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Suzuki N, Oota-Ishigaki A, Kaizuka T, Itoh M, Yamazaki M, Natsume R, Abe M, Sakimura K, Mishina M, Hayashi T. Limb-Clasping Response in NMDA Receptor Palmitoylation-Deficient Mice. Mol Neurobiol 2024:10.1007/s12035-024-04166-9. [PMID: 38592586 DOI: 10.1007/s12035-024-04166-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 04/01/2024] [Indexed: 04/10/2024]
Abstract
Proper regulation of N-methyl-D-aspartate-type glutamate receptor (NMDA receptor) expression is responsible for excitatory synaptic functions in the mammalian brain. NMDA receptor dysfunction can cause various neuropsychiatric disorders and neurodegenerative diseases. Posttranslational protein S-palmitoylation, the covalent attachment of palmitic acid to intracellular cysteine residues via thioester bonds, occurs in the carboxyl terminus of GluN2B, which is the major regulatory NMDA receptor subunit. Mutations of three palmitoylatable cysteine residues in the membrane-proximal cluster of GluN2B to non-palmitoylatable serine (3CS) lead to the dephosphorylation of GluN2B Tyr1472 in the hippocampus and cerebral cortex, inducing a reduction in the surface expression of GluN2B-containig NMDA receptors. Furthermore, adult GluN2B 3CS homozygous mice demonstrated a definite clasping response without abnormalities in the gross brain structure, other neurological reflexes, or expression levels of synaptic proteins in the cerebrum. This behavioral disorder, observed in the GluN2B 3CS knock-in mice, indicated that complex higher brain functions are coordinated through the palmitoylation-dependent regulation of NMDA receptors in excitatory synapses.
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Affiliation(s)
- Nami Suzuki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6 (6-10), 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan
| | - Akiko Oota-Ishigaki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6 (6-10), 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan
| | - Toshie Kaizuka
- National Center of Neurology and Psychiatry (NCNP), National Institute of Neuroscience, Kodaira, Tokyo, 187-8502, Japan
| | - Masayuki Itoh
- National Center of Neurology and Psychiatry (NCNP), National Institute of Neuroscience, Kodaira, Tokyo, 187-8502, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Rie Natsume
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Masayoshi Mishina
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo, 113-0033, Japan
- Brain Science Laboratory, The Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan
| | - Takashi Hayashi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6 (6-10), 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan.
- National Center of Neurology and Psychiatry (NCNP), National Institute of Neuroscience, Kodaira, Tokyo, 187-8502, Japan.
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo, 113-0033, Japan.
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Liao D, Huang Y, Liu D, Zhang H, Shi X, Li X, Luo P. The role of s-palmitoylation in neurological diseases: implication for zDHHC family. Front Pharmacol 2024; 14:1342830. [PMID: 38293675 PMCID: PMC10824933 DOI: 10.3389/fphar.2023.1342830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 12/31/2023] [Indexed: 02/01/2024] Open
Abstract
S-palmitoylation is a reversible posttranslational modification, and the palmitoylation reaction in human-derived cells is mediated by the zDHHC family, which is composed of S-acyltransferase enzymes that possess the DHHC (Asp-His-His-Cys) structural domain. zDHHC proteins form an autoacylation intermediate, which then attaches the fatty acid to cysteine a residue in the target protein. zDHHC proteins sublocalize in different neuronal structures and exert dif-ferential effects on neurons. In humans, many zDHHC proteins are closely related to human neu-rological disor-ders. This review focuses on a variety of neurological disorders, such as AD (Alz-heimer's disease), HD (Huntington's disease), SCZ (schizophrenia), XLID (X-linked intellectual disability), attention deficit hyperactivity disorder and glioma. In this paper, we will discuss and summarize the research progress regarding the role of zDHHC proteins in these neu-rological disorders.
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Affiliation(s)
- Dan Liao
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Yutao Huang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Dan Liu
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
- School of Life Science, Northwest University, Xi’an, China
| | - Haofuzi Zhang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Xinyu Shi
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Xin Li
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
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Hayashi T. Membrane lipid rafts are required for AMPA receptor tyrosine phosphorylation. Front Synaptic Neurosci 2022; 14:921772. [PMID: 36387774 PMCID: PMC9662747 DOI: 10.3389/fnsyn.2022.921772] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 10/11/2022] [Indexed: 12/24/2023] Open
Abstract
Membrane lipid rafts are sphingolipids and cholesterol-enriched membrane microdomains, which form a center for the interaction or assembly of palmitoylated signaling molecules, including Src family non-receptor type protein tyrosine kinases. Lipid rafts abundantly exist in neurons and function in the maintenance of synapses. Excitatory synaptic strength is largely controlled by the surface expression of α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors in the mammalian brain. AMPA receptor endocytosis from the synaptic surface is regulated by phosphorylation of the GluA2 subunit at tyrosine 876 by Src family kinases. Here, I revealed that tyrosine phosphorylated GluA2 is concentrated in the lipid rafts fraction. Furthermore, stimulation-induced upregulation of GluA2 tyrosine phosphorylation is disrupted by the treatment of neurons with a cholesterol-depleting compound, filipin III. These results indicate the importance of lipid rafts as enzymatic reactive sites for AMPA receptor tyrosine phosphorylation and subsequent AMPA receptor internalization from the synaptic surface.
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Affiliation(s)
- Takashi Hayashi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Hayashi T. Evolutionarily Established Palmitoylation-Dependent Regulatory Mechanisms of the Vertebrate Glutamatergic Synapse and Diseases Caused by Their Disruption. Front Mol Neurosci 2021; 14:796912. [PMID: 34867194 PMCID: PMC8634674 DOI: 10.3389/fnmol.2021.796912] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 10/26/2021] [Indexed: 11/13/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the vertebrate brain and various modifications have been established in the glutamatergic synapses. Generally, many neuronal receptors and ion channels are regulated by S-palmitoylation, a reversible post-translational protein modification. Genome sequence databases show the evolutionary acquisition and conservation concerning vertebrate-specific palmitoylation of synaptic proteins including glutamate receptors. Moreover, palmitoylation of some glutamate receptor-binding proteins is subsequently acquired only in some mammalian lineages. Recent progress in genome studies has revealed that some palmitoylation-catalyzing enzymes are the causative genes of neuropsychiatric disorders. In this review, I will summarize the evolutionary development of palmitoylation-dependent regulation of glutamatergic synapses and their dysfunctions which are caused by the disruption of palmitoylation mechanism.
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Affiliation(s)
- Takashi Hayashi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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Effects of corticosterone injections in mid-to-late mouse postnatal development on adult motor activity and coordination. Neurosci Res 2020; 164:22-32. [PMID: 32320709 DOI: 10.1016/j.neures.2020.03.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 02/08/2023]
Abstract
Glucocorticoids are involved in the developing brain but, in excessive amounts, may depress its growth and cause psychomotor development disorders. To test the long-term vulnerability of motor structures such as the cerebellum to supraphysiological corticosterone (CORT), the hormone was subcutaneously delivered at a dose of 20 mg/kg from postnatal day (P) 8 to P29 in C57BL/6 male mice evaluated for sensorimotor functions at P15, P22, P29, and 3 months. Relative to placebo, CORT increased motor activity in the open-field at P29 and 3 months as well as facilitating rotorod acquisition and visuomotor control necessary for swimming towards a visible goal without affecting spatial learning in the Morris water maze. CORT caused lobule-specific effects on cerebellar morphology by decreasing granule cell layer thickness in simplex lobule but increasing molecular and granule cell layer thickness in crus 2. The functional impact of these changes is indicated by significant correlations found between cerebellar size and activity levels or proficiency on the rotorod test of motor coordination.
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Hayashi T. Post-translational palmitoylation of ionotropic glutamate receptors in excitatory synaptic functions. Br J Pharmacol 2020; 178:784-797. [PMID: 32159240 DOI: 10.1111/bph.15050] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/07/2020] [Accepted: 03/05/2020] [Indexed: 12/17/2022] Open
Abstract
In the mammalian CNS, glutamate is the major excitatory neurotransmitter. Ionotropic glutamate receptors (iGluRs) are responsible for the glutamate-mediated postsynaptic excitation of neurons. Regulation of glutamatergic synapses is critical for higher brain functions including neural communication, memory formation, learning, emotion, and behaviour. Many previous studies have shown that post-translational protein S-palmitoylation, the only reversible covalent attachment of lipid to protein, regulates synaptic expression, intracellular localization, and membrane trafficking of iGluRs and their scaffolding proteins in neurons. This modification mechanism is extremely conserved in the vertebrate lineages. The failure of appropriate palmitoylation-dependent regulation of iGluRs leads to hyperexcitability that reduces the maintenance of network stability, resulting in brain disorders, such as epileptic seizures. This review summarizes advances in the study of palmitoylation of iGluRs, especially AMPA receptors and NMDA receptors, and describes the current understanding of palmitoylation-dependent regulation of excitatory glutamatergic synapses. LINKED ARTICLES: This article is part of a themed issue on Neurochemistry in Japan. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.4/issuetoc.
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Affiliation(s)
- Takashi Hayashi
- Section of Cellular Biochemistry, Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan
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7
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Deficiency of AMPAR-Palmitoylation Aggravates Seizure Susceptibility. J Neurosci 2018; 38:10220-10235. [PMID: 30355633 DOI: 10.1523/jneurosci.1590-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/13/2018] [Accepted: 10/12/2018] [Indexed: 01/01/2023] Open
Abstract
Synaptic AMPAR expression controls the strength of excitatory synaptic transmission and plasticity. An excess of synaptic AMPARs leads to epilepsy in response to seizure-inducible stimulation. The appropriate regulation of AMPARs plays a crucial role in the maintenance of the excitatory/inhibitory synaptic balance; however, the detailed mechanisms underlying epilepsy remain unclear. Our previous studies have revealed that a key modification of AMPAR trafficking to and from postsynaptic membranes is the reversible, posttranslational S-palmitoylation at the C-termini of receptors. To clarify the role of palmitoylation-dependent regulation of AMPARs in vivo, we generated GluA1 palmitoylation-deficient (Cys811 to Ser substitution) knock-in mice. These mutant male mice showed elevated seizure susceptibility and seizure-induced neuronal activity without impairments in synaptic transmission, gross brain structure, or behavior at the basal level. Disruption of the palmitoylation site was accompanied by upregulated GluA1 phosphorylation at Ser831, but not at Ser845, in the hippocampus and increased GluA1 protein expression in the cortex. Furthermore, GluA1 palmitoylation suppressed excessive spine enlargement above a certain size after LTP. Our findings indicate that an abnormality in GluA1 palmitoylation can lead to hyperexcitability in the cerebrum, which negatively affects the maintenance of network stability, resulting in epileptic seizures.SIGNIFICANCE STATEMENT AMPARs predominantly mediate excitatory synaptic transmission. AMPARs are regulated in a posttranslational, palmitoylation-dependent manner in excitatory synapses of the mammalian brain. Reversible palmitoylation dynamically controls synaptic expression and intracellular trafficking of the receptors. Here, we generated GluA1 palmitoylation-deficient knock-in mice to clarify the role of AMPAR palmitoylation in vivo We showed that an abnormality in GluA1 palmitoylation led to hyperexcitability, resulting in epileptic seizure. This is the first identification of a specific palmitoylated protein critical for the seizure-suppressing process. Our data also provide insight into how predicted receptors such as AMPARs can effectively preserve network stability in the brain. Furthermore, these findings help to define novel key targets for developing anti-epileptic drugs.
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Enga RM, Rice AC, Weller P, Subler MA, Lee D, Hall CP, Windle JJ, Beardsley PM, van den Oord EJ, McClay JL. Initial characterization of behavior and ketamine response in a mouse knockout of the post-synaptic effector gene Anks1b. Neurosci Lett 2017; 641:26-32. [PMID: 28115237 DOI: 10.1016/j.neulet.2017.01.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 01/13/2017] [Accepted: 01/17/2017] [Indexed: 12/19/2022]
Abstract
The human ANKS1B gene encodes an activity-dependent effector of post-synaptic signaling. It was recently associated with neuropsychiatric phenotypes in genome-wide studies. While the biological function of ANKS1B has been partly elucidated, its role in behavior is poorly understood. Here, we breed and characterize a full knockout (KO) for murine Anks1b. We found that the homozygous KO genotype was partially lethal, showing significant deviation from expected segregation ratios at weaning. Behaviorally, KOs exhibited no difference in baseline acoustic startle response, but showed deficits in prepulse inhibition (PPI). KOs also exhibited locomotor hyperactivity and increased stereotypy at baseline. Administration of ketamine, a non-competitive NMDA-receptor antagonist, greatly exacerbated locomotor activity in the KOs at lower doses, but genotype groups were almost indistinguishable as dose increased. Stereotypy showed a complex response to ketamine in the KOs, with elevated stereotypy at lower doses and markedly less at high doses, compared to wild type. Our study is the first to probe the behavioral phenotypes associated with ablation of Anks1b. Deficits in PPI, locomotor hyperactivity, elevated stereotypy and altered response to NMDA receptor antagonism are murine behavioral outcomes with translational relevance for psychiatric disorders. These findings are also consistent with the role of Anks1b as an effector of glutamatergic signaling. As an intermediary between post-synaptic receptor stimulation and long-term changes to neuronal protein expression, further investigation of Anks1b is warranted.
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Affiliation(s)
- Rachel M Enga
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA
| | - Ann C Rice
- Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA
| | - Pamela Weller
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Mark A Subler
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Daiyoon Lee
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA, USA
| | - Chelsea P Hall
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA, USA
| | - Jolene J Windle
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Patrick M Beardsley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA; Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Edwin J van den Oord
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Joseph L McClay
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA, USA.
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Hamada S, Ogawa I, Yamasaki M, Kiyama Y, Kassai H, Watabe AM, Nakao K, Aiba A, Watanabe M, Manabe T. The glutamate receptor GluN2 subunit regulates synaptic trafficking of AMPA receptors in the neonatal mouse brain. Eur J Neurosci 2014; 40:3136-46. [DOI: 10.1111/ejn.12682] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 07/03/2014] [Accepted: 07/04/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Shun Hamada
- Division of Neuronal Network; Institute of Medical Science; University of Tokyo; Tokyo 108-8639 Japan
| | - Itone Ogawa
- Division of Neuronal Network; Institute of Medical Science; University of Tokyo; Tokyo 108-8639 Japan
| | - Miwako Yamasaki
- Department of Anatomy; Hokkaido University Graduate School of Medicine; Sapporo Japan
| | - Yuji Kiyama
- Division of Neuronal Network; Institute of Medical Science; University of Tokyo; Tokyo 108-8639 Japan
| | - Hidetoshi Kassai
- Laboratory of Animal Resources; Center for Disease Biology and Integrative Medicine; Faculty of Medicine; University of Tokyo; Tokyo Japan
- Division of Molecular Genetics; Kobe University Graduate School of Medicine; Kobe Japan
| | - Ayako M. Watabe
- Division of Neuronal Network; Institute of Medical Science; University of Tokyo; Tokyo 108-8639 Japan
- PRESTO JST; Kawaguchi Saitama Japan
| | - Kazuki Nakao
- Laboratory of Animal Resources; Center for Disease Biology and Integrative Medicine; Faculty of Medicine; University of Tokyo; Tokyo Japan
- Laboratory for Animal Resources and Genetic Engineering; Center for Developmental Biology; RIKEN; Kobe Japan
| | - Atsu Aiba
- Laboratory of Animal Resources; Center for Disease Biology and Integrative Medicine; Faculty of Medicine; University of Tokyo; Tokyo Japan
- Division of Molecular Genetics; Kobe University Graduate School of Medicine; Kobe Japan
| | - Masahiko Watanabe
- Department of Anatomy; Hokkaido University Graduate School of Medicine; Sapporo Japan
| | - Toshiya Manabe
- Division of Neuronal Network; Institute of Medical Science; University of Tokyo; Tokyo 108-8639 Japan
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Petrenko AB, Yamakura T, Sakimura K, Baba H. Defining the role of NMDA receptors in anesthesia: Are we there yet? Eur J Pharmacol 2014; 723:29-37. [DOI: 10.1016/j.ejphar.2013.11.039] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 11/05/2013] [Accepted: 11/24/2013] [Indexed: 12/26/2022]
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Thomas GM, Hayashi T. Smarter neuronal signaling complexes from existing components: How regulatory modifications were acquired during animal evolution. Bioessays 2013; 35:929-39. [DOI: 10.1002/bies.201300076] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Gareth M. Thomas
- Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology; Temple University Medical School; Philadelphia PA USA
| | - Takashi Hayashi
- Department of Molecular Neurobiology and Pharmacology; Graduate School of Medicine; The University of Tokyo; Bunkyo-ku Tokyo Japan
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Gao C, Tronson NC, Radulovic J. Modulation of behavior by scaffolding proteins of the post-synaptic density. Neurobiol Learn Mem 2013; 105:3-12. [PMID: 23701866 DOI: 10.1016/j.nlm.2013.04.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/05/2013] [Accepted: 04/09/2013] [Indexed: 12/23/2022]
Abstract
Scaffolding proteins of the neuronal post-synaptic density (PSD) are principal organizers of glutamatergic neurotransmission that bring together glutamate receptors and signaling molecules at discrete synaptic locations. Genetic alterations of individual PSD scaffolds therefore disrupt the function of entire multiprotein modules rather than a single glutamatergic mechanism, and thus induce a range of molecular and structural abnormalities in affected neurons. Despite such broad molecular consequences, knockout, knockdown, or knockin of glutamate receptor scaffolds typically affect a subset of specific behaviors and thereby mold and specialize the actions of the ubiquitous glutamatergic neurotransmitter system. Approaches designed to control the function of neuronal scaffolds may therefore have high potential to restore behavioral morbidities and comorbidities in patients with psychiatric disorders. Here we summarize a series of experiments with genetically modified mice revealing the roles of main N-methyl-d-aspartate (NMDA) and group I metabotropic glutamate (mGluR1/5) receptor scaffolds in behavior, discuss the clinical implications of the findings, and propose future research directions.
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Affiliation(s)
- Can Gao
- Jiangsu Key Laboratory of Anesthesiology, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu 221004, China.
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Comparing the Efficacy of Oral Sucrose and Acetaminophen in Pain Relief for Ophthalmologic Screening of Retinopathy of Prematurity. ACTA ACUST UNITED AC 2013. [DOI: 10.12691/ajmsm-1-2-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Petrenko AB, Yamakura T, Kohno T, Sakimura K, Baba H. Increased brain monoaminergic tone after the NMDA receptor GluN2A subunit gene knockout is responsible for resistance to the hypnotic effect of nitrous oxide. Eur J Pharmacol 2013; 698:200-5. [DOI: 10.1016/j.ejphar.2012.10.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 10/16/2012] [Accepted: 10/23/2012] [Indexed: 11/30/2022]
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Giusi G, Zizza M, Facciolo RM, Chew SF, Ip YK, Canonaco M. Aestivation and hypoxia-related events share common silent neuron trafficking processes. BMC Neurosci 2012; 13:39. [PMID: 22520032 PMCID: PMC3407487 DOI: 10.1186/1471-2202-13-39] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 04/20/2012] [Indexed: 11/10/2022] Open
Abstract
Background The availability of oxygen is a limiting factor for neuronal survival since low levels account not only for the impairment of physiological activities such as sleep-wake cycle, but above all for ischemic-like neurodegenerative disorders. In an attempt to improve our knowledge concerning the type of molecular mechanisms operating during stressful states like those of hypoxic conditions, attention was focused on eventual transcriptional alterations of some key AMPAergic silent neuronal receptor subtypes (GluR1 and GluR2) along with HSPs and HIF-1α during either a normoxic or a hypoxic aestivation of a typical aquatic aestivator, i.e. the lungfish (Protopterus annectens). Results The identification of partial nucleotide fragments codifying for both AMPA receptor subtypes in Protopterus annectens displayed a putative high degree of similarity to that of not only fish but also to those of amphibians, birds and mammals. qPCR and in situ hybridization supplied a very high (p < 0.001) reduction of GluR1 mRNA expression in diencephalic areas after 6 months of aerial normoxic aestivation (6mAE). Concomitantly, high (p < 0.01) levels of HSP70 mRNAs in hypothalamic, mesencephalic and cerebellar areas of both 6mAE and after 6 months of mud hypoxic aestivation (6mMUD) were detected together with evident apoptotic signals. Surprisingly, very high levels of GluR2 mRNAs were instead detected in thalamic along with mesencephalic areas after 6 days of normoxic (6dAE) and hypoxic (6dMUD) aestivation. Moreover, even short- and long-term hypoxic states featured high levels of HIF-1α and HSP27 transcripts in the different brain regions of the lungfish. Conclusions The distinct transcriptional variations of silent neurons expressing GluR1/2 and HSPs tend to corroborate these factors as determining elements for the physiological success of normoxic and hypoxic aestivation. A distinct switching among these AMPA receptor subtypes during aestivation highlights new potential adaptive strategies operating in key brain regions of the lungfish in relation to oxygen availability. This functional relationship might have therapeutic bearings for hypoxia-related dysfunctions, above all in view of recently identified silent neuron-dependent motor activity ameliorations in mammals.
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Affiliation(s)
- Giuseppina Giusi
- Comparative Neuroanatomy Laboratory, University of Calabria, 87030 Arcavacata di Rende-CS, Italy.
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Hagino Y, Kasai S, Han W, Yamamoto H, Nabeshima T, Mishina M, Ikeda K. Essential role of NMDA receptor channel ε4 subunit (GluN2D) in the effects of phencyclidine, but not methamphetamine. PLoS One 2010; 5:e13722. [PMID: 21060893 PMCID: PMC2965660 DOI: 10.1371/journal.pone.0013722] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 10/05/2010] [Indexed: 11/23/2022] Open
Abstract
Phencyclidine (PCP), a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, increases locomotor activity in rodents and causes schizophrenia-like symptoms in humans. Although activation of the dopamine (DA) pathway is hypothesized to mediate these effects of PCP, the precise mechanisms by which PCP induces its effects remain to be elucidated. The present study investigated the effect of PCP on extracellular levels of DA (DA(ex)) in the striatum and prefrontal cortex (PFC) using in vivo microdialysis in mice lacking the NMDA receptor channel ε1 or ε4 subunit (GluRε1 [GluN2A] or GluRε4 [GluN2D]) and locomotor activity. PCP significantly increased DA(ex) in wildtype and GluRε1 knockout mice, but not in GluRε4 knockout mice, in the striatum and PFC. Acute and repeated administration of PCP did not increase locomotor activity in GluRε4 knockout mice. The present results suggest that PCP enhances dopaminergic transmission and increases locomotor activity by acting at GluRε4.
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Affiliation(s)
- Yoko Hagino
- Division of Psychobiology, Tokyo Institute of Psychiatry, Tokyo, Japan
| | - Shinya Kasai
- Division of Psychobiology, Tokyo Institute of Psychiatry, Tokyo, Japan
| | - Wenhua Han
- Division of Psychobiology, Tokyo Institute of Psychiatry, Tokyo, Japan
| | - Hideko Yamamoto
- Division of Psychobiology, Tokyo Institute of Psychiatry, Tokyo, Japan
| | - Toshitaka Nabeshima
- Comparative Cognitive Science Institutes and Department of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Meijo University, Nagoya, Japan
| | - Masayoshi Mishina
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazutaka Ikeda
- Division of Psychobiology, Tokyo Institute of Psychiatry, Tokyo, Japan
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17
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Affiliation(s)
- Hisashi Mori
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
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18
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Petrenko AB, Yamakura T, Kohno T, Sakimura K, Baba H. Reduced immobilizing properties of isoflurane and nitrous oxide in mutant mice lacking the N-methyl-D-aspartate receptor GluR(epsilon)1 subunit are caused by the secondary effects of gene knockout. Anesth Analg 2010; 110:461-5. [PMID: 19933527 DOI: 10.1213/ane.0b013e3181c76e73] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Until recently, the N-methyl-D-aspartate (NMDA) receptor was considered to possibly mediate the immobility produced by inhaled anesthetics such as isoflurane and nitrous oxide. However, new evidence suggests that the role of this receptor in abolition of the movement response may be less important than previously thought. To provide further evidence supporting or challenging this view, we examined the anesthetic potencies of isoflurane and nitrous oxide in genetically modified animals with established NMDA receptor dysfunction caused by GluRepsilon1 subunit knockout. METHODS The immobilizing properties of inhaled anesthetics in mice quantitated by the minimum alveolar anesthetic concentration (MAC) were evaluated using the classic tail clamp method. RESULTS Compared with wild-type controls, NMDA receptor GluRepsilon1 subunit knockout mice displayed larger isoflurane MAC values indicating a resistance to the immobilizing action of isoflurane. Knockout mice were previously shown to have enhanced monoaminergic tone as a result of genetic manipulation, and this increase in MAC could be abolished in our experiments by pretreatment with the serotonin 5-hydroxytryptamine type 2A receptor antagonist ketanserin or with the dopamine D2 receptor antagonist droperidol at doses that did not affect MAC values in wild-type animals. Mutant mice also displayed resistance to the isoflurane MAC-sparing effect of nitrous oxide, but this resistance was similarly abolished by ketanserin and droperidol. Thus, resistance to the immobilizing action of inhaled anesthetics in knockout mice seems to be secondary to increased monoaminergic activation after knockout rather than a direct result of impaired NMDA receptor function. CONCLUSIONS Our results confirm recent findings indicating no critical contribution of NMDA receptors to the immobility induced by isoflurane and nitrous oxide. In addition, they demonstrate the ability of changes secondary to genetic manipulation to affect the results obtained in global knockout studies.
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Affiliation(s)
- Andrey B Petrenko
- Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi, Niigata 951-8510, Japan.
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19
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Spontaneous hyperactivity in mutant mice lacking the NMDA receptor GluRε1 subunit is aggravated during exposure to 0.1 MAC sevoflurane and is preserved after emergence from sevoflurane anaesthesia. Eur J Anaesthesiol 2008; 25:953-60. [DOI: 10.1017/s0265021508004626] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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20
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Yu TG, Zhang QZ, Zhang ZG, Wang WW, Ji SL, Du GH. Protective effect of ultra low molecular weight heparin on glutamate-induced apoptosis in cortical cells. Yonsei Med J 2008; 49:486-95. [PMID: 18581600 PMCID: PMC2615332 DOI: 10.3349/ymj.2008.49.3.486] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
PURPOSE To investigate the effect of ultra low molecular weight heparin (ULMWH) on glutamate induced apoptosis in rat cortical cells and to explore the possible mechanisms. MATERIALS AND METHODS Cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was first analyzed with Hoechst 33258 and then confirmed by DNA fragmentation. The concentration of free intracellular calcium ([Ca(2+)](i)) was determined with fura-2/AM fluorometry. The expression of Bcl-2 family protein and caspase-3 were evaluated with Western blot. RESULTS Typical apoptotic morphological change in rat cortical cells treated with 100 micromol/L glutamate for 24h was detected by Hoechst 33258 staining, which was then confirmed by the DNA ladder of agarose gel electrophoresis. The apoptotic rate of the glutamate treated cells was up to 33.21%, and 24 h of treatment with glutamate increased [Ca(2+)](i), down-regulated Bcl-2 expression, up-regulated Bax expression, and increased caspase-3 activation in rat cortical cells. Our research demonstrated that ULMWH pretreatment can prevent the glutamate-induced apoptosis, attenuate the increase of [Ca(2+)](i) not only in medium containing Ca(2+) but also in Ca(2+)-free medium, up-regulate the expression of Bcl-2, down-regulate the expression of Bax, and decrease caspase-3 activation. CONCLUSION ULMWH has neuroprotective capacity to antagonize glutamate-induced apoptosis in cortical cells, through decrease of Ca(2+) release and modulation of apoptotic processes.
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Affiliation(s)
- Tian-Gui Yu
- Pharmacological Institute of New Drugs, School of Pharmacy, Shandong University, 44 Wen Hua Xi Road, Jinan, China
| | - Qing-Zhu Zhang
- Pharmacological Institute of New Drugs, School of Pharmacy, Shandong University, 44 Wen Hua Xi Road, Jinan, China
| | - Zhi-Guo Zhang
- Pharmacological Institute of New Drugs, School of Pharmacy, Shandong University, 44 Wen Hua Xi Road, Jinan, China
| | - Wei-Wei Wang
- Pharmacological Institute of New Drugs, School of Pharmacy, Shandong University, 44 Wen Hua Xi Road, Jinan, China
| | - Sheng-Li Ji
- Institute of Biochemical and Biotechnological Drugs, School of Pharmacy, Shandong University, 44 Wen Hua Xi Road, Jinan, China
| | - Guan-Hua Du
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
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21
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Matsuo M, Takahashi Y, Taniguchi K, Sasaki K, Hamasaki Y. Chronic myoclonia of subcortical origin with antiglutamate receptor antibodies. J Child Neurol 2007; 22:1393-6. [PMID: 18174558 DOI: 10.1177/0883073807307089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We report a 10-year-old girl with chronic nonprogressive continuous myoclonia with mild muscle weakness and dissociated sensory impairment of the ipsilateral side of myoclonic jerks. Irregular myoclonic jerks continuously appeared in the right upper limb. The jerk-locked back averaging of electroencephalographic activity failed to show any activity preceded by the muscle contraction. Magnetic resonance imaging of the brain and cervical spine revealed no abnormal findings. Single photon emission computed tomography showed an increased blood perfusion in the left thalamus. (18)F-deoxyglucose-positron emission tomography (PET) also showed a slight high density in the posterior region of the left thalamus. Antiglutamate receptor epsilon2 and delta2 antibodies were detected in the serum and cerebrospinal fluid. The patient's symptoms have now been stable with clonazepam treatment for 2 years. The left thalamus was suspected to have been the region at least partly responsible for the patient's symptoms.
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Affiliation(s)
- Muneaki Matsuo
- Department of Pediatrics, Faculty of Medicine, Saga University, Saga, Japan.
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22
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Piochon C, Irinopoulou T, Brusciano D, Bailly Y, Mariani J, Levenes C. NMDA receptor contribution to the climbing fiber response in the adult mouse Purkinje cell. J Neurosci 2007; 27:10797-809. [PMID: 17913913 PMCID: PMC6672834 DOI: 10.1523/jneurosci.2422-07.2007] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Among integrative neurons displaying long-term synaptic plasticity, adult Purkinje cells seemed to be an exception by lacking functional NMDA receptors (NMDA-Rs). Although numerous anatomical studies have shown both NR1 and NR2 NMDA-R subunits in adult Purkinje cells, patch-clamp studies failed to detect any NMDA currents. Using more recent pharmacological and immunodetection tools, we demonstrate here that Purkinje cells from adult mice respond to exogenous NMDA application and that postsynaptic NMDA-Rs carry part of the climbing fiber-mediated EPSC (CF-EPSC), with undetectable contribution from presynaptic or polysynaptic NMDA currents. We also detect NR2-A/B subunits in adult Purkinje cells by immunohistochemistry. The NMDA-mediated CF-EPSC is barely detectable before 3 weeks postnatal. From the end of the third week, the number of cells displaying the NMDA-mediated CF-EPSC rapidly increases. Soon, this EPSC becomes detectable in all the Purkinje cells but is still very small. Its amplitude continues to increase until 12 weeks after birth. In mature Purkinje cells, we show that the NMDA-Rs contribute to the depolarizing plateau of complex spikes and increase their number of spikelets. Together, these observations demonstrate that mature Purkinje cells express functional NMDA receptors that become detectable in CF-EPSCs at approximately 21 d after birth and control the complex spike waveform.
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Affiliation(s)
- Claire Piochon
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche (UMR) 7102, Centre National de la Recherche Scientifique (CNRS), Laboratoire Neurobiologie des Processus Adaptifs, Équipe Développement et Vieillissement du Système Nerveux, 75005 Paris, France
| | - Theano Irinopoulou
- Unité 536/Unité 706, Inserm, Institut du Fer à Moulin, F-75005 Paris, France
| | - Daniel Brusciano
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche (UMR) 7102, Centre National de la Recherche Scientifique (CNRS), Laboratoire Neurobiologie des Processus Adaptifs, Équipe Développement et Vieillissement du Système Nerveux, 75005 Paris, France
| | - Yannick Bailly
- Neurotransmission et Sécrétion Neuroendocrine, Institut des Neurosciences Cellulaires et Intégratives UMR 7168, CNRS, Université Louis Pasteur, 67084 Strasbourg, France, and
| | - Jean Mariani
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche (UMR) 7102, Centre National de la Recherche Scientifique (CNRS), Laboratoire Neurobiologie des Processus Adaptifs, Équipe Développement et Vieillissement du Système Nerveux, 75005 Paris, France
- Hôpital Charles Foix, Assistance Publique–Hôpitaux de Paris, 94 Ivry sur Seine, France
| | - Carole Levenes
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche (UMR) 7102, Centre National de la Recherche Scientifique (CNRS), Laboratoire Neurobiologie des Processus Adaptifs, Équipe Développement et Vieillissement du Système Nerveux, 75005 Paris, France
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Petrenko AB, Yamakura T, Askalany AR, Kohno T, Sakimura K, Baba H. Effects of ketamine on acute somatic nociception in wild-type and N-methyl-d-aspartate (NMDA) receptor ɛ1 subunit knockout mice. Neuropharmacology 2006; 50:741-7. [PMID: 16427663 DOI: 10.1016/j.neuropharm.2005.11.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Revised: 11/14/2005] [Accepted: 11/29/2005] [Indexed: 10/25/2022]
Abstract
Although the properties of ketamine appear to be well characterized, there is a lot of ambiguity in the literature regarding its analgesic effects. After careful selection of proper experimental conditions and drug doses, we systematically characterized the effects of systemic ketamine on acute somatic nociception in mice and examined the role of the NMDA receptor epsilon1 subunit in mediating its analgesia. Intraperitoneal administration of ketamine was not analgesic in any of the phasic pain assays (thermal, mechanical, electrical) applied to C57BL/6 (wild-type) and NMDA receptor epsilon1 subunit knockout (mutant) mice. Surprisingly, rather than being analgesic for thermal nociception, ketamine showed pronociceptive properties in case of low-intensity heat stimulation in wild-type mice. In the formalin test (tonic pain), ketamine significantly reduced phase 2 nociceptive behavior in both wild-type and mutant mice. These data indicate that in wild-type mice ketamine has no analgesic effect on phasic pain in normal somatic tissues, but alleviates tonic pain after inflammation. Such analgesic spectrum of ketamine can be fully explained by its NMDA receptor antagonist properties. The results for the mutant mice suggest that the epsilon1 subunit of the NMDA receptor does not mediate the analgesic effects of ketamine in tonic pain.
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Affiliation(s)
- Andrey B Petrenko
- Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi 1-757, Niigata 951-8510, Japan
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Noguchi J, Matsuzaki M, Ellis-Davies GCR, Kasai H. Spine-neck geometry determines NMDA receptor-dependent Ca2+ signaling in dendrites. Neuron 2005; 46:609-22. [PMID: 15944129 PMCID: PMC4151245 DOI: 10.1016/j.neuron.2005.03.015] [Citation(s) in RCA: 318] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Revised: 02/03/2005] [Accepted: 03/11/2005] [Indexed: 10/25/2022]
Abstract
Increases in cytosolic Ca2+ concentration ([Ca2+]i) mediated by NMDA-sensitive glutamate receptors (NMDARs) are important for synaptic plasticity. We studied a wide variety of dendritic spines on rat CA1 pyramidal neurons in acute hippocampal slices. Two-photon uncaging and Ca2+ imaging revealed that NMDAR-mediated currents increased with spine-head volume and that even the smallest spines contained a significant number of NMDARs. The fate of Ca2+ that entered spine heads through NMDARs was governed by the shape (length and radius) of the spine neck. Larger spines had necks that permitted greater efflux of Ca2+ into the dendritic shaft, whereas smaller spines manifested a larger increase in [Ca2+]i within the spine compartment as a result of a smaller Ca2+ flux through the neck. Spine-neck geometry is thus an important determinant of spine Ca2+ signaling, allowing small spines to be the preferential sites for isolated induction of long-term potentiation.
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Affiliation(s)
- Jun Noguchi
- Department of Cell Physiology, National Institute for Physiological Sciences and Graduate University of Advanced Studies (SOKENDAI), Myodaiji, Okazaki 444-8787, Japan
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Rassoulpour A, Wu HQ, Albuquerque EX, Schwarcz R. Prolonged nicotine administration results in biphasic, brain-specific changes in kynurenate levels in the rat. Neuropsychopharmacology 2005; 30:697-704. [PMID: 15496939 DOI: 10.1038/sj.npp.1300583] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The content of the endogenous NMDA and alpha7 nicotinic acetylcholine receptor antagonist kynurenate (KYNA) is increased in the cerebral cortex and cerebrospinal fluid of patients with schizophrenia. In view of the very high incidence of smoking in schizophrenic individuals, a study was designed to examine the effect of acute and prolonged nicotine administration on brain KYNA levels in experimental animals. Adult male rats received subcutaneous nicotine injections twice daily for up to 10 days, and animals were routinely killed 1 h after the last injection. Neither acute treatment nor a 2-day regimen with 1 mg/kg nicotine (= 0.35 mg/kg pure base) caused changes in cerebral KYNA levels. Four- or 6 day-treatment with this dose resulted in 20-40% decreases in cerebral KYNA content. Animals treated with 1 or 10 mg/kg nicotine for 10 days showed dose-dependent, significant increases in KYNA in hippocampus, striatum, and cortex, but not in the serum. Discontinuation of nicotine treatment for 7 days restored brain KYNA to control levels. Separate animals, implanted with osmotic minipumps delivering 2 mg/kg of nicotine/day for 10 days also showed significant elevations in brain KYNA. Hippocampal microdialysis, performed in animals receiving nicotine (1 mg/kg) for 10 days, revealed a significant increase in basal extracellular KYNA levels compared to controls, whereas acute treatment with this dose produced no such change. Measurements of KYNA's bioprecursor kynurenine in brain or blood did not reveal any nicotine-induced changes. These results indicate that nicotine has a brain-specific, biphasic effect on the transamination of kynurenine to KYNA. Such nicotine-induced fluctuations in brain KYNA may cause functional changes in processes that regulate glutamatergic and cholinergic neurotransmission in the normal and diseased brain.
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Affiliation(s)
- Arash Rassoulpour
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA
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