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Bendorius M, Po C, Muller S, Jeltsch-David H. From Systemic Inflammation to Neuroinflammation: The Case of Neurolupus. Int J Mol Sci 2018; 19:E3588. [PMID: 30428632 PMCID: PMC6274746 DOI: 10.3390/ijms19113588] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/06/2018] [Accepted: 11/09/2018] [Indexed: 12/17/2022] Open
Abstract
It took decades to arrive at the general consensus dismissing the notion that the immune system is independent of the central nervous system. In the case of uncontrolled systemic inflammation, the relationship between the two systems is thrown off balance and results in cognitive and emotional impairment. It is specifically true for autoimmune pathologies where the central nervous system is affected as a result of systemic inflammation. Along with boosting circulating cytokine levels, systemic inflammation can lead to aberrant brain-resident immune cell activation, leakage of the blood⁻brain barrier, and the production of circulating antibodies that cross-react with brain antigens. One of the most disabling autoimmune pathologies known to have an effect on the central nervous system secondary to the systemic disease is systemic lupus erythematosus. Its neuropsychiatric expression has been extensively studied in lupus-like disease murine models that develop an autoimmunity-associated behavioral syndrome. These models are very useful for studying how the peripheral immune system and systemic inflammation can influence brain functions. In this review, we summarize the experimental data reported on murine models developing autoimmune diseases and systemic inflammation, and we explore the underlying mechanisms explaining how systemic inflammation can result in behavioral deficits, with a special focus on in vivo neuroimaging techniques.
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Affiliation(s)
- Mykolas Bendorius
- UMR 7242 Biotechnologie et Signalisation Cellulaire, École Supérieure de Biotechnologie de Strasbourg (ESBS), Laboratoire d'Excellence Médalis, Université de Strasbourg/CNRS, 67412 Illkirch, France.
| | - Chrystelle Po
- ICube UMR 7357, Université de Strasbourg/CNRS, Fédération de Médecine Translationnelle de Strasbourg, 67000 Strasbourg, France.
| | - Sylviane Muller
- UMR 7242 Biotechnologie et Signalisation Cellulaire, École Supérieure de Biotechnologie de Strasbourg (ESBS), Laboratoire d'Excellence Médalis, Université de Strasbourg/CNRS, 67412 Illkirch, France.
- University of Strasbourg Institute for Advanced Study (USIAS), 67000 Strasbourg, France.
| | - Hélène Jeltsch-David
- UMR 7242 Biotechnologie et Signalisation Cellulaire, École Supérieure de Biotechnologie de Strasbourg (ESBS), Laboratoire d'Excellence Médalis, Université de Strasbourg/CNRS, 67412 Illkirch, France.
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Falsafi SK, Ghafari M, Miklósi AG, Engidawork E, Gröger M, Höger H, Lubec G. Mouse hippocampal GABAB1 but not GABAB2 subunit-containing receptor complex levels are paralleling retrieval in the multiple-T-maze. Front Behav Neurosci 2015; 9:276. [PMID: 26539091 PMCID: PMC4609755 DOI: 10.3389/fnbeh.2015.00276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/28/2015] [Indexed: 11/13/2022] Open
Abstract
GABAB receptors are heterodimeric G-protein coupled receptors known to be involved in learning and memory. Although a role for GABAB receptors in cognitive processes is evident, there is no information on hippocampal GABAB receptor complexes in a multiple T maze (MTM) task, a robust paradigm for evaluation of spatial learning. Trained or untrained (yoked control) C57BL/6J male mice (n = 10/group) were subjected to the MTM task and sacrificed 6 h following their performance. Hippocampi were taken, membrane proteins extracted and run on blue native PAGE followed by immunoblotting with specific antibodies against GABAB1, GABAB1a, and GABAB2. Immunoprecipitation with subsequent mass spectrometric identification of co-precipitates was carried out to show if GABAB1 and GABAB2 as well as other interacting proteins co-precipitate. An antibody shift assay (ASA) and a proximity ligation assay (PLA) were also used to see if the two GABAB subunits are present in the receptor complex. Single bands were observed on Western blots, each representing GABAB1, GABAB1a, or GABAB2 at an apparent molecular weight of approximately 100 kDa. Subsequently, densitometric analysis revealed that levels of GABAB1 and GABAB1a but not GABAB2- containing receptor complexes were significantly higher in trained than untrained groups. Immunoprecipitation followed by mass spectrometric studies confirmed the presence of GABAB1, GABAB2, calcium calmodulin kinases I and II, GluA1 and GluA2 as constituents of the complex. ASA and PLA also showed the presence of the two subunits of GABAB receptor within the complex. It is shown that increased levels of GABAB1 subunit-containing complexes are paralleling performance in a land maze.
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Affiliation(s)
- Soheil K Falsafi
- Department of Pediatrics, Medical University of Vienna Vienna, Austria
| | - Maryam Ghafari
- Department of Pediatrics, Medical University of Vienna Vienna, Austria
| | - András G Miklósi
- Department of Pediatrics, Medical University of Vienna Vienna, Austria
| | - Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University Addis Ababa, Ethiopia
| | - Marion Gröger
- Skin and Endothelium Research Division, Department of Dermatology, Medical University Vienna, Austria
| | - Harald Höger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna Vienna, Austria
| | - Gert Lubec
- Department of Pediatrics, Medical University of Vienna Vienna, Austria
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Falsafi SK, Dierssen M, Ghafari M, Pollak A, Lubec G. Reduced cortical neurotransmitter receptor complex levels in fetal Down syndrome brain. Amino Acids 2015; 48:103-16. [PMID: 26269195 DOI: 10.1007/s00726-015-2062-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 07/24/2015] [Indexed: 12/27/2022]
Abstract
In this study, cortical receptor complex levels were determined in fetal Down syndrome (DS, trisomy 21) brain. Frontal cortices were obtained from individuals with DS (19th-22nd week of gestation) and controls. Membrane proteins were extracted, assayed on blue native gels and immunoblotted with brain receptor antibodies. Levels of a D1R-containing complex were markedly decreased in male and female cortices of DS individuals. Females with DS had significant reductions of nicotinic acetylcholine receptors α4 and α7, NMDA receptor GluN1 and AMPA receptor GluA1- and GluA3-containing receptor complexes. Levels of other brain receptor complexes (5-hydroxytryptamine 1A, GluA2 and GluR4 receptor-containing complexes) were comparable between the groups of females. Levels of GluA2- and GluA3-containing complexes were significantly increased in males. Decreased levels of D1R complexes in both sexes, along with the significant reduction of α4, α7-containing receptor complexes observed in females, may explain the brain deficits and impaired cognition observed in DS.
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Affiliation(s)
- Soheil Keihan Falsafi
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
| | - Mara Dierssen
- Genes and Disease Program, Center for Genomic Regulation and CIBERER, Barcelona, Spain
| | - Maryam Ghafari
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - Arnold Pollak
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - Gert Lubec
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
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Sase S, Sase A, Sialana FJ, Gröger M, Bennett KL, Stork O, Lubec G, Li L. Individual phases of contextual fear conditioning differentially modulate dorsal and ventral hippocampal GluA1-3, GluN1-containing receptor complexes and subunits. Hippocampus 2015; 25:1501-16. [DOI: 10.1002/hipo.22470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Sunetra Sase
- Department of Pediatrics; Medical University of Vienna; Austria
| | - Ajinkya Sase
- Department of Pediatrics; Medical University of Vienna; Austria
| | - Fernando J. Sialana
- Department of Pediatrics; Medical University of Vienna; Austria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences; Vienna Austria
| | | | - Keiryn L. Bennett
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences; Vienna Austria
| | - Oliver Stork
- Institute of Biology, Otto Von Guericke University; Magdeburg Germany
| | - Gert Lubec
- Department of Pediatrics; Medical University of Vienna; Austria
| | - Lin Li
- Department of Pediatrics; Medical University of Vienna; Austria
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Ghafari M, Keihan Falsafi S, Höger H, Bennett KL, Lubec G. Identification of new phosphorylation sites of AMPA receptors in the rat hippocampus--A resource for neuroscience research. Proteomics Clin Appl 2015; 9:808-16. [PMID: 25656447 DOI: 10.1002/prca.201400057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 10/16/2014] [Accepted: 02/03/2015] [Indexed: 12/14/2022]
Abstract
PURPOSE AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors (AMPARs) are glutamate-gated ion channels that mediate the majority of fast excitatory synaptic transmissions in the mammalian brain. A series of phosphorylation sites have been predicted or identified and knowledge on phosphorylations is mandatory for understanding receptor biology and functions. EXPERIMENTAL DESIGN Immunoprecipitation from extracted hippocampal rat proteins was carried out using an antibody against the AMPAR GluA1 subunit, followed by identification of GluA1 and binding partners by MS. Bands from SDS-PAGE were picked, peptides were generated by trypsin and chymotrypsin digestion and identified by MS/MS (LTQ Orbitrap Velos). RESULTS Using Mascot as a search engine, phosphorylation sites S506, S645, S720, S849, S863, S895, T858, Y228, Y419, and T734 were found on GluA1; S357, S513, S656, S727, T243, T420, T741, Y 143, Y301,Y426 on GluA2; S301, S516, S657, S732, T222, and T746 were observed on GluA3; and S514, S653 was phosphorylated on GluA4. CONCLUSIONS AND CLINICAL RELEVANCE A series of additional protein modifications were observed and in particular, tyrosine and tryptophan nitrations on GluA1 were detected that may raise questions on additional regulation mechanisms for AMPARs in addition to phosphorylations. The findings are relevant for interpretation of previous work and design of future studies using AMPAR serving as a resource for neuroscience research and indeed, phosphorylations and PTMs per se would have to be respected when neuropathological and neurological disorders are being studied.
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Affiliation(s)
- Maryam Ghafari
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | | | - Harald Höger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Himberg, Austria
| | - Keiryn L Bennett
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Gert Lubec
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
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Shanmugasundaram B, Sase A, Miklosi AG, Sialana FJ, Subramaniyan S, Aher YD, Gröger M, Höger H, Bennett KL, Lubec G. Frontal cortex and hippocampus neurotransmitter receptor complex level parallels spatial memory performance in the radial arm maze. Behav Brain Res 2015; 289:157-68. [PMID: 25930220 DOI: 10.1016/j.bbr.2015.04.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 04/21/2015] [Accepted: 04/23/2015] [Indexed: 12/14/2022]
Abstract
Several neurotransmitter receptors have been proposed to be involved in memory formation. However, information on receptor complexes (RCs) in the radial arm maze (RAM) is missing. It was therefore the aim of this study to determine major neurotransmitter RCs levels that are modulated by RAM training because receptors are known to work in homo-or heteromeric assemblies. Immediate early gene Arc expression was determined by immunohistochemistry to show if prefrontal cortices (PFC) and hippocampi were activated following RAM training as these regions are known to be mainly implicated in spatial memory. Twelve rats per group, trained and untrained in the twelve arm RAM were used, frontal cortices and hippocampi were taken, RCs in membrane protein were quantified by blue-native PAGE immunoblotting. RCs components were characterised by co-immunoprecipitation followed by mass spectrometrical analysis and by the use of the proximity ligation assay. Arc expression was significantly higher in PFC of trained as compared to untrained rats whereas it was comparable in hippocampi. Frontal cortical levels of RCs containing AMPA receptors GluA1, GluA2, NMDA receptors GluN1 and GluN2A, dopamine receptor D1, acetylcholine nicotinic receptor alpha 7 (nAChR-α7) and hippocampal levels of RCs containing D1, GluN1, GluN2B and nAChR-α7 were increased in the trained group; phosphorylated dopamine transporter levels were decreased in the trained group. D1 and GluN1 receptors were shown to be in the same complex. Taken together, distinct RCs were paralleling performance in the RAM which is relevant for interpretation of previous and design of future work on RCs in memory studies.
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Affiliation(s)
| | - Ajinkya Sase
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria
| | - András G Miklosi
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria
| | - Fernando J Sialana
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria; CeMM Research Center for Molecular Medicine of the Austrian Academy of Science, Lazarettgasse 14, AKH BT 25.3, A-1090 Vienna, Austria
| | - Saraswathi Subramaniyan
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria
| | - Yogesh D Aher
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria
| | - Marion Gröger
- Core Facility, Medical University of Vienna, Lazarettegasse 14, A-1090 Vienna, Austria
| | - Harald Höger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Brauhausgasse 34, A-2325 Himberg, Austria
| | - Keiryn L Bennett
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Science, Lazarettgasse 14, AKH BT 25.3, A-1090 Vienna, Austria
| | - Gert Lubec
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria.
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Saroja SR, Sase A, Kircher SG, Wan J, Berger J, Höger H, Pollak A, Lubec G. Hippocampal proteoglycans brevican and versican are linked to spatial memory of Sprague-Dawley rats in the morris water maze. J Neurochem 2014; 130:797-804. [DOI: 10.1111/jnc.12783] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/22/2014] [Accepted: 06/01/2014] [Indexed: 01/21/2023]
Affiliation(s)
| | - Ajinkya Sase
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
| | - Susanne G. Kircher
- Department of Medical Chemistry; Medical University of Vienna; Vienna Austria
| | - Jia Wan
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System; Center for Brain Research; Medical University of Vienna; Vienna Austria
| | - Harald Höger
- Core Unit of Biomedical Research; Division of Laboratory Animal Science and Genetics; Medical University of Vienna; Himberg Austria
| | - Arnold Pollak
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
| | - Gert Lubec
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
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Dietary magnesium restriction reduces amygdala-hypothalamic GluN1 receptor complex levels in mice. Brain Struct Funct 2014; 220:2209-21. [PMID: 24807818 DOI: 10.1007/s00429-014-0779-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 04/11/2014] [Indexed: 10/25/2022]
Abstract
Reduced daily intake of magnesium (Mg(2+)) is suggested to contribute to depression. Indeed, preclinical studies show dietary magnesium restriction (MgR) elicits enhanced depression-like behaviour establishing a causal relationship. Amongst other mechanisms, Mg(2+) gates the activity of N-methyl-D-asparte (NMDA) receptors; however, it is not known whether reduced dietary Mg(2+) intake can indeed affect brain NMDA receptor complexes. Thus, the aim of the current study was to reveal whether MgR induces changes in brain NMDA receptor subunit composition that would indicate altered NMDA receptor regulation. The results revealed that enhanced depression-like behaviour elicited by MgR was associated with reduced amygdala-hypothalamic protein levels of GluN1-containing NMDA complexes. No change in GluN1 mRNA levels was observed indicating posttranslational changes were induced by dietary Mg(2+) restriction. To reveal possible protein interaction partners, GluN1 immunoprecipitation and proximity ligation assays were carried out revealing the expected GluN1 subunit association with GluN2A, GluN2B, but also novel interactions with GluA1, GluA2 in addition to known downstream signalling proteins. Chronic paroxetine treatment in MgR mice normalized enhanced depression-like behaviour, but did not alter protein levels of GluN1-containing NMDA receptors, indicating targets downstream of the NMDA receptor. Collectively, present data demonstrate that dietary MgR alters brain levels of GluN1-containing NMDA receptor complexes, containing GluN2A, GluN2B, AMPA receptors GluA1, GluA2 and several protein kinases. These data indicate that the modulation of dietary Mg(2+) intake may alter the function and signalling of this receptor complex indicating its involvement in the enhanced depression-like behaviour elicited by MgR.
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Falsafi SK, Roßner S, Ghafari M, Groessl M, Morawski M, Gerner C, Lubec G. Changes of several brain receptor complexes in the cerebral cortex of patients with Alzheimer disease: probable new potential pharmaceutical targets. Amino Acids 2013; 46:223-33. [PMID: 24292102 DOI: 10.1007/s00726-013-1623-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 11/04/2013] [Indexed: 12/31/2022]
Abstract
Although Alzheimer disease (AD) has been linked to defects in major brain receptors, studies thus far have been limited to the determination of receptor subunits or specific ligand binding studies. However, the availability of current technology enables the determination and quantification of brain receptor complexes. Thus, we examined levels of native receptor complexes in the brains of patients with AD. Cortical tissue was obtained from control subjects (n = 12 females and 12 males) and patients with AD (n = 12 females and 12 males) within a 3-h postmortem time period. The tissues were kept frozen until further biochemical analyses. Membrane proteins were extracted and subsequently enriched by ultracentrifugation using a sucrose gradient. Membrane proteins were then electrophoresed onto native gels and immunoblotted using antibodies against individual brain receptors. We found that the levels were comparable for complexes containing GluR2, GluR3 and GluR4 as well as 5-HT1A. Moreover, the levels of complexes containing muscarinic AChR M1, NR1 and GluR1 were significantly increased in male patients with AD. Nicotinic AChRs 4 and 7 as well as dopaminergic receptors D1 and D2 were also increased in males and females with AD. These findings reveal a pattern of altered receptor complex levels that may contribute to the deterioration of the concerted activity of these receptors and thus result in cognitive deficits observed in patients with AD. It should be emphasised that receptor complexes function as working units rather than individual subunits. Thus, the receptor deficits identified may be relevant for the design of experimental therapies. Therefore, specific pharmacological modulation of these receptors is within the pharmaceutical repertoire.
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Affiliation(s)
- Soheil Keihan Falsafi
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
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Zheng Y, Wilson G, Stiles L, Smith PF. Glutamate receptor subunit and calmodulin kinase II expression, with and without T maze training, in the rat hippocampus following bilateral vestibular deafferentation. PLoS One 2013; 8:e54527. [PMID: 23408944 PMCID: PMC3567128 DOI: 10.1371/journal.pone.0054527] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 12/12/2012] [Indexed: 12/11/2022] Open
Abstract
Many previous studies have shown that lesions of the peripheral vestibular system result in spatial memory deficits and electrophysiological dysfunction in the hippocampus. Given the importance of glutamate as a neurotransmitter in the hippocampus, it was predicted that bilateral vestibular deafferentation (BVD) would alter the expression of NMDA and AMPA receptors in this area of the brain.
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Affiliation(s)
- Yiwen Zheng
- Department of Pharmacology and Toxicology, School of Medical Sciences, and the Brain Health Research Centre, University of Otago Medical School, Dunedin, New Zealand
| | - Georgina Wilson
- Department of Pharmacology and Toxicology, School of Medical Sciences, and the Brain Health Research Centre, University of Otago Medical School, Dunedin, New Zealand
| | - Lucy Stiles
- Department of Pharmacology and Toxicology, School of Medical Sciences, and the Brain Health Research Centre, University of Otago Medical School, Dunedin, New Zealand
| | - Paul F. Smith
- Department of Pharmacology and Toxicology, School of Medical Sciences, and the Brain Health Research Centre, University of Otago Medical School, Dunedin, New Zealand
- * E-mail:
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Falsafi SK, Deli A, Höger H, Pollak A, Lubec G. Scopolamine administration modulates muscarinic, nicotinic and NMDA receptor systems. PLoS One 2012; 7:e32082. [PMID: 22384146 PMCID: PMC3285663 DOI: 10.1371/journal.pone.0032082] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 01/19/2012] [Indexed: 11/25/2022] Open
Abstract
Studies on the effect of scopolamine on memory are abundant but so far only regulation of the muscarinic receptor (M1) has been reported. We hypothesized that levels of other cholinergic brain receptors as the nicotinic receptors and the N-methyl-D-aspartate (NMDA) receptor, known to be involved in memory formation, would be modified by scopolamine administration. C57BL/6J mice were used for the experiments and divided into four groups. Two groups were given scopolamine 1 mg/kg i.p. (the first group was trained and the second group untrained) in the multiple T-maze (MTM), a paradigm for evaluation of spatial memory. Likewise, vehicle-treated mice were trained or untrained thus serving as controls. Hippocampal levels of M1, nicotinic receptor alpha 4 (Nic4) and 7 (Nic7) and subunit NR1containing complexes were determined by immunoblotting on blue native gel electrophoresis. Vehicle-treated trained mice learned the task and showed memory retrieval on day 8, while scopolamine-treatment led to significant impairment of performance in the MTM. At the day of retrieval, hippocampal levels for M1, Nic7 and NR1 were higher in the scopolamine treated groups than in vehicle-treated groups. The concerted action, i.e. the pattern of four brain receptor complexes regulated by the anticholinergic compound scopolamine, is shown. Insight into probable action mechanisms of scopolamine at the brain receptor complex level in the hippocampus is provided. Scopolamine treatment is a standard approach to test cognitive enhancers and other psychoactive compounds in pharmacological studies and therefore knowledge on mechanisms is of pivotal interest.
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Affiliation(s)
| | - Alev Deli
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Harald Höger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Vienna, Austria
| | - Arnold Pollak
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Gert Lubec
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
- * E-mail:
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Hippocampal glutamate transporter 1 (GLT-1) complex levels are paralleling memory training in the Multiple T-maze in C57BL/6J mice. Brain Struct Funct 2011; 217:363-78. [PMID: 22113856 DOI: 10.1007/s00429-011-0362-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 11/08/2011] [Indexed: 12/25/2022]
Abstract
The glutamate transporter 1 (GLT-1) is essential for glutamate uptake in the brain and associated with various psychiatric and neurological disorders. Pharmacological inhibition of GLT-1 results in memory deficits, but no study linking native GLT-1 complexes was published so far. It was therefore the aim of the study to associate this highly hydrophobic, eight transmembrane spanning domains containing transporter to memory training in the Multiple T-maze (MTM). C57BL/6J mice were used for the spatial memory training experiments, and trained mice were compared to untrained (yoked) animals. Mouse hippocampi were dissected out 6 h after training on day 4, and a total enriched membrane fraction was prepared by ultracentrifugation. Membrane proteins were separated by blue native polyacrylamide gel electrophoresis (BN-PAGE) with subsequent Western blotting against GLT-1 on these native gels. Moreover, GLT-1 complexes were identified by mass spectrometry (nano-LC-ESI-MS/MS). Animals learned the MTM task and multiple GLT-1 complexes were detected at apparent molecular weights of 242, 480 and 720 kDa on BN-PAGE Western blotting. GLT-1 complex levels were significantly higher in the trained group as compared to yoked controls, and antibody specificity was verified by immunoblotting on multidimensional gels. Hippocampal GLT-1 was unambiguously identified by mass spectrometry with high sequence coverage, and glycosylation was observed. It is revealed that increased GLT-1 complex levels are paralleling and are linked to spatial memory training. We provide evidence that signal termination, represented by the excitatory amino acid transporter GLT-1 complexes, is involved in spatial memory mechanisms.
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Sase A, Khan D, Höger H, Lubec G. Intraperitoneal injection of saline modulates hippocampal brain receptor complex levels but does not impair performance in the Morris Water Maze. Amino Acids 2011; 43:783-92. [DOI: 10.1007/s00726-011-1130-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 10/19/2011] [Indexed: 01/03/2023]
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