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Yang YM, Fekete A, Arsenault J, Sengar AS, Aitoubah J, Grande G, Li A, Salter EW, Wang A, Mark MD, Herlitze S, Egan SE, Salter MW, Wang LY. Intersectin-1 enhances calcium-dependent replenishment of the readily releasable pool of synaptic vesicles during development. J Physiol 2024. [PMID: 39383250 DOI: 10.1113/jp286462] [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: 05/03/2024] [Accepted: 09/06/2024] [Indexed: 10/11/2024] Open
Abstract
Intersectin-1 (Itsn1) is a scaffold protein that plays a key role in coupling exocytosis and endocytosis of synaptic vesicles (SVs). However, it is unclear whether and how Itsn1 regulates these processes to support efficient neurotransmission during development. To address this, we examined the calyx of Held synapse in the auditory brainstem of wild-type and Itsn1 mutant mice before (immature) and after (mature) the onset of hearing. Itsn1 was present in the pre- and postsynaptic compartments at both developmental stages. Loss of function of Itsn1 did not alter presynaptic action potentials, Ca2+ entry via voltage-gated Ca2+ channels (VGCCs), transmitter release or short-term depression (STD) induced by depletion of SVs in the readily releasable pool (RRP) in either age group. Yet, fast Ca2+-dependent recovery from STD was attenuated in mature mutant synapses, while it was unchanged in immature mutant synapses. This deficit at mature synapses was rescued by introducing the DH-PH domains of Itsn1 into the presynaptic terminals. Inhibition of dynamin, which interacts with Itsn1 during endocytosis, had no effect on STD recovery. Interestingly, we found a developmental enrichment of Itsn1 near VGCCs, which may underlie the Itsn1-mediated fast replenishment of the RRP. Consequently, the absence of Itsn1 in mature synapses led to a higher failure rate of postsynaptic spiking during high-frequency synaptic transmission. Taken together, our findings suggest that Itsn1 translocation to the vicinity of VGCCs during development is crucial for accelerating Ca2+-dependent RRP replenishment and sustaining high-fidelity neurotransmission. KEY POINTS: Itsn1 is expressed in the pre- and postsynaptic compartments of the calyx of Held synapse. Developmental upregulation of vesicular glutamate transporter-1 is Itsn1 dependent. Itsn1 does not affect basal synaptic transmission at different developmental stages. Itsn1 is required for Ca2+-dependent recovery from short-term depression in mature synapses. Itsn1 mediates the recovery through its DH-PH domains, independent of its interactive partner dynamin. Itsn1 translocates to the vicinity of presynaptic Ca2+ channels during development. Itsn1 supports high-fidelity neurotransmission by enabling rapid recovery from vesicular depletion during repetitive activity.
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Affiliation(s)
- Yi-Mei Yang
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Biomedical Sciences, University of Minnesota, Duluth, Minnesota, USA
| | - Adam Fekete
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jason Arsenault
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Ameet S Sengar
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
| | - Jamila Aitoubah
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Giovanbattista Grande
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Angela Li
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
| | - Eric W Salter
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Neuroscience, Brown University, Providence, Rhode Island, USA
| | - Alex Wang
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Neuroscience, Yale University, New Haven, Connecticut, USA
| | - Melanie D Mark
- Department of Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Stefan Herlitze
- Department of Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Sean E Egan
- Cell Biology, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Ontario, Canada
| | - Michael W Salter
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Lu-Yang Wang
- Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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Chrobak AA, Siwek M. Drugs with glutamate-based mechanisms of action in psychiatry. Pharmacol Rep 2024:10.1007/s43440-024-00656-8. [PMID: 39333460 DOI: 10.1007/s43440-024-00656-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2024] [Revised: 09/13/2024] [Accepted: 09/16/2024] [Indexed: 09/29/2024]
Abstract
Psychopharmacotherapy of major psychiatric disorders is mostly based on drugs that modulate serotonergic, dopaminergic, or noradrenergic neurotransmission, either by inhibiting their reuptake or by acting as agonists or antagonists on specific monoamine receptors. The effectiveness of this approach is limited by a significant delay in the therapeutic mechanism and self-perpetuating growth of treatment resistance with a consecutive number of ineffective trials. A growing number of studies suggest that drugs targeting glutamate receptors offer an opportunity for rapid therapeutic effect that may overcome the limitations of monoaminergic drugs. In this article, we present a review of glutamate-modulating drugs, their mechanism of action, as well as preclinical and clinical studies of their efficacy in treating mental disorders. Observations of the rapid, robust, and long-lasting effects of ketamine and ketamine encourages further research on drugs targeting glutamatergic transmission. A growing number of studies support the use of memantine and minocycline in major depressive disorder and schizophrenia. Amantadine, zinc, and Crocus sativus extracts yield the potential to ameliorate depressive symptoms in patients with affective disorders. Drugs with mechanisms of action based on glutamate constitute a promising pharmacological group in the treatment of mental disorders that do not respond to standard methods of therapy. However, further research is needed on their efficacy, safety, dosage, interactions, and side effects, to determine their optimal clinical use.
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Affiliation(s)
- Adrian Andrzej Chrobak
- Department of Adult Psychiatry, Jagiellonian University Medical College, Kopernika 21A, 31-501, Kraków, Poland
| | - Marcin Siwek
- Department of Affective Disorders, Jagiellonian University Medical College, Kopernika 21A, 31-501, Kraków, Poland.
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Hamoudi W, Tripathi MK, Ojha SK, Amal H. A cross-talk between nitric oxide and the glutamatergic system in a Shank3 mouse model of autism. Free Radic Biol Med 2022; 188:83-91. [PMID: 35716826 DOI: 10.1016/j.freeradbiomed.2022.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/21/2022]
Abstract
Nitric oxide (NO) is a multifunctional signaling molecule that plays a crucial role in synaptic transmission and neuronal function. Pioneering studies show that nitric oxide (NO) and S-nitrosylation (SNO, the NO-mediated posttranslational modification) can engender nitrosative stress in the brain, contributing to neurodegenerative diseases. Little is known, however, about the aberrant NO signaling in neurodevelopmental disorders including autism spectrum disorder (ASD). We have recently shown that the Shank3 mutation in mice representing a model of ASD causes excessive NO levels and aberrant protein SNO. The glutamatergic system is involved in ASD, specifically in SHANK3 pathology. We used SNOTRAP technology to identify the SNO-proteome in the brain of the Shank3 mutant mice to understand the role of SNO in the glutamatergic system during the development of these mice. We conducted a systems biology analysis of the SNO-proteome to investigate the biological processes and signaling pathways in the brain of juvenile and adult Shank3 mutant and wild-type mice. The Shank3 mutation caused significant SNO-enrichment of a glutamate signaling pathway in the juvenile and adult mutant mice, although different protein subsets were S-nitrosylated in both ages. Cellular compartments analysis showed that "glutamatergic Synapse" is SNO-enriched significantly in the mutant mice of both ages. We also found eight S-nitrosylated proteins involved in glutamate transmission in both ages. 38 SNO-proteins found in the mutant mice are among the high-risk SFARI gene list. Biochemical examination shows a reduction in the levels of NMDA Receptor (NR1) in the cortex and striatum of the mutant mice of both ages. Neuronal NOS knockdown in SHSY-5Y rescued NR1 levels. In conclusion, this study reveals novel SNO of key glutamatergic proteins in Shank3 mutant mice and a cross-talk between nitric oxide and the glutamatergic system.
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Affiliation(s)
- Wajeha Hamoudi
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Manish Kumar Tripathi
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Shashank Kumar Ojha
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Haitham Amal
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel.
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Role of NMDAR plasticity in a computational model of synaptic memory. Sci Rep 2021; 11:21182. [PMID: 34707139 PMCID: PMC8551337 DOI: 10.1038/s41598-021-00516-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 10/12/2021] [Indexed: 11/08/2022] Open
Abstract
A largely unexplored question in neuronal plasticity is whether synapses are capable of encoding and learning the timing of synaptic inputs. We address this question in a computational model of synaptic input time difference learning (SITDL), where N-methyl-d-aspartate receptor (NMDAR) isoform expression in silent synapses is affected by time differences between glutamate and voltage signals. We suggest that differences between NMDARs' glutamate and voltage gate conductances induce modifications of the synapse's NMDAR isoform population, consequently changing the timing of synaptic response. NMDAR expression at individual synapses can encode the precise time difference between signals. Thus, SITDL enables the learning and reconstruction of signals across multiple synapses of a single neuron. In addition to plausibly predicting the roles of NMDARs in synaptic plasticity, SITDL can be usefully applied in artificial neural network models.
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Gurma M, Yang YM, Wang LY. Developmental plasticity of NMDA receptors at the calyx of Held synapse. Neuropharmacology 2021; 196:108697. [PMID: 34242682 DOI: 10.1016/j.neuropharm.2021.108697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/11/2021] [Accepted: 06/12/2021] [Indexed: 11/25/2022]
Abstract
Excitatory synaptic transmission is largely mediated by glutamate receptors in central synapses, such as the calyx of Held synapse in the auditory brainstem. This synapse is best known for undergoing extensive morphological and functional changes throughout early development and thereby has served as a prominent model system to study presynaptic mechanisms of neurotransmitter release. However, the pivotal roles of N-methyl-d-aspartate receptors (NMDARs) in gating acute forms of activity-dependent, persistent plasticity in vitro and chronic developmental remodeling in vivo are hardly noted. This article will provide a retrospective review of key experimental evidence to conceptualize the impact of a transient abundance of NMDARs during the early postnatal stage on the functionality of fast-spiking central synapses while raising a series of outstanding questions that are of general significance for understanding the developing brain in health and diseases. This article is part of the special Issue on "Glutamate Receptors - NMDA receptors".
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Affiliation(s)
- Maria Gurma
- Program in Neurosciences & Mental Health, SickKids Research Institute, 555 University Ave, Toronto, Ontario M5G 1X8, Canada; Department of Physiology, University of Toronto, 1 Kings Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Yi-Mei Yang
- Department of Biomedical Sciences, University of Minnesota, Duluth MN, 55812, USA
| | - Lu-Yang Wang
- Program in Neurosciences & Mental Health, SickKids Research Institute, 555 University Ave, Toronto, Ontario M5G 1X8, Canada; Department of Physiology, University of Toronto, 1 Kings Circle, Toronto, Ontario, M5S 1A8, Canada.
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Marins FR, Limborço-Filho M, Iddings JA, Xavier CH, Biancardi VC, Stern JE, Ramiro Diaz J, Oppenheimer SM, Filosa JA, Peliky Fontes MA. Tachycardia evoked from insular stroke in rats is dependent on glutamatergic neurotransmission in the dorsomedial hypothalamus. Eur J Neurol 2021; 28:3640-3649. [PMID: 34152065 DOI: 10.1111/ene.14987] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Damage to the insula results in cardiovascular complications. In rats, activation of N-methyl-d-aspartate receptors (NMDARs) in the intermediate region of the posterior insular cortex (iIC) results in sympathoexcitation, tachycardia and arterial pressure increases. Similarly, focal experimental hemorrhage at the iIC results in a marked sympathetic-mediated increase in baseline heart rate. The dorsomedial hypothalamic region (DMH) is critical for the integration of sympathetic-mediated tachycardic responses. Here, whether responses evoked from the iIC are dependent on a synaptic relay in the DMH was evaluated. METHODS Wistar rats were prepared for injections into the iIC and DMH. Anatomical (tracing combined with immunofluorescence) and functional experiments (cardiovascular and sympathetic recordings) were performed. RESULTS The iIC sends dense projections to the DMH. Approximately 50% of iIC neurons projecting to the DMH express NMDARs, NR1 subunit. Blockade of glutamatergic receptors in the DMH abolishes the cardiovascular and autonomic responses evoked by the activation of NMDARs in the iIC (change in mean arterial pressure 7 ± 1 vs. 1 ± 1 mmHg after DMH blockade; change in heart rate 28 ± 3 vs. 0 ± 3 bpm after DMH blockade; change in renal sympathetic nerve activity 23% ± 1% vs. -1% ± 4% after DMH blockade). Experimental hemorrhage at the iIC resulted in a marked tachycardia (change 89 ± 14 bpm) that was attenuated by 65% ± 5% (p = 0.0009) after glutamatergic blockade at the DMH. CONCLUSIONS The iIC-induced tachycardia is largely dependent upon a glutamatergic relay in the DMH. Our study reveals the presence of an excitatory glutamatergic pathway from the iIC to the DMH that may be involved in the cardiovascular alterations observed after insular stroke.
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Affiliation(s)
- Fernanda Ribeiro Marins
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Marcelo Limborço-Filho
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Carlos Henrique Xavier
- Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiânia, Brazil
| | - Vinicia C Biancardi
- Department of Anatomy, Physiology, and Pharmacology, Auburn University, and Center for Neurosciences Research Initiative, Auburn University, Auburn, AL, USA
| | - Javier E Stern
- Department of Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | | | - Stephen M Oppenheimer
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Yu Y, Yang Z, Jin B, Qin X, Zhu X, Sun J, Huo L, Wang R, Shi Y, Jia Z, Shi YS, Chu S, Kong D, Zhang W. Cannabidiol inhibits febrile seizure by modulating AMPA receptor kinetics through its interaction with the N-terminal domain of GluA1/GluA2. Pharmacol Res 2020; 161:105128. [DOI: 10.1016/j.phrs.2020.105128] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 07/30/2020] [Accepted: 08/05/2020] [Indexed: 12/15/2022]
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Abstract
Current treatment paradigm in Alzheimer’s disease (AD) involves multiple approaches combining pharmacological and nonpharmacological intervention to mitigate the clinical symptoms, slow the progressive loss of cognitive and functional abilities, or modify the disease course. So far, beyond anti-cholinesterase inhibitors (AChEIs), donepezil, rivastigmine, galantamine, and antagonist of N-methyl-D-aspartic acid (NMDA) receptor, there are no newly approved medicines to treat AD. Under pharmacological treatment, the personal characteristic and the intra-individual therapeutic evaluations to examine various cognitive domains, behavioral and psychological problems, and global function should be considered when choosing any of AChEIs. The use of optimal dosage referring to the expected clinical outcomes and currently reported deficits from patient with AD has become an important issue in clinical treatment. Establishing and maintaining a strong therapeutic alliance to physician, patient, and caregiver is crucial and central to the comprehensive care in AD.
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Affiliation(s)
- Yuan-Han Yang
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Taiwan, China
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, China
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung City, Taiwan, China
| | - Rajka Liscic
- Department of Neurology, Johannes Kepler University Linz, Austria
| | - Jacqueline Dominguez
- Institute for Neurosciences, St. Luke’s Medical Center, Quezon City, Philippines
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Lesperance LS, Yang YM, Wang LY. Delayed expression of activity-dependent gating switch in synaptic AMPARs at a central synapse. Mol Brain 2020; 13:6. [PMID: 31941524 PMCID: PMC6961283 DOI: 10.1186/s13041-019-0536-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/17/2019] [Indexed: 01/11/2023] Open
Abstract
Developing central synapses exhibit robust plasticity and undergo experience-dependent remodeling. Evidently, synapses in sensory systems such as auditory brainstem circuits mature rapidly to achieve high-fidelity neurotransmission for sound localization. This depends on a developmental switch in AMPAR composition from slow-gating GluA1-dominant to fast-gating GluA4-dominant, but the mechanisms underlying this switch remain unknown. We hypothesize that patterned stimuli mimicking spontaneous/sound evoked activity in the early postnatal stage drives this gating switch. We examined activity-dependent changes in evoked and miniature excitatory postsynaptic currents (eEPSCs and mEPSCs) at the calyx of Held synapse by breaking through the postsynaptic membrane at different time points following 2 min of theta burst stimulation (TBS) to afferents in mouse brainstem slices. We found the decay time course of eEPSCs accelerated, but this change was not apparent until > 30 min after TBS. Histogram analyses of the decay time constants of mEPSCs for naive and tetanized synapses revealed two populations centered around τfast ≈ 0.4 and 0.8 ms, but the relative weight of the τ0.4 population over the τ0.8 population increased significantly only in tetanized synapses. Such changes are blocked by NMDAR or mGluR1/5 antagonists or inhibitors of CaMKII, PKC and protein synthesis, and more importantly precluded in GluA4−/− synapses, suggesting GluA4 is the substrate underlying the acceleration. Our results demonstrate a novel form of plasticity working through NMDAR and mGluR activation to trigger a gating switch of AMPARs with a temporally delayed onset of expression, ultimately enhancing the development of high-fidelity synaptic transmission.
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Affiliation(s)
- Lee Stephen Lesperance
- Program in Neurosciences & Mental Health, SickKids Research Institute, 555 University Ave, Toronto, Ontario, M5G 1X8, Canada
| | - Yi-Mei Yang
- Program in Neurosciences & Mental Health, SickKids Research Institute, 555 University Ave, Toronto, Ontario, M5G 1X8, Canada.,Department of Biomedical Sciences, University of Minnesota, Duluth, MN 55812, USA
| | - Lu-Yang Wang
- Program in Neurosciences & Mental Health, SickKids Research Institute, 555 University Ave, Toronto, Ontario, M5G 1X8, Canada.
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Kishi T, Matsuda Y, Iwata N. Combination Therapy of Serotonin Reuptake Inhibitors and Memantine for Obsessive- Compulsive Disorder: A Meta-Analysis of Double-Blind, Randomized, Placebo-Controlled Trials. J Alzheimers Dis 2019; 64:43-48. [PMID: 29865079 DOI: 10.3233/jad-180237] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We performed a meta-analysis to determine whether combination therapy with serotonin reuptake inhibitors (SRIs) and memantine (MEM) was beneficial for the treatment of obsessive- compulsive disorder. This study included three double-blind, randomized, placebo-controlled trials. MEM+SRI was superior to placebo+SRI with regard to response rate [primary outcome, n = 97; risk ratio = 0.22; 95% confidence intervals (CI) = 0.12-0.42; p < 0.00001; I2 = 0%; number needed to treat = 2], the Yale- Brown Obsessive- Compulsive Scale total [standardized mean difference (SMD) = - 4.56; 95% CI = - 8.50, - 0.62; p = 0.02], obsession subscale (SMD = - 4.39; 95% CI = - 5.94, - 2.85; p < 0.00001), and compulsion subscale score (SMD = - 4.60; 95% CI = - 7.64, - 1.55; p = 0.003). No significant differences in any safety outcome were found between the groups.
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Affiliation(s)
- Taro Kishi
- Department of Psychiatry, Fujita Health University School of Medicine, Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Yuki Matsuda
- Department of Psychiatry, Fujita Health University School of Medicine, Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, Japan.,Department of Psychiatry, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Nakao Iwata
- Department of Psychiatry, Fujita Health University School of Medicine, Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, Japan
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Kishi T, Matsunaga S, Oya K, Nomura I, Ikuta T, Iwata N. Memantine for Alzheimer's Disease: An Updated Systematic Review and Meta-analysis. J Alzheimers Dis 2018; 60:401-425. [PMID: 28922160 DOI: 10.3233/jad-170424] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND The clinical benefit of memantine for Alzheimer's disease (AD) remains inconclusive. OBJECTIVE We performed an updated systematic review and meta-analysis of the efficacy/safety of memantine in AD. METHODS We included randomized trials of memantine for AD patients. Cognitive function scores (CF), behavioral disturbances scores (BD), and all-cause discontinuation were used as primary measures. Effect size based on a random-effects model was evaluated in the meta-analyses. RESULTS Thirty studies (n = 7,567; memantine versus placebo: N = 11, n = 3,298; memantine + cholinesterase inhibitors (M+ChEIs) versus ChEIs: N = 17, n = 4,175) were identified. Memantine showed a significant improvement in CF [standardized mean difference (SMD) = -0.24, 95% confidence intervals (95% CIs) = -0.34, -0.15, p < 0.00001, I2 = 35% ] and BD (SMD = -0.16, 95% CIs = -0.29, -0.04, p = 0.01, I2 = 52%) compared with placebo. In the sensitivity analysis including only patients with moderate-severe AD, memantine was superior to the placebo in reducing BD without considerable heterogeneity (SMD = -0.20, 95% CIs = -0.34, -0.07, p = 0.003, I2 = 36%). Compared with ChEIs, M+ChEIs showed a greater reduction in BD (SMD = -0.20, 95% CIs = -0.36, -0.03, p = 0.02, I2 = 77%) and a trend of CF improvement (SMD = -0.11, 95% CIs = -0.22, 0.01, p = 0.06, I2 = 56%). However, in the sensitivity analysis of double-blind, placebo-controlled studies only, M+ChEIs showed a significant reduction in BD compared with ChEIs without considerable heterogeneity (SMD = -0.11, 95% CIs = -0.21, -0.01, p = 0.04, I2 = 40%). When performing the sensitivity analysis of donepezil studies only, M+ChEIs was superior to ChEIs in improving CF without considerable heterogeneity (SMD = -0.18, 95% CIs = -0.31, -0.05, p = 0.006, I2 = 49%). No differences were detected in all-cause discontinuation between the groups. CONCLUSIONS The meta-analyses suggest the credible efficacy and safety of memantine in treating AD when used alone or in combination with ChEIs.
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Affiliation(s)
- Taro Kishi
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Shinji Matsunaga
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Kazuto Oya
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Ikuo Nomura
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
| | - Toshikazu Ikuta
- Department of Communication Sciences and Disorders, School of Applied Sciences, University of Mississippi, University MS, USA
| | - Nakao Iwata
- Department of Psychiatry, Fujita Health University School of Medicine, Kutsukake-cho, Toyoake, Aichi, Japan
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Low Somatic Sodium Conductance Enhances Action Potential Precision in Time-Coding Auditory Neurons. J Neurosci 2017; 36:11999-12009. [PMID: 27881784 DOI: 10.1523/jneurosci.1475-16.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 09/21/2016] [Accepted: 10/04/2016] [Indexed: 01/14/2023] Open
Abstract
Auditory nerve fibers encode sounds in the precise timing of action potentials (APs), which is used for such computations as sound localization. Timing information is relayed through several cell types in the auditory brainstem that share an unusual property: their APs are not overshooting, suggesting that the cells have very low somatic sodium conductance (gNa). However, it is not clear how gNa influences temporal precision. We addressed this by comparing bushy cells (BCs) in the mouse cochlear nucleus with T-stellate cells (SCs), which do have normal overshooting APs. BCs play a central role in both relaying and refining precise timing information from the auditory nerve, whereas SCs discard precise timing information and encode the envelope of sound amplitude. Nucleated-patch recording at near-physiological temperature indicated that the Na current density was 62% lower in BCs, and the voltage dependence of gNa inactivation was 13 mV hyperpolarized compared with SCs. We endowed BCs with SC-like gNa using two-electrode dynamic clamp and found that synaptic activity at physiologically relevant rates elicited APs with significantly lower probability, through increased activation of delayed rectifier channels. In addition, for two near-simultaneous synaptic inputs, the window of coincidence detection widened significantly with increasing gNa, indicating that refinement of temporal information by BCs is degraded by gNa Thus, reduced somatic gNa appears to be an adaption for enhancing fidelity and precision in time-coding neurons. SIGNIFICANCE STATEMENT Proper hearing depends on analyzing temporal aspects of sounds with high precision. Auditory neurons that specialize in precise temporal information have a suite of unusual intrinsic properties, including nonovershooting action potentials and few sodium channels in the soma. However, it was not clear how low sodium channel availability in the soma influenced the temporal precision of action potentials initiated in the axon initial segment. We studied this using dynamic clamp to mimic sodium channels in the soma, which yielded normal, overshooting action potentials. Increasing somatic sodium conductance had major negative consequences: synaptic activity evoked action potentials with lower fidelity, and the precision of coincidence detection was degraded. Thus, low somatic sodium channel availability appears to enhance fidelity and temporal precision.
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Memantine add-on to antipsychotic treatment for residual negative and cognitive symptoms of schizophrenia: a meta-analysis. Psychopharmacology (Berl) 2017; 234:2113-2125. [PMID: 28508107 DOI: 10.1007/s00213-017-4616-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 03/25/2017] [Indexed: 12/17/2022]
Abstract
RATIONALE We examined whether memantine add-on to antipsychotic treatment is beneficial in schizophrenia treatment. OBJECTIVE This systematic review and meta-analysis aimed to achieve stronger evidence on the efficacy and safety of memantine add-on for treating schizophrenia. METHODS We analyzed double-blind, randomized, placebo-controlled trials of memantine add-on treatment in schizophrenia patients receiving antipsychotics. The primary outcomes were amelioration of negative symptoms and all-cause discontinuation. Dichotomous outcomes are presented as risk ratios (RRs), and continuous outcomes are presented as mean differences (MDs) or standardized mean differences (SMDs). RESULTS Eight studies (n = 448) were included. Although memantine add-on treatment was superior to placebo for ameliorating negative symptoms (SMD = -0.96, p = 0.006, I 2 = 88%; N = 7, n = 367) in the Positive and Negative Syndrome Scale general subscale (MD = -1.62, p = 0.002, I 2 = 0%; N = 4, n = 151) and Mini-Mental Status Examination score (MD = -3.07, p < 0.0001, I 2 = 21%; N = 3, n = 83), there were no statistically significant differences in the amelioration of overall (SMD = -0.75, p = 0.06, I 2 = 86%; N = 5, n = 271), positive (SMD = -0.46, p = 0.07, I 2 = 80%; N = 7, n = 367), and depressive symptoms (SMD = -0.127, p = 0.326, I 2 = 0%; N = 4, n = 201); all-cause discontinuation (RR = 1.34, p = 0.31, I 2 = 0%; N = 8, n = 448); and individual adverse events (fatigue, dizziness, headache, nausea, constipation) between the groups. For negative symptoms, the significant heterogeneity disappeared when risperidone studies alone were considered (I 2 = 0%). However, memantine add-on treatment remained superior to placebo (SMD = -1.29, p = 0.00001). Meta-regression analysis showed that patient age was associated with memantine-associated amelioration of negative symptoms (slope = 0.171, p = 0.0206). CONCLUSIONS Memantine add-on treatment may be beneficial for treating psychopathological symptoms (especially negative symptoms) in schizophrenia patients. The negative-symptom effect size may be associated with younger adult schizophrenia patients.
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Kishi T, Matsunaga S, Iwata N. The effects of memantine on behavioral disturbances in patients with Alzheimer's disease: a meta-analysis. Neuropsychiatr Dis Treat 2017; 13:1909-1928. [PMID: 28790827 PMCID: PMC5530072 DOI: 10.2147/ndt.s142839] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Memantine is effective in the treatment of behavioral disturbances in patients with Alzheimer's disease. It has not yet been fully determined which behavioral disturbances respond best to memantine. METHODS We conducted a meta-analysis of memantine vs control (placebo or usual care) for the treatment of individual behavioral disturbances (delusion, hallucination, agitation/aggression, dysphoria, anxiety/phobia, euphoria, apathy, disinhibition, irritability/lability, aberrant motor activity/activity disturbances, nighttime disturbance/diurnal rhythm disturbances, and eating disturbances). Randomized controlled studies of memantine in patients with Alzheimer's disease were included in this study. To evaluate these outcomes, standardized mean difference (SMD), with 95% confidence intervals (95% CIs), based upon a random-effects model was evaluated in the meta-analysis. RESULTS A total of 11 studies (n=4,261; memantine vs placebo: N=4, n=1,500; memantine + cholinesterase inhibitors [M + ChEIs] vs ChEIs: N=7, n=2,761) were included in the meta-analysis. Compared to control, memantine showed significant improvement in agitation/aggression (SMD =-0.11; 95% CIs =-0.20, -0.03; P=0.01; I2=47%), delusion (SMD =-0.12; 95% CIs =-0.18, -0.06; P=0.0002; I2=0%), disinhibition (SMD =-0.08; 95% CIs =-0.15, -0.00; P=0.04; I2=0%), and nighttime disturbance/diurnal rhythm disturbances (SMD =-0.10; 95% CIs =-0.18, -0.02; P=0.02; I2=36%). Memantine was also marginally superior to control in hallucination (SMD =-0.06; 95% CIs =-0.12, 0.01; P=0.07; I2=0%) and irritability/lability (SMD =-0.09; 95% CIs =-0.19, 0.01; P=0.07; I2=42%). Memantine is similar to control in dysphoria, anxiety/phobia, euphoria, apathy, and eating disturbance. CONCLUSION The meta-analysis suggest that memantine has benefits for the treatment of most of the behavioral disturbances in patients with Alzheimer's disease. Memantine does not deteriorate negative symptoms as behavioral disturbances in patients with Alzheimer's disease.
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Affiliation(s)
- Taro Kishi
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Shinji Matsunaga
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Nakao Iwata
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
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Sierksma MC, Tedja MS, Borst JGG. In vivo matching of postsynaptic excitability with spontaneous synaptic inputs during formation of the rat calyx of Held synapse. J Physiol 2016; 595:207-231. [PMID: 27426483 DOI: 10.1113/jp272780] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/07/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Neurons in the medial nucleus of the trapezoid body of anaesthetized rats of postnatal day (P)2-6 showed burst firing with a preferred interval of about 100 ms, which was stable, and a second preferred interval of 5-30 ms, which shortened during development. In 3 out of 132 cases, evidence for the presence of two large inputs was found. In vivo whole-cell recordings revealed that the excitability of the principal neuron and the size of its largest synaptic inputs were developmentally matched. At P2-4, action potentials were triggered by barrages of small synaptic events that summated to plateau potentials, while at later stages firing depended on a single, large and often prespike-associated input, which is probably the nascent calyx of Held. Simulations with a Hodgkin-Huxley-like model, which was based on fits of the intrinsic postsynaptic properties, suggested an essential role for the low-threshold potassium conductance in this transition. ABSTRACT In the adult, principal neurons of the medial nucleus of the trapezoid body (MNTB) are typically contacted by a single, giant terminal called the calyx of Held, whereas during early development a principal neuron receives inputs from many axons. How these changes in innervation impact the postsynaptic activity has not yet been studied in vivo. We therefore recorded spontaneous inputs and intrinsic properties of principal neurons in anaesthetized rat pups during the developmental period in which the calyx forms. A characteristic bursting pattern could already be observed at postnatal day (P)2, before formation of the calyx. At this age, action potentials (APs) were triggered by barrages of summating EPSPs causing plateau depolarizations. In contrast, at P5, a single EPSP reliably triggered APs, resulting in a close match between pre- and postsynaptic firing. Postsynaptic excitability and the size of the largest synaptic events were developmentally matched. The developmental changes in intrinsic properties were estimated by fitting in vivo current injections to a Hodgkin-Huxley-type model of the principal neuron. Our simulations indicated that the developmental increases in Ih , low-threshold K+ channels and leak currents contributed to the reduction in postsynaptic excitability, but that low-threshold K+ channels specifically functioned as a dampening influence in the near-threshold range, thus precluding small inputs from triggering APs. Together, these coincident changes help to propagate bursting activity along the auditory brainstem, and are essential steps towards establishing the relay function of the calyx of Held synapse.
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Affiliation(s)
- Martijn C Sierksma
- Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Milly S Tedja
- Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - J Gerard G Borst
- Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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17
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Veerman SRT, Schulte PFJ, Smith JD, de Haan L. Memantine augmentation in clozapine-refractory schizophrenia: a randomized, double-blind, placebo-controlled crossover study. Psychol Med 2016; 46:1909-21. [PMID: 27048954 PMCID: PMC4954262 DOI: 10.1017/s0033291716000398] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/30/2015] [Accepted: 02/04/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND Dysfunction of neuroplasticity due to N-methyl-d-aspartate (NMDA) receptor hypofunction may be a causal factor for memory and executive dysfunctioning in schizophrenia. Deregulation of NMDA transmission in the prefrontal cortex may also explain negative and positive symptoms. Clozapine augmentation with memantine targets altered NMDA receptor-mediated neurotransmission in schizophrenia and showed substantial beneficial effects on several symptom domains in a small proof-of-concept study. We evaluate effects of memantine add-on treatment to clozapine for memory and executive function, and negative and positive symptoms in schizophrenia. METHOD Clozapine-treated patients with refractory schizophrenia were randomly assigned to 12 weeks of double-blind adjunctive treatment with memantine (n = 26) or placebo (n = 26). Crossover occurred after a 2-week placebo wash-out period. Primary endpoints were change from baseline to 12 weeks treatment and 14 weeks to 26 weeks treatment on memory and executive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB), Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impression Severity Scale (CGI-S). Side effects were assessed using the Liverpool University Neuroleptic Side-Effect Rating Scale. RESULTS When compared with placebo, memantine improved a composite memory score comprising verbal recognition memory and paired associates learning task scores on the CANTAB (effect size = 0.30) and PANSS negative subscale score (effect size = 0.29). Side effects were mild and transient. CONCLUSIONS In patients with clozapine-treated refractory schizophrenia, memantine addition significantly improved verbal and visual memory and negative symptoms without serious adverse effects. These results justify further investigations on long-term memantine augmentation to clozapine in treatment-resistant schizophrenia.
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Affiliation(s)
- S. R. T. Veerman
- Mental Health Service Organization North Holland
North, Community Mental Health Division, Flexible Assertive
Community Treatment, Alkmaar, The
Netherlands
| | - P. F. J. Schulte
- Mental Health Service Organization North Holland
North, Division for Specialized Treatment, Treatment Center for
Bipolar Disorders, Alkmaar, The
Netherlands
| | - J. D. Smith
- Department of Psychiatry and Behavioral
Sciences, Northwestern University, Feinberg School of Medicine,
Center for Prevention Implementation Methodology, Chicago,
IL, USA
| | - L. de Haan
- Early Psychosis Department,
Academic Medical Center, University of Amsterdam, Academic Psychiatric
Center, Arkin, Amsterdam,
The Netherlands
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Abstract
Efficient endocytosis is crucial for maintaining synaptic transmission because of its role in retrieving constituent membrane and associated proteins. In the past three decades three modes of endocytosis have been proposed involving the central nervous system: clathrin-mediated endocytosis, kiss-and-run endocytosis and bulk endocytosis. These forms of endocytosis can be induced under different conditions, but their detailed molecular mechanisms and functions are largely unknown. Here, we review the existence and initiation of all three modes of endocytosis at a giant glutamatergic synapse, the calyx of Held. The possibility of direct electrophysiology recording in this synapse allows for accurate tracking of exocytosis and endocytosis via capacitance measurements. Future aims will be focused on identifying the molecules that undergo the different mechanisms of endocytosis and the conditions under which different forms of endocytosis predominate.
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Friedman LK, Segal M. Early exposure of cultured hippocampal neurons to excitatory amino acids protects from later excitotoxicity. Int J Dev Neurosci 2009; 28:195-205. [DOI: 10.1016/j.ijdevneu.2009.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 09/10/2009] [Accepted: 11/05/2009] [Indexed: 10/20/2022] Open
Affiliation(s)
- Linda K. Friedman
- Neuroscience DepartmentNew York College of Osteopathic Medicine/New York Institute of TechnologyNorthern BoulevardOld WestburyNY11568United States
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Newpher TM, Ehlers MD. Spine microdomains for postsynaptic signaling and plasticity. Trends Cell Biol 2009; 19:218-27. [PMID: 19328694 DOI: 10.1016/j.tcb.2009.02.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 02/14/2009] [Accepted: 02/20/2009] [Indexed: 10/21/2022]
Abstract
Changes in the molecular composition and signaling properties of excitatory glutamatergic synapses onto dendritic spines mediate learning-related plasticity in the mammalian brain. This molecular adaptation serves as the most celebrated cell biological model for learning and memory. Within their micron-sized dimensions, dendritic spines restrict the diffusion of signaling molecules and spatially confine the activation of signal transduction pathways. Much of this local regulation occurs by spatial compartmentalization of glutamate receptors. Here, we review recently identified cell biological mechanisms regulating glutamate receptor mobility within individual dendritic spines. We discuss the emerging functions of glutamate receptors residing within sub-spine microdomains and propose a model for distinct signaling platforms with specialized functions in synaptic plasticity.
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Affiliation(s)
- Thomas M Newpher
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
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Presynaptic release probability and readily releasable pool size are regulated by two independent mechanisms during posttetanic potentiation at the calyx of Held synapse. J Neurosci 2008; 28:7945-53. [PMID: 18685020 DOI: 10.1523/jneurosci.2165-08.2008] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
At the immature calyx of Held, the fast decay phase of a Ca(2+) transient induced by tetanic stimulation (TS) was followed by a period of elevated [Ca(2+)](i) for tens of seconds, referred to as posttetanic residual calcium (Ca(res)). We investigated the source of Ca(res) and its contribution to posttetanic potentiation (PTP). After TS (100 Hz for 4 s), posttetanic Ca(res) at the calyx of Held was largely abolished by tetraphenylphosphonium (TPP(+)) or Ru360, which inhibit mitochondrial Na(+)-dependent Ca(2+) efflux and Ca(2+) uniporter, respectively. Whereas the control PTP lasted longer than Ca(res), inhibition of Ca(res) by TPP(+) resulted in preferential suppression of the early phase of PTP, the decay time course of which well matched with that of Ca(res). TS induced significant increases in release probability (P(r)) and the size of the readily releasable pool (RRP), which were estimated from plots of cumulative EPSC amplitudes. TPP(+) or Ru360 suppressed the posttetanic increase in P(r), whereas it had little effect on the increase in RRP size. Moreover, the posttetanic increase in P(r), but not in RRP size, showed a linear correlation with the amount of Ca(res). In contrast, myosin light chain kinase (MLCK) inhibitors and blebbistatin reduced the posttetanic increase in RRP size with no effect on the increase in P(r). Application of TPP(+) in the presence of MLCK inhibitor peptide caused further suppression of PTP. These findings suggest that Ca(res) released from mitochondria and activation of MLCK are primarily responsible for the increase in P(r) and that in the RRP size, respectively.
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