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Li GG, Xu YH, Sun MZ, Bing YH, Jin WZ, Qiu DL. Etomidate enhances cerebellar CF-PC synaptic plasticity through CB1 receptor/PKA cascade in vitro in mice. Neurosci Lett 2024; 826:137733. [PMID: 38492880 DOI: 10.1016/j.neulet.2024.137733] [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: 02/20/2024] [Revised: 02/28/2024] [Accepted: 03/13/2024] [Indexed: 03/18/2024]
Abstract
Etomidate (ET) is a widely used intravenous imidazole general anesthetic, which depresses the cerebellar neuronal activity by modulating various receptors activity and synaptic transmission. In this study, we investigated the effects of ET on the cerebellar climbing fiber-Purkinje cells (CF-PC) plasticity in vitro in mice using whole-cell recording technique and pharmacological methods. Our results demonstrated that CF tetanic stimulation produced a mGluR1-dependent long-term depression (LTD) of CF-PC excitatory postsynaptic currents (EPSCs), which was enhanced by bath application of ET (10 µM). Blockade of mGluR1 receptor with JNJ16259685, ET triggered the tetanic stimulation to induce a CF-PC LTD accompanied with an increase in paired-pulse ratio (PPR). The ET-triggered CF-PC LTD was abolished by extracellular administration of an N-methyl-(D)-aspartate (NMDA) receptor antagonist, D-APV, as well as by intracellular blockade of NMDA receptors activity with MK801. Furthermore, blocking cannabinoids 1 (CB1) receptor with AM251 or chelating intracellular Ca2+ with BAPTA, ET failed to trigger the CF-PC LTD. Moreover, the ET-triggered CF-PC LTD was abolished by inhibition of protein kinase A (PKA), but not by inhibition of protein kinase C inhibiter. The present results suggest that ET acts on postsynaptic NMDA receptor resulting in an enhancement of the cerebellar CF-PC LTD through CB1 receptor/PKA cascade in vitro in mice. These results provide new evidence and possible mechanism for ET anesthesia to affect motor learning and motor coordination by regulating cerebellar CF-PC LTD.
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Affiliation(s)
- Guang-Gao Li
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji City, Jilin Province 133002, China; Department of Orthopedics, Affiliated Hospital of Yanbian University, Yanji City, Jilin Province 133000, China
| | - Ying-Han Xu
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji City, Jilin Province 133002, China; Department of Orthopedics, Affiliated Hospital of Yanbian University, Yanji City, Jilin Province 133000, China
| | - Ming-Ze Sun
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji City, Jilin Province 133002, China; Institute of Brain Science, Jilin Medical University, Jilin City, Jilin Province 132013, China
| | - Yan-Hua Bing
- Functional Experiment Center, College of Medicine, Yanbian University, Yanji City, Jilin Province 133000, China
| | - Wen-Zhe Jin
- Department of Pain, Affiliated Hospital of Yanbian University, Yanji City, Jilin Province 133000, China
| | - De-Lai Qiu
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji City, Jilin Province 133002, China; Institute of Brain Science, Jilin Medical University, Jilin City, Jilin Province 132013, China; Department of Physiology, College of Basic Medicine, Jilin Meidcal University, Jilin City, Jilin Province 132013, China.
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2
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Xu FX, Wang XT, Cai XY, Liu JY, Guo JW, Yang F, Chen W, Schonewille M, De Zeeuw C, Zhou L, Shen Y. Purkinje-cell-specific MeCP2 deficiency leads to motor deficits and autistic-like behavior due to aberrations in PTP1B-TrkB-SK signaling. Cell Rep 2023; 42:113559. [PMID: 38100348 DOI: 10.1016/j.celrep.2023.113559] [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: 10/27/2022] [Revised: 10/05/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023] Open
Abstract
Patients with Rett syndrome suffer from a loss-of-function mutation of the Mecp2 gene, which results in various symptoms including autistic traits and motor deficits. Deletion of Mecp2 in the brain mimics part of these symptoms, but the specific function of methyl-CpG-binding protein 2 (MeCP2) in the cerebellum remains to be elucidated. Here, we demonstrate that Mecp2 deletion in Purkinje cells (PCs) reduces their intrinsic excitability through a signaling pathway comprising the small-conductance calcium-activated potassium channel PTP1B and TrkB, the receptor of brain-derived neurotrophic factor. Aberration of this cascade, in turn, leads to autistic-like behaviors as well as reduced vestibulocerebellar motor learning. Interestingly, increasing activity of TrkB in PCs is sufficient to rescue PC dysfunction and abnormal motor and non-motor behaviors caused by Mecp2 deficiency. Our findings highlight how PC dysfunction may contribute to Rett syndrome, providing insight into the underlying mechanism and paving the way for rational therapeutic designs.
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Affiliation(s)
- Fang-Xiao Xu
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China
| | - Xin-Tai Wang
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China; Institute of Life Sciences, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Xin-Yu Cai
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China
| | - Jia-Yu Liu
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China
| | - Jing-Wen Guo
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China
| | - Fan Yang
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Wei Chen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China
| | - Martijn Schonewille
- Department of Neuroscience, Erasmus University Medical Center, 3000 DR Rotterdam, the Netherlands
| | - Chris De Zeeuw
- Department of Neuroscience, Erasmus University Medical Center, 3000 DR Rotterdam, the Netherlands; The Netherlands Institute for Neuroscience, Royal Dutch Academy of Arts and Science, 1105 CA Amsterdam, the Netherlands.
| | - Lin Zhou
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China.
| | - Ying Shen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China; International Institutes of Medicine, Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China; Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310000, China.
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3
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Ablation of TFR1 in Purkinje Cells Inhibits mGlu1 Trafficking and Impairs Motor Coordination, But Not Autistic-Like Behaviors. J Neurosci 2017; 37:11335-11352. [PMID: 29054881 DOI: 10.1523/jneurosci.1223-17.2017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/28/2017] [Accepted: 10/06/2017] [Indexed: 11/21/2022] Open
Abstract
Group 1 metabotropic glutamate receptors (mGlu1/5s) are critical to synapse formation and participate in synaptic LTP and LTD in the brain. mGlu1/5 signaling alterations have been documented in cognitive impairment, neurodegenerative disorders, and psychiatric diseases, but underlying mechanisms for its modulation are not clear. Here, we report that transferrin receptor 1 (TFR1), a transmembrane protein of the clathrin complex, modulates the trafficking of mGlu1 in cerebellar Purkinje cells (PCs) from male mice. We show that conditional knock-out of TFR1 in PCs does not affect the cytoarchitecture of PCs, but reduces mGlu1 expression at synapses. This regulation by TFR1 acts in concert with that by Rab8 and Rab11, which modulate the internalization and recycling of mGlu1, respectively. TFR1 can bind to Rab proteins and facilitate their expression at synapses. PC ablation of TFR1 inhibits parallel fiber-PC LTD, whereas parallel fiber-LTP and PC intrinsic excitability are not affected. Finally, we demonstrate that PC ablation of TFR1 impairs motor coordination, but does not affect social behaviors in mice. Together, these findings underscore the importance of TFR1 in regulating mGlu1 trafficking and suggest that mGlu1- and mGlu1-dependent parallel fiber-LTD are associated with regulation of motor coordination, but not autistic behaviors.SIGNIFICANCE STATEMENT Group 1 metabotropic glutamate receptor (mGlu1/5) signaling alterations have been documented in cognitive impairment, neurodegenerative disorders, and psychiatric diseases. Recent work suggests that altered mGlu1 signaling in Purkinje cells (PCs) may be involved in not only motor learning, but also autistic-like behaviors. We find that conditional knock-out of transferrin receptor 1 (TFR1) in PCs reduces synaptic mGlu1 by tethering Rab8 and Rab11 in the cytosol. PC ablation of TFR1 inhibits parallel fiber-PC LTD, whereas parallel fiber-PC LTP and PC intrinsic excitability are intact. Motor coordination is impaired, but social behaviors are normal in TFR1flox/flox;pCP2-cre mice. Our data reveal a new regulator for trafficking and synaptic expression of mGlu1 and suggest that mGlu1-dependent LTD is associated with motor coordination, but not autistic-like behaviors.
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Jiang NW, Wang DJ, Xie YJ, Zhou L, Su LD, Li H, Wang QW, Shen Y. Downregulation of Glutamate Transporter EAAT4 by Conditional Knockout of Rheb1 in Cerebellar Purkinje Cells. THE CEREBELLUM 2017; 15:314-21. [PMID: 26194056 DOI: 10.1007/s12311-015-0701-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Excitatory amino acid transporter 4 (EAAT4) is believed to be critical to the synaptic activity of cerebellar Purkinje cells by limiting extracellular glutamate concentrations and facilitating the induction of long-term depression. However, the modulation of EAAT4 expression has not been elucidated. It has been shown that Ras homolog enriched in brain (Rheb)/mammalian target of rapamycin (mTOR) signaling plays essential roles in the regulation of protein translation, cell size, and cell growth. In addition, we previously found that a cascade including mTOR suppression and Akt activation induces increased expression of EAAT2 in astrocytes. In the present work, we explored whether Rheb/mTOR signaling is involved in the regulation of EAAT4 expression using conditional Rheb1 knockout mice. Our results demonstrated that Rheb1 deficiency resulted in the downregulation of EAAT4 expression, as well as decreased activity of mTOR and increased activity of Akt. The downregulation of EAAT4 was also confirmed by reduced EAAT4 currents and slowed kinetics of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor-mediated currents. On the other hand, conditional knockout of Rheb1 did not alter the morphology of Purkinje cell layer and the number of Purkinje cells. Overall, our findings suggest that small GTPase Rheb1 is a modulator in the expression of EAAT4 in Purkinje cells.
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Affiliation(s)
- Nan-Wei Jiang
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, Department of Physiology and Pharmacology, Ningbo University School of Medicine, Ningbo, 315211, China
| | - De-Juan Wang
- Department of Neurobiology, Zhejiang University School of Medicine, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Ya-Jun Xie
- Department of Neurobiology, Zhejiang University School of Medicine, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Liang Zhou
- Department of Neurobiology, Zhejiang University School of Medicine, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Li-Da Su
- Department of Neurobiology, Zhejiang University School of Medicine, 866 Yu Hang Tang Road, Hangzhou, 310058, China.,Neuroscience Care Unit, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Huashun Li
- Shenzhen Key laboratory for Molecular Biology of Neural Development, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Qin-Wen Wang
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, Department of Physiology and Pharmacology, Ningbo University School of Medicine, Ningbo, 315211, China.
| | - Ying Shen
- Department of Neurobiology, Zhejiang University School of Medicine, 866 Yu Hang Tang Road, Hangzhou, 310058, China.
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5
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Chrobak AA, Soltys Z. Bergmann Glia, Long-Term Depression, and Autism Spectrum Disorder. Mol Neurobiol 2016; 54:1156-1166. [PMID: 26809583 PMCID: PMC5310553 DOI: 10.1007/s12035-016-9719-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/12/2016] [Indexed: 12/22/2022]
Abstract
Bergmann glia (BG), a specific type of radial astrocytes in the cerebellum, play a variety of vital functions in the development of this structure. However, the possible role of BG in the development of abnormalities observed in individuals with autism spectrum disorder (ASD) seems to be underestimated. One of the most consistent findings observed in ASD patients is loss of Purkinje cells (PCs). Such a defect may be caused by dysregulation of glutamate homeostasis, which is maintained mainly by BG. Moreover, these glial cells are involved in long-term depression (LTD), a form of plasticity which can additionally subserve neuroprotective functions. The aim of presented review is to summarize the current knowledge about interactions which occur between PC and BG, with special emphasis on those which are relevant to the survival and proper functioning of cerebellar neurons.
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Affiliation(s)
- Adrian Andrzej Chrobak
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Gronostajowa St. 9, Cracow, 30-387, Poland. .,Faculty of Medicine, Jagiellonian University Medical College, Kopernika St. 21A, Cracow, 31-501, Poland.
| | - Zbigniew Soltys
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Gronostajowa St. 9, Cracow, 30-387, Poland
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Smeets CJLM, Verbeek DS. Climbing fibers in spinocerebellar ataxia: A mechanism for the loss of motor control. Neurobiol Dis 2016; 88:96-106. [PMID: 26792399 DOI: 10.1016/j.nbd.2016.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 11/19/2015] [Accepted: 01/09/2016] [Indexed: 11/26/2022] Open
Abstract
The spinocerebellar ataxias (SCAs) form an ever-growing group of neurodegenerative disorders causing dysfunction of the cerebellum and loss of motor control in patients. Currently, 41 different genetic causes have been identified, with each mutation affecting a different gene. Interestingly, these diverse genetic causes all disrupt cerebellar function and produce similar symptoms in patients. In order to understand the disease better, and define possible therapeutic targets for multiple SCAs, the field has been searching for common ground among the SCAs. In this review, we discuss the physiology of climbing fibers and the possibility that climbing fiber dysfunction is a point of convergence for at least a subset of SCAs.
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Affiliation(s)
- C J L M Smeets
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - D S Verbeek
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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7
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Long-term potentiation at cerebellar parallel fiber-Purkinje cell synapses requires presynaptic and postsynaptic signaling cascades. J Neurosci 2014; 34:2355-64. [PMID: 24501374 DOI: 10.1523/jneurosci.4064-13.2014] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Long-term depression (LTD) and long-term potentiation (LTP) at cerebellar parallel fiber-Purkinje cell (PF-PC) synapses play critical roles in motor learning. The 1 Hz stimulation at PF-PC synapses induces a postsynaptically expressed LTP that requires a postsynaptic Ca(2+) transient, phosphatases, and nitric oxide (NO). However, the mechanism underlying 1 Hz PF-LTP remains unclear because none of the known events is related to each other. Here, we demonstrated that 1 Hz PF-LTP requires postsynaptic cytosolic phospholipase A2 α (cPLA2α)/arachidonic acid (AA) signaling and presynaptic endocannabinoid receptors. Using patch-clamp recording in cerebellar slices, we found that 1 Hz PF-LTP was abolished in cPLA2α-knock-out mice. This deficit was effectively rescued by the conjunction of 1 Hz PF stimulation and the local application of AA. 2-Arachidonoylglycerol and the retrograde activation of cannabinoid receptor 1 (CB1R) were also involved in 1 Hz LTP because it was blocked by the hydrolysis of 2-AG or by inhibiting CB1Rs. The amount of NO released was detected using an NO electrode in cultured granule cells and PF terminals. Our results showed that the activation of CB1Rs at PF terminals activated NO synthetase and promoted NO production. The 1 Hz PF-stimuli evoked limited NO, but 100 Hz PF stimulation generated a large amount. Therefore, 1 Hz PF-LTP, distinct from classical postsynaptically expressed plasticity, requires concurrent presynaptic and postsynaptic activity. In addition, NO of sufficient amplitude decides between the weakening and strengthening of PF-PC synapses.
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8
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Wang Z, Wang YN, Sun CL, Yang D, Su LD, Xie YJ, Zhou L, Wang Y, Shen Y. C-terminal domain of ICA69 interacts with PICK1 and acts on trafficking of PICK1-PKCα complex and cerebellar plasticity. PLoS One 2013; 8:e83862. [PMID: 24358315 PMCID: PMC3865253 DOI: 10.1371/journal.pone.0083862] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 11/08/2013] [Indexed: 01/19/2023] Open
Abstract
Background PICK1 (protein interacting with C-kinase 1) is a PKC (protein kinase C)-binding protein, which is essential for synaptic plasticity. The trafficking of PKCα-PICK1 complex to plasma membrane is critical for the internalization of GluR2 and induction of long-term depression. ICA69 (islet cell autoantigen 69 kDa) is identified as a major binding partner of PICK1. While heteromeric BAR domain complex is suggested to underlie the interaction between PICK1 and ICA69, the role of C-terminal domain of ICA69 (ICAC) in PICK1-ICA69 complex is unknown. Methodology/Principal Findings We found that ICAC interacted with PICK1 and regulated the trafficking of PICK1-PKCα complex. ICAC and ΔICAC (containing BAR domain) might function distinctly in the association of ICA69 with PICK1. While ΔICAC domain inclined to form clusters, the distribution of ICAC was diffuse. The trafficking of PICK1 to plasma membrane mediated by activated PKCα was inhibited by ICA69. This action might ascribe to ICAC, because overexpression of ICAC, but not ΔICAC, interrupted PKCα-mediated PICK1 trafficking. Notably, infusion of maltose binding protein (MBP) fusion protein, MBP-ICA69 or MBP-ICAC, in cerebellar Purkinje cells significantly inhibited the induction of long-term depression at parallel fiber- and climbing fiber-Purkinje cell synapses. Conclusions Our experiments showed that ICAC is an important domain for the ICA69-PICK1 interaction and plays essential roles in PICK1-mediated neuronal plasticity.
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Affiliation(s)
- Zhen Wang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Ya-Nan Wang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Cheng-Long Sun
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Dong Yang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Li-Da Su
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Ya-Jun Xie
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Lin Zhou
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Yin Wang
- Department of Neurobiology, Center of Scientific Technology, Cranial Cerebral Disease Laboratory, Ningxia Medical University, Yinchuan, P. R. China
| | - Ying Shen
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, P. R. China
- * E-mail:
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9
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Wang DJ, Yang D, Su LD, Xie YJ, Zhou L, Sun CL, Wang Y, Wang XX, Zhou L, Shen Y. Cytosolic phospholipase A2 alpha/arachidonic acid signaling mediates depolarization-induced suppression of excitation in the cerebellum. PLoS One 2012; 7:e41499. [PMID: 22927908 PMCID: PMC3425552 DOI: 10.1371/journal.pone.0041499] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Accepted: 06/21/2012] [Indexed: 12/22/2022] Open
Abstract
Background Depolarization-induced suppression of excitation (DSE) at parallel fiber-Purkinje cell synapse is an endocannabinoid-mediated short-term retrograde plasticity. Intracellular Ca2+ elevation is critical for the endocannabinoid production and DSE. Nevertheless, how elevated Ca2+ leads to DSE is unclear. Methodology/Principal Findings We utilized cytosolic phospholipase A2 alpha (cPLA2α) knock-out mice and whole-cell patch clamp in cerebellar slices to observed the action of cPLA2α/arachidonic acid signaling on DSE at parallel fiber-Purkinje cell synapse. Our data showed that DSE was significantly inhibited in cPLA2α knock-out mice, which was rescued by arachidonic acid. The degradation enzyme of 2-arachidonoylglycerol (2-AG), monoacylglycerol lipase (MAGL), blocked DSE, while another catabolism enzyme for N-arachidonoylethanolamine (AEA), fatty acid amide hydrolase (FAAH), did not affect DSE. These results suggested that 2-AG is responsible for DSE in Purkinje cells. Co-application of paxilline reversed the blockade of DSE by internal K+, indicating that large conductance Ca2+-activated potassium channel (BK) is sufficient to inhibit cPLA2α/arachidonic acid-mediated DSE. In addition, we showed that the release of 2-AG was independent of soluble NSF attachment protein receptor (SNARE), protein kinase C and protein kinase A. Conclusions/Significance Our data first showed that cPLA2α/arachidonic acid/2-AG signaling pathway mediates DSE at parallel fiber-Purkinje cell synapse.
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Affiliation(s)
- De-Juan Wang
- Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Dong Yang
- Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Li-Da Su
- Neuroscience Care Unit, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Ya-jun Xie
- Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Lin Zhou
- Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Cheng-Long Sun
- Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Yin Wang
- Department of Neurobiology, Center of Scientific Technology, Cranial Cerebral Disease Lab, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Xin-Xin Wang
- Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Liang Zhou
- Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Ying Shen
- Key Laboratory of Medical Neurobiology of the Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
- * E-mail:
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10
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Su LD, Sun CL, Shen Y. Ethanol acutely modulates mGluR1-dependent long-term depression in cerebellum. Alcohol Clin Exp Res 2010; 34:1140-5. [PMID: 20477778 DOI: 10.1111/j.1530-0277.2010.01190.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Acute and chronic ethanol exposure produces profound impairments in motor functioning. Individuals with lower sensitivity to the acute motor impairing effects of ethanol have an increased risk of developing alcohol dependence and abuse, and infants with subtle delays in motor coordination development may have an increased risk for subsequently developing alcoholism. Thus, understanding the mechanism by which ethanol disrupts motor functioning is very important. METHODS Parasagittal slices of the cerebellar vermis (250 microM thick) were prepared from P17 to 20 Sprague-Dawley rats. Whole-cell recordings of Purkinje cells were obtained with an Axopatch 200B amplifier. Parallel fiber-Purkinje cell synaptic currents were sampled at 1 kHz and digitized at 10 kHz, and synaptic long-term depression (LTD) was observed in either external or internal application of ethanol for comparison. RESULTS We determined whether ethanol acutely affects parallel fiber LTD using whole-cell patch-clamp recordings from Purkinje cells. Application of ethanol both externally (50 mM) and internally (17 and 10 mM) significantly suppressed mGluR-mediate slow currents. Short-term external ethanol exposure (50 but not 17 mM) during tetanus blocked mGluR-dependent parallel fiber LTD. Furthermore, internal 17 and 10 mM ethanol completely inhibited this LTD. CONCLUSIONS The results of the current study demonstrate that ethanol acutely suppresses parallel fiber LTD and may influence the mGluR-mediated slow current intracellularly. This study, plus previous evidence by Carta and colleagues (2006) and Belmeguenai and colleagues (2008), suggests significant actions of ethanol on mGluR-mediated currents and its dependent plasticity in brain.
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Affiliation(s)
- Li-Da Su
- Department of Neurobiology/Institute of Neuroscience, Zhejiang University School of Medicine, Hangzhou, China
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Schorge S, van de Leemput J, Singleton A, Houlden H, Hardy J. Human ataxias: a genetic dissection of inositol triphosphate receptor (ITPR1)-dependent signaling. Trends Neurosci 2010; 33:211-9. [PMID: 20226542 PMCID: PMC4684264 DOI: 10.1016/j.tins.2010.02.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 02/17/2010] [Accepted: 02/17/2010] [Indexed: 10/19/2022]
Abstract
A persistent mystery about the ataxias has been why mutations in genes--many of which are expressed widely in the brain--primarily cause ataxia, and not, for example, epilepsy or dementia. Why should a polyglutamine stretch in the TATA-binding protein (that is important in all cells) particularly disrupt cerebellar coordination? We propose that advances in the genetics of cerebellar ataxias suggest a rational hypothesis for how so many different genes lead to predominantly cerebellar defects. We argue that the unifying feature of many genes involved in cerebellar ataxias is their impact on the signaling protein ITPR1 (inositiol 1,4,5-triphosphate receptor type 1), that underlies coincidence detection in Purkinje cells and could play an important role in cerebellar coordination.
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Affiliation(s)
- Stephanie Schorge
- Reta Lila Weston Laboratories and Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK
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