1
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Chin M, Kaeser PS. The intracellular C-terminus confers compartment-specific targeting of voltage-gated calcium channels. Cell Rep 2024; 43:114428. [PMID: 38996073 DOI: 10.1016/j.celrep.2024.114428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 06/07/2024] [Accepted: 06/18/2024] [Indexed: 07/14/2024] Open
Abstract
To achieve the functional polarization that underlies brain computation, neurons sort protein material into distinct compartments. Ion channel composition, for example, differs between axons and dendrites, but the molecular determinants for their polarized trafficking remain obscure. Here, we identify mechanisms that target voltage-gated Ca2+ channels (CaVs) to distinct subcellular compartments. In hippocampal neurons, CaV2s trigger neurotransmitter release at the presynaptic active zone, and CaV1s localize somatodendritically. After knockout of all three CaV2s, expression of CaV2.1, but not CaV1.3, restores neurotransmitter release. We find that chimeric CaV1.3s with CaV2.1 intracellular C-termini localize to the active zone, mediate synaptic vesicle exocytosis, and render release sensitive to CaV1 blockers. This dominant targeting function of the CaV2.1 C-terminus requires the first EF hand in its proximal segment, and replacement of the CaV2.1 C-terminus with that of CaV1.3 abolishes CaV2.1 active zone localization and function. We conclude that CaV intracellular C-termini mediate compartment-specific targeting.
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Affiliation(s)
- Morven Chin
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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2
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Duffy BC, King KM, Nepal B, Nonnemacher MR, Kortagere S. Acute Administration of HIV-1 Tat Protein Drives Glutamatergic Alterations in a Rodent Model of HIV-Associated Neurocognitive Disorders. Mol Neurobiol 2024:10.1007/s12035-024-04113-8. [PMID: 38514527 DOI: 10.1007/s12035-024-04113-8] [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: 01/20/2024] [Accepted: 03/12/2024] [Indexed: 03/23/2024]
Abstract
HIV-1-associated neurocognitive disorders (HAND) are a major comorbidity of HIV-1 infection, marked by impairment of executive function varying in severity. HAND affects nearly half of people living with HIV (PLWH), with mild forms predominating since the use of anti-retroviral therapies (ART). The HIV-1 transactivator of transcription (Tat) protein is found in the cerebrospinal fluid of patients adherent to ART, and its administration or expression in animals causes cognitive symptoms. Studies of Tat interaction with the N-methyl-D-aspartate receptor (NMDAR) suggest that glutamate toxicity contributes to Tat-induced impairments. To identify changes in regional glutamatergic circuitry underlying cognitive impairment, we injected recombinant Tat86 or saline to medial prefrontal cortex (mPFC) of male Sprague-Dawley rats. Rats were assessed with behavioral tasks that involve intact functioning of mPFC including the novel object recognition (NOR), spatial object recognition (SOR), and temporal order (TO) tasks at 1 and 2 postoperative weeks. Following testing, mPFC tissue was collected and analyzed by RT-PCR. Results showed Tat86 in mPFC-induced impairment in SOR, and upregulation of Grin1 and Grin2a transcripts. To further understand the mechanism of Tat toxicity, we assessed the effects of full-length Tat101 on gene expression in mPFC by RNA sequencing. The results of RNAseq suggest that glutamatergic effects of Tat86 are maintained with Tat101, as Grin2a was upregulated in Tat101-injected tissue, among other differentially expressed genes. Spatial learning and memory impairment and Grin2a upregulation suggest that exposure to Tat protein drives adaptation in mPFC, altering the function of circuitry supporting spatial learning and memory.
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Affiliation(s)
- Brenna C Duffy
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Kirsten M King
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Binod Nepal
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA.
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA.
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA.
| | - Sandhya Kortagere
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA.
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA.
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3
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Vandael D, Jonas P. Structure, biophysics, and circuit function of a "giant" cortical presynaptic terminal. Science 2024; 383:eadg6757. [PMID: 38452088 DOI: 10.1126/science.adg6757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 01/19/2024] [Indexed: 03/09/2024]
Abstract
The hippocampal mossy fiber synapse, formed between axons of dentate gyrus granule cells and dendrites of CA3 pyramidal neurons, is a key synapse in the trisynaptic circuitry of the hippocampus. Because of its comparatively large size, this synapse is accessible to direct presynaptic recording, allowing a rigorous investigation of the biophysical mechanisms of synaptic transmission and plasticity. Furthermore, because of its placement in the very center of the hippocampal memory circuit, this synapse seems to be critically involved in several higher network functions, such as learning, memory, pattern separation, and pattern completion. Recent work based on new technologies in both nanoanatomy and nanophysiology, including presynaptic patch-clamp recording, paired recording, super-resolution light microscopy, and freeze-fracture and "flash-and-freeze" electron microscopy, has provided new insights into the structure, biophysics, and network function of this intriguing synapse. This brings us one step closer to answering a fundamental question in neuroscience: how basic synaptic properties shape higher network computations.
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Affiliation(s)
- David Vandael
- Institute of Science and Technology Austria (ISTA), A-3400 Klosterneuburg, Austria
| | - Peter Jonas
- Institute of Science and Technology Austria (ISTA), A-3400 Klosterneuburg, Austria
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4
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Lauerer RJ, Lerche H. Voltage-gated calcium channels in genetic epilepsies. J Neurochem 2023. [PMID: 37822150 DOI: 10.1111/jnc.15983] [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: 07/08/2023] [Revised: 09/17/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
Voltage-gated calcium channels (VGCC) are abundant in the central nervous system and serve a broad spectrum of functions, either directly in cellular excitability or indirectly to regulate Ca2+ homeostasis. Ca2+ ions act as one of the main connections in excitation-transcription coupling, muscle contraction and excitation-exocytosis coupling, including synaptic transmission. In recent years, many genes encoding VGCCs main α or additional auxiliary subunits have been associated with epilepsy. This review sums up the current state of knowledge on disease mechanisms and provides guidance on disease-specific therapies where applicable.
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Affiliation(s)
- Robert J Lauerer
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University and University Hospital Tuebingen, Tuebingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University and University Hospital Tuebingen, Tuebingen, Germany
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5
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Fukaya R, Miyano R, Hirai H, Sakaba T. Mechanistic insights into cAMP-mediated presynaptic potentiation at hippocampal mossy fiber synapses. Front Cell Neurosci 2023; 17:1237589. [PMID: 37519634 PMCID: PMC10372368 DOI: 10.3389/fncel.2023.1237589] [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: 06/09/2023] [Accepted: 06/30/2023] [Indexed: 08/01/2023] Open
Abstract
Presynaptic plasticity is an activity-dependent change in the neurotransmitter release and plays a key role in dynamic modulation of synaptic strength. Particularly, presynaptic potentiation mediated by cyclic adenosine monophosphate (cAMP) is widely seen across the animals and thought to contribute to learning and memory. Hippocampal mossy fiber-CA3 pyramidal cell synapses have been used as a model because of robust presynaptic potentiation in short- and long-term forms. Moreover, direct presynaptic recordings from large mossy fiber terminals allow one to dissect the potentiation mechanisms. Recently, super-resolution microscopy and flash-and-freeze electron microscopy have revealed the localizations of release site molecules and synaptic vesicles during the potentiation at a nanoscale, identifying the molecular mechanisms of the potentiation. Incorporating these growing knowledges, we try to present plausible mechanisms underlying the cAMP-mediated presynaptic potentiation.
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Affiliation(s)
- Ryota Fukaya
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Rinako Miyano
- Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| | - Himawari Hirai
- Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| | - Takeshi Sakaba
- Graduate School of Brain Science, Doshisha University, Kyoto, Japan
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6
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Kwak MJ, Kim WY, Jung SH, Chung YJ, Kim JH. Differential transcriptome profile underlying risky choice in a rat gambling task. J Behav Addict 2022; 11:845-857. [PMID: 36094860 PMCID: PMC9872528 DOI: 10.1556/2006.2022.00068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 07/20/2022] [Accepted: 08/22/2022] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND AND AIMS Proper measurement of expected risk is important for making rational decisions, and maladaptive decision making may underlie various psychiatric disorders. However, differentially expressed genetic profiling involved in this process is still largely unknown. A rodent version of the gambling task (rGT) has been developed to measure decision-making by adopting the same principle of Iowa Gambling Task in humans. In the present study, we examined using next-generation sequencing (NGS) technique whether there are differences in gene expression profiles in the medial prefrontal cortex (mPFC) and the nucleus accumbens (NAc) when rats make different choices toward risk in rGT. METHODS Rats were trained in a touch screen chamber to learn the relationships between 4 different light signals on the window of the screen and accompanied reward outcomes or punishments set up with different magnitudes and probabilities. Once they showed a stabilized pattern of preference upon free choice, rats were classified into risk-averse or risk-seeking groups. After performing the rGT, rats were decapitated, the mPFC and the NAc was dissected out, and NGS was performed with the total RNA extracted. RESULTS We found that 477 and 36 genes were differentially expressed (approximately 75 and 83% out of them were downregulated) in the mPFC and the NAc, respectively, in risk-seeking compared to risk-averse rats. Among those, we suggested a few top ranked genes that may contribute to promoting risky choices. DISCUSSION AND CONCLUSIONS Our findings provide insights into transcriptional components underlying risky choices in rats.
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Affiliation(s)
- Myung Ji Kwak
- Department of Medical Sciences, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, South Korea
| | - Wha Young Kim
- Department of Physiology, Yonsei University College of Medicine, Seoul 03722, South Korea
| | - Seung-Hyun Jung
- Department of Biochemistry, Cancer Evolution Research Center, The Catholic University of Korea College of Medicine, Seoul 06591, South Korea,Department of Biomedicine & Health Sciences, The Catholic University of Korea College of Medicine, Seoul 06591, South Korea,Precision Medicine Research Center, The Catholic University of Korea College of Medicine, Seoul 06591, South Korea,Corresponding authors. E-mail: , ,
| | - Yeun-Jun Chung
- Department of Biomedicine & Health Sciences, The Catholic University of Korea College of Medicine, Seoul 06591, South Korea,Precision Medicine Research Center, The Catholic University of Korea College of Medicine, Seoul 06591, South Korea,Department of Microbiology, IRCGP, The Catholic University of Korea College of Medicine, Seoul 06591, South Korea,Corresponding authors. E-mail: , ,
| | - Jeong-Hoon Kim
- Department of Medical Sciences, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, South Korea,Department of Physiology, Yonsei University College of Medicine, Seoul 03722, South Korea,Corresponding authors. E-mail: , ,
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7
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Tan C, Wang SSH, de Nola G, Kaeser PS. Rebuilding essential active zone functions within a synapse. Neuron 2022; 110:1498-1515.e8. [PMID: 35176221 PMCID: PMC9081183 DOI: 10.1016/j.neuron.2022.01.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 12/21/2021] [Accepted: 01/24/2022] [Indexed: 01/15/2023]
Abstract
Presynaptic active zones are molecular machines that control neurotransmitter secretion. They form sites for vesicle docking and priming and couple vesicles to Ca2+ entry for release triggering. The complexity of active zone machinery has made it challenging to determine its mechanisms in release. Simultaneous knockout of the active zone proteins RIM and ELKS disrupts active zone assembly, abolishes vesicle docking, and impairs release. We here rebuild docking, priming, and Ca2+ secretion coupling in these mutants without reinstating active zone networks. Re-expression of RIM zinc fingers recruited Munc13 to undocked vesicles and rendered the vesicles release competent. Action potential triggering of release was reconstituted by docking these primed vesicles to Ca2+ channels through attaching RIM zinc fingers to CaVβ4-subunits. Our work identifies an 80-kDa β4-Zn protein that bypasses the need for megadalton-sized secretory machines, establishes that fusion competence and docking are mechanistically separable, and defines RIM zinc finger-Munc13 complexes as hubs for active zone function.
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Affiliation(s)
- Chao Tan
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Shan Shan H Wang
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Giovanni de Nola
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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8
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Shahoha M, Cohen R, Ben-Simon Y, Ashery U. cAMP-Dependent Synaptic Plasticity at the Hippocampal Mossy Fiber Terminal. Front Synaptic Neurosci 2022; 14:861215. [PMID: 35444523 PMCID: PMC9013808 DOI: 10.3389/fnsyn.2022.861215] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/23/2022] [Indexed: 11/24/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is a crucial second messenger involved in both pre- and postsynaptic plasticity in many neuronal types across species. In the hippocampal mossy fiber (MF) synapse, cAMP mediates presynaptic long-term potentiation and depression. The main cAMP-dependent signaling pathway linked to MF synaptic plasticity acts via the activation of the protein kinase A (PKA) molecular cascade. Accordingly, various downstream putative synaptic PKA target proteins have been linked to cAMP-dependent MF synaptic plasticity, such as synapsin, rabphilin, synaptotagmin-12, RIM1a, tomosyn, and P/Q-type calcium channels. Regulating the expression of some of these proteins alters synaptic release probability and calcium channel clustering, resulting in short- and long-term changes to synaptic efficacy. However, despite decades of research, the exact molecular mechanisms by which cAMP and PKA exert their influences in MF terminals remain largely unknown. Here, we review current knowledge of different cAMP catalysts and potential downstream PKA-dependent molecular cascades, in addition to non-canonical cAMP-dependent but PKA-independent cascades, which might serve as alternative, compensatory or competing pathways to the canonical PKA cascade. Since several other central synapses share a similar form of presynaptic plasticity with the MF, a better description of the molecular mechanisms governing MF plasticity could be key to understanding the relationship between the transcriptional and computational levels across brain regions.
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Affiliation(s)
- Meishar Shahoha
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ronni Cohen
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Yoav Ben-Simon
- Department of Neurophysiology, Vienna Medical University, Vienna, Austria
- *Correspondence: Yoav Ben-Simon,
| | - Uri Ashery
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Uri Ashery,
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9
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Timic Stamenic T, Manzella FM, Maksimovic S, Krishnan K, Covey DF, Jevtovic-Todorovic V, Todorovic SM. Further Evidence that Inhibition of Neuronal Voltage-Gated Calcium Channels Contributes to the Hypnotic Effect of Neurosteroid Analogue, 3β-OH. Front Pharmacol 2022; 13:850658. [PMID: 35677453 PMCID: PMC9169093 DOI: 10.3389/fphar.2022.850658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 04/26/2022] [Indexed: 11/13/2022] Open
Abstract
We recently reported that a neurosteroid analogue with T-channel-blocking properties (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH), induced hypnosis in rat pups without triggering neuronal apoptosis. Furthermore, we found that the inhibition of the CaV3.1 isoform of T-channels contributes to the hypnotic properties of 3β-OH in adult mice. However, the specific mechanisms underlying the role of other subtypes of voltage-gated calcium channels in thalamocortical excitability and oscillations in vivo during 3β-OH-induced hypnosis are largely unknown. Here, we used patch-clamp recordings from acute brain slices, in vivo electroencephalogram (EEG) recordings, and mouse genetics with wild-type (WT) and CaV2.3 knock-out (KO) mice to further investigate the molecular mechanisms of neurosteroid-induced hypnosis. Our voltage-clamp recordings showed that 3β-OH inhibited recombinant CaV2.3 currents. In subsequent current-clamp recordings in thalamic slices ex vivo, we found that selective CaV2.3 channel blocker (SNX-482) inhibited stimulated tonic firing and increased the threshold for rebound burst firing in WT animals. Additionally, in thalamic slices we found that 3β-OH inhibited spike-firing more profoundly in WT than in mutant mice. Furthermore, 3β-OH reduced bursting frequencies in WT but not mutant animals. In ensuing in vivo experiments, we found that intra-peritoneal injections of 3β-OH were less effective in inducing LORR in the mutant mice than in the WT mice, with expected sex differences. Furthermore, the reduction in total α, β, and low γ EEG power was more profound in WT than in CaV2.3 KO females over time, while at 60 min after injections of 3β-OH, the increase in relative β power was higher in mutant females. In addition, 3β-OH depressed EEG power more strongly in the male WT than in the mutant mice and significantly increased the relative δ power oscillations in WT male mice in comparison to the mutant male animals. Our results demonstrate for the first time the importance of the CaV2.3 subtype of voltage-gated calcium channels in thalamocortical excitability and the oscillations that underlie neurosteroid-induced hypnosis.
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Affiliation(s)
- Tamara Timic Stamenic
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
| | - Francesca M Manzella
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
- Neuroscience Graduate Program, University of Colorado, Anschutz Medical Campus, Aurora, United States
| | - Stefan Maksimovic
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, MO, United States
| | - Douglas F Covey
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, MO, United States
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Saint Louis, MO, United States
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
- Neuroscience Graduate Program, University of Colorado, Anschutz Medical Campus, Aurora, United States
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10
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Vandael D, Okamoto Y, Jonas P. Transsynaptic modulation of presynaptic short-term plasticity in hippocampal mossy fiber synapses. Nat Commun 2021; 12:2912. [PMID: 34006874 PMCID: PMC8131630 DOI: 10.1038/s41467-021-23153-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 04/06/2021] [Indexed: 11/21/2022] Open
Abstract
The hippocampal mossy fiber synapse is a key synapse of the trisynaptic circuit. Post-tetanic potentiation (PTP) is the most powerful form of plasticity at this synaptic connection. It is widely believed that mossy fiber PTP is an entirely presynaptic phenomenon, implying that PTP induction is input-specific, and requires neither activity of multiple inputs nor stimulation of postsynaptic neurons. To directly test cooperativity and associativity, we made paired recordings between single mossy fiber terminals and postsynaptic CA3 pyramidal neurons in rat brain slices. By stimulating non-overlapping mossy fiber inputs converging onto single CA3 neurons, we confirm that PTP is input-specific and non-cooperative. Unexpectedly, mossy fiber PTP exhibits anti-associative induction properties. EPSCs show only minimal PTP after combined pre- and postsynaptic high-frequency stimulation with intact postsynaptic Ca2+ signaling, but marked PTP in the absence of postsynaptic spiking and after suppression of postsynaptic Ca2+ signaling (10 mM EGTA). PTP is largely recovered by inhibitors of voltage-gated R- and L-type Ca2+ channels, group II mGluRs, and vacuolar-type H+-ATPase, suggesting the involvement of retrograde vesicular glutamate signaling. Transsynaptic regulation of PTP extends the repertoire of synaptic computations, implementing a brake on mossy fiber detonation and a "smart teacher" function of hippocampal mossy fiber synapses.
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Affiliation(s)
- David Vandael
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Klosterneuburg, Austria.
- Netherlands Institute for Neuroscience, Royal Netherlands Academy for Arts and Sciences (KNAW), Amsterdam, The Netherlands.
| | - Yuji Okamoto
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Klosterneuburg, Austria
| | - Peter Jonas
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Klosterneuburg, Austria.
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11
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Retrograde Suppression of Post-Tetanic Potentiation at the Mossy Fiber-CA3 Pyramidal Cell Synapse. eNeuro 2021; 8:ENEURO.0450-20.2021. [PMID: 33593734 PMCID: PMC7986537 DOI: 10.1523/eneuro.0450-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/17/2020] [Accepted: 01/16/2021] [Indexed: 11/21/2022] Open
Abstract
In the hippocampus, the excitatory synapse between dentate granule cell (GC) axons, or mossy fibers (MFs), and CA3 pyramidal cells (MF-CA3) expresses robust forms of short-term plasticity, such as frequency facilitation and post-tetanic potentiation (PTP). These forms of plasticity are due to increases in presynaptic neurotransmitter release, and can be engaged when dentate GCs fire in bursts (e.g., during exploratory behaviors) and bring CA3 pyramidal neurons above threshold. While frequency facilitation at this synapse is limited by endogenous activation of presynaptic metabotropic glutamate receptors (mGluRs), whether MF-PTP can be regulated in an activity-dependent manner is unknown. Here, using physiologically relevant patterns of MF stimulation in acute mouse hippocampal slices, we found that disrupting postsynaptic Ca2+ dynamics increases MF-PTP, strongly suggesting a form of Ca2+-dependent retrograde suppression of this form of plasticity. PTP suppression requires a few seconds of MF bursting activity and Ca2+ release from internal stores. Our findings raise the possibility that the powerful MF-CA3 synapse can negatively regulate its own strength not only during PTP-inducing activity typical of normal exploratory behaviors, but also during epileptic activity.
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12
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Neumaier F, Schneider T, Albanna W. Ca v2.3 channel function and Zn 2+-induced modulation: potential mechanisms and (patho)physiological relevance. Channels (Austin) 2020; 14:362-379. [PMID: 33079629 PMCID: PMC7583514 DOI: 10.1080/19336950.2020.1829842] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Voltage-gated calcium channels (VGCCs) are critical for Ca2+ influx into all types of excitable cells, but their exact function is still poorly understood. Recent reconstruction of homology models for all human VGCCs at atomic resolution provides the opportunity for a structure-based discussion of VGCC function and novel insights into the mechanisms underlying Ca2+ selective flux through these channels. In the present review, we use these data as a basis to examine the structure, function, and Zn2+-induced modulation of Cav2.3 VGCCs, which mediate native R-type currents and belong to the most enigmatic members of the family. Their unique sensitivity to Zn2+ and the existence of multiple mechanisms of Zn2+ action strongly argue for a role of these channels in the modulatory action of endogenous loosely bound Zn2+, pools of which have been detected in a number of neuronal, endocrine, and reproductive tissues. Following a description of the different mechanisms by which Zn2+ has been shown or is thought to alter the function of these channels, we discuss their potential (patho)physiological relevance, taking into account what is known about the magnitude and function of extracellular Zn2+ signals in different tissues. While still far from complete, the picture that emerges is one where Cav2.3 channel expression parallels the occurrence of loosely bound Zn2+ pools in different tissues and where these channels may serve to translate physiological Zn2+ signals into changes of electrical activity and/or intracellular Ca2+ levels.
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Affiliation(s)
- Felix Neumaier
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5) , Jülich, Germany.,University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute of Radiochemistry and Experimental Molecular Imaging , Cologne, Germany
| | - Toni Schneider
- Institute of Neurophysiology , Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Walid Albanna
- Department of Neurosurgery, RWTH Aachen University , Aachen, Germany
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13
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Dolphin AC, Lee A. Presynaptic calcium channels: specialized control of synaptic neurotransmitter release. Nat Rev Neurosci 2020; 21:213-229. [PMID: 32161339 PMCID: PMC7873717 DOI: 10.1038/s41583-020-0278-2] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2020] [Indexed: 11/09/2022]
Abstract
Chemical synapses are heterogeneous junctions formed between neurons that are specialized for the conversion of electrical impulses into the exocytotic release of neurotransmitters. Voltage-gated Ca2+ channels play a pivotal role in this process as they are the major conduits for the Ca2+ ions that trigger the fusion of neurotransmitter-containing vesicles with the presynaptic membrane. Alterations in the intrinsic function of these channels and their positioning within the active zone can profoundly alter the timing and strength of synaptic output. Advances in optical and electron microscopic imaging, structural biology and molecular techniques have facilitated recent breakthroughs in our understanding of the properties of voltage-gated Ca2+ channels that support their presynaptic functions. Here we examine the nature of these channels, how they are trafficked to and anchored within presynaptic boutons, and the mechanisms that allow them to function optimally in shaping the flow of information through neural circuits.
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Affiliation(s)
- Annette C Dolphin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
| | - Amy Lee
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.
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14
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Abstract
Synaptic plasticity is a fundamental property of neurons referring to the activity-dependent changes in the strength and efficacy of synaptic transmission at preexisting synapses. Such changes can last from milliseconds to hours, days, or even longer and are involved in learning and memory as well as in development and response of the brain to injuries. Several types of synaptic plasticity have been described across neuronal types, brain regions, and species, but all of them share in one way or another capital importance of Ca2+-mediated processes. In this chapter, we will focus on the Ca2+-dependent events necessary for the induction and expression of multiple forms of synaptic plasticity.
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15
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Dumenieu M, Senkov O, Mironov A, Bourinet E, Kreutz MR, Dityatev A, Heine M, Bikbaev A, Lopez-Rojas J. The Low-Threshold Calcium Channel Cav3.2 Mediates Burst Firing of Mature Dentate Granule Cells. Cereb Cortex 2019; 28:2594-2609. [PMID: 29790938 PMCID: PMC5998957 DOI: 10.1093/cercor/bhy084] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Indexed: 12/11/2022] Open
Abstract
Mature granule cells are poorly excitable neurons that were recently shown to fire action potentials, preferentially in bursts. It is believed that the particularly pronounced short-term facilitation of mossy fiber synapses makes granule cell bursting a very effective means of properly transferring information to CA3. However, the mechanism underlying the unique bursting behavior of mature granule cells is currently unknown. Here, we show that Cav3.2 T-type channels at the axon initial segment are responsible for burst firing of mature granule cells in rats and mice. Accordingly, Cav3.2 knockout mice fire tonic spikes and exhibit impaired bursting, synaptic plasticity and dentate-to-CA3 communication. The data show that Cav3.2 channels are strong modulators of bursting and can be considered a critical molecular switch that enables effective information transfer from mature granule cells to the CA3 pyramids.
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Affiliation(s)
- Mael Dumenieu
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Oleg Senkov
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Andrey Mironov
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.,Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.,Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Emmanuel Bourinet
- Calcium Channel Dynamics & Nociception Group, Institute of Functional Genomics, Montpellier, France
| | - Michael R Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany.,Leibniz Group "Dendritic Organelles and Synaptic Function," University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology (ZMNH), Hamburg, Germany
| | - Alexander Dityatev
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany.,Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Martin Heine
- Research Group Molecular Physiology, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Arthur Bikbaev
- Research Group Molecular Physiology, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Jeffrey Lopez-Rojas
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
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16
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Huang C, Yang X, Zeng B, Zeng L, Gong X, Zhou C, Xia J, Lian B, Qin Y, Yang L, Liu L, Xie P. Proteomic analysis of olfactory bulb suggests CACNA1E as a promoter of CREB signaling in microbiota-induced depression. J Proteomics 2019; 194:132-147. [DOI: 10.1016/j.jprot.2018.11.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 11/24/2018] [Accepted: 11/26/2018] [Indexed: 12/18/2022]
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17
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He R, Zhang J, Yu Y, Jizi L, Wang W, Li M. New Insights Into Interactions of Presynaptic Calcium Channel Subtypes and SNARE Proteins in Neurotransmitter Release. Front Mol Neurosci 2018; 11:213. [PMID: 30061813 PMCID: PMC6054978 DOI: 10.3389/fnmol.2018.00213] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 05/30/2018] [Indexed: 12/11/2022] Open
Abstract
Action potential (AP) induces presynaptic membrane depolarization and subsequent opening of Ca2+ channels, and then triggers neurotransmitter release at the active zone of presynaptic terminal. Presynaptic Ca2+ channels and SNARE proteins (SNAREs) interactions form a large signal transfer complex, which are core components for exocytosis. Ca2+ channels serve to regulate the activity of Ca2+ channels through direct binding and indirect activation of active zone proteins and SNAREs. The activation of Ca2+ channels promotes synaptic vesicle recruitment, docking, priming, fusion and neurotransmission release. Intracellular calcium increase is a key step for the initiation of vesicle fusion. Various voltage-gated calcium channel (VGCC) subtypes exert different physiological functions. Until now, it has not been clear how different subtypes of calcium channels integrally regulate the release of neurotransmitters within 200 μs of the AP arriving at the active zone of synaptic terminal. In this mini review, we provide a brief overview of the structure and physiological function of Ca2+ channel subtypes, interactions of Ca2+ channels and SNAREs in neurotransmitter release, and dynamic fine-tune Ca2+ channel activities by G proteins (Gβγ), multiple protein kinases and Ca2+ sensor (CaS) proteins.
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Affiliation(s)
- Rongfang He
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China.,Infectious Disease Department, The Affiliated Hospital of Southwest Medical University, Southwest Medical University, Luzhou, China
| | - Juan Zhang
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Yiyan Yu
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Laluo Jizi
- Department of Neurology, Liangshan Hospital of Integrated Traditional and Western Medicine, Xichang, China
| | - Weizhong Wang
- Department of Physiology and Center of Polar Medical Research, Second Military Medical University, Shanghai, China
| | - Miaoling Li
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
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18
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Hoshino K, Hasegawa K, Kamiya H, Morimoto Y. Synapse-specific effects of IL-1β on long-term potentiation in the mouse hippocampus. Biomed Res 2018. [PMID: 28637953 DOI: 10.2220/biomedres.38.183] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Interleukin-1β (IL-1β) is a key molecule in the inflammatory responses elicited during infection and injury. It exerts local effects on synaptic plasticity by binding to IL-1 receptors that are expressed at high levels in the hippocampus. We examined the effects of IL-1β on synaptic plasticity in different hippocampal regions in acute mouse brain slices by measuring long-term potentiation (LTP). IL-1β (1 ng/mL) was applied for 30 min before LTP was induced with high-frequency stimulation (HFS). LTP was significantly impaired by either IL-1β application to the Schaffer collateral-CA1 synapses or the associational/commissural (A/C) fiber-CA3 synapses, which are both dependent on N-methyl-D-aspartate (NMDA) receptor activation. However, mossy fiber-CA3 LTP, which is expressed presynaptically in an NMDA-independent manner, was not impaired by IL-1β. Our results demonstrate that IL-1β exerts variable effects on LTP at different kinds of synapses, indicating that IL-1β has synapse-specific effects on hippocampal synaptic plasticity.
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Affiliation(s)
- Koji Hoshino
- Department of Anesthesiology and Cristical Care Medicine, Hokkaido University Graduate School of medicine.,Department of Neurobiology, Hokkaido University Graduate School of Medicine
| | - Kan Hasegawa
- Department of Anesthesiology and Cristical Care Medicine, Hokkaido University Graduate School of medicine.,Department of Neurobiology, Hokkaido University Graduate School of Medicine
| | - Haruyuki Kamiya
- Department of Neurobiology, Hokkaido University Graduate School of Medicine
| | - Yuji Morimoto
- Department of Anesthesiology and Cristical Care Medicine, Hokkaido University Graduate School of medicine
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19
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Schneider T, Alpdogan S, Hescheler J, Neumaier F. In vitro and in vivo phosphorylation of the Ca v2.3 voltage-gated R-type calcium channel. Channels (Austin) 2018; 12:326-334. [PMID: 30165790 PMCID: PMC6986797 DOI: 10.1080/19336950.2018.1516984] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/20/2018] [Accepted: 08/22/2018] [Indexed: 02/07/2023] Open
Abstract
During the recording of whole cell currents from stably transfected HEK-293 cells, the decline of currents carried by the recombinant human Cav2.3+β3 channel subunits is related to adenosine triphosphate (ATP) depletion after rupture of the cells. It reduces the number of functional channels and leads to a progressive shift of voltage-dependent gating to more negative potentials (Neumaier F., et al., 2018). Both effects can be counteracted by hydrolysable ATP, whose protective action is almost completely prevented by inhibition of serine/threonine but not tyrosine or lipid kinases. These findings indicate that ATP promotes phosphorylation of either the channel or an associated protein, whereas dephosphorylation during cell dialysis results in run-down. Protein phosphorylation is required for Cav2.3 channel function and could directly influence the normal features of current carried by these channels. Therefore, results from in vitro and in vivo phosphorylation of Cav2.3 are summarized to come closer to a functional analysis of structural variations in Cav2.3 splice variants.
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Affiliation(s)
- T. Schneider
- Center of Physiology and Pathophysiology, Institute of Neurophysiology, Cologne, Germany
| | - S. Alpdogan
- Center of Physiology and Pathophysiology, Institute of Neurophysiology, Cologne, Germany
| | - J. Hescheler
- Center of Physiology and Pathophysiology, Institute of Neurophysiology, Cologne, Germany
| | - F. Neumaier
- Center of Physiology and Pathophysiology, Institute of Neurophysiology, Cologne, Germany
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20
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Takeda A, Tamano H. The Impact of Synaptic Zn 2+ Dynamics on Cognition and Its Decline. Int J Mol Sci 2017; 18:ijms18112411. [PMID: 29135924 PMCID: PMC5713379 DOI: 10.3390/ijms18112411] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/31/2017] [Accepted: 11/09/2017] [Indexed: 11/16/2022] Open
Abstract
The basal levels of extracellular Zn2+ are in the range of low nanomolar concentrations and less attention has been paid to Zn2+, compared to Ca2+, for synaptic activity. However, extracellular Zn2+ is necessary for synaptic activity. The basal levels of extracellular zinc are age-dependently increased in the rat hippocampus, implying that the basal levels of extracellular Zn2+ are also increased age-dependently and that extracellular Zn2+ dynamics are linked with age-related cognitive function and dysfunction. In the hippocampus, the influx of extracellular Zn2+ into postsynaptic neurons, which is often linked with Zn2+ release from neuron terminals, is critical for cognitive activity via long-term potentiation (LTP). In contrast, the excess influx of extracellular Zn2+ into postsynaptic neurons induces cognitive decline. Interestingly, the excess influx of extracellular Zn2+ more readily occurs in aged dentate granule cells and intracellular Zn2+-buffering, which is assessed with ZnAF-2DA, is weakened in the aged dentate granule cells. Characteristics (easiness) of extracellular Zn2+ influx seem to be linked with the weakened intracellular Zn2+-buffering in the aged dentate gyrus. This paper deals with the impact of synaptic Zn2+ signaling on cognition and its decline in comparison with synaptic Ca2+ signaling.
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Affiliation(s)
- Atsushi Takeda
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
| | - Hanuna Tamano
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
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21
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Effect of the spider toxin Tx3-3 on spinal processing of sensory information in naive and neuropathic rats: an in vivo electrophysiological study. Pain Rep 2017; 2:e610. [PMID: 29392225 PMCID: PMC5741365 DOI: 10.1097/pr9.0000000000000610] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 05/20/2017] [Accepted: 05/24/2017] [Indexed: 11/25/2022] Open
Abstract
The P/Q- and R-type voltage-gated calcium channel blocker Tx3-3 inhibits dorsal horn neuronal response of rats with greater potency after nerve injury. Introduction: Drugs that counteract nociceptive transmission in the spinal dorsal horn preferentially after nerve injury are being pursued as possible neuropathic pain treatments. In a previous behavioural study, the peptide toxin Tx3-3, which blocks P/Q- and R-type voltage-gated calcium channels, was effective in neuropathic pain models. Objectives: In the present study, we aimed to investigate the effect of Tx3-3 on dorsal horn neuronal responses in rats under physiological conditions and neuropathic pain condition induced by spinal nerve ligation (SNL). Methods: In vivo electrophysiological recordings of dorsal horn neuronal response to electrical and natural (mechanical and thermal) stimuli were made in rats under normal physiological state (naive rats) or after the SNL model of neuropathic pain. Results: Tx3-3 (0.3–100 pmol/site) exhibited greater inhibitory effect on electrical-evoked neuronal response of SNL rats than naive rats, inhibiting nociceptive C-fibre and Aδ-fibre responses only in SNL rats. The wind-up of neurones, a measurement of spinal cord hyperexcitability, was also more susceptible to a dose-related inhibition by Tx3-3 after nerve injury. Moreover, Tx3-3 exhibited higher potency to inhibit mechanical- and thermal-evoked neuronal response in conditions of neuropathy. Conclusion: Tx3-3 mediated differential inhibitory effect under physiological and neuropathic conditions, exhibiting greater potency in conditions of neuropathic pain.
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22
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Saul MC, Seward CH, Troy JM, Zhang H, Sloofman LG, Lu X, Weisner PA, Caetano-Anolles D, Sun H, Zhao SD, Chandrasekaran S, Sinha S, Stubbs L. Transcriptional regulatory dynamics drive coordinated metabolic and neural response to social challenge in mice. Genome Res 2017; 27:959-972. [PMID: 28356321 PMCID: PMC5453329 DOI: 10.1101/gr.214221.116] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 03/24/2017] [Indexed: 12/22/2022]
Abstract
Agonistic encounters are powerful effectors of future behavior, and the ability to learn from this type of social challenge is an essential adaptive trait. We recently identified a conserved transcriptional program defining the response to social challenge across animal species, highly enriched in transcription factor (TF), energy metabolism, and developmental signaling genes. To understand the trajectory of this program and to uncover the most important regulatory influences controlling this response, we integrated gene expression data with the chromatin landscape in the hypothalamus, frontal cortex, and amygdala of socially challenged mice over time. The expression data revealed a complex spatiotemporal patterning of events starting with neural signaling molecules in the frontal cortex and ending in the modulation of developmental factors in the amygdala and hypothalamus, underpinned by a systems-wide shift in expression of energy metabolism-related genes. The transcriptional signals were correlated with significant shifts in chromatin accessibility and a network of challenge-associated TFs. Among these, the conserved metabolic and developmental regulator ESRRA was highlighted for an especially early and important regulatory role. Cell-type deconvolution analysis attributed the differential metabolic and developmental signals in this social context primarily to oligodendrocytes and neurons, respectively, and we show that ESRRA is expressed in both cell types. Localizing ESRRA binding sites in cortical chromatin, we show that this nuclear receptor binds both differentially expressed energy-related and neurodevelopmental TF genes. These data link metabolic and neurodevelopmental signaling to social challenge, and identify key regulatory drivers of this process with unprecedented tissue and temporal resolution.
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Affiliation(s)
- Michael C Saul
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Christopher H Seward
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Joseph M Troy
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Illinois Informatics Institute, Urbana, Illinois 61801, USA
| | - Huimin Zhang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Laura G Sloofman
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Xiaochen Lu
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Patricia A Weisner
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Derek Caetano-Anolles
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Hao Sun
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sihai Dave Zhao
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Statistics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sriram Chandrasekaran
- Harvard Society of Fellows, Harvard University, Cambridge, Massachusetts 02138, USA
- Faculty of Arts and Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Saurabh Sinha
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Computer Science
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Lisa Stubbs
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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23
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Tamano H, Koike Y, Nakada H, Shakushi Y, Takeda A. Significance of synaptic Zn 2+ signaling in zincergic and non-zincergic synapses in the hippocampus in cognition. J Trace Elem Med Biol 2016; 38:93-98. [PMID: 26995290 DOI: 10.1016/j.jtemb.2016.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/07/2016] [Accepted: 03/07/2016] [Indexed: 11/24/2022]
Abstract
A portion of zinc concentrates in the synaptic vesicles in the brain and is released from glutamatergic (zincergic) neuron terminals. It serves as a signaling factor (in a form of free Zn2+). Both extracellular Zn2+ signaling, which predominantly originates in Zn2+ release from zincergic neuron terminals, and intracellular Zn2+ signaling, which is often linked to extracellular Zn2+ signaling, are involved in hippocampus-dependent memory. At mossy fiber-CA3 pyramidal cell synapses and Schaffer collateral-CA1 pyramidal cell synapses, which are zincergic, extracellular Zn2+ signaling leads to intracellular Zn2+ signaling and is involved in learning and memory. At medial perforant pathway-dentate granule cell synapses, which are non-zincergic, intracellular Zn2+ signaling, which originates in the internal stores containing Zn2+, is involved in learning and memory. The blockade of Zn2+ signaling with Zn2+ chelators induces memory deficit, while the optimal amount range of Zn2+ signaling is unknown. It is possible that the degree and frequency of Zn2+ signaling, which determine the increased Zn2+ levels, modulates learning and memory as well as intracellular Ca2+ signaling. To understand the precise role of synaptic Zn2+ signaling in the hippocampus, the present paper summarizes the current knowledge on Zn2+ signaling at zincergic and non-zincergic synapses in the hippocampus in cognition and involvement of zinc transporters and zinc-binding proteins in synaptic Zn2+ signaling.
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Affiliation(s)
- Hanuna Tamano
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yuta Koike
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Hiroyuki Nakada
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yukina Shakushi
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Atsushi Takeda
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
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24
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Wormuth C, Lundt A, Henseler C, Müller R, Broich K, Papazoglou A, Weiergräber M. Review: Ca v2.3 R-type Voltage-Gated Ca 2+ Channels - Functional Implications in Convulsive and Non-convulsive Seizure Activity. Open Neurol J 2016; 10:99-126. [PMID: 27843503 PMCID: PMC5080872 DOI: 10.2174/1874205x01610010099] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/16/2016] [Accepted: 06/24/2016] [Indexed: 11/22/2022] Open
Abstract
Background: Researchers have gained substantial insight into mechanisms of synaptic transmission, hyperexcitability, excitotoxicity and neurodegeneration within the last decades. Voltage-gated Ca2+ channels are of central relevance in these processes. In particular, they are key elements in the etiopathogenesis of numerous seizure types and epilepsies. Earlier studies predominantly targeted on Cav2.1 P/Q-type and Cav3.2 T-type Ca2+ channels relevant for absence epileptogenesis. Recent findings bring other channels entities more into focus such as the Cav2.3 R-type Ca2+ channel which exhibits an intriguing role in ictogenesis and seizure propagation. Cav2.3 R-type voltage gated Ca2+ channels (VGCC) emerged to be important factors in the pathogenesis of absence epilepsy, human juvenile myoclonic epilepsy (JME), and cellular epileptiform activity, e.g. in CA1 neurons. They also serve as potential target for various antiepileptic drugs, such as lamotrigine and topiramate. Objective: This review provides a summary of structure, function and pharmacology of VGCCs and their fundamental role in cellular Ca2+ homeostasis. We elaborate the unique modulatory properties of Cav2.3 R-type Ca2+ channels and point to recent findings in the proictogenic and proneuroapoptotic role of Cav2.3 R-type VGCCs in generalized convulsive tonic–clonic and complex-partial hippocampal seizures and its role in non-convulsive absence like seizure activity. Conclusion: Development of novel Cav2.3 specific modulators can be effective in the pharmacological treatment of epilepsies and other neurological disorders.
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Affiliation(s)
- Carola Wormuth
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Andreas Lundt
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Christina Henseler
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Ralf Müller
- Department of Psychiatry and Psychotherapy, University of Cologne, Faculty of Medicine, Cologne, Germany
| | - Karl Broich
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Anna Papazoglou
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Marco Weiergräber
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
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25
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Berecki G, Motin L, Adams DJ. Voltage-Gated R-Type Calcium Channel Inhibition via Human μ-, δ-, and κ-opioid Receptors Is Voltage-Independently Mediated by Gβγ Protein Subunits. Mol Pharmacol 2015; 89:187-96. [PMID: 26490245 DOI: 10.1124/mol.115.101154] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/19/2015] [Indexed: 01/07/2023] Open
Abstract
Elucidating the mechanisms that modulate calcium channels via opioid receptor activation is fundamental to our understanding of both pain perception and how opioids modulate pain. Neuronal voltage-gated N-type calcium channels (Cav2.2) are inhibited by activation of G protein-coupled opioid receptors (ORs). However, inhibition of R-type (Cav2.3) channels by μ- or κ-ORs is poorly defined and has not been reported for δ-ORs. To investigate such interactions, we coexpressed human μ-, δ-, or κ-ORs with human Cav2.3 or Cav2.2 in human embryonic kidney 293 cells and measured depolarization-activated Ba(2+) currents (IBa). Selective agonists of μ-, δ-, and κ-ORs inhibited IBa through Cav2.3 channels by 35%. Cav2.2 channels were inhibited to a similar extent by κ-ORs, but more potently (60%) via μ- and δ-ORs. Antagonists of δ- and κ-ORs potentiated IBa amplitude mediated by Cav2.3 and Cav2.2 channels. Consistent with G protein βγ (Gβγ) interaction, modulation of Cav2.2 was primarily voltage-dependent and transiently relieved by depolarizing prepulses. In contrast, Cav2.3 modulation was voltage-independent and unaffected by depolarizing prepulses. However, Cav2.3 inhibition was sensitive to pertussis toxin and to intracellular application of guanosine 5'-[β-thio]diphosphate trilithium salt and guanosine 5'-[γ-thio]triphosphate tetralithium salt. Coexpression of Gβγ-specific scavengers-namely, the carboxyl terminus of the G protein-coupled receptor kinase 2 or membrane-targeted myristoylated-phosducin-attenuated or abolished Cav2.3 modulation. Our study reveals the diversity of OR-mediated signaling at Cav2 channels and identifies neuronal Cav2.3 channels as potential targets for opioid analgesics. Their novel modulation is dependent on pre-existing OR activity and mediated by membrane-delimited Gβγ subunits in a voltage-independent manner.
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Affiliation(s)
- Géza Berecki
- Health Innovations Research Institute, RMIT University, Melbourne, Victoria, Australia
| | - Leonid Motin
- Health Innovations Research Institute, RMIT University, Melbourne, Victoria, Australia
| | - David J Adams
- Health Innovations Research Institute, RMIT University, Melbourne, Victoria, Australia
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Böhm C, Pangalos M, Schmitz D, Winterer J. Serotonin Attenuates Feedback Excitation onto O-LM Interneurons. Cereb Cortex 2015; 25:4572-83. [PMID: 26021702 PMCID: PMC4816800 DOI: 10.1093/cercor/bhv098] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The serotonergic system is a subcortical neuromodulatory center that controls cortical information processing in a state-dependent manner. In the hippocampus, serotonin (5-HT) is released by ascending serotonergic fibers from the midbrain raphe nuclei, thereby mediating numerous modulatory functions on various neuronal subtypes. Here, we focus on the neuromodulatory effects of 5-HT on GABAergic inhibitory oriens lacunosum-moleculare (O-LM) cells in the hippocampal area CA1 of the rat. These interneurons are thought to receive primarily local excitatory input and are, via their axonal projections to stratum lacunosum-moleculare, ideally suited to control entorhinal cortex input. We show that 5-HT reduces excitatory glutamatergic transmission onto O-LM interneurons. By means of paired recordings from synaptically connected CA1 pyramidal cells and O-LM interneurons we reveal that this synapse is modulated by 5-HT. Furthermore, we demonstrate that the reduction of glutamatergic transmission by serotonin is likely to be mediated via a decrease of calcium influx into presynaptic terminals of CA1 pyramidal cells. This modulation of excitatory synaptic transmission onto O-LM interneurons by 5-HT might be a mechanism to vary the activation of O-LM interneurons during ongoing network activity and serve as a brain state-dependent switch gating the efficiency of entorhinal cortex input to CA1 pyramidal neurons.
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Affiliation(s)
- Claudia Böhm
- Neuroscience Research Center, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Maria Pangalos
- Neuroscience Research Center, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Dietmar Schmitz
- Neuroscience Research Center, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, 10115 Berlin, Germany Cluster of Excellence "NeuroCure", Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany Einstein Foundation Berlin, 10117 Berlin, Germany Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), c/o Charité - Universitätsmedizin Berlin, Neuroscience Research Center, 10117 Berlin, Germany
| | - Jochen Winterer
- Neuroscience Research Center, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
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Wang Y, Chakravarty P, Ranes M, Kelly G, Brooks PJ, Neilan E, Stewart A, Schiavo G, Svejstrup JQ. Dysregulation of gene expression as a cause of Cockayne syndrome neurological disease. Proc Natl Acad Sci U S A 2014; 111:14454-9. [PMID: 25249633 PMCID: PMC4210037 DOI: 10.1073/pnas.1412569111] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cockayne syndrome (CS) is a multisystem disorder with severe neurological symptoms. The majority of CS patients carry mutations in Cockayne syndrome group B (CSB), best known for its role in transcription-coupled nucleotide excision repair. Indeed, because various repair pathways are compromised in patient cells, CS is widely considered a genome instability syndrome. Here, we investigate the connection between the neuropathology of CS and dysregulation of gene expression. Transcriptome analysis of human fibroblasts revealed that even in the absence of DNA damage, CSB affects the expression of thousands of genes, many of which are neuronal genes. CSB is present in a significant subset of these genes, suggesting that regulation is direct, at the level of transcription. Importantly, reprogramming of CS fibroblasts to neuron-like cells is defective unless an exogenous CSB gene is introduced. Moreover, neuroblastoma cells from which CSB is depleted show defects in gene expression programs required for neuronal differentiation, and fail to differentiate and extend neurites. Likewise, neuron-like cells cannot be maintained without CSB. Finally, a number of disease symptoms may be explained by marked gene expression changes in the brain of patients with CS. Together, these data point to dysregulation of gene regulatory networks as a cause of the neurological symptoms in CS.
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Affiliation(s)
- Yuming Wang
- Mechanisms of Transcription Laboratory, Cancer Research UK London Research Institute, South Mimms EN6 3LD, United Kingdom
| | - Probir Chakravarty
- Bioinformatics and Biostatistics Group, Cancer Research UK London Research Institute, London WC2A 3LY, United Kingdom
| | - Michael Ranes
- Mechanisms of Transcription Laboratory, Cancer Research UK London Research Institute, South Mimms EN6 3LD, United Kingdom
| | - Gavin Kelly
- Bioinformatics and Biostatistics Group, Cancer Research UK London Research Institute, London WC2A 3LY, United Kingdom
| | - Philip J Brooks
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism and Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892
| | - Edward Neilan
- Genetics and Metabolism, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115; and
| | - Aengus Stewart
- Bioinformatics and Biostatistics Group, Cancer Research UK London Research Institute, London WC2A 3LY, United Kingdom
| | - Giampietro Schiavo
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
| | - Jesper Q Svejstrup
- Mechanisms of Transcription Laboratory, Cancer Research UK London Research Institute, South Mimms EN6 3LD, United Kingdom;
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28
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Licon Y, Leandro D, Romero-Mendez C, Rodriguez-Menchaca AA, Sanchez-Armass S, Meza U. Inhibition of CaV2.3 channels by NK1 receptors is sensitive to membrane cholesterol but insensitive to caveolin-1. Pflugers Arch 2014; 467:1699-709. [DOI: 10.1007/s00424-014-1605-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/27/2014] [Accepted: 08/29/2014] [Indexed: 12/12/2022]
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Todorovic SM, Jevtovic-Todorovic V. Redox regulation of neuronal voltage-gated calcium channels. Antioxid Redox Signal 2014; 21:880-91. [PMID: 24161125 PMCID: PMC4116091 DOI: 10.1089/ars.2013.5610] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
SIGNIFICANCE Voltage-gated calcium channels are ubiquitously expressed in neurons and are key regulators of cellular excitability and synaptic transmitter release. There is accumulating evidence that multiple subtypes of voltage-gated calcium channels may be regulated by oxidation and reduction. However, the redox mechanisms involved in the regulation of channel function are not well understood. RECENT ADVANCES Several studies have established that both T-type and high-voltage-activated subtypes of voltage-gated calcium channel can be redox-regulated. This article reviews different mechanisms that can be involved in redox regulation of calcium channel function and their implication in neuronal function, particularly in pain pathways and thalamic oscillation. CRITICAL ISSUES A current critical issue in the field is to decipher precise mechanisms of calcium channel modulation via redox reactions. In this review we discuss covalent post-translational modification via oxidation of cysteine molecules and chelation of trace metals, and reactions involving nitric oxide-related molecules and free radicals. Improved understanding of the roles of redox-based reactions in regulation of voltage-gated calcium channels may lead to improved understanding of novel redox mechanisms in physiological and pathological processes. FUTURE DIRECTIONS Identification of redox mechanisms and sites on voltage-gated calcium channel may allow development of novel and specific ion channel therapies for unmet medical needs. Thus, it may be possible to regulate the redox state of these channels in treatment of pathological process such as epilepsy and neuropathic pain.
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Affiliation(s)
- Slobodan M Todorovic
- 1 Department of Anesthesiology, University of Virginia School of Medicine , Charlottesville, Virginia
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Chamberland S, Evstratova A, Tóth K. Interplay between synchronization of multivesicular release and recruitment of additional release sites support short-term facilitation at hippocampal mossy fiber to CA3 pyramidal cells synapses. J Neurosci 2014; 34:11032-47. [PMID: 25122902 PMCID: PMC6705252 DOI: 10.1523/jneurosci.0847-14.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 06/07/2014] [Accepted: 06/27/2014] [Indexed: 11/21/2022] Open
Abstract
Synaptic short-term plasticity is a key regulator of neuronal communication and is controlled via various mechanisms. A well established property of mossy fiber to CA3 pyramidal cell synapses is the extensive short-term facilitation during high-frequency bursts. We investigated the mechanisms governing facilitation using a combination of whole-cell electrophysiological recordings, electrical minimal stimulation, and random-access two-photon microscopy in acute mouse hippocampal slices. Two distinct presynaptic mechanisms were involved in short-term facilitation, with their relative contribution dependent on extracellular calcium concentration. The synchronization of multivesicular release was observed during trains of facilitating EPSCs recorded in 1.2 mM external Ca(2+) ([Ca(2+)]e). Indeed, covariance analysis revealed a gradual augmentation in quantal size during trains of EPSCs, and application of the low-affinity glutamate receptor antagonist γ-D-glutamylglycine showed an increase in cleft glutamate concentration during paired-pulse stimulation. Whereas synchronization of multivesicular release contributed to the facilitation in 1.2 mM [Ca(2+)]e, variance-mean analysis showed that recruitment of more release sites (N) was likely to account for the larger facilitation observed in 2.5 mM [Ca(2+)]e. Furthermore, this increase in N could be promoted by calcium microdomains of heterogeneous amplitudes observed in single mossy fiber boutons. Our findings suggest that the combination of multivesicular release and the recruitment of additional release sites act together to increase glutamate release during burst activity. This is supported by the compartmentalized spatial profile of calcium elevations in boutons and helps to expand the dynamic range of mossy fibers information transfer.
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Affiliation(s)
- Simon Chamberland
- Quebec Mental Health Institute, Department of Psychiatry and Neuroscience, Laval University, Quebec City, Quebec, Canada, G1J 2G3
| | - Alesya Evstratova
- Quebec Mental Health Institute, Department of Psychiatry and Neuroscience, Laval University, Quebec City, Quebec, Canada, G1J 2G3
| | - Katalin Tóth
- Quebec Mental Health Institute, Department of Psychiatry and Neuroscience, Laval University, Quebec City, Quebec, Canada, G1J 2G3
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Midorikawa M, Okamoto Y, Sakaba T. Developmental changes in Ca2+ channel subtypes regulating endocytosis at the calyx of Held. J Physiol 2014; 592:3495-510. [PMID: 24907302 DOI: 10.1113/jphysiol.2014.273243] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
At the mammalian central synapse, Ca(2+) influx through Ca(2+) channels triggers neurotransmitter release by exocytosis of synaptic vesicles, which fuse with the presynaptic membrane and are subsequently retrieved by endocytosis. At the calyx of Held terminal, P/Q-type Ca(2+) channels mainly mediate exocytosis, while N- and R-type channels have a minor role in young terminals (postnatal days 8-11). The role of each Ca(2+) channel subtype in endocytosis remains to be elucidated; therefore, we examined the role of each type of Ca(2+) channel in endocytosis, by using whole-cell patch-clamp recordings in conjunction with capacitance measurement techniques. We found that at the young calyx terminal, when R-type Ca(2+) channels were blocked, the slow mode of endocytosis was further slowed, while blocking of either P/Q- or N-type Ca(2+) channels had no major effect. In more mature terminals (postnatal days 14-17), the slow mode of endocytosis was mainly triggered by P/Q-type Ca(2+) channels, suggesting developmental changes in the regulation of the slow mode of endocytosis by different Ca(2+) channel subtypes. In contrast, a fast mode of endocytosis was observed after strong stimulation in young terminals that was mediated mainly by P/Q-type, but not R- or N-type Ca(2+) channels. These results suggest that different types of Ca(2+) channels regulate the two different modes of endocytosis. The results may also suggest that exo- and endocytosis are regulated independently at different sites in young animals but are more tightly coupled in older animals, allowing more efficient synaptic vesicle cycling adapted for fast signalling.
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Affiliation(s)
| | - Yuji Okamoto
- Graduate School of Brain Science, Doshisha University, Kyoto, 6190225, Japan
| | - Takeshi Sakaba
- Graduate School of Brain Science, Doshisha University, Kyoto, 6190225, Japan
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32
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T-type channel-mediated neurotransmitter release. Pflugers Arch 2014; 466:677-87. [PMID: 24595475 DOI: 10.1007/s00424-014-1489-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 02/18/2014] [Indexed: 10/25/2022]
Abstract
Besides controlling a wide variety of cell functions, T-type channels have been shown to regulate neurotransmitter release in peripheral and central synapses and neuroendocrine cells. Growing evidence over the last 10 years suggests a key role of Cav3.2 and Cav3.1 channels in controlling basal neurosecretion near resting conditions and sustained release during mild stimulations. In some cases, the contribution of low-voltage-activated (LVA) channels is not directly evident but requires either the activation of coupled presynaptic receptors, block of ion channels, or chelation of metal ions. Concerning the coupling to the secretory machinery, T-type channels appear loosely coupled to neurotransmitter and hormone release. In neurons, Cav3.2 and Cav3.1 channels mainly control the asynchronous appearance of "minis" [miniature inhibitory postsynaptic currents (mIPSCs) and miniature excitatory postsynaptic currents (mEPSCs)]. The same loose coupling is evident from membrane capacity and amperometric recordings in chromaffin cells and melanotropes where the low-threshold-driven exocytosis possesses the same linear Ca(2+) dependence of the other voltage-gated Ca(2+) channels (Cav1 and Cav2) that is strongly attenuated by slow calcium buffers. The intriguing issue is that, despite not expressing a consensus "synprint" site, Cav3.2 channels do interact with syntaxin 1A and SNAP-25 and, thus, may form nanodomains with secretory vesicles that can be regulated at low voltages. In this review, we discuss all the past and recent issues related to T-type channel-secretion coupling in neurons and neuroendocrine cells.
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33
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Ricoy UM, Frerking ME. Distinct roles for Cav2.1-2.3 in activity-dependent synaptic dynamics. J Neurophysiol 2014; 111:2404-13. [PMID: 24523520 DOI: 10.1152/jn.00335.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Synaptic transmission throughout most of the CNS is steeply dependent on presynaptic calcium influx through the voltage-gated calcium channels Cav2.1-Cav2.3. In addition to triggering exocytosis, this calcium influx also recruits short-term synaptic plasticity. During the complex patterns of presynaptic activity that occur in vivo, several forms of plasticity combine to generate a synaptic output that is dynamic, in which the size of a given excitatory postsynaptic potential (EPSP) in response to a given spike depends on the short-term history of presynaptic activity. It remains unclear whether the different Cav2 channels play distinct roles in defining these synaptic dynamics and, if so, under what conditions different Cav2 family members most effectively determine synaptic output. We examined these questions by measuring the effects of calcium channel-selective toxins on synaptic transmission at the Schaffer collateral synapse in hippocampal slices from adult mice in response to both low-frequency stimulation and complex stimulus trains derived from in vivo recordings. Blockade of Cav2.1 had a greater inhibitory effect on synaptic transmission during low-frequency components of the stimulus train than on synaptic transmission during high-frequency components of the train, indicating that Cav2.1 had a greater fractional contribution to synaptic transmission at low frequencies than at high frequencies. Relative to Cav2.1, Cav2.2 had a disproportionately reduced contribution to synaptic transmission at frequencies >20 Hz, while Cav2.3 had a disproportionately increased contribution to synaptic transmission at frequencies >1 Hz. These activity-dependent effects of different Cav2 family members shape the filtering characteristics of GABAB receptor-mediated presynaptic inhibition. Thus different Cav2 channels vary in their coupling to synaptic transmission over different frequency ranges, with consequences for the frequency tuning of both synaptic dynamics and presynaptic neuromodulation.
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Affiliation(s)
- Ulises M Ricoy
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
| | - Matthew E Frerking
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
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34
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Evstratova A, Tóth K. Information processing and synaptic plasticity at hippocampal mossy fiber terminals. Front Cell Neurosci 2014; 8:28. [PMID: 24550783 PMCID: PMC3912358 DOI: 10.3389/fncel.2014.00028] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 01/20/2014] [Indexed: 11/13/2022] Open
Abstract
Granule cells of the dentate gyrus receive cortical information and they transform and transmit this code to the CA3 area via their axons, the mossy fibers (MFs). Structural and functional complexity of this network has been extensively studied at various organizational levels. This review is focused on the anatomical and physiological properties of the MF system. We will discuss the mechanism by which dentate granule cells process signals from single action potentials (APs), short bursts and longer stimuli. Various parameters of synaptic interactions at different target cells such as quantal transmission, short- and long-term plasticity (LTP) will be summarized. Different types of synaptic contacts formed by MFs have unique sets of rules for information processing during different rates of granule cell activity. We will investigate the complex interactions between key determinants of information transfer between the dentate gyrus and the CA3 area of the hippocampus.
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Affiliation(s)
- Alesya Evstratova
- Faculty of Medicine, Department of Psychiatry and Neuroscience, Quebec Mental Health Institute, Université Laval Quebec City, QC, Canada
| | - Katalin Tóth
- Faculty of Medicine, Department of Psychiatry and Neuroscience, Quebec Mental Health Institute, Université Laval Quebec City, QC, Canada
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35
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Carta M, Lanore F, Rebola N, Szabo Z, Da Silva SV, Lourenço J, Verraes A, Nadler A, Schultz C, Blanchet C, Mulle C. Membrane lipids tune synaptic transmission by direct modulation of presynaptic potassium channels. Neuron 2014; 81:787-99. [PMID: 24486086 DOI: 10.1016/j.neuron.2013.12.028] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2013] [Indexed: 12/20/2022]
Abstract
Voltage-gated potassium (Kv) channels are involved in action potential (AP) repolarization in excitable cells. Exogenous application of membrane-derived lipids, such as arachidonic acid (AA), regulates the gating of Kv channels. Whether membrane-derived lipids released under physiological conditions have an impact on neuronal coding through this mechanism is unknown. We show that AA released in an activity-dependent manner from postsynaptic hippocampal CA3 pyramidal cells acts as retrograde messenger, inducing a robust facilitation of mossy fiber (Mf) synaptic transmission over several minutes. AA acts by broadening presynaptic APs through the direct modulation of Kv channels. This form of short-term plasticity can be triggered when postsynaptic cell fires with physiologically relevant patterns and sets the threshold for the induction of the presynaptic form of long-term potentiation (LTP) at hippocampal Mf synapses. Hence, direct modulation of presynaptic Kv channels by activity-dependent release of lipids serves as a physiological mechanism for tuning synaptic transmission.
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Affiliation(s)
- Mario Carta
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Frederic Lanore
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Nelson Rebola
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Zsolt Szabo
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Silvia Viana Da Silva
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Joana Lourenço
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Agathe Verraes
- Institut Jacques Monod, UMR 7592, CNRS and INSERM ERL U950, University Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
| | - André Nadler
- EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Carsten Schultz
- EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Christophe Blanchet
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France
| | - Christophe Mulle
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, 33000 Bordeaux, France.
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36
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Cardiac functions of voltage-gated Ca(2+) channels: role of the pharmacoresistant type (E-/R-Type) in cardiac modulation and putative implication in sudden unexpected death in epilepsy (SUDEP). Rev Physiol Biochem Pharmacol 2014; 167:115-39. [PMID: 25280639 DOI: 10.1007/112_2014_21] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Voltage-gated Ca(2+) channels (VGCCs) are ubiquitous in excitable cells. These channels play key roles in many physiological events like cardiac regulation/pacemaker activity due to intracellular Ca(2+) transients. In the myocardium, the Cav1 subfamily (L-type: Cav1.2 and Cav1.3) is the main contributor to excitation-contraction coupling and/or pacemaking, whereas the Cav3 subfamily (T-type: Cav3.1 and Cav3.2) is important in rhythmically firing of the cardiac nodal cells. No established cardiac function has been attributed to the Cav2 family (E-/R-type: Cav2.3) despite accumulating evidence of cardiac dysregulation observed upon deletion of the Cav2.3 gene, the only member of this family so far detected in cardiomyocytes. In this review, we summarize the pathophysiological changes observed after ablation of the E-/R-type VGCC and propose a cardiac mechanism of action for this channel. Also, considering the role played by this channel in epilepsy and its reported sensitivity to antiepileptic drugs, a putative involvement of this channel in the cardiac mechanism of sudden unexpected death in epilepsy is also discussed.
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37
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Yang Y, Calakos N. Presynaptic long-term plasticity. Front Synaptic Neurosci 2013; 5:8. [PMID: 24146648 PMCID: PMC3797957 DOI: 10.3389/fnsyn.2013.00008] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 09/09/2013] [Indexed: 01/01/2023] Open
Abstract
Long-term synaptic plasticity is a major cellular substrate for learning, memory, and behavioral adaptation. Although early examples of long-term synaptic plasticity described a mechanism by which postsynaptic signal transduction was potentiated, it is now apparent that there is a vast array of mechanisms for long-term synaptic plasticity that involve modifications to either or both the presynaptic terminal and postsynaptic site. In this article, we discuss current and evolving approaches to identify presynaptic mechanisms as well as discuss their limitations. We next provide examples of the diverse circuits in which presynaptic forms of long-term synaptic plasticity have been described and discuss the potential contribution this form of plasticity might add to circuit function. Finally, we examine the present evidence for the molecular pathways and cellular events underlying presynaptic long-term synaptic plasticity.
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Affiliation(s)
- Ying Yang
- Department of Pediatrics, Stanford University School of Medicine Stanford, CA, USA
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38
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Schneider T, Dibué M, Hescheler J. How "Pharmacoresistant" is Cav2.3, the Major Component of Voltage-Gated R-type Ca2+ Channels? Pharmaceuticals (Basel) 2013; 6:759-76. [PMID: 24276260 PMCID: PMC3816731 DOI: 10.3390/ph6060759] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/26/2013] [Accepted: 05/06/2013] [Indexed: 12/04/2022] Open
Abstract
Membrane-bound voltage-gated Ca2+ channels (VGCCs) are targets for specific signaling complexes, which regulate important processes like gene expression, neurotransmitter release and neuronal excitability. It is becoming increasingly evident that the so called “resistant” (R-type) VGCC Cav2.3 is critical in several physiologic and pathophysiologic processes in the central nervous system, vascular system and in endocrine systems. However its eponymous attribute of pharmacologic inertness initially made in depth investigation of the channel difficult. Although the identification of SNX-482 as a fairly specific inhibitor of Cav2.3 in the nanomolar range has enabled insights into the channels properties, availability of other pharmacologic modulators of Cav2.3 with different chemical, physical and biological properties are of great importance for future investigations. Therefore the literature was screened systematically for molecules that modulate Cav2.3 VGCCs.
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Affiliation(s)
- Toni Schneider
- Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, Cologne D-50931, Germany; E-Mail:
- Authors to whom correspondence should be addressed; E-Mails: (T.S.); (M.D.); Tel.: +49-221-478-69446 (T.S.); Fax: +49-221-478-6965 (T.S.)
| | - Maxine Dibué
- Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, Cologne D-50931, Germany; E-Mail:
- Department for Neurosurgery, Medical Faculty, Heinrich Heine University, Moorenstraße 5, Duesseldorf D-40225, Germany & Center of Molecular Medicine, Cologne D-50931, Germany
- Authors to whom correspondence should be addressed; E-Mails: (T.S.); (M.D.); Tel.: +49-221-478-69446 (T.S.); Fax: +49-221-478-6965 (T.S.)
| | - Jürgen Hescheler
- Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, Cologne D-50931, Germany; E-Mail:
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Control of low-threshold exocytosis by T-type calcium channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:1579-86. [PMID: 22885170 DOI: 10.1016/j.bbamem.2012.07.031] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 07/30/2012] [Accepted: 07/30/2012] [Indexed: 12/11/2022]
Abstract
Low-voltage-activated (LVA) T-type Ca²⁺ channels differ from their high-voltage-activated (HVA) homologues by unique biophysical properties. Hence, whereas HVA channels convert action potentials into intracellular Ca²⁺ elevations, T-type channels control Ca²⁺ entry during small depolarizations around the resting membrane potential. They play an important role in electrical activities by generating low-threshold burst discharges that occur during various physiological and pathological forms of neuronal rhythmogenesis. In addition, they mediate a previously unrecognized function in the control of synaptic transmission where they directly trigger the release of neurotransmitters at rest. In this review, we summarize our present knowledge of the role of T-type Ca²⁺ channels in vesicular exocytosis, and emphasize the critical importance of localizing the exocytosis machinery close to the Ca²⁺ source for reliable synaptic transmission. This article is part of a Special Issue entitled: Calcium channels.
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40
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Shcheglovitov A, Vitko I, Lazarenko RM, Orestes P, Todorovic SM, Perez-Reyes E. Molecular and biophysical basis of glutamate and trace metal modulation of voltage-gated Ca(v)2.3 calcium channels. ACTA ACUST UNITED AC 2012; 139:219-34. [PMID: 22371363 PMCID: PMC3289959 DOI: 10.1085/jgp.201110699] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Here, we describe a new mechanism by which glutamate (Glu) and trace metals reciprocally modulate activity of the Cav2.3 channel by profoundly shifting its voltage-dependent gating. We show that zinc and copper, at physiologically relevant concentrations, occupy an extracellular binding site on the surface of Cav2.3 and hold the threshold for activation of these channels in a depolarized voltage range. Abolishing this binding by chelation or the substitution of key amino acid residues in IS1–IS2 (H111) and IS2–IS3 (H179 and H183) loops potentiates Cav2.3 by shifting the voltage dependence of activation toward more negative membrane potentials. We demonstrate that copper regulates the voltage dependence of Cav2.3 by affecting gating charge movements. Thus, in the presence of copper, gating charges transition into the “ON” position slower, delaying activation and reducing the voltage sensitivity of the channel. Overall, our results suggest a new mechanism by which Glu and trace metals transiently modulate voltage-dependent gating of Cav2.3, potentially affecting synaptic transmission and plasticity in the brain.
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Kamp MA, Shakeri B, Tevoufouet EE, Krieger A, Henry M, Behnke K, Herzig S, Hescheler J, Radhakrishnan K, Parent L, Schneider T. The C-terminus of human Ca(v)2.3 voltage-gated calcium channel interacts with alternatively spliced calmodulin-2 expressed in two human cell lines. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:1045-57. [PMID: 22633975 DOI: 10.1016/j.bbapap.2012.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/27/2012] [Accepted: 05/16/2012] [Indexed: 01/20/2023]
Abstract
Ca(v)2.3 containing voltage-activated Ca(2+) channels are expressed in excitable cells and trigger neurotransmitter and peptide-hormone release. Their expression remote from the fast release sites leads to the accumulation of presynaptic Ca(2+) which can both, facilitate and inhibit the influx of Ca(2+) ions through Ca(v)2.3. The facilitated Ca(2+) influx was recently related to hippocampal postsynaptic facilitation and long term potentiation. To analyze Ca(2+) mediated modulation of cellular processes more in detail, protein partners of the carboxy terminal tail of Ca(v)2.3 were identified by yeast-2-hybrid screening, leading in two human cell lines to the detection of a novel, extended and rarely occurring splice variant of calmodulin-2 (CaM-2), called CaM-2-extended (CaM-2-ext). CaM-2-ext interacts biochemically with the C-terminus of Ca(v)2.3 similar to the classical CaM-2 as shown by co-immunoprecipitation. Functionally, only CaM-2-ext reduces whole cell inward currents significantly. The insertion of the novel 46 nts long exon and the consecutive expression of CaM-2-ext must be dependent on a new upstream translation initiation site which is only rarely used in the tested human cell lines. The structure of the N-terminal extension is predicted to be more hydrophobic than the remaining CaM-2-ext protein, suggesting that it may help to dock it to the lipophilic membrane surrounding.
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Affiliation(s)
- Marcel A Kamp
- Institute for Neurophysiology, University of Cologne, Germany
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42
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Castillo PE. Presynaptic LTP and LTD of excitatory and inhibitory synapses. Cold Spring Harb Perspect Biol 2012; 4:cshperspect.a005728. [PMID: 22147943 DOI: 10.1101/cshperspect.a005728] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ubiquitous forms of long-term potentiation (LTP) and depression (LTD) are caused by enduring increases or decreases in neurotransmitter release. Such forms or presynaptic plasticity are equally observed at excitatory and inhibitory synapses and the list of locations expressing presynaptic LTP and LTD continues to grow. In addition to the mechanistically distinct forms of postsynaptic plasticity, presynaptic plasticity offers a powerful means to modify neural circuits. A wide range of induction mechanisms has been identified, some of which occur entirely in the presynaptic terminal, whereas others require retrograde signaling from the postsynaptic to presynaptic terminals. In spite of this diversity of induction mechanisms, some common induction rules can be identified across synapses. Although the precise molecular mechanism underlying long-term changes in transmitter release in most cases remains unclear, increasing evidence indicates that presynaptic LTP and LTD can occur in vivo and likely mediate some forms of learning.
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Affiliation(s)
- Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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A novel form of low-frequency hippocampal mossy fiber plasticity induced by bimodal mGlu1 receptor signaling. J Neurosci 2012; 31:16897-906. [PMID: 22114260 DOI: 10.1523/jneurosci.1264-11.2011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mossy fiber synapses act as the critical mediators of highly dynamic communication between hippocampal granule cells in the dentate gyrus and CA3 pyramidal neurons. Excitatory synaptic strength at mossy fiber to CA3 pyramidal cell synapses is potentiated rapidly and reversibly by brief trains of low-frequency stimulation of mossy fiber axons. We show that slight modifications to the pattern of stimulation convert this short-term potentiation into prolonged synaptic strengthening lasting tens of minutes in rodent hippocampal slices. This low-frequency potentiation of mossy fiber EPSCs requires postsynaptic mGlu1 receptors for induction but is expressed presynaptically as an increased release probability and therefore impacts both AMPA and NMDA components of the mossy fiber EPSC. A nonconventional signaling pathway initiated by mGlu1 receptors contributes to induction of plasticity, because EPSC potentiation was prevented by a tyrosine kinase inhibitor and only partially reduced by guanosine 5'-O-(2-thiodiphosphate). A slowly reversible state of enhanced synaptic efficacy could serve as a mechanism for altering the integrative properties of this synapse within a relatively broad temporal window.
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Voltage-Gated Ca2+ Channel Mediated Ca2+ Influx in Epileptogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:1219-47. [DOI: 10.1007/978-94-007-2888-2_55] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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45
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Regulation of voltage-gated calcium channels by synaptic proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:759-75. [PMID: 22453968 DOI: 10.1007/978-94-007-2888-2_33] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Calcium entry through neuronal voltage-gated calcium channels into presynaptic nerve terminal is a key step in synaptic exocytosis. In order to receive the calcium signal and trigger fast, efficient and spatially delimited neurotransmitter release, the vesicle-docking/release machinery must be located near the calcium source. In many cases, this close localization is achieved by a direct interaction of several members of the vesicle release machinery with the calcium channels. In turn, the binding of synaptic proteins to presynaptic calcium channels modulates channel activity to provide fine control over calcium entry, and thus modulates synaptic strength. In this chapter we summarize our present knowledge of the molecular mechanisms by which synaptic proteins regulate presynaptic calcium channel activity.
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Pan E, Zhang XA, Huang Z, Krezel A, Zhao M, Tinberg CE, Lippard SJ, McNamara JO. Vesicular zinc promotes presynaptic and inhibits postsynaptic long-term potentiation of mossy fiber-CA3 synapse. Neuron 2011; 71:1116-26. [PMID: 21943607 DOI: 10.1016/j.neuron.2011.07.019] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2011] [Indexed: 01/05/2023]
Abstract
The presence of zinc in glutamatergic synaptic vesicles of excitatory neurons of mammalian cerebral cortex suggests that zinc might regulate plasticity of synapses formed by these neurons. Long-term potentiation (LTP) is a form of synaptic plasticity that may underlie learning and memory. We tested the hypothesis that zinc within vesicles of mossy fibers (mf) contributes to mf-LTP, a classical form of presynaptic LTP. We synthesized an extracellular zinc chelator with selectivity and kinetic properties suitable for study of the large transient of zinc in the synaptic cleft induced by mf stimulation. We found that vesicular zinc is required for presynaptic mf-LTP. Unexpectedly, vesicular zinc also inhibits a form of postsynaptic mf-LTP. Because the mf-CA3 synapse provides a major source of excitatory input to the hippocampus, regulating its efficacy by these dual actions, vesicular zinc is critical to proper function of hippocampal circuitry in health and disease.
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Affiliation(s)
- Enhui Pan
- Department of Medicine (Neurology), Duke University Medical Center, Durham, NC 27710, USA
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Radhakrishnan K, Kamp MA, Siapich SA, Hescheler J, Lüke M, Schneider T. Ca(v)2.3 Ca2+ channel interacts with the G1-subunit of V-ATPase. Cell Physiol Biochem 2011; 27:421-32. [PMID: 21691059 DOI: 10.1159/000329963] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2011] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Calcium channels are essential in coupling action potential to signal transduction in cells. There are several types of calcium channels, which can be pharmacologically classified as L-, N-, P/Q-, R- and T-type. But molecular basis of R-type channels is less clearly understood compared the other channel types. Therefore the current study aims at understanding the molecular functions of R-type calcium channels by identifying interaction partners of the channel. METHODS In order to do so, a yeast two hybrid (Y2H) screen, with carboxy terminus of α1 subunit of the channel, as the bait, was performed. G1 subunit of v-ATPase was identified as a putative interaction partner of human Ca(v)2.3 by using the Y2H screening. The interaction was confirmed by immunoprecipitation. To study the functional importance of the interaction, bafilomycin A(1), a potent and specific inhibitor of v-ATPase was used in patch-clamp recordings in Ca(v)2.3 stably-transfected HEK-293 cells (2C6) as well as in electroretinography of the isolated bovine retina expressing R-type Ca(2+) channels. RESULTS G1 subunit of v-ATPase interacts with C-terminal tail of Ca(v)2.3 and bafilomycin A(1) reduces Ca(v)2.3 mediated calcium currents. Additionally peak I(Ca) is inhibited in retinal signal transduction when recorded as ERG b-wave. CONCLUSIONS The results suggest that v-ATPase interacts physically and also functionally with Ca(v)2.3. This is the first demonstration of association of Ca(v)2.3 C-terminus with a protein complex which is involved in transmembrane signalling.
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Affiliation(s)
- Kayalvizhi Radhakrishnan
- Institute of Neurophysiology, Center of Molecular Medicine Cologne, University of Cologne, Robert-Koch-Strasse 39, Cologne, Germany
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Calcium microdomains near R-type calcium channels control the induction of presynaptic long-term potentiation at parallel fiber to purkinje cell synapses. J Neurosci 2011; 31:5235-43. [PMID: 21471358 DOI: 10.1523/jneurosci.5252-10.2011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
R-type calcium channels in postsynaptic spines signal through functional calcium microdomains to regulate a calcium/calmodulin-sensitive potassium channel that in turn regulates postsynaptic hippocampal long-term potentiation (LTP). Here, we ask whether R-type calcium channels in presynaptic terminals also signal through calcium microdomains to control presynaptic LTP. We focus on presynaptic LTP at parallel fiber to Purkinje cell synapses in the cerebellum (PF-LTP), which is mediated by calcium/calmodulin-stimulated adenylyl cyclases. Although most presynaptic calcium influx is through N-type and P/Q-type calcium channels, blocking these channels does not disrupt PF-LTP, but blocking R-type calcium channels does. Moreover, global calcium signaling cannot account for the calcium dependence of PF-LTP because R-type channels contribute modestly to overall calcium entry. These findings indicate that, within presynaptic terminals, R-type calcium channels produce calcium microdomains that evoke presynaptic LTP at moderate frequencies that do not greatly increase global calcium levels.
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Cav2.3 channels are critical for oscillatory burst discharges in the reticular thalamus and absence epilepsy. Neuron 2011; 70:95-108. [PMID: 21482359 DOI: 10.1016/j.neuron.2011.02.042] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/21/2011] [Indexed: 11/27/2022]
Abstract
Neurons of the reticular thalamus (RT) display oscillatory burst discharges that are believed to be critical for thalamocortical network oscillations related to absence epilepsy. Ca²+-dependent mechanisms underlie such oscillatory discharges. However, involvement of high-voltage activated (HVA) Ca²+ channels in this process has been discounted. We examined this issue closely using mice deficient for the HVA Ca(v)2.3 channels. In brain slices of Ca(v)2.3⁻/⁻, a hyperpolarizing current injection initiated a low-threshold burst of spikes in RT neurons; however, subsequent oscillatory burst discharges were severely suppressed, with a significantly reduced slow afterhyperpolarization (AHP). Consequently, the lack of Ca(v)2.3 resulted in a marked decrease in the sensitivity of the animal to γ-butyrolactone-induced absence epilepsy. Local blockade of Ca(v)2.3 channels in the RT mimicked the results of Ca(v)2.3⁻/⁻ mice. These results provide strong evidence that Ca(v)2.3 channels are critical for oscillatory burst discharges in RT neurons and for the expression of absence epilepsy.
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Cosgrove KE, Meriney SD, Barrionuevo G. High affinity group III mGluRs regulate mossy fiber input to CA3 interneurons. Hippocampus 2010; 21:1302-17. [PMID: 20824730 DOI: 10.1002/hipo.20842] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2010] [Indexed: 11/10/2022]
Abstract
Stratum lacunosum-moleculare interneurons (L-Mi) in hippocampal area CA3 target the apical dendrite of pyramidal cells providing feedforward inhibition. Here we report that selective activation of group III metabotropic glutamate receptors (mGluRs) 4/8 with L(+)-2-amino-4-phosphnobytyric acid (L-AP4; 10 μM) decreased the probability of glutamate release from the mossy fiber (MF) terminals synapsing onto L-Mi. Consistent with this interpretation, application of L-AP4 in the presence of 3 mM strontium decreased the frequency of asynchronous MF EPSCs in L-Mi. Furthermore, the dose response curve showed that L-AP4 at 400 μM produced no further decrease in MF EPSC amplitude compared with 20 μM L-AP4, indicating the lack of mGluRs 7 at these MF terminals. We also found that one mechanism of mGluRs 4/8-mediated inhibition of release is linked to N-type voltage gated calcium channels at MF terminals. Application of the group III mGluR antagonist MSOP (100 μM) demonstrated that mGluRs 4/8 are neither tonically active nor activated by low and moderate frequencies of activity. However, trains of stimuli to the MF at 20 and 40 Hz delivered during the application of MSOP revealed a relief of inhibition of transmitter release and an increase in the overall probability of action potential firing in the postsynaptic L-Mi. Interestingly, the time to first action potential was significantly shorter in the presence of MSOP, indicating that mGluR 4/8 activation delays L-Mi firing in response to MF activity. Taken together, our data demonstrate that the timing and probability of action potentials in L-Mi evoked by MF synaptic input is regulated by the activation of presynaptic high affinity group III mGluRs.
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Affiliation(s)
- Kathleen E Cosgrove
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
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