1
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Żakowski W, Zawistowski P. Neurochemistry of the mammillary body. Brain Struct Funct 2023; 228:1379-1398. [PMID: 37378855 PMCID: PMC10335970 DOI: 10.1007/s00429-023-02673-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 06/19/2023] [Indexed: 06/29/2023]
Abstract
The mammillary body (MB) is a component of the extended hippocampal system and many studies have shown that its functions are vital for mnemonic processes. Together with other subcortical structures, such as the anterior thalamic nuclei and tegmental nuclei of Gudden, the MB plays a crucial role in the processing of spatial and working memory, as well as navigation in rats. The aim of this paper is to review the distribution of various substances in the MB of the rat, with a description of their possible physiological roles. The following groups of substances are reviewed: (1) classical neurotransmitters (glutamate and other excitatory transmitters, gamma-aminobutyric acid, acetylcholine, serotonin, and dopamine), (2) neuropeptides (enkephalins, substance P, cocaine- and amphetamine-regulated transcript, neurotensin, neuropeptide Y, somatostatin, orexins, and galanin), and (3) other substances (calcium-binding proteins and calcium sensor proteins). This detailed description of the chemical parcellation may facilitate a better understanding of the MB functions and its complex relations with other structures of the extended hippocampal system.
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Affiliation(s)
- Witold Żakowski
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland.
| | - Piotr Zawistowski
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland
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2
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Cervetto C, Pistollato F, Amato S, Mendoza-de Gyves E, Bal-Price A, Maura G, Marcoli M. Assessment of neurotransmitter release in human iPSC-derived neuronal/glial cells: a missing in vitro assay for regulatory developmental neurotoxicity testing. Reprod Toxicol 2023; 117:108358. [PMID: 36863571 PMCID: PMC10112275 DOI: 10.1016/j.reprotox.2023.108358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/04/2023]
Abstract
Human induced pluripotent stem cell (hiPSC)-derived neural stem cells (NSCs) and their differentiated neuronal/glial derivatives have been recently considered suitable to assess in vitro developmental neurotoxicity (DNT) triggered by exposure to environmental chemicals. The use of human-relevant test systems combined with in vitro assays specific for different neurodevelopmental events, enables a mechanistic understanding of the possible impact of environmental chemicals on the developing brain, avoiding extrapolation uncertainties associated with in vivo studies. Currently proposed in vitro battery for regulatory DNT testing accounts for several assays suitable to study key neurodevelopmental processes, including NSC proliferation and apoptosis, differentiation into neurons and glia, neuronal migration, synaptogenesis, and neuronal network formation. However, assays suitable to measure interference of compounds with neurotransmitter release or clearance are at present not included, which represents a clear gap of the biological applicability domain of such a testing battery. Here we applied a HPLC-based methodology to measure the release of neurotransmitters in a previously characterized hiPSC-derived NSC model undergoing differentiation towards neurons and glia. Glutamate release was assessed in control cultures and upon depolarization, as well as in cultures repeatedly exposed to some known neurotoxicants (BDE47 and lead) and chemical mixtures. Obtained data indicate that these cells have the ability to release glutamate in a vesicular manner, and that both glutamate clearance and vesicular release concur in the maintenance of extracellular glutamate levels. In conclusion, analysis of neurotransmitter release is a sensitive readout that should be included in the envisioned battery of in vitro assays for DNT testing.
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Affiliation(s)
- Chiara Cervetto
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy; Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research, Centro 3R, Pisa, Italy.
| | | | - Sarah Amato
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy
| | | | - Anna Bal-Price
- European Commission, Joint Research Centre, JRC, Ispra, Italy.
| | - Guido Maura
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy
| | - Manuela Marcoli
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Italy; Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research, Centro 3R, Pisa, Italy.
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3
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Baldassari S, Cervetto C, Amato S, Fruscione F, Balagura G, Pelassa S, Musante I, Iacomino M, Traverso M, Corradi A, Scudieri P, Maura G, Marcoli M, Zara F. Vesicular Glutamate Release from Feeder-FreehiPSC-Derived Neurons. Int J Mol Sci 2022; 23:ijms231810545. [PMID: 36142455 PMCID: PMC9501332 DOI: 10.3390/ijms231810545] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/02/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
Human-induced pluripotent stem cells (hiPSCs) represent one of the main and powerful tools for the in vitro modeling of neurological diseases. Standard hiPSC-based protocols make use of animal-derived feeder systems to better support the neuronal differentiation process. Despite their efficiency, such protocols may not be appropriate to dissect neuronal specific properties or to avoid interspecies contaminations, hindering their future translation into clinical and drug discovery approaches. In this work, we focused on the optimization of a reproducible protocol in feeder-free conditions able to generate functional glutamatergic neurons. This protocol is based on a generation of neuroprecursor cells differentiated into human neurons with the administration in the culture medium of specific neurotrophins in a Geltrex-coated substrate. We confirmed the efficiency of this protocol through molecular analysis (upregulation of neuronal markers and neurotransmitter receptors assessed by gene expression profiling and expression of the neuronal markers at the protein level), morphological analysis, and immunfluorescence detection of pre-synaptic and post-synaptic markers at synaptic boutons. The hiPSC-derived neurons acquired Ca2+-dependent glutamate release properties as a hallmark of neuronal maturation. In conclusion, our study describes a new methodological approach to achieve feeder-free neuronal differentiation from hiPSC and adds a new tool for functional characterization of hiPSC-derived neurons.
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Affiliation(s)
- Simona Baldassari
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Via G. Gaslini 5, 16147 Genova, Italy
| | - Chiara Cervetto
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
- Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research (Centro 3R), 56100 Pisa, Italy
- Correspondence: (C.C.); (M.M.)
| | - Sarah Amato
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
| | - Floriana Fruscione
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Via G. Gaslini 5, 16147 Genova, Italy
| | - Ganna Balagura
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Via G. Gaslini 5, 16147 Genova, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Largo Paolo Daneo 3, 16132 Genova, Italy
| | - Simone Pelassa
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
| | - Ilaria Musante
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Largo Paolo Daneo 3, 16132 Genova, Italy
| | - Michele Iacomino
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Via G. Gaslini 5, 16147 Genova, Italy
| | - Monica Traverso
- Paediatric Neurology and Neuromuscular Disorders Unit, IRCCS Istituto Giannina Gaslini, Via G. Gaslini 5, 16147 Genova, Italy
| | - Anna Corradi
- Department of Experimental Medicine, University of Genoa, Viale Benedetto XV 3, 16132 Genova, Italy
- IRCCS Ospedale Policlinico San Martino Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Paolo Scudieri
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Via G. Gaslini 5, 16147 Genova, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Largo Paolo Daneo 3, 16132 Genova, Italy
| | - Guido Maura
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
| | - Manuela Marcoli
- Department of Pharmacy (DIFAR), Section of Pharmacology and Toxicology, University of Genoa, Viale Cembrano 4, 16148 Genova, Italy
- Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research (Centro 3R), 56100 Pisa, Italy
- Center of Excellence for Biomedical Research, Viale Benedetto XV, 16132 Genova, Italy
- Correspondence: (C.C.); (M.M.)
| | - Federico Zara
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Via G. Gaslini 5, 16147 Genova, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Largo Paolo Daneo 3, 16132 Genova, Italy
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Ormel L, Lauritzen KH, Schreiber R, Kunzelmann K, Gundersen V. GABA, but Not Bestrophin-1, Is Localized in Astroglial Processes in the Mouse Hippocampus and the Cerebellum. Front Mol Neurosci 2020; 13:135. [PMID: 32848599 PMCID: PMC7399226 DOI: 10.3389/fnmol.2020.00135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 07/07/2020] [Indexed: 11/13/2022] Open
Abstract
GABA is proposed to act as a gliotransmitter in the brain. Differences in GABA release from astroglia are thought to underlie differences in tonic inhibition between the cerebellum and the CA1 hippocampus. Here we used quantitative immunogold cytochemistry to localize and compare the levels of GABA in astroglia in these brain regions. We found that the density of GABA immunogold particles was similar in delicate processes of Bergman glia in the cerebellum and astrocytes in the CA1 hippocampus. The astrocytic GABA release is proposed to be mediated by, among others, the Ca2+ activated Cl- channel bestrophin-1. The bestrophin-1 antibodies did not show any significant bestrophin-1 signal in the brain of wt mice, nor in bestrophin-1 knockout mice. The bestrophin-1 signal was low both on Western blots and immunofluorescence laser scanning microscopic images. These results suggest that GABA is localized in astroglia, but in similar concentrations in the cerebellum and CA1 hippocampus, and thus cannot account for differences in tonic inhibition between these brain regions. Furthermore, our data seem to suggest that the GABA release from astroglia previously observed in the hippocampus and cerebellum occurs via mechanisms other than bestrophin-1.
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Affiliation(s)
- Lasse Ormel
- Section of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Ullevål, Oslo, Norway
| | - Knut H Lauritzen
- Section of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Rainer Schreiber
- Department of Physiology, University of Regensburg, Regensburg, Germany
| | - Karl Kunzelmann
- Department of Physiology, University of Regensburg, Regensburg, Germany
| | - Vidar Gundersen
- Section of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Section for Movement Disorders, Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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5
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Qureshi T, Bjørkmo M, Nordengen K, Gundersen V, Utheim TP, Watne LO, Storm-Mathisen J, Hassel B, Chaudhry FA. Slc38a1 Conveys Astroglia-Derived Glutamine into GABAergic Interneurons for Neurotransmitter GABA Synthesis. Cells 2020; 9:E1686. [PMID: 32668809 PMCID: PMC7407890 DOI: 10.3390/cells9071686] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 12/17/2022] Open
Abstract
GABA signaling is involved in a wide range of neuronal functions, such as synchronization of action potential firing, synaptic plasticity and neuronal development. Sustained GABA signaling requires efficient mechanisms for the replenishment of the neurotransmitter pool of GABA. The prevailing theory is that exocytotically released GABA may be transported into perisynaptic astroglia and converted to glutamine, which is then shuttled back to the neurons for resynthesis of GABA-i.e., the glutamate/GABA-glutamine (GGG) cycle. However, an unequivocal demonstration of astroglia-to-nerve terminal transport of glutamine and the contribution of astroglia-derived glutamine to neurotransmitter GABA synthesis is lacking. By genetic inactivation of the amino acid transporter Solute carrier 38 member a1 (Slc38a1)-which is enriched on parvalbumin+ GABAergic neurons-and by intraperitoneal injection of radiolabeled acetate (which is metabolized to glutamine in astroglial cells), we show that Slc38a1 mediates import of astroglia-derived glutamine into GABAergic neurons for synthesis of GABA. In brain slices, we demonstrate the role of Slc38a1 for the uptake of glutamine specifically into GABAergic nerve terminals for the synthesis of GABA depending on demand and glutamine supply. Thus, while leaving room for other pathways, our study demonstrates a key role of Slc38a1 for newly formed GABA, in harmony with the existence of a GGG cycle.
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Affiliation(s)
- Tayyaba Qureshi
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway; (T.Q.); (M.B.); (K.N.); (V.G.); (J.S.-M.)
| | - Mona Bjørkmo
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway; (T.Q.); (M.B.); (K.N.); (V.G.); (J.S.-M.)
| | - Kaja Nordengen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway; (T.Q.); (M.B.); (K.N.); (V.G.); (J.S.-M.)
| | - Vidar Gundersen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway; (T.Q.); (M.B.); (K.N.); (V.G.); (J.S.-M.)
| | - Tor Paaske Utheim
- Department of Plastic and Reconstructive Surgery, Oslo University Hospital, 0424 Oslo, Norway;
| | - Leiv Otto Watne
- Department of Geriatric Medicine, Oslo University Hospital, 0424 Oslo, Norway;
| | - Jon Storm-Mathisen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway; (T.Q.); (M.B.); (K.N.); (V.G.); (J.S.-M.)
| | - Bjørnar Hassel
- Department of Neurohabilitation, Oslo University Hospital and University of Oslo, 0424 Oslo, Norway;
| | - Farrukh Abbas Chaudhry
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway; (T.Q.); (M.B.); (K.N.); (V.G.); (J.S.-M.)
- Department of Plastic and Reconstructive Surgery, Oslo University Hospital, 0424 Oslo, Norway;
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6
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Wen W, Chen H, Fu K, Wei J, Qin L, Pan T, Xu S. Fructus Viticis methanolic extract attenuates trigeminal hyperalgesia in migraine by regulating injury signal transmission. Exp Ther Med 2019; 19:85-94. [PMID: 31853276 PMCID: PMC6909769 DOI: 10.3892/etm.2019.8201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 10/07/2019] [Indexed: 11/14/2022] Open
Abstract
Migraine, characterized by hyperalgesia of the trigeminovascular system, is a severe condition that leads to severe reductions in the quality of life. Upon external stimulation, the levels of various neurotransmitters, including aspartic acid (Asp), glutamic acid (Glu), γ-amino butyric acid (GABA), norepinephrine (NE) and 5-hydroxytryptamine (5-HT), are significantly altered; this directly or indirectly promotes trigeminal hypersensitivity. Fructus Viticis is a Traditional Chinese Medicine with analgesic properties to provide efficient relief of migraine. In the present study, the underlying mechanisms of the analgesic effect of Fructus Viticis methanolic extract were assessed in rats with nitroglycerin-induced migraine. The plasma levels of the neurotransmitters calcitonin gene-related peptide (CGRP) and substance P (SP), as well as the amount of c-fos immunoreactive cells (c-fos IR cells) in the brain, were detected. The analgesic effect was obvious, as Fructus Viticis methanolic extract ameliorated migraine-like behaviours in nitroglycerin-induced rats. The levels of 5-HT, GABA and NE in the brain of migraine model rats was lower compared with that of control rats, whereas opposite observations were made in the contents of excitatory amino acids. Pre-treatment with Fructus Viticis methanolic extract elevated the levels of 5-HT, GABA and NE, and also lowered the levels of excitatory amino acids, including Glu and Asp. In addition, treatment with Fructus Viticis methanolic extract lowered the plasma levels of CGRP and SP and decreased the c-fos IR cells in the brainstem. The present study provided a further scientific basis for the anti-migraine effects of Fructus Viticis.
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Affiliation(s)
- Wen Wen
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China.,Institute of Materia Medica Integration and Transformation for Brain Disorders, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Huan Chen
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China.,Institute of Materia Medica Integration and Transformation for Brain Disorders, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Kun Fu
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China.,Department of Pharmacy, The Third People's Hospital of Chengdu, The Second Affiliated Chengdu Clinical College of Chongqing Medical University, Chengdu, Sichuan 610031, P.R. China
| | - Jiangping Wei
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China.,Institute of Materia Medica Integration and Transformation for Brain Disorders, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Lixia Qin
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China.,Institute of Materia Medica Integration and Transformation for Brain Disorders, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Ting Pan
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China.,Institute of Materia Medica Integration and Transformation for Brain Disorders, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Shijun Xu
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China.,Institute of Materia Medica Integration and Transformation for Brain Disorders, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
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7
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Dopamine in the hippocampal dentate gyrus modulates spatial learning via D1-like receptors. Brain Res Bull 2019; 144:101-107. [DOI: 10.1016/j.brainresbull.2018.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 11/08/2018] [Accepted: 11/19/2018] [Indexed: 10/27/2022]
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8
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Orally Administered D-Aspartate Depresses Rectal Temperature and Alters Plasma Triacylglycerol and Glucose Concentrations in Broiler Chicks. J Poult Sci 2017; 54:205-211. [PMID: 32908427 PMCID: PMC7477212 DOI: 10.2141/jpsa.0160010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
L-Aspartate (L-Asp), D-aspartate (D-Asp) or their chemical conjugates plays important physiological roles in regulating food intake, plasma metabolites and thermoregulation in animals. However, there are very few studies available in layers and no reports have been found in broilers. Broilers are very important commercial birds for meat production, so effects of L- or D-Asp in broilers would provide new physiological insight of this strain. Therefore, the purpose of this study was to determine the effect of oral administration of L- or D-Asp on feed intake, rectal temperature and some plasma metabolites in broiler chicks. Broiler chicks (5 days old) were orally administered with different doses (0, 3.75, 7.5 and 15 mmol/kg body weight) of L- or D-Asp. At 120 min after administration of L- or D-Asp, the blood was immediately collected through the jugular vein. The rectal temperature of chicks was measured at 30, 60 and 120 min after administration using a digital thermometer with an accuracy of ±0.1°C, by inserting the thermistor probe in the rectum to a depth of 2 cm. A repeated-measures two-way ANOVA was applied for the analysis of feed intake and rectal temperature. Plasma metabolites were statistically analyzed by one-way ANOVA and regression equations. The study showed that oral administration of both L- and D-Asp did not alter feed intake. However, D-Asp, but not L-Asp, dose-dependently decreased the rectal temperature in chicks. It was also found that D-Asp increased plasma glucose and decreased triacylglycerol concentrations. The changes in plasma metabolites further indicate that D-Asp treatment modulates the energy metabolism in broiler chicks. In conclusion, D-Asp may be a beneficial nutrient not only for layers but also for broilers, since orally administered D-Asp lowered rectal temperature without reducing feed intake.
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9
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Enger R. Automated gold particle quantification of immunogold labeled micrographs. J Neurosci Methods 2017; 286:31-37. [PMID: 28527623 DOI: 10.1016/j.jneumeth.2017.05.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/10/2017] [Accepted: 05/13/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND Immunogold cytochemistry is the method of choice for precise localization of antigens on a subcellular scale. The process of immunogold quantification in electron micrographs is laborious, especially for proteins with a dense distribution pattern. NEW METHODS Here I present a MATLAB based toolbox that is optimized for a typical immunogold analysis workflow. It combines automatic detection of gold particles through a multi-threshold algorithm with manual segmentation of cell membranes and regions of interests. RESULTS The automated particle detection algorithm was applied to a typical immunogold dataset of neural tissue, and was able to detect particles with a high degree of precision. Without manual correction, the algorithm detected 97% of all gold particles, with merely a 0.1% false-positive rate. COMPARISONS WITH EXISTING METHOD(S) To my knowledge, this is the first free and publicly available software custom made for immunogold analyses. The proposed particle detection method compares favorably to previously published algorithms. CONCLUSIONS The software presented here will be valuable tool for researchers in neuroscience working with immunogold cytochemistry.
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Affiliation(s)
- Rune Enger
- Oslo University Hospital, Department of Neurology, N-0027 Oslo, Norway; Letten Centre and GliaLab, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway.
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10
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Żakowski W. Neurochemistry of the Anterior Thalamic Nuclei. Mol Neurobiol 2016; 54:5248-5263. [DOI: 10.1007/s12035-016-0077-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/23/2016] [Indexed: 01/19/2023]
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11
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A simple solution for antibody signal enhancement in immunofluorescence and triple immunogold assays. Histochem Cell Biol 2016; 146:421-30. [DOI: 10.1007/s00418-016-1447-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2016] [Indexed: 10/21/2022]
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12
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Lewerenz J, Maher P. Chronic Glutamate Toxicity in Neurodegenerative Diseases-What is the Evidence? Front Neurosci 2015; 9:469. [PMID: 26733784 PMCID: PMC4679930 DOI: 10.3389/fnins.2015.00469] [Citation(s) in RCA: 461] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/24/2015] [Indexed: 12/13/2022] Open
Abstract
Together with aspartate, glutamate is the major excitatory neurotransmitter in the brain. Glutamate binds and activates both ligand-gated ion channels (ionotropic glutamate receptors) and a class of G-protein coupled receptors (metabotropic glutamate receptors). Although the intracellular glutamate concentration in the brain is in the millimolar range, the extracellular glutamate concentration is kept in the low micromolar range by the action of excitatory amino acid transporters that import glutamate and aspartate into astrocytes and neurons. Excess extracellular glutamate may lead to excitotoxicity in vitro and in vivo in acute insults like ischemic stroke via the overactivation of ionotropic glutamate receptors. In addition, chronic excitotoxicity has been hypothesized to play a role in numerous neurodegenerative diseases including amyotrophic lateral sclerosis, Alzheimer's disease and Huntington's disease. Based on this hypothesis, a good deal of effort has been devoted to develop and test drugs that either inhibit glutamate receptors or decrease extracellular glutamate. In this review, we provide an overview of the different pathways that are thought to lead to an over-activation of the glutamatergic system and glutamate toxicity in neurodegeneration. In addition, we summarize the available experimental evidence for glutamate toxicity in animal models of neurodegenerative diseases.
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Affiliation(s)
- Jan Lewerenz
- Department of Neurology, Ulm UniversityUlm, Germany
| | - Pamela Maher
- Cellular Neurobiology Laboratory, Salk Institute for Biological StudiesLa Jolla, CA, USA
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13
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Frahm S, Antolin-Fontes B, Görlich A, Zander JF, Ahnert-Hilger G, Ibañez-Tallon I. An essential role of acetylcholine-glutamate synergy at habenular synapses in nicotine dependence. eLife 2015; 4:e11396. [PMID: 26623516 PMCID: PMC4718731 DOI: 10.7554/elife.11396] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/03/2015] [Indexed: 12/24/2022] Open
Abstract
A great deal of interest has been focused recently on the habenula and its critical role in aversion, negative-reward and drug dependence. Using a conditional mouse model of the ACh-synthesizing enzyme choline acetyltransferase (Chat), we report that local elimination of acetylcholine (ACh) in medial habenula (MHb) neurons alters glutamate corelease and presynaptic facilitation. Electron microscopy and immuno-isolation analyses revealed colocalization of ACh and glutamate vesicular transporters in synaptic vesicles (SVs) in the central IPN. Glutamate reuptake in SVs prepared from the IPN was increased by ACh, indicating vesicular synergy. Mice lacking CHAT in habenular neurons were insensitive to nicotine-conditioned reward and withdrawal. These data demonstrate that ACh controls the quantal size and release frequency of glutamate at habenular synapses, and suggest that the synergistic functions of ACh and glutamate may be generally important for modulation of cholinergic circuit function and behavior.
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Affiliation(s)
- Silke Frahm
- Molecular Neurobiology Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Beatriz Antolin-Fontes
- Molecular Neurobiology Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
- Laboratory of Molecular Biology, The Rockefeller University, New York, United States
| | - Andreas Görlich
- Laboratory of Molecular Biology, The Rockefeller University, New York, United States
| | | | - Gudrun Ahnert-Hilger
- Institute for Integrative Neuroanatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ines Ibañez-Tallon
- Molecular Neurobiology Group, Max Delbrück Center for Molecular Medicine, Berlin, Germany
- Laboratory of Molecular Biology, The Rockefeller University, New York, United States
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14
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Omote H, Miyaji T, Hiasa M, Juge N, Moriyama Y. Structure, Function, and Drug Interactions of Neurotransmitter Transporters in the Postgenomic Era. Annu Rev Pharmacol Toxicol 2015; 56:385-402. [PMID: 26514205 DOI: 10.1146/annurev-pharmtox-010814-124816] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vesicular neurotransmitter transporters are responsible for the accumulation of neurotransmitters in secretory vesicles and play essential roles in chemical transmission. The SLC17 family contributes to sequestration of anionic neurotransmitters such as glutamate, aspartate, and nucleotides. Identification and subsequent cellular and molecular biological studies of SLC17 transporters unveiled the principles underlying the actions of these transporters. Recent progress in reconstitution methods in combination with postgenomic approaches has advanced studies on neurotransmitter transporters. This review summarizes the molecular properties of SLC17-type transporters and recent findings regarding the novel SLC18 transporter.
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Affiliation(s)
- Hiroshi Omote
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, Japan; ,
| | - Takaaki Miyaji
- Advanced Science Research Center, Okayama University, Okayama 700-8530, Japan
| | - Miki Hiasa
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, Japan; ,
| | - Narinobu Juge
- Advanced Science Research Center, Okayama University, Okayama 700-8530, Japan
| | - Yoshinori Moriyama
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, Japan; , .,Advanced Science Research Center, Okayama University, Okayama 700-8530, Japan
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15
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Stensrud MJ, Sogn CJ, Gundersen V. Immunogold characteristics of VGLUT3-positive GABAergic nerve terminals suggest corelease of glutamate. J Comp Neurol 2015; 523:2698-713. [PMID: 26010578 DOI: 10.1002/cne.23811] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 05/18/2015] [Accepted: 05/18/2015] [Indexed: 12/20/2022]
Abstract
There is compelling evidence that glutamate can act as a cotransmitter in the mammalian brain. Interestingly, the third vesicular glutamate transporter (VGLUT3) is primarily found in neurons that were anticipated to be nonglutamatergic. Whereas the function of VGLUT3 in acetylcholinergic and serotoninergic neurons has been elucidated, the role of VGLUT3 in neurons releasing gamma-aminobutyric acid (GABA) is not settled. We have previously shown that VGLUT3 is found together with the vesicular GABA transporter (VIAAT) on synaptic vesicle membranes in the hippocampus. Now we provide novel electron microscopic data from the rat hippocampus suggesting that glutamate is enriched in inhibitory nerve terminals containing VGLUT3 compared to those lacking VGLUT3. The opposite was found for GABA; VGLUT3-positive inhibitory terminals contained lower density of GABA labeling compared to VGLUT3-negative inhibitory terminals. In addition, semiquantitative confocal immunofluorescence showed that N-methyl-D-aspartate (NMDA)-receptor labeling was present more frequently in VGLUT3-positive/VIAAT-positive synapses versus in VGLUT3-negative/VIAAT-positive synapses. Electron microscopic immunogold data further suggest that NMDA receptors are enriched in VGLUT3 containing inhibitory terminals. Our data reveal new chemical characteristics of a subset of GABAergic interneurons in the hippocampus. The analyses suggest that glutamate is coreleased with GABA from hippocampal basket cell-synapses to act on NMDA receptors.
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Affiliation(s)
- Mats Julius Stensrud
- Department of Anatomy and Healthy Brain Ageing Centre Regional Research Network, Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Carl Johan Sogn
- Department of Anatomy and Healthy Brain Ageing Centre Regional Research Network, Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Vidar Gundersen
- Department of Anatomy and Healthy Brain Ageing Centre Regional Research Network, Institute of Basic Medical Sciences, University of Oslo, Norway.,Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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16
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Oral administration of D-aspartate, but not L-aspartate, depresses rectal temperature and alters plasma metabolites in chicks. Life Sci 2014; 109:65-71. [PMID: 24881518 DOI: 10.1016/j.lfs.2014.05.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 05/14/2014] [Accepted: 05/19/2014] [Indexed: 11/22/2022]
Abstract
AIMS L-Aspartate (L-Asp) and D-aspartate (D-Asp) are physiologically important amino acids in mammals and birds. However, the functions of these amino acids have not yet been fully understood. In this study, we therefore examined the effects of L-Asp and D-Asp in terms of regulating body temperature, plasma metabolites and catecholamines in chicks. MAIN METHODS Chicks were first orally administered with different doses (0, 3.75, 7.5 and 15 mmol/kg body weight) of L- or D-Asp to monitor the effects of these amino acids on rectal temperature during 120 min of the experimental period. KEY FINDINGS Oral administration of D-Asp, but not of L-Asp, linearly decreased the rectal temperature in chicks. Importantly, orally administered D-Asp led to a significant reduction in body temperature in chicks even under high ambient temperature (HT) conditions. However, centrally administered D-Asp did not significantly influence the body temperature in chicks. As for plasma metabolites and catecholamines, orally administered D-Asp led to decreased triacylglycerol and uric acid concentrations and increased glucose and chlorine concentrations but did not alter plasma catecholamines. SIGNIFICANCE These results suggest that oral administration of D-Asp may play a potent role in reducing body temperature under both normal and HT conditions. The alteration of plasma metabolites further indicates that D-Asp may contribute to the regulation of metabolic activity in chicks.
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17
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Richards DS, Griffith RW, Romer SH, Alvarez FJ. Motor axon synapses on renshaw cells contain higher levels of aspartate than glutamate. PLoS One 2014; 9:e97240. [PMID: 24816812 PMCID: PMC4016288 DOI: 10.1371/journal.pone.0097240] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 04/16/2014] [Indexed: 12/17/2022] Open
Abstract
Motoneuron synapses on spinal cord interneurons known as Renshaw cells activate nicotinic, AMPA and NMDA receptors consistent with co-release of acetylcholine and excitatory amino acids (EAA). However, whether these synapses express vesicular glutamate transporters (VGLUTs) capable of accumulating glutamate into synaptic vesicles is controversial. An alternative possibility is that these synapses release other EAAs, like aspartate, not dependent on VGLUTs. To clarify the exact EAA concentrated at motor axon synapses we performed a quantitative postembedding colloidal gold immunoelectron analysis for aspartate and glutamate on motor axon synapses (identified by immunoreactivity to the vesicular acetylcholine transporter; VAChT) contacting calbindin-immunoreactive (-IR) Renshaw cell dendrites. The results show that 71% to 80% of motor axon synaptic boutons on Renshaw cells contained aspartate immunolabeling two standard deviations above average neuropil labeling. Moreover, VAChT-IR synapses on Renshaw cells contained, on average, aspartate immunolabeling at 2.5 to 2.8 times above the average neuropil level. In contrast, glutamate enrichment was lower; 21% to 44% of VAChT-IR synapses showed glutamate-IR two standard deviations above average neuropil labeling and average glutamate immunogold density was 1.7 to 2.0 times the neuropil level. The results were not influenced by antibody affinities because glutamate antibodies detected glutamate-enriched brain homogenates more efficiently than aspartate antibodies detecting aspartate-enriched brain homogenates. Furthermore, synaptic boutons with ultrastructural features of Type I excitatory synapses were always labeled by glutamate antibodies at higher density than motor axon synapses. We conclude that motor axon synapses co-express aspartate and glutamate, but aspartate is concentrated at higher levels than glutamate.
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Affiliation(s)
- Dannette S. Richards
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio, United States of America
| | - Ronald W. Griffith
- Department of Physiology, Emory University, Atlanta, Georgia, United States of America
| | - Shannon H. Romer
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio, United States of America
| | - Francisco J. Alvarez
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio, United States of America
- Department of Physiology, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
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18
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Villar-Cerviño V, Fernández-López B, Celina Rodicio M, Anadón R. Aspartate-containing neurons of the brainstem and rostral spinal cord of the sea lampreyPetromyzon marinus: Distribution and comparison with γ-aminobutyric acid. J Comp Neurol 2014; 522:1209-31. [DOI: 10.1002/cne.23493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 10/29/2013] [Accepted: 10/29/2013] [Indexed: 12/26/2022]
Affiliation(s)
- Verona Villar-Cerviño
- Departamento de Biología Celular y Ecología; Facultad de Biología, Universidad de Santiago de Compostela; Santiago de Compostela 15782 Spain
| | - Blanca Fernández-López
- Departamento de Biología Celular y Ecología; Facultad de Biología, Universidad de Santiago de Compostela; Santiago de Compostela 15782 Spain
| | - María Celina Rodicio
- Departamento de Biología Celular y Ecología; Facultad de Biología, Universidad de Santiago de Compostela; Santiago de Compostela 15782 Spain
| | - Ramón Anadón
- Departamento de Biología Celular y Ecología; Facultad de Biología, Universidad de Santiago de Compostela; Santiago de Compostela 15782 Spain
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19
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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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20
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Nordengen K, Heuser C, Rinholm JE, Matalon R, Gundersen V. Localisation of N-acetylaspartate in oligodendrocytes/myelin. Brain Struct Funct 2013; 220:899-917. [PMID: 24379086 DOI: 10.1007/s00429-013-0691-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 12/14/2013] [Indexed: 11/29/2022]
Abstract
The role of N-acetylaspartate in the brain is unclear. Here we used specific antibodies against N-acetylaspartate and immunocytochemistry of carbodiimide-fixed adult rodent brain to show that, besides staining of neuronal cell bodies in the grey matter, N-acetylaspartate labelling was present in oligodendrocytes/myelin in white matter tracts. Immunoelectron microscopy of the rat hippocampus showed that N-acetylaspartate was concentrated in the myelin. Also neuronal cell bodies and axons contained significant amounts of N-acetylaspartate, while synaptic elements and astrocytes were low in N-acetylaspartate. Mitochondria in axons and neuronal cell bodies contained higher levels of N-acetylaspartate compared to the cytosol, compatible with synthesis of N-acetylaspartate in mitochondria. In aspartoacylase knockout mice, in which catabolism of N-acetylaspartate is blocked, the levels of N-acetylaspartate were largely increased in oligodendrocytes/myelin. In these mice, the highest myelin concentration of N-acetylaspartate was found in the cerebellum, a region showing overt dysmyelination. In organotypic cortical slice cultures there was no evidence for N-acetylaspartate-induced myelin toxicity, supporting the notion that myelin damage is induced by the lack of N-acetylaspartate for lipid production. Our findings also implicate that N-acetylaspartate signals on magnetic resonance spectroscopy reflect not only vital neurons but also vital oligodendrocytes/myelin.
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Affiliation(s)
- Kaja Nordengen
- Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, PO Box 1105, 0317, Oslo, Norway
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21
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Organic cation transporter 2 (SLC22A2), a low-affinity and high-capacity choline transporter, is preferentially enriched on synaptic vesicles in cholinergic neurons. Neuroscience 2013; 252:212-21. [DOI: 10.1016/j.neuroscience.2013.08.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 08/07/2013] [Accepted: 08/07/2013] [Indexed: 01/11/2023]
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22
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Stensrud M, Chaudhry F, Leergaard T, Bjaalie J, Gundersen V. Vesicular glutamate transporter-3 in the rodent brain: Vesicular colocalization with vesicular γ-aminobutyric acid transporter. J Comp Neurol 2013; 521:3042-56. [DOI: 10.1002/cne.23331] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 03/08/2013] [Accepted: 03/13/2013] [Indexed: 01/12/2023]
Affiliation(s)
- M.J. Stensrud
- Department of Anatomy; Institute of Basic Medical Sciences, and Centre for Molecular Biology and Neuroscience (CMBN), University of Oslo; 0317 Oslo; Norway
| | - F.A. Chaudhry
- The Biotechnology Centre of Oslo and The Centre for Molecular Biology and Neuroscience (CMBN); University of Oslo; 0317 Oslo; Norway
| | - T.B. Leergaard
- Department of Anatomy; Institute of Basic Medical Sciences, and Centre for Molecular Biology and Neuroscience (CMBN), University of Oslo; 0317 Oslo; Norway
| | - J.G. Bjaalie
- Department of Anatomy; Institute of Basic Medical Sciences, and Centre for Molecular Biology and Neuroscience (CMBN), University of Oslo; 0317 Oslo; Norway
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23
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GABA is localized in dopaminergic synaptic vesicles in the rodent striatum. Brain Struct Funct 2013; 219:1901-12. [DOI: 10.1007/s00429-013-0609-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 07/03/2013] [Indexed: 11/24/2022]
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24
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Kletke O, Gisselmann G, May A, Hatt H, A. Sergeeva O. Partial agonism of taurine at gamma-containing native and recombinant GABAA receptors. PLoS One 2013; 8:e61733. [PMID: 23637894 PMCID: PMC3640040 DOI: 10.1371/journal.pone.0061733] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 03/13/2013] [Indexed: 11/18/2022] Open
Abstract
Taurine is a semi-essential sulfonic acid found at high concentrations in plasma and mammalian tissues which regulates osmolarity, ion channel activity and glucose homeostasis. The structural requirements of GABAA-receptors (GABAAR) gated by taurine are not yet known. We determined taurine potency and efficacy relative to GABA at different types of recombinant GABAAR occurring in central histaminergic neurons of the mouse hypothalamic tuberomamillary nucleus (TMN) which controls arousal. At binary α1/2β1/3 receptors taurine was as efficient as GABA, whereas incorporation of the γ1/2 subunit reduced taurine efficacy to 60–90% of GABA. The mutation γ2F77I, which abolishes zolpidem potentiation, significantly reduced taurine efficacy at recombinant and native receptors compared to the wild type controls. As taurine was a full- or super- agonist at recombinant αxβ1δ-GABAAR, we generated a chimeric γ2 subunit carrying the δ subunit motif around F77 (MTVFLH). At α1/2β1γ2(MTVFLH) receptors taurine became a super-agonist, similar to δ-containing ternary receptors, but remained a partial agonist at β3-containing receptors. In conclusion, using site-directed mutagenesis we found structural determinants of taurine’s partial agonism at γ-containing GABAA receptors. Our study sheds new light on the β1 subunit conferring the widest range of taurine-efficacies modifying GABAAR function under (patho)physiological conditions.
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Affiliation(s)
- Olaf Kletke
- Department of Cell Physiology of the Ruhr-University, Bochum, Germany
- Department of Neurophysiology, Medical Faculty of Heinrich-Heine University, Düsseldorf, Germany
| | | | - Andrea May
- Department of Neurophysiology, Medical Faculty of Heinrich-Heine University, Düsseldorf, Germany
| | - Hanns Hatt
- Department of Cell Physiology of the Ruhr-University, Bochum, Germany
| | - Olga A. Sergeeva
- Department of Neurophysiology, Medical Faculty of Heinrich-Heine University, Düsseldorf, Germany
- * E-mail:
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25
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Oral Administration of D-aspartate, but not of L-aspartate, Reduces Food Intake in Chicks. J Poult Sci 2013. [DOI: 10.2141/jpsa.0120116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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26
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Morland C, Nordengen K, Larsson M, Prolo LM, Farzampour Z, Reimer RJ, Gundersen V. Vesicular uptake and exocytosis of L-aspartate is independent of sialin. FASEB J 2012; 27:1264-74. [PMID: 23221336 DOI: 10.1096/fj.12-206300] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The mechanism of release and the role of l-aspartate as a central neurotransmitter are controversial. A vesicular release mechanism for l-aspartate has been difficult to prove, as no vesicular l-aspartate transporter was identified until it was found that sialin could transport l-aspartate and l-glutamate when reconstituted into liposomes. We sought to clarify the release mechanism of l-aspartate and the role of sialin in this process by combining l-aspartate uptake studies in isolated synaptic vesicles with immunocyotchemical investigations of hippocampal slices. We found that radiolabeled l-aspartate was taken up into synaptic vesicles. The vesicular l-aspartate uptake, relative to the l-glutamate uptake, was twice as high in the hippocampus as in the whole brain, the striatum, and the entorhinal and frontal cortices and was not inhibited by l-glutamate. We further show that sialin is not essential for exocytosis of l-aspartate, as there was no difference in ATP-dependent l-aspartate uptake in synaptic vesicles from sialin-knockout and wild-type mice. In addition, expression of sialin in PC12 cells did not result in significant vesicle uptake of l-aspartate, and depolarization-induced depletion of l-aspartate from hippocampal nerve terminals was similar in hippocampal slices from sialin-knockout and wild-type mice. Further, there was no evidence for nonvesicular release of l-aspartate via volume-regulated anion channels or plasma membrane excitatory amino acid transporters. This suggests that l-aspartate is exocytotically released from nerve terminals after vesicular accumulation by a transporter other than sialin.
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Affiliation(s)
- Cecilie Morland
- Department of Anatomy, University of Oslo, POB 1105 Blindern, 0317 Oslo, Norway
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27
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Hanics J, Bálint E, Milanovich D, Zachar G, Adám A, Csillag A. Amygdalofugal axon terminals immunoreactive for L-aspartate or L-glutamate in the nucleus accumbens of rats and domestic chickens: a comparative electron microscopic immunocytochemical study combined with anterograde pathway tracing. Cell Tissue Res 2012; 350:409-23. [PMID: 23064903 DOI: 10.1007/s00441-012-1494-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 08/22/2012] [Indexed: 01/26/2023]
Abstract
Several studies have shown that L-aspartate (Asp) is present in synaptic vesicles and released exocytotically from presynaptic terminals, possibly by Ca(2+)-dependent corelease of Asp and L-glutamate (Glu). It has been demonstrated that both excitatory amino acids (EAAs) are released from the rat striatum as part of corticostriatal neurotransmission. The single or colocalized occurrence of Asp and Glu in specific synaptic boutons of the chicken medial striatum/nucl. accumbens has been demonstrated by our group using ultrastructural immunocytochemistry. However, evidence for the presence of EAAs in any specific striatal pathway was only circumstantial. Here, we report on the distribution of Asp and Glu in specific synaptic terminals of the amygdalostriatal pathway, both in rat and chicken brains, combining anterograde tracing with postembedding immunogold labeling of Asp or Glu. Immunoreactivity for Asp and Glu was observed in amygdalofugal terminals with asymmetrical synaptic junctions (morphologically representing excitatory synapses) in both species. The postsynaptic targets were either dendritic spines or small dendrites, whereas axosomatic or axo-axonic connections were not observed. Ultrastructurally, the synaptic terminals immunoreactive for Asp were indistinguishable from those immunoreactive for Glu. The findigs are consistent with an Asp-Glu corelease mechanism, with a distinct synaptic contingent, evolutionarily conserved in the amygdalostriatal pathway.
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Affiliation(s)
- János Hanics
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
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28
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Morland C, Nordengen K, Gundersen V. Valproate causes reduction of the excitatory amino acid aspartate in nerve terminals. Neurosci Lett 2012; 527:100-4. [DOI: 10.1016/j.neulet.2012.08.042] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 08/10/2012] [Accepted: 08/23/2012] [Indexed: 10/28/2022]
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29
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Balázs D, Csillag A, Gerber G. l-aspartate effects on single neurons and interactions with glutamate in striatal slice preparation from chicken brain. Brain Res 2012; 1474:1-7. [DOI: 10.1016/j.brainres.2012.07.049] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 06/21/2012] [Accepted: 07/24/2012] [Indexed: 02/05/2023]
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30
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Reaux-Le Goazigo A, Rivat C, Kitabgi P, Pohl M, Melik Parsadaniantz S. Cellular and subcellular localization of CXCL12 and CXCR4 in rat nociceptive structures: physiological relevance. Eur J Neurosci 2012; 36:2619-31. [PMID: 22694179 DOI: 10.1111/j.1460-9568.2012.08179.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Initial studies implicated the chemokine CXC motif ligand 12 (CXCL12) and its cognate CXC motif receptor 4 (CXCR4) in pain modulation. However, there has been no description of the distribution, transport and axonal sorting of CXCL12 and CXCR4 in rat nociceptive structures, and their direct participation in nociception modulation has not been demonstrated. Here, we report that acute intrathecal administration of CXCL12 induced mechanical hypersensitivity in naive rats. This effect was prevented by a CXCR4-neutralizing antibody. To determine the morphological basis of this behavioural response, we used light and electron microscopic immunohistochemistry to map CXCL12- and CXCR4-immunoreactive elements in dorsal root ganglia, lumbar spinal cord, sciatic nerve and skin. Light microscopy analysis revealed CXCL12 and CXCR4 immunoreactivity in calcitonin gene related peptide-containing peptidergic primary sensory neurons, which were both conveyed to central and peripheral sensory nerve terminals. Electron microscopy clearly demonstrated CXCL12 and CXCR4 immunoreactivity in primary sensory nerve terminals in the dorsal horn; both were sorted into small clear vesicles and large dense-core vesicles. This suggests that CXCL12 and CXCR4 are trafficked from nerve cell bodies to the dorsal horn. Double immunogold labelling for CXCL12 and calcitonin gene related peptide revealed partial vesicular colocalization in axonal terminals. We report, for the first time, that CXCR4 receptors are mainly located on the neuronal plasma membrane, where they are present at pre-synaptic and post-synaptic sites of central terminals. Receptor inactivation experiments, behavioural studies and morphological analyses provide strong evidence that the CXCL12/CXCR4 system is involved in modulation of nociceptive signalling.
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Affiliation(s)
- Annabelle Reaux-Le Goazigo
- Centre de recherche de l'Institut Cerveau Moelle (CrICM), UMR S 975 INSERM-UMR 7225 CNRS-UPMC, Université Pierre et Marie Curie, Faculty of Medicine Pitié Salpêtrière, 91 Boulevard de l'Hôpital, 75013 Paris, France.
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31
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Zachar G, Wagner Z, Tábi T, Bálint E, Szökő É, Csillag A. Differential Changes of Extracellular Aspartate and Glutamate in the Striatum of Domestic Chicken Evoked by High Potassium or Distress: An In Vivo Microdialysis Study. Neurochem Res 2012; 37:1730-7. [DOI: 10.1007/s11064-012-0783-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 04/01/2012] [Accepted: 04/12/2012] [Indexed: 02/03/2023]
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32
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Skytt DM, Klawonn AM, Stridh MH, Pajęcka K, Patruss Y, Quintana-Cabrera R, Bolaños JP, Schousboe A, Waagepetersen HS. siRNA knock down of glutamate dehydrogenase in astrocytes affects glutamate metabolism leading to extensive accumulation of the neuroactive amino acids glutamate and aspartate. Neurochem Int 2012; 61:490-7. [PMID: 22542772 DOI: 10.1016/j.neuint.2012.04.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 04/02/2012] [Accepted: 04/11/2012] [Indexed: 11/27/2022]
Abstract
Glutamate is the most abundant excitatory neurotransmitter in the brain and astrocytes are key players in sustaining glutamate homeostasis. Astrocytes take up the predominant part of glutamate after neurotransmission and metabolism of glutamate is necessary for a continuous efficient removal of glutamate from the synaptic area. Glutamate may either be amidated by glutamine synthetase or oxidatively metabolized in the mitochondria, the latter being at least to some extent initiated by oxidative deamination by glutamate dehydrogenase (GDH). To explore the particular importance of GDH for astrocyte metabolism we have knocked down GDH in cultured cortical astrocytes employing small interfering RNA (siRNA) achieving a reduction of the enzyme activity by approximately 44%. The astrocytes were incubated for 2h in medium containing either 1.0mM [(15)NH(4)(+)] or 100 μM [(15)N]glutamate. For those exposed to [(15)N]glutamate an additional 100 μM was added after 1h. Metabolic mapping was performed from isotope incorporation measured by mass spectrometry into relevant amino acids of cell extracts and media. The contents of the amino acids were measured by HPLC. The (15)N incorporation from [(15)NH(4)(+)] into glutamate, aspartate and alanine was decreased in astrocytes exhibiting reduced GDH activity. However, the reduced GDH activity had no effect on the cellular contents of these amino acids. This supports existing in vivo and in vitro studies that GDH is predominantly working in the direction of oxidative deamination and not reductive amination. In contrast, when exposing the astrocytes to [(15)N]glutamate, the reduced GDH activity led to an increased (15)N incorporation into glutamate, aspartate and alanine and a large increase in the content of glutamate and aspartate. Surprisingly, this accumulation of glutamate and net-synthesis of aspartate were not reflected in any alterations in either the glutamine content or labeling, but a slight increase in mono labeling of glutamine in the medium. We suggest that this extensive net-synthesis of aspartate due to lack of GDH activity is occurring via the concerted action of AAT and the part of TCA cycle operating from α-ketoglutarate to oxaloacetate, i.e. the truncated TCA cycle.
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Affiliation(s)
- Dorte M Skytt
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
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Rosas-Arellano A, Machuca-Parra AI, Reyes-Haro D, Miledi R, Martínez-Torres A. Expression of GABAρ receptors in the neostriatum: localization in aspiny, medium spiny neurons and GFAP-positive cells. J Neurochem 2012; 122:900-10. [PMID: 22168837 DOI: 10.1111/j.1471-4159.2011.07621.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
GABAergic transmission in the neostriatum plays a central role in motor coordination, in which a plethora of GABA-A receptor subunits combine to modulate neural inhibition. GABAρ receptors were originally described in the mammalian retina. These receptors possess special electrophysiological and pharmacological properties, forming a characteristic class of ionotropic receptors. In previous studies, we suggested that GABAρ receptors are expressed in the neostriatum, and in this report we show that they are indeed present in all the calretinin-positive interneurons of the neostriatum. In addition, they are located in calbindin-positive interneurons and projection neurons that express the dopamine D(2) receptor. GABAρ receptors were also located in 30% of the glial fibrillary acidic protein-positive cells, and may therefore also contribute to gliotransmission. Quantitative reverse transcription-PCR suggested that the mRNAs of this receptor do not express as much as in the retina, and that GABAρ2 is more abundant than GABAρ1. Electrophysiological recordings in brain slices provided evidence of neurons expressing a cis-4-aminocrotonic acid-activated, 1,2,5,6-tetrahydropyridine-4-yl methylphosphinic acid-sensitive ionotropic GABA receptor, indicating the presence of functional GABAρ receptors in the neostriatum. Finally, electron-microscopy and immunogold located the receptors mainly in perisynaptic as well as in extrasynaptic sites. All these observations reinforce the importance of GABAρ receptors in the neostriatum and contribute to the diversity of inhibitory regulation in this area.
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Affiliation(s)
- Abraham Rosas-Arellano
- Departamento de Neurobiología Celular y Molecular, Universidad Nacional Autónoma de México, Instituto de Neurobiología, Campus Juriquilla, Querétaro, Mexico
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Abstract
Glutamine (Gln) is found abundantly in the central nervous system (CNS) where it participates in a variety of metabolic pathways. Its major role in the brain is that of a precursor of the neurotransmitter amino acids: the excitatory amino acids, glutamate (Glu) and aspartate (Asp), and the inhibitory amino acid, γ-amino butyric acid (GABA). The precursor-product relationship between Gln and Glu/GABA in the brain relates to the intercellular compartmentalization of the Gln/Glu(GABA) cycle (GGC). Gln is synthesized from Glu and ammonia in astrocytes, in a reaction catalyzed by Gln synthetase (GS), which, in the CNS, is almost exclusively located in astrocytes (Martinez-Hernandez et al., 1977). Newly synthesized Gln is transferred to neurons and hydrolyzed by phosphate-activated glutaminase (PAG) to give rise to Glu, a portion of which may be decarboxylated to GABA or transaminated to Asp. There is a rich body of evidence which indicates that a significant proportion of the Glu, Asp and GABA derived from Gln feed the synaptic, neurotransmitter pools of the amino acids. Depolarization-induced-, calcium- and PAG activity-dependent releases of Gln-derived Glu, GABA and Asp have been observed in CNS preparations in vitro and in the brain in situ. Immunocytochemical studies in brain slices have documented Gln transfer from astrocytes to neurons as well as the location of Gln-derived Glu, GABA and Asp in the synaptic terminals. Patch-clamp studies in brain slices and astrocyte/neuron co-cultures have provided functional evidence that uninterrupted Gln synthesis in astrocytes and its transport to neurons, as mediated by specific carriers, promotes glutamatergic and GABA-ergic transmission. Gln entry into the neuronal compartment is facilitated by its abundance in the extracellular spaces relative to other amino acids. Gln also appears to affect neurotransmission directly by interacting with the NMDA class of Glu receptors. Transmission may also be modulated by alterations in cell membrane polarity related to the electrogenic nature of Gln transport or to uncoupled ion conductances in the neuronal or glial cell membranes elicited by Gln transporters. In addition, Gln appears to modulate the synthesis of the gaseous messenger, nitric oxide (NO), by controlling the supply to the cells of its precursor, arginine. Disturbances of Gln metabolism and/or transport contribute to changes in Glu-ergic or GABA-ergic transmission associated with different pathological conditions of the brain, which are best recognized in epilepsy, hepatic encephalopathy and manganese encephalopathy.
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Ormel L, Stensrud MJ, Bergersen LH, Gundersen V. VGLUT1 is localized in astrocytic processes in several brain regions. Glia 2011; 60:229-38. [DOI: 10.1002/glia.21258] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 09/26/2011] [Indexed: 01/26/2023]
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Bergersen LH, Morland C, Ormel L, Rinholm JE, Larsson M, Wold JFH, Røe AT, Stranna A, Santello M, Bouvier D, Ottersen OP, Volterra A, Gundersen V. Immunogold detection of L-glutamate and D-serine in small synaptic-like microvesicles in adult hippocampal astrocytes. ACTA ACUST UNITED AC 2011; 22:1690-7. [PMID: 21914633 DOI: 10.1093/cercor/bhr254] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Glutamate and the N-methyl-D-aspartate receptor ligand D-serine are putative gliotransmitters. Here, we show by immunogold cytochemistry of the adult hippocampus that glutamate and D-serine accumulate in synaptic-like microvesicles (SLMVs) in the perisynaptic processes of astrocytes. The estimated concentration of fixed glutamate in the astrocytic SLMVs is comparable to that in synaptic vesicles of excitatory nerve terminals (≈ 45 and ≈ 55 mM, respectively), whereas the D-serine level is about 6 mM. The vesicles are organized in small spaced clusters located near the astrocytic plasma membrane. Endoplasmic reticulum is regularly found in close vicinity to SLMVs, suggesting that astrocytes contain functional nanodomains, where a local Ca(2+) increase can trigger release of glutamate and/or D-serine.
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Affiliation(s)
- L H Bergersen
- Department of Anatomy, Centre for Molecular Biology and Neuroscience, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway
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Miyaji T, Omote H, Moriyama Y. Functional characterization of vesicular excitatory amino acid transport by human sialin. J Neurochem 2011; 119:1-5. [PMID: 21781115 DOI: 10.1111/j.1471-4159.2011.07388.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sialin, the protein coded by SLC17A5, is responsible for membrane potential (Δψ)-driven aspartate and glutamate transport into synaptic vesicles in addition to H+/sialic acid co-transport in lysosomes. Rodent sialin mutants harboring the mutations associated with Salla disease in humans did not transport aspartate and glutamate whereas H+/sialic acid co-transport activity was about one-third of the wild-type protein. In this study, we investigate the effects of various mutations on the transport activities of human sialin. Proteoliposomes containing purified heterologously expressed human sialin exhibited both Δψ-driven aspartate and glutamate transport activity and H+/sialic acid co-transport activity. Aspartate and glutamate transport was not detected in the R39C and K136E mutant forms of SLC17A5 protein associated with Salla disease, whereas H+/sialic acid co-transport activity corresponded to 30-50% of the recombinant wild-type protein. In contrast, SLC17A5 protein harboring the mutations associated with infantile sialic acid storage disease, H183R and Δ268SSLRN272 still showed normal levels of Δψ-driven aspartate and glutamate transport even though H+/sialic acid co-transport activity was absent. Human sialin carrying the G328E mutation that causes both phenotypes, and P334R and G378V mutations that cause infantile sialic acid storage disease showed no transport activity. These results support the idea that people suffering from Salla disease have been defective in aspartergic and glutamatergic neurotransmissions.
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Affiliation(s)
- Takaaki Miyaji
- Advanced Science Research Center, Okayama University, Okayama, Japan.
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A role for glutamate transporters in the regulation of insulin secretion. PLoS One 2011; 6:e22960. [PMID: 21853059 PMCID: PMC3154915 DOI: 10.1371/journal.pone.0022960] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 07/02/2011] [Indexed: 11/19/2022] Open
Abstract
In the brain, glutamate is an extracellular transmitter that mediates cell-to-cell communication. Prior to synaptic release it is pumped into vesicles by vesicular glutamate transporters (VGLUTs). To inactivate glutamate receptor responses after release, glutamate is taken up into glial cells or neurons by excitatory amino acid transporters (EAATs). In the pancreatic islets of Langerhans, glutamate is proposed to act as an intracellular messenger, regulating insulin secretion from β-cells, but the mechanisms involved are unknown. By immunogold cytochemistry we show that insulin containing secretory granules express VGLUT3. Despite the fact that they have a VGLUT, the levels of glutamate in these granules are low, indicating the presence of a protein that can transport glutamate out of the granules. Surprisingly, in β-cells the glutamate transporter EAAT2 is located, not in the plasma membrane as it is in brain cells, but exclusively in insulin-containing secretory granules, together with VGLUT3. In EAAT2 knock out mice, the content of glutamate in secretory granules is higher than in wild type mice. These data imply a glutamate cycle in which glutamate is carried into the granules by VGLUT3 and carried out by EAAT2. Perturbing this cycle by knocking down EAAT2 expression with a small interfering RNA, or by over-expressing EAAT2 or a VGLUT in insulin granules, significantly reduced the rate of granule exocytosis. Simulations of granule energetics suggest that VGLUT3 and EAAT2 may regulate the pH and membrane potential of the granules and thereby regulate insulin secretion. These data suggest that insulin secretion from β-cells is modulated by the flux of glutamate through the secretory granules.
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Besson M, Sinakevitch I, Melon C, Iché-Torres M, Birman S. Involvement of the drosophila taurine/aspartate transporter dEAAT2 in selective olfactory and gustatory perceptions. J Comp Neurol 2011; 519:2734-57. [DOI: 10.1002/cne.22649] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Miyaji T, Omote H, Moriyama Y. A vesicular transporter that mediates aspartate and glutamate neurotransmission. Biol Pharm Bull 2011; 33:1783-5. [PMID: 21048299 DOI: 10.1248/bpb.33.1783] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aspartate, an excitatory amino acid, is known to be stored in synaptic vesicles and exocytosed from some neurons to perform aspartergic neurotransmission. Through in vitro reconstitution, we found that sialin, a lysosomal sialic acid exporter, is responsible for the vesicular storage of aspartate in hippocampal neurons and pinealocytes. Mutations found in Salla disease cause decreased aspartate transport activity without affecting sialic acid transport. Thus, sialin is a multifunctional transporter. It is possible that people with Salla disease lose the ability of aspartergic neurotransmission, and this could explain why Salla disease involves severe neurological defects.
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Affiliation(s)
- Takaaki Miyaji
- Department of Genomics and Proteomics, Advanced Science Research Center, Okayama University, Okayama 700–8530, Japan
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41
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Stutz B, Yamasaki EN, de Mello MCF, de Mello FG. Exchange of extracellular l-glutamate by intracellular d-aspartate: The main mechanism of d-aspartate release in the avian retina. Neurochem Int 2011; 58:767-75. [DOI: 10.1016/j.neuint.2011.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 01/18/2011] [Accepted: 03/02/2011] [Indexed: 10/18/2022]
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Zappettini S, Grilli M, Salamone A, Fedele E, Marchi M. Pre-synaptic nicotinic receptors evoke endogenous glutamate and aspartate release from hippocampal synaptosomes by way of distinct coupling mechanisms. Br J Pharmacol 2011; 161:1161-71. [PMID: 20633015 DOI: 10.1111/j.1476-5381.2010.00958.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The present work aimed to investigate whether and through which mechanisms selective α7 and α4β2 nicotinic receptor (nAChR) agonists stimulate endogenous glutamate (GLU) and aspartate (ASP) release in rat hippocampus. EXPERIMENTAL APPROACH Rat hippocampal synaptosomes were purified on Percoll gradients and superfused in vitro to study endogenous GLU and ASP release. The synaptosomes were superfused with selective α7 and α4β2 nAChR agonists and antagonists. The excitatory amino acid (EAA) content of the samples of superfusate was determined by HPLC after pre-column derivatization and separation on a chromatographic column coupled with fluorimetric detection. KEY RESULTS Choline (Ch), a selective α7 receptor agonist, elicited a significant release of both GLU and ASP which was blocked by the α7 receptor antagonist methyllycaconitine (MLA), but was unaltered by the α4β2 receptor antagonist dihydro-β-erythroidine (DHβE). The stimulant effect of Ch was strongly reduced in a Ca(2+) -free medium, was not inhibited by Cd(2+) and tetrodotoxin (TTX), but was antagonized by dantrolene, xestospongin C and thapsigargin. 5-Iodo-A-85380 dihydrochloride (5IA85380), a selective α4β2 receptor agonist, elicited EAA release in a DHβE-sensitive, MLA-insensitive fashion. The 5IA85380-evoked release was dependent on extracellular Ca(2+) , blocked by Cd(2+) and TTX, but unaffected by dantrolene. CONCLUSIONS AND IMPLICATIONS Our study shows for the first time that rat hippocampal synaptosomes possess α7 and α4β2 nAChR subtypes, which can enhance the release of endogenous GLU and ASP via two distinct mechanisms of action. These results extend our knowledge of the nicotinic modulation of excitatory synaptic transmission in the hippocampus.
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Affiliation(s)
- S Zappettini
- Department of Experimental Medicine, Section of Pharmacology and Toxicology Center of Excellence for Biomedical Research National Institute of Neuroscience, University of Genoa, Viale Cembrano 4, Genoa, Italy
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Osorio-Espinoza A, Alatorre A, Ramos-Jiménez J, Garduño-Torres B, García-Ramírez M, Querejeta E, Arias-Montaño JA. Pre-synaptic histamine H₃ receptors modulate glutamatergic transmission in rat globus pallidus. Neuroscience 2010; 176:20-31. [PMID: 21195747 DOI: 10.1016/j.neuroscience.2010.12.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 12/22/2010] [Accepted: 12/24/2010] [Indexed: 02/04/2023]
Abstract
The globus pallidus, a neuronal nucleus involved in the control of motor behavior, expresses high levels of histamine H(3) receptors (H(3)Rs) most likely located on the synaptic afferents to the nucleus. In this work we studied the effect of the activation of rat pallidal H(3)Rs on depolarization-evoked neurotransmitter release from slices, neuronal firing rate in vivo and turning behavior. Perfusion of globus pallidus slices with the selective H(3)R agonist immepip had no effect on the release of [(3)H]-GABA ([(3)H]-γ-aminobutyric acid) or [(3)H]-dopamine evoked by depolarization with high (20 mM) K(+), but significantly reduced [(3)H]-d-aspartate release (-44.8 ± 2.6% and -63.7 ± 6.2% at 30 and 100 nM, respectively). The effect of 30 nM immepip was blocked by 10 μM of the selective H(3)R antagonist A-331440 (4'-[3-[(3(R)-dimethylamino-1-pyrrolidinyl]propoxy]-[1,1-biphenyl]-4'-carbonitrile). Intra-pallidal injection of immepip (0.1 μl, 100 μM) decreased spontaneous neuronal firing rate in anaesthetized rats (peak inhibition 68.8±10.3%), and this effect was reversed in a partial and transitory manner by A-331440 (0.1 μl, 1 mM). In free-moving rats the infusion of immepip (0.5 μl; 10, 50 and 100 μM) into the globus pallidus induced dose-related ipsilateral turning following systemic apomorphine (0.5 mg/kg, s.c.). Turning behavior induced by immepip (0.5 μl, 50 μM) and apomorphine was partially prevented by the local injection of A-331440 (0.5 μl, 1 mM) and was not additive to the turning evoked by the intra-pallidal injection of antagonists at ionotropic glutamate receptors (0.5 μl, 1 mM each of AP-5, dl-2-amino-5-phosphonovaleric acid, and CNQX, 6-nitro-7-sulphamoylbenzo[f]quinoxaline-2,3-dione). These results indicate that pre-synaptic H(3)Rs modulate glutamatergic transmission in rat globus pallidus and thus participate in the control of movement by basal ganglia.
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Affiliation(s)
- A Osorio-Espinoza
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508, Zacatenco, 07360 México, D.F., México
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Cardoso S, Carvalho C, Santos R, Correia S, Santos MS, Seiça R, Oliveira CR, Moreira PI. Impact of STZ-induced hyperglycemia and insulin-induced hypoglycemia in plasma amino acids and cortical synaptosomal neurotransmitters. Synapse 2010; 65:457-66. [PMID: 20853444 DOI: 10.1002/syn.20863] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2010] [Accepted: 08/25/2010] [Indexed: 01/21/2023]
Abstract
In this work, we evaluated the effects of streptozotocin (STZ)-induced hyperglycemia and an acute episode of insulin-induced hypoglycemia in plasma amino acids and cortical neurotransmitters. For that purpose, we used citrate (vehicle)-treated Wistar rats, STZ-treated rats [i.p., 50 mg/kg body weight], and STZ-treated rats injected with insulin [s.c., dose adjusted with blood glucose levels] 1 h prior to sacrifice to induce an acute episode of hypoglycemia. Plasma was collected for determination of amino acids levels. In addition, cortical synaptosomal preparations were obtained and the total levels of neurotransmitters, levels of aspartate, glutamate, taurine, and GABA released by the action of KCl, iodoacetic acid (IAA), ouabain, and veratridine, membrane potential and ATP levels were evaluated. Compared with control rats, plasma from hypoglycemic rats presented increased levels of aspartate, glutamate, glutamine, and taurine whereas GABA levels were decreased in STZ and hypoglycemic rats. Similarly, glutamate and taurine levels were increased in hypoglycemic synaptosomes while GABA decreased in hypoglycemic and STZ-diabetic synaptosomes. The depolarizing agent KCl promoted an increase in aspartate, glutamate, and taurine release from hypoglycemic synaptosomes. The highest release of neurotransmitters occurred in the presence of veratridine and ouabain, two other depolarizing agents, in all groups of experimental animals. However, a higher release of glutamate was observed in the diabetic and hypoglycemic synaptosomes. No alterations were observed in synaptosomal membrane potential and ATP levels. These results show that in the presence of a metabolic insult a higher release of excitatory amino acids occurs, which may underlay the neuronal injury observed in type 1 diabetic patients under insulin therapy.
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Affiliation(s)
- Susana Cardoso
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
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Abstract
The Ca(2+)-dependent release of aspartate from hippocampal preparations was first reported 35 years ago, but the functional significance of this process remains uncertain. Aspartate satisfies all the criteria normally required for identification of a CNS transmitter. It is synthesized in nerve terminals, is accumulated and stored in synaptic vesicles, is released by exocytosis upon nerve terminal depolarization, and activates postsynaptic NMDA receptors. Aspartate may be employed as a neuropeptide-like co-transmitter by pathways that release either glutamate or GABA as their principal transmitter. Aspartate mechanisms include vesicular transport by sialin, vesicular content sensitive to glucose concentration, release mainly outside the presynaptic active zones, and selective activation of extrasynaptic NR1-NR2B NMDA receptors. Possible neurobiological functions of aspartate in immature neurons include activation of cAMP-dependent gene transcription and in mature neurons inhibition of CREB function, reduced BDNF expression, and induction of excitotoxic neuronal death. Recent findings suggest new experimental approaches toward resolving the functional significance of aspartate release.
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Affiliation(s)
- J Victor Nadler
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
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Paban V, Fauvelle F, Alescio-Lautier B. Age-related changes in metabolic profiles of rat hippocampus and cortices. Eur J Neurosci 2010; 31:1063-73. [DOI: 10.1111/j.1460-9568.2010.07126.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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47
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Vallee N, Rostain JC, Risso JJ. A Pressurized Nitrogen Counterbalance to Cortical Glutamatergic Pathway Stimulation. Neurochem Res 2010; 35:718-26. [DOI: 10.1007/s11064-010-0125-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2010] [Indexed: 10/19/2022]
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48
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Featherstone DE. Intercellular glutamate signaling in the nervous system and beyond. ACS Chem Neurosci 2010; 1:4-12. [PMID: 22778802 DOI: 10.1021/cn900006n] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 09/25/2009] [Indexed: 01/22/2023] Open
Abstract
Most intercellular glutamate signaling in the nervous system occurs at synapses. Some intercellular glutamate signaling occurs outside synapses, however, and even outside the nervous system where high ambient extracellular glutamate might be expected to preclude the effectiveness of glutamate as an intercellular signal. Here, I briefly review the types of intercellular glutamate signaling in the nervous system and beyond, with emphasis on the diversity of signaling mechanisms and fundamental unanswered questions.
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Affiliation(s)
- David E. Featherstone
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois 60607
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49
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Vallee N, Rostain JC, Risso JJ. How can an inert gas counterbalance a NMDA-induced glutamate release? J Appl Physiol (1985) 2009; 107:1951-8. [PMID: 19696368 DOI: 10.1152/japplphysiol.00097.2009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous neurochemical studies performed in rats have revealed a decrease of striatal dopamine and glutamate induced by inert gas narcosis. We sought to establish the hypothetical role of glutamate and its main receptor, the N-methyl-d-aspartate (NMDA) receptor, in this syndrome. We aimed to counteract the nitrogen narcosis-induced glutamate and dopamine decreases by stimulating the NMDA receptor in the striatum. We used bilateral retrodialysis on awake rats, submitted to nitrogen under pressure (3 MPa). Continuous infusion of 2 mM of NMDA under normobaric conditions (0.01 MPa) (n = 8) significantly increased extracellular average levels of glutamate, aspartate, glutamine, and asparagine by 241.8%, 292.5%, 108.3%, and 195.3%, respectively. The same infusion conducted under nitrogen at 3 MPa (n = 6) revealed significant lower levels of these amino acids (n = 8/6, P > 0.001). In opposition, the NMDA-induced effects on dopamine, dihydrophenylacetic acid (DOPAC), and homovanillic acid (HVA) levels were statistically not affected by the nitrogen at 3 MPa exposure (n = 8/6, P > 0.05). Dopamine was increased by >240% on average. HVA was decreased (down to 40%), and there was no change in DOPAC levels, in both conditions. Results highlight that the NMDA receptor is not directly affected by nitrogen under pressure as indicated by the elevation in NMDA-induced dopamine release under hyperbaric nitrogen. On the other hand, the NMDA-evoked glutamate increase is counteracted by nitrogen narcosis. No improvement in motor and locomotor disturbances was observed with high striatal concentration in dopamine. Further experiments have to be done to specify why the striatal glutamate pathways, in association with the inhibition of its metabolism, only are affected by nitrogen narcosis in this study.
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Affiliation(s)
- Nicolas Vallee
- Department of Marine and Underwater Research, UMR-MD2, Institut de Médecine Navale du Service de Santé des Armées, IRBA Toulon, Toulon Cedex 9, France.
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Postsynaptic response to stimulation of the Schaffer collaterals with properties similar to those of synaptosomal aspartate release. Brain Res 2009; 1295:13-20. [PMID: 19664606 DOI: 10.1016/j.brainres.2009.07.104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 07/17/2009] [Accepted: 07/30/2009] [Indexed: 11/23/2022]
Abstract
Aspartate satisfies all the criteria normally required for identification of a CNS neurotransmitter. Nevertheless, little electrophysiological evidence supports the existence of aspartate transmission. In studies with rat hippocampal synaptosomes, chemically evoked aspartate release differed from glutamate release in its relative sensitivity to increased Ca(2+) concentration outside the presynaptic active zones, inefficient coupling to P/Q-type Ca(2+) channels, sensitivity to KB-R7943, and resistance to native Clostridial toxins. We took advantage of these differences to search for a potential aspartate-mediated response at Schaffer collateral synapses in organotypic hippocampal slice cultures. The slice cultures were pretreated with botulinum neurotoxin C (BoNT/C) to eliminate most of the glutamate release so that an expectedly smaller aspartate-like component of the compound EPSC could be detected by whole cell patch clamp recording. In control cultures, NMDA receptor activation accounted for only 18% of the evoked EPSC and an NR2B-selective antagonist reduced the NMDA receptor-mediated component by only 20%. Block of P/Q-type Ca(2+) channels essentially eliminated the response and 0.1 muM KB-R7943 had no significant effect. In BoNT/C-pretreated cultures, however, NMDA receptor activation accounted for 77% of the evoked EPSC and an NR2B-selective antagonist reduced the NMDA receptor-mediated component by 57%. Block of P/Q-type Ca(2+) channels reduced the response by only 28%, but 0.1 muM KB-R7943 reduced it by 45%. These results suggest that part of the Schaffer collateral synaptic response has pharmacological properties similar to those of synaptosomal aspartate release and may therefore be mediated at least partly by released aspartate.
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