLUT3 mRNA was localized in scarce neurons within the cerebral cortex, hippocampus, striatum and raphe nuclei. Following immunoautoradiographic labeling, intense VGLUT1- and VGLUT2-immunoreactivities were observed in all regions investigated (cerebral cortex, hippocampus, caudate-putamen, cerebellum, thalamus, amygdala, substantia nigra, raphe) while VGLUT3 was absent from the thalamus and cerebellum. This extensive mapping of VGLUT1-3 in human brain reveals distributions that correspond for the most part to those previously described in rodent brains.
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Affiliation(s)
- Érika Vigneault
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Odile Poirel
- Institut National de la Santé et de la Recherche Médicale, UMR-S 1130, Neuroscience Paris Seine Paris, France ; Centre National de la Recherche Scientifique UMR 8246, Neuroscience Paris Seine Paris, France ; Sorbonne University, Université Pierre et Marie Curie Paris 06, UM119, Neuroscience Paris Seine Paris, France
| | - Mustapha Riad
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Josée Prud'homme
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | | | - Gustavo Turecki
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Caroline Fasano
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Naguib Mechawar
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Salah El Mestikawy
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada ; Institut National de la Santé et de la Recherche Médicale, UMR-S 1130, Neuroscience Paris Seine Paris, France ; Centre National de la Recherche Scientifique UMR 8246, Neuroscience Paris Seine Paris, France ; Sorbonne University, Université Pierre et Marie Curie Paris 06, UM119, Neuroscience Paris Seine Paris, France
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37
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Karim MR, Atoji Y. Distribution of Vesicular Glutamate Transporter 2 and Ionotropic Glutamate Receptors in the Auditory Ganglion and Cochlear Nuclei of Pigeons (Columba livia). Anat Histol Embryol 2015; 45:73-80. [PMID: 25639143 DOI: 10.1111/ahe.12173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 01/11/2015] [Indexed: 10/24/2022]
Abstract
Glutamate is a principal excitatory neurotransmitter in the auditory system. Our previous studies revealed localization of glutamate receptor mRNAs in the pigeon cochlear nuclei, suggesting the existence of glutamatergic input from the auditory nerve to the brainstem. This study demonstrated localization of mRNAs for vesicular glutamate transporter 2 (vGluT2) and ionotropic glutamate receptors (AMPA, kainate and NMDA) in the auditory ganglion (AG) and cochlear nuclei (magnocellular, angular and laminar nuclei). VGluT2 mRNA was intensely expressed in AG and intensely or moderately in the cochlear nuclei. The AG and cochlear nuclei showed intense-to-moderate mRNA signals for GluA2, GluA3, GluA4, GluK4 and GluN1. These results suggest that the pigeon AG neurons receives glutamatergic input from hair cells and in turn projects to the magnocellular and angular nuclei. Glutamate may play a pivotal role in the excitatory synapse transmission in the peripheral auditory pathway of birds.
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Affiliation(s)
- M R Karim
- Department of Anatomy and Histology, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh.,Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu, 501-1193, Japan
| | - Y Atoji
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu, 501-1193, Japan
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38
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Preobraschenski J, Zander JF, Suzuki T, Ahnert-Hilger G, Jahn R. Vesicular Glutamate Transporters Use Flexible Anion and Cation Binding Sites for Efficient Accumulation of Neurotransmitter. Neuron 2014; 84:1287-301. [DOI: 10.1016/j.neuron.2014.11.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2014] [Indexed: 11/16/2022]
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39
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Atoji Y, Karim MR. Expression of vesicular glutamate transporter 3 mRNA in the brain and retina of the pigeon. J Chem Neuroanat 2014; 61-62:124-31. [DOI: 10.1016/j.jchemneu.2014.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 08/04/2014] [Accepted: 08/04/2014] [Indexed: 11/26/2022]
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40
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Zhou Y, Danbolt NC. Glutamate as a neurotransmitter in the healthy brain. J Neural Transm (Vienna) 2014; 121:799-817. [PMID: 24578174 PMCID: PMC4133642 DOI: 10.1007/s00702-014-1180-8] [Citation(s) in RCA: 529] [Impact Index Per Article: 52.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 02/11/2014] [Indexed: 12/13/2022]
Abstract
Glutamate is the most abundant free amino acid in the brain and is at the crossroad between multiple metabolic pathways. Considering this, it was a surprise to discover that glutamate has excitatory effects on nerve cells, and that it can excite cells to their death in a process now referred to as "excitotoxicity". This effect is due to glutamate receptors present on the surface of brain cells. Powerful uptake systems (glutamate transporters) prevent excessive activation of these receptors by continuously removing glutamate from the extracellular fluid in the brain. Further, the blood-brain barrier shields the brain from glutamate in the blood. The highest concentrations of glutamate are found in synaptic vesicles in nerve terminals from where it can be released by exocytosis. In fact, glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. It took, however, a long time to realize that. The present review provides a brief historical description, gives a short overview of glutamate as a transmitter in the healthy brain, and comments on the so-called glutamate-glutamine cycle. The glutamate transporters responsible for the glutamate removal are described in some detail.
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Affiliation(s)
- Y. Zhou
- The Neurotransporter Group, Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Blindern, P.O. Box 1105, 0317 Oslo, Norway
| | - N. C. Danbolt
- The Neurotransporter Group, Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Blindern, P.O. Box 1105, 0317 Oslo, Norway
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41
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Karim MR, Saito S, Atoji Y. Distribution of vesicular glutamate transporter 2 in auditory and song control brain regions in the adult zebra finch (Taeniopygia guttata). J Comp Neurol 2014; 522:2129-51. [DOI: 10.1002/cne.23522] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 12/05/2013] [Accepted: 12/06/2013] [Indexed: 12/20/2022]
Affiliation(s)
- Mohammad Rabiul Karim
- Department of Basic Veterinary Science; United Graduate School of Veterinary Sciences, Gifu University; Gifu 501-1193 Japan
- Department of Anatomy and Histology; Bangladesh Agricultural University; Mymensingh 2202 Bangladesh
| | - Shouichiro Saito
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences; Gifu University; Gifu 501-1193 Japan
| | - Yasuro Atoji
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences; Gifu University; Gifu 501-1193 Japan
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42
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Krzyżanowska W, Pomierny B, Filip M, Pera J. Glutamate transporters in brain ischemia: to modulate or not? Acta Pharmacol Sin 2014; 35:444-62. [PMID: 24681894 DOI: 10.1038/aps.2014.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 01/03/2014] [Indexed: 01/18/2023] Open
Abstract
In this review, we briefly describe glutamate (Glu) metabolism and its specific transports and receptors in the central nervous system (CNS). Thereafter, we focus on excitatory amino acid transporters, cystine/glutamate antiporters (system xc-) and vesicular glutamate transporters, specifically addressing their location and roles in CNS and the molecular mechanisms underlying the regulation of Glu transporters. We provide evidence from in vitro or in vivo studies concerning alterations in Glu transporter expression in response to hypoxia or ischemia, including limited human data that supports the role of Glu transporters in stroke patients. Moreover, the potential to induce brain tolerance to ischemia through modulation of the expression and/or activities of Glu transporters is also discussed. Finally we present strategies involving the application of ischemic preconditioning and pharmacological agents, eg β-lactam antibiotics, amitriptyline, riluzole and N-acetylcysteine, which result in the significant protection of nervous tissues against ischemia.
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43
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Atoji Y, Karim MR. Glutamatergic thalamopallial projections in the pigeon identified by retrograde labeling and expression of vGluT2 mRNA. Neurosci Res 2014; 84:43-6. [PMID: 24657707 DOI: 10.1016/j.neures.2014.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 03/06/2014] [Accepted: 03/07/2014] [Indexed: 11/19/2022]
Abstract
A neocortical hypothesis as to homology of certain nuclear components of the avian brain proposes that the entopallium and field L2 are homologous to layer 4 of mammalian extrastriate and auditory neocortex, respectively. However, the hypothesis lacks support from the neurochemistry of thalamopallial projections. We investigated whether these projections are glutamatergic by injecting cholera toxin B into either the entopallium or field L2 in combination with in situ hybridization. Retrogradely labeled neurons in nucleus rotundus and nucleus ovoidalis were found to express vesicular glutamate transporter 2 mRNA, showing that the thalamopallial projections are glutamatergic. The results are consistent with the neocortical hypothesis.
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Affiliation(s)
- Yasuro Atoji
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan.
| | - Mohammad Rabiul Karim
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan; Department of Anatomy and Histology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh
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44
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Omote H, Moriyama Y. Vesicular neurotransmitter transporters: an approach for studying transporters with purified proteins. Physiology (Bethesda) 2014; 28:39-50. [PMID: 23280356 DOI: 10.1152/physiol.00033.2012] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vesicular storage and subsequent release of neurotransmitters are the key processes of chemical signal transmission. In this process, vesicular neurotransmitter transporters are responsible for loading the signaling molecules. The use of a "clean biochemical" approach with purified, recombinant transporters has helped in the identification of novel vesicular neurotransmitter transporters and in the analysis of the control of signal transmission.
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Affiliation(s)
- Hiroshi Omote
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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45
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Anne C, Gasnier B. Vesicular neurotransmitter transporters: mechanistic aspects. CURRENT TOPICS IN MEMBRANES 2014; 73:149-74. [PMID: 24745982 DOI: 10.1016/b978-0-12-800223-0.00003-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Secondary transporters driven by a V-type H⁺-ATPase accumulate nonpeptide neurotransmitters into synaptic vesicles. Distinct transporter families are involved depending on the neurotransmitter. Monoamines and acetylcholine on the one hand, and glutamate and ATP on the other hand, are accumulated by SLC18 and SLC17 transporters, respectively, which belong to the major facilitator superfamily (MFS). GABA and glycine accumulate through a common SLC32 transporter from the amino acid/polyamine/organocation (APC) superfamily. Although crystallographic structures are not yet available for any vesicular transporter, homology modeling studies of MFS-type vesicular transporters based on distantly related bacterial structures recently provided significant advances, such as the characterization of substrate-binding pockets or the identification of spatial clusters acting as hinge points during the alternating-access cycle. However, several basic issues, such as the ion stoichiometry of vesicular amino acid transporters, remain unsettled.
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Affiliation(s)
- Christine Anne
- Université Paris Descartes, Sorbonne Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8192, Centre Universitaire des Saints-Pères, Paris, France
| | - Bruno Gasnier
- Université Paris Descartes, Sorbonne Paris Cité, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8192, Centre Universitaire des Saints-Pères, Paris, France.
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Münster-Wandowski A, Gómez-Lira G, Gutiérrez R. Mixed neurotransmission in the hippocampal mossy fibers. Front Cell Neurosci 2013; 7:210. [PMID: 24319410 PMCID: PMC3837298 DOI: 10.3389/fncel.2013.00210] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 10/23/2013] [Indexed: 01/14/2023] Open
Abstract
The hippocampal mossy fibers (MFs), the axons of the granule cells (GCs) of the dentate gyrus, innervate mossy cells and interneurons in the hilus on their way to CA3 where they innervate interneurons and pyramidal cells. Synapses on each target cell have distinct anatomical and functional characteristics. In recent years, the paradigmatic view of the MF synapses being only glutamatergic and, thus, excitatory has been questioned. Several laboratories have provided data supporting the hypothesis that the MFs can transiently release GABA during development and, in the adult, after periods of enhanced excitability. This transient glutamate-GABA co-transmission coincides with the transient up-regulation of the machinery for the synthesis and release of GABA in the glutamatergic GCs. Although some investigators have deemed this evidence controversial, new data has appeared with direct evidence of co-release of glutamate and GABA from single, identified MF boutons. However, this must still be confirmed by other groups and with other methodologies. A second, intriguing observation is that MF activation produced fast spikelets followed by excitatory postsynaptic potentials in a number of pyramidal cells, which, unlike the spikelets, underwent frequency potentiation and were strongly depressed by activation of metabotropic glutamate receptors. The spikelets persisted during blockade of chemical transmission and were suppressed by the gap junction blocker carbenoxolone. These data are consistent with the hypothesis of mixed electrical-chemical synapses between MFs and some pyramidal cells. Dye coupling between these types of principal cells and ultrastructural studies showing the co-existence of AMPA receptors and connexin 36 in this synapse corroborate their presence. A deeper consideration of mixed neurotransmission taking place in this synapse may expand our search and understanding of communication channels between different regions of the mammalian CNS.
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VGLUTs in Peripheral Neurons and the Spinal Cord: Time for a Review. ISRN NEUROLOGY 2013; 2013:829753. [PMID: 24349795 PMCID: PMC3856137 DOI: 10.1155/2013/829753] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 08/25/2013] [Indexed: 02/07/2023]
Abstract
Vesicular glutamate transporters (VGLUTs) are key molecules for the incorporation of glutamate in synaptic vesicles across the nervous system, and since their discovery in the early 1990s, research on these transporters has been intense and productive. This review will focus on several aspects of VGLUTs research on neurons in the periphery and the spinal cord. Firstly, it will begin with a historical account on the evolution of the morphological analysis of glutamatergic systems and the pivotal role played by the discovery of VGLUTs. Secondly, and in order to provide an appropriate framework, there will be a synthetic description of the neuroanatomy and neurochemistry of peripheral neurons and the spinal cord. This will be followed by a succinct description of the current knowledge on the expression of VGLUTs in peripheral sensory and autonomic neurons and neurons in the spinal cord. Finally, this review will address the modulation of VGLUTs expression after nerve and tissue insult, their physiological relevance in relation to sensation, pain, and neuroprotection, and their potential pharmacological usefulness.
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Neale SA, Copeland CS, Salt TE. Effect of VGLUT inhibitors on glutamatergic synaptic transmission in the rodent hippocampus and prefrontal cortex. Neurochem Int 2013; 73:159-65. [PMID: 24121008 DOI: 10.1016/j.neuint.2013.10.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/30/2013] [Accepted: 10/02/2013] [Indexed: 01/23/2023]
Abstract
Vesicular glutamate transporters (VGLUTs) are known to be important in the uptake of glutamate into vesicles in the presynaptic terminal; thereby playing a role in synaptic function. VGLUT dysfunction has also been suggested in neurological and psychiatric disorders such as epilepsy and schizophrenia. A number of compounds have been identified as VGLUT inhibitors; however, little is known as to how these compounds affect synaptic transmission. We therefore investigated the effects of structurally unrelated VGLUT inhibitors on synaptic transmission in the rodent hippocampus and prefrontal cortex. In the CA1 and dentate gyrus regions of the in vitro slice preparation of mouse hippocampus, AMPA receptor-mediated field excitatory postsynaptic potentials (fEPSPs) were evoked in response to Schaffer collateral/commissural pathway stimulation. Application of the VGLUT inhibitors Rose Bengal (RB), Congo Red (CR) or Chicago Sky Blue 6B (CB) resulted in a concentration-related reduction of fEPSP amplitudes. RB (30μM) or CB (300μM) also depressed NMDA receptor-mediated responses in the CA1 region. The naturally occurring kynurenine Xanthurenic Acid (XA) is reported to be a VGLUT inhibitor. We found XA attenuated both AMPA and NMDA receptor-mediated synaptic transmission. The potency order of the VGLUT inhibitors was consistent with literature Ki values for VGLUT inhibition. Impaired glutamatergic neurotransmission is believed to contribute to schizophrenia, and VGLUTs have also been implicated in this disease. We therefore investigated the effect of VGLUT inhibition in the prefrontal cortex. Application of the VGLUT inhibitors RB or CB resulted in a concentration-dependent reduction in the amplitude of glutamate receptor-mediated fEPSPs recorded in layer V/VI in response to stimulation in the forceps minor. We conclude that VGLUT inhibitors can modulate glutamatergic synaptic transmission in the PFC and hippocampus. This could be important in the pathophysiology of nervous system disorders and might represent a target for developing novel pharmacological therapies.
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Affiliation(s)
- S A Neale
- Neurexpert Ltd., Kemp House, London EC1V 2NX, UK; UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - C S Copeland
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - T E Salt
- UCL Institute of Ophthalmology, London EC1V 9EL, UK.
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Malet M, Vieytes CA, Lundgren KH, Seal RP, Tomasella E, Seroogy KB, Hökfelt T, Gebhart GF, Brumovsky PR. Transcript expression of vesicular glutamate transporters in lumbar dorsal root ganglia and the spinal cord of mice - effects of peripheral axotomy or hindpaw inflammation. Neuroscience 2013; 248:95-111. [PMID: 23727452 PMCID: PMC3800240 DOI: 10.1016/j.neuroscience.2013.05.044] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 05/22/2013] [Accepted: 05/22/2013] [Indexed: 11/30/2022]
Abstract
Using specific riboprobes, we characterized the expression of vesicular glutamate transporter (VGLUT)₁-VGLUT₃ transcripts in lumbar 4-5 (L4-5) dorsal root ganglions (DRGs) and the thoracolumbar to lumbosacral spinal cord in male BALB/c mice after a 1- or 3-day hindpaw inflammation, or a 7-day sciatic nerve axotomy. Sham animals were also included. In sham and contralateral L4-5 DRGs of injured mice, VGLUT₁-, VGLUT₂- and VGLUT₃ mRNAs were expressed in ∼45%, ∼69% or ∼17% of neuron profiles (NPs), respectively. VGLUT₁ was expressed in large and medium-sized NPs, VGLUT₂ in NPs of all sizes, and VGLUT₃ in small and medium-sized NPs. In the spinal cord, VGLUT₁ was restricted to a number of NPs at thoracolumbar and lumbar segments, in what appears to be the dorsal nucleus of Clarke, and in mid laminae III-IV. In contrast, VGLUT₂ was present in numerous NPs at all analyzed spinal segments, except the lateral aspects of the ventral horns, especially at the lumbar enlargement, where it was virtually absent. VGLUT₃ was detected in a discrete number of NPs in laminae III-IV of the dorsal horn. Axotomy resulted in a moderate decrease in the number of DRG NPs expressing VGLUT₃, whereas VGLUT₁ and VGLUT₂ were unaffected. Likewise, the percentage of NPs expressing VGLUT transcripts remained unaltered after hindpaw inflammation, both in DRGs and the spinal cord. Altogether, these results confirm previous descriptions on VGLUTs expression in adult mice DRGs, with the exception of VGLUT₁, whose protein expression was detected in a lower percentage of mouse DRG NPs. A detailed account on the location of neurons expressing VGLUTs transcripts in the adult mouse spinal cord is also presented. Finally, the lack of change in the number of neurons expressing VGLUT₁ and VGLUT₂ transcripts after axotomy, as compared to data on protein expression, suggests translational rather than transcriptional regulation of VGLUTs after injury.
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Affiliation(s)
- M Malet
- Faculty of Biomedical Sciences, Austral University, Buenos Aires, Argentina; CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina
| | - C A Vieytes
- Faculty of Biomedical Sciences, Austral University, Buenos Aires, Argentina
| | - K H Lundgren
- Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
| | - R P Seal
- Pittsburgh Center for Pain Research, Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - E Tomasella
- Faculty of Biomedical Sciences, Austral University, Buenos Aires, Argentina; CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina
| | - K B Seroogy
- Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
| | - T Hökfelt
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - G F Gebhart
- Pittsburgh Center for Pain Research, Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - P R Brumovsky
- Faculty of Biomedical Sciences, Austral University, Buenos Aires, Argentina; CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina; Pittsburgh Center for Pain Research, Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA.
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Reimer RJ. SLC17: a functionally diverse family of organic anion transporters. Mol Aspects Med 2013; 34:350-9. [PMID: 23506876 DOI: 10.1016/j.mam.2012.05.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 03/29/2012] [Indexed: 11/28/2022]
Abstract
Molecular studies have determined that the SLC17 transporters, a family of nine proteins initially implicated in phosphate transport, mediate the transport of organic anions. While their role in phosphate transport remains uncertain, it is now clear that the transport of organic anions facilitated by this family of proteins is involved in diverse processes ranging from the vesicular storage of the neurotransmitters, to urate metabolism, to the degradation and metabolism of glycoproteins.
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Affiliation(s)
- Richard J Reimer
- Neurogenetics Division Department of Neurology and Neurological Sciences, Stanford University School of Medicine, P211 MSLS, 1201 Welch Road, Stanford, CA 94305, USA.
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