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Sayegh FJP, Mouledous L, Macri C, Pi Macedo J, Lejards C, Rampon C, Verret L, Dahan L. Ventral tegmental area dopamine projections to the hippocampus trigger long-term potentiation and contextual learning. Nat Commun 2024; 15:4100. [PMID: 38773091 PMCID: PMC11109191 DOI: 10.1038/s41467-024-47481-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 03/28/2024] [Indexed: 05/23/2024] Open
Abstract
In most models of neuronal plasticity and memory, dopamine is thought to promote the long-term maintenance of Long-Term Potentiation (LTP) underlying memory processes, but not the initiation of plasticity or new information storage. Here, we used optogenetic manipulation of midbrain dopamine neurons in male DAT::Cre mice, and discovered that stimulating the Schaffer collaterals - the glutamatergic axons connecting CA3 and CA1 regions - of the dorsal hippocampus concomitantly with midbrain dopamine terminals within a 200 millisecond time-window triggers LTP at glutamatergic synapses. Moreover, we showed that the stimulation of this dopaminergic pathway facilitates contextual learning in awake behaving mice, while its inhibition hinders it. Thus, activation of midbrain dopamine can operate as a teaching signal that triggers NeoHebbian LTP and promotes supervised learning.
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Affiliation(s)
- Fares J P Sayegh
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse, France.
| | - Lionel Mouledous
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse, France
| | - Catherine Macri
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse, France
| | - Juliana Pi Macedo
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse, France
| | - Camille Lejards
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse, France
| | - Claire Rampon
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse, France
| | - Laure Verret
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse, France
| | - Lionel Dahan
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse, France.
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2
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Wiseman AL, Briggs CA, Peritt A, Kapecki N, Peterson DA, Shim SS, Stutzmann GE. Lithium Provides Broad Therapeutic Benefits in an Alzheimer's Disease Mouse Model. J Alzheimers Dis 2023; 91:273-290. [PMID: 36442195 DOI: 10.3233/jad-220758] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is a chronic neurodegenerative disorder with a progressive loss of cognitive function. Currently, no effective treatment regimen is available. Lithium, a mood stabilizer for bipolar disorder, exerts broad neuroprotective and neurotrophic actions and improves cognitive function. OBJECTIVE The study investigated if lithium stabilizes Ca2+ signaling abnormalities in hippocampal neurons and subsequently normalize downstream effects on AD neuropathology and synaptic plasticity in young AD mice. METHODS Four-month-old 3xTg-AD mice were treated with a LiCl diet chow for 30 days. At the end of the lithium treatment, a combination of two-photon Ca2+ imaging, electrophysiology, and immunohistochemistry assays were used to assess the effects of the LiCl treatment on inositol trisphosphate receptor (IP3R)-dependent endoplasmic reticulum (ER) Ca2+ and voltage-gated Ca2+ channel (VGCC)-mediated Ca2+ signaling in CA1 neurons, neuronal nitric oxide synthase (nNOS) and hyperphosphorylated tau (p-tau) levels and synaptic plasticity in the hippocampus and overlying cortex from 3xTg-ADmice. RESULTS Thirty-day LiCl treatment reduced aberrant IP3R-dependent ER Ca2+ and VGCC-mediated Ca2+ signaling in CA1 pyramidal neurons from 3xTg-AD mice and restored neuronal nitric oxide synthase (nNOS) and hyperphosphorylated tau (p-tau) levels to control levels in the hippocampal subfields and overlying cortex. The LiCl treatment enhanced post-tetanic potentiation (PTP), a form of short-term plasticity in the hippocampus. CONCLUSION The study found that lithium exerts therapeutic effects across several AD-associated early neuronal signaling abnormalities including aberrant Ca2+ signaling, nNOS, and p-tau formation and enhances short-term synaptic plasticity. Lithium could serve as an effective treatment or co-therapeutic for AD.
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Affiliation(s)
- Alyssa L Wiseman
- Discipline of Neuroscience, The Chicago Medical School, Rosalind Franklin University, North Chicago, IL, USA.,School of Graduate and Postdoctoral Studies, Rosalind Franklin University, North Chicago, IL, USA
| | - Clark A Briggs
- Discipline of Neuroscience, The Chicago Medical School, Rosalind Franklin University, North Chicago, IL, USA
| | - Ariel Peritt
- Discipline of Neuroscience, The Chicago Medical School, Rosalind Franklin University, North Chicago, IL, USA.,Sackler School of Medicine, New York State/American Program of Tel Aviv University, Tel Aviv, Israel
| | - Nicolas Kapecki
- Discipline of Neuroscience, The Chicago Medical School, Rosalind Franklin University, North Chicago, IL, USA
| | - Daniel A Peterson
- Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University, North Chicago, IL, USA.,Discipline of Neuroscience, The Chicago Medical School, Rosalind Franklin University, North Chicago, IL, USA.,School of Graduate and Postdoctoral Studies, Rosalind Franklin University, North Chicago, IL, USA
| | - Seong S Shim
- Discipline of Psychiatry and Behavioral Sciences, The Chicago Medical School, Rosalind Franklin University, North Chicago, IL, USA.,Captain James A. Lovell Federal Health Care Center, Mental Health, North Chicago, IL, USA
| | - Grace E Stutzmann
- Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University, North Chicago, IL, USA.,Discipline of Neuroscience, The Chicago Medical School, Rosalind Franklin University, North Chicago, IL, USA.,School of Graduate and Postdoctoral Studies, Rosalind Franklin University, North Chicago, IL, USA
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3
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A Novel and Selective Dopamine Transporter Inhibitor, (S)-MK-26, Promotes Hippocampal Synaptic Plasticity and Restores Effort-Related Motivational Dysfunctions. Biomolecules 2022; 12:biom12070881. [PMID: 35883437 PMCID: PMC9312958 DOI: 10.3390/biom12070881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/09/2022] [Accepted: 06/21/2022] [Indexed: 11/20/2022] Open
Abstract
Dopamine (DA), the most abundant human brain catecholaminergic neurotransmitter, modulates key behavioral and neurological processes in young and senescent brains, including motricity, sleep, attention, emotion, learning and memory, and social and reward-seeking behaviors. The DA transporter (DAT) regulates transsynaptic DA levels, influencing all these processes. Compounds targeting DAT (e.g., cocaine and amphetamines) were historically used to shape mood and cognition, but these substances typically lead to severe negative side effects (tolerance, abuse, addiction, and dependence). DA/DAT signaling dysfunctions are associated with neuropsychiatric and progressive brain disorders, including Parkinson’s and Alzheimer diseases, drug addiction and dementia, resulting in devastating personal and familial concerns and high socioeconomic costs worldwide. The development of low-side-effect, new/selective medicaments with reduced abuse-liability and which ameliorate DA/DAT-related dysfunctions is therefore crucial in the fields of medicine and healthcare. Using the rat as experimental animal model, the present work describes the synthesis and pharmacological profile of (S)-MK-26, a new modafinil analogue with markedly improved potency and selectivity for DAT over parent drug. Ex vivo electrophysiology revealed significantly augmented hippocampal long-term synaptic potentiation upon acute, intraperitoneally delivered (S)-MK-26 treatment, whereas in vivo experiments in the hole-board test showed only lesser effects on reference memory performance in aged rats. However, in effort-related FR5/chow and PROG/chow feeding choice experiments, (S)-MK-26 treatment reversed the depression-like behavior induced by the dopamine-depleting drug tetrabenazine (TBZ) and increased the selection of high-effort alternatives. Moreover, in in vivo microdialysis experiments, (S)-MK-26 significantly increased extracellular DA levels in the prefrontal cortex and in nucleus accumbens core and shell. These studies highlight (S)-MK-26 as a potent enhancer of transsynaptic DA and promoter of synaptic plasticity, with predominant beneficial effects on effort-related behaviors, thus proposing therapeutic potentials for (S)-MK-26 in the treatment of low-effort exertion and motivational dysfunctions characteristic of depression and aging-related disorders.
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4
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Wang CC, Weyrer C, Fioravante D, Kaeser PS, Regehr WG. Presynaptic Short-Term Plasticity Persists in the Absence of PKC Phosphorylation of Munc18-1. J Neurosci 2021; 41:7329-7339. [PMID: 34290081 PMCID: PMC8412997 DOI: 10.1523/jneurosci.0347-21.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 07/03/2021] [Accepted: 07/09/2021] [Indexed: 12/22/2022] Open
Abstract
Post-tetanic potentiation (PTP) is a form of short-term plasticity that lasts for tens of seconds following a burst of presynaptic activity. It has been proposed that PTP arises from protein kinase C (PKC) phosphorylation of Munc18-1, an SM (Sec1/Munc-18 like) family protein that is essential for release. To test this model, we made a knock-in mouse in which all Munc18-1 PKC phosphorylation sites were eliminated through serine-to-alanine point mutations (Munc18-1SA mice), and we studied mice of either sex. The expression of Munc18-1 was not altered in Munc18-1SA mice, and there were no obvious behavioral phenotypes. At the hippocampal CA3-to-CA1 synapse and the granule cell parallel fiber (PF)-to-Purkinje cell (PC) synapse, basal transmission was largely normal except for small decreases in paired-pulse facilitation that are consistent with a slight elevation in release probability. Phorbol esters that mimic the activation of PKC by diacylglycerol still increased synaptic transmission in Munc18-1SA mice. In Munc18-1SA mice, 70% of PTP remained at CA3-to-CA1 synapses, and the amplitude of PTP was not reduced at PF-to-PC synapses. These findings indicate that at both CA3-to-CA1 and PF-to-PC synapses, phorbol esters and PTP enhance synaptic transmission primarily by mechanisms that are independent of PKC phosphorylation of Munc18-1.SIGNIFICANCE STATEMENT A leading mechanism for a prevalent form of short-term plasticity, post-tetanic potentiation (PTP), involves protein kinase C (PKC) phosphorylation of Munc18-1. This study tests this mechanism by creating a knock-in mouse in which Munc18-1 is replaced by a mutated form of Munc18-1 that cannot be phosphorylated. The main finding is that most PTP at hippocampal CA3-to-CA1 synapses or at cerebellar granule cell-to-Purkinje cell synapses does not rely on PKC phosphorylation of Munc18-1. Thus, mechanisms independent of PKC phosphorylation of Munc18-1 are important mediators of PTP.
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Affiliation(s)
- Chih-Chieh Wang
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Christopher Weyrer
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
- Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge CB2 3EG, United Kingdom
| | - Diasynou Fioravante
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
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5
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O'Neil SD, Rácz B, Brown WE, Gao Y, Soderblom EJ, Yasuda R, Soderling SH. Action potential-coupled Rho GTPase signaling drives presynaptic plasticity. eLife 2021; 10:63756. [PMID: 34269176 PMCID: PMC8285108 DOI: 10.7554/elife.63756] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 07/06/2021] [Indexed: 12/30/2022] Open
Abstract
In contrast to their postsynaptic counterparts, the contributions of activity-dependent cytoskeletal signaling to presynaptic plasticity remain controversial and poorly understood. To identify and evaluate these signaling pathways, we conducted a proteomic analysis of the presynaptic cytomatrix using in vivo biotin identification (iBioID). The resultant proteome was heavily enriched for actin cytoskeleton regulators, including Rac1, a Rho GTPase that activates the Arp2/3 complex to nucleate branched actin filaments. Strikingly, we find Rac1 and Arp2/3 are closely associated with synaptic vesicle membranes in adult mice. Using three independent approaches to alter presynaptic Rac1 activity (genetic knockout, spatially restricted inhibition, and temporal optogenetic manipulation), we discover that this pathway negatively regulates synaptic vesicle replenishment at both excitatory and inhibitory synapses, bidirectionally sculpting short-term synaptic depression. Finally, we use two-photon fluorescence lifetime imaging to show that presynaptic Rac1 activation is coupled to action potentials by voltage-gated calcium influx. Thus, this study uncovers a previously unrecognized mechanism of actin-regulated short-term presynaptic plasticity that is conserved across excitatory and inhibitory terminals. It also provides a new proteomic framework for better understanding presynaptic physiology, along with a blueprint of experimental strategies to isolate the presynaptic effects of ubiquitously expressed proteins.
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Affiliation(s)
| | - Bence Rácz
- Department of Anatomy and Histology, University of Veterinary Medicine, Budapest, Hungary
| | - Walter Evan Brown
- Department of Cell Biology, Duke University Medical Center, Durham, United States
| | - Yudong Gao
- Department of Cell Biology, Duke University Medical Center, Durham, United States
| | - Erik J Soderblom
- Department of Cell Biology, Duke University Medical Center, Durham, United States.,Proteomics and Metabolomics Shared Resource and Center for Genomic and Computational Biology, Duke University Medical Center, Durham, United States
| | - Ryohei Yasuda
- Max Planck Florida Institute for Neuroscience, Jupiter, United States
| | - Scott H Soderling
- Department of Neurobiology, Duke University Medical Center, Durham, United States.,Department of Cell Biology, Duke University Medical Center, Durham, United States
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6
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Silva M, Tran V, Marty A. Calcium-dependent docking of synaptic vesicles. Trends Neurosci 2021; 44:579-592. [PMID: 34049722 DOI: 10.1016/j.tins.2021.04.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/23/2021] [Accepted: 04/09/2021] [Indexed: 10/21/2022]
Abstract
The concentration of calcium ions in presynaptic terminals regulates transmitter release, but underlying mechanisms have remained unclear. Here we review recent studies that shed new light on this issue. Fast-freezing electron microscopy and total internal reflection fluorescence microscopy studies reveal complex calcium-dependent vesicle movements including docking on a millisecond time scale. Recordings from so-called 'simple synapses' indicate that calcium not only triggers exocytosis, but also modifies synaptic strength by controlling a final, rapid vesicle maturation step before release. Molecular studies identify several calcium-sensitive domains on Munc13 and on synaptotagmin-1 that are likely involved in bringing the vesicular and plasma membranes closer together in response to calcium elevation. Together, these results suggest that calcium-dependent vesicle docking occurs in a wide range of time domains and plays a crucial role in several phenomena including synaptic facilitation, post-tetanic potentiation, and neuromodulator-induced potentiation.
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Affiliation(s)
- Melissa Silva
- Université de Paris, SPPIN-Saints Pères Paris Institute for the Neurosciences, CNRS, F-75006 Paris, France
| | - Van Tran
- Université de Paris, SPPIN-Saints Pères Paris Institute for the Neurosciences, CNRS, F-75006 Paris, France
| | - Alain Marty
- Université de Paris, SPPIN-Saints Pères Paris Institute for the Neurosciences, CNRS, F-75006 Paris, France.
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7
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Tang F, Xiao D, Chen L, Gao H, Li X. Role of Munc18-1 in the biological functions and pathogenesis of neurological disorders (Review). Mol Med Rep 2021; 23:198. [PMID: 33495808 PMCID: PMC7821349 DOI: 10.3892/mmr.2021.11837] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 12/30/2020] [Indexed: 11/06/2022] Open
Abstract
The release of neurotransmitters following the fusion of synaptic vesicles and the presynaptic membrane is an important process in the transmission of neuronal information. Syntaxin-binding protein 1 (Munc18-1) is a synaptic fusion protein binding protein, which mainly regulates synaptic vesicle fusion and neurotransmitter release by interacting with soluble N-ethylmaleimide sensitive factor attachment protein receptor. In addition to affecting neurotransmitter transmission, Munc18-1 is also involved in regulating neurosynaptic plasticity, neurodevelopment and neuroendocrine cell release functions (including thyroxine and insulin release). A number of previous studies have demonstrated that Munc18-1 has diverse and vital biological functions, and that its abnormal expression serves an important role in the pathogenesis of a variety of neurological diseases, including epileptic encephalopathy, schizophrenia, autism, Parkinsons disease, Alzheimers disease, multiple sclerosis, Duchennes muscular dystrophy and neuronal ceroid lipofuscinosis. The present review summarizes the function of Munc18-1 and its possible relationship to the pathogenesis of various neurological diseases.
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Affiliation(s)
- Fajuan Tang
- Department of Emergency, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Dongqiong Xiao
- Department of Emergency, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Lin Chen
- Department of Emergency, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Hu Gao
- Department of Emergency, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Xihong Li
- Department of Emergency, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
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8
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Chen IS, Liang WZ, Wang JL, Kuo CC, Hao LJ, Chou CT, Jan CR. Exploration of thioridazine-induced Ca 2+ signaling and non-Ca 2+-triggered cell death in HepG2 human hepatocellular carcinoma cells. CHINESE J PHYSIOL 2020; 63:187-194. [PMID: 32859886 DOI: 10.4103/cjp.cjp_45_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Thioridazine, belonging to first-generation antipsychotic drugs, is a prescription used to treat schizophrenia. However, the effect of thioridazine on intracellular Ca2+ concentration ([Ca2+]i) and viability in human liver cancer cells is unclear. This study examined whether thioridazine altered Ca2+ signaling and viability in HepG2 human hepatocellular carcinoma cells. Ca2+ concentrations in suspended cells were measured using the fluorescent Ca2+-sensitive dye fura-2. Cell viability was examined by WST-1 assay. Thioridazine at concentrations of 25-100 μM induced [Ca2+]i rises. Ca2+ removal reduced the signal by 20%. Thioridazine (100 μM) induced Mn2+ influx suggesting of Ca2+ entry. Thioridazine-induced Ca2+ entry was inhibited by 20% by protein kinase C (PKC) activator (phorbol 12-myristate 13 acetate) and inhibitor (GF109203X) and by three inhibitors of store-operated Ca2+ channels: nifedipine, econazole, and SKF96365. In Ca2+-free medium, treatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (TG) abolished thioridazine-evoked [Ca2+]i rises. On the other hand, thioridazine preincubation completely inhibited the [Ca2+]i rises induced by TG. Furthermore, U73122 totally suppressed the [Ca2+]i rises induced by thioridazine via inhibition of phospholipase C (PLC). Regarding cytotoxicity, at 30-80 μM, thioridazine reduced cell viability in a concentration-dependent fashion. This cytotoxicity was not prevented by preincubation with 1,2-bis (2-aminophenoxy) ethane-N, N, N', N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM) (a Ca2+ chelator). To conclude, thioridazine caused concentration-dependent [Ca2+]i rises in HepG2 human hepatoma cells by inducing Ca2+ release from the endoplasmic reticulum via PLC-associated pathways and Ca2+ influx from extracellular medium through PKC-sensitive store-operated Ca2+ entry. In addition, thioridazine induced cytotoxicity in a Ca2+-independent manner.
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Affiliation(s)
- I-Shu Chen
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Wei-Zhe Liang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung; Department of Pharmacy, Tajen University, Pingtung, Taiwan
| | - Jue-Long Wang
- Department of Rehabilitation, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Chun-Chi Kuo
- Department of Nursing, Tzu Hui Institute of Technology, Pingtung, Taiwan
| | - Lyh-Jyh Hao
- Department of Endocrinology and Metabolism, Kaohsiung Veteran General Hospital Tainan Branch; Chung Hwa University of Medical and Technology, Tainan, Taiwan
| | - Chiang-Ting Chou
- Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chiayi Campus; Division of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital Chiayi Branch, Puzi City, Chiayi County, Taiwan
| | - Chung-Ren Jan
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
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9
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Huson V, Meijer M, Dekker R, Ter Veer M, Ruiter M, van Weering JR, Verhage M, Cornelisse LN. Post-tetanic potentiation lowers the energy barrier for synaptic vesicle fusion independently of Synaptotagmin-1. eLife 2020; 9:55713. [PMID: 32831174 PMCID: PMC7500951 DOI: 10.7554/elife.55713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 08/23/2020] [Indexed: 11/13/2022] Open
Abstract
Previously, we showed that modulation of the energy barrier for synaptic vesicle fusion boosts release rates supralinearly (Schotten, 2015). Here we show that mouse hippocampal synapses employ this principle to trigger Ca2+-dependent vesicle release and post-tetanic potentiation (PTP). We assess energy barrier changes by fitting release kinetics in response to hypertonic sucrose. Mimicking activation of the C2A domain of the Ca2+-sensor Synaptotagmin-1 (Syt1), by adding a positive charge (Syt1D232N) or increasing its hydrophobicity (Syt14W), lowers the energy barrier. Removing Syt1 or impairing its release inhibitory function (Syt19Pro) increases spontaneous release without affecting the fusion barrier. Both phorbol esters and tetanic stimulation potentiate synaptic strength, and lower the energy barrier equally well in the presence and absence of Syt1. We propose a model where tetanic stimulation activates Syt1-independent mechanisms that lower the energy barrier and act additively with Syt1-dependent mechanisms to produce PTP by exerting multiplicative effects on release rates.
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Affiliation(s)
- Vincent Huson
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Marieke Meijer
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Rien Dekker
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Mirelle Ter Veer
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Marvin Ruiter
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Jan Rt van Weering
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Lennart Niels Cornelisse
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
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10
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Quirion JG, Parsons MP. The Onset and Progression of Hippocampal Synaptic Plasticity Deficits in the Q175FDN Mouse Model of Huntington Disease. Front Cell Neurosci 2019; 13:326. [PMID: 31379510 PMCID: PMC6650530 DOI: 10.3389/fncel.2019.00326] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/03/2019] [Indexed: 12/22/2022] Open
Abstract
Huntington disease (HD) is an inherited neurodegenerative disease characterized by a clinical triad of motor, psychiatric and cognitive symptoms. HD is caused by a CAG repeat expansion in the gene encoding the huntingtin protein. Homozygosity for the HD-causing mutation is extremely rare; thus, the majority of HD patients express the mutant huntingtin protein in addition to reduced levels of the non-pathogenic huntingtin protein. Deficits in synaptic plasticity, including hippocampal long-term potentiation (LTP), have been identified in various mouse models of HD and are thought to contribute to the debilitating cognitive symptoms associated with the disease. However, the bulk of these studies used N-terminal fragment or homozygous knock-in mouse models of HD at symptomatic ages, and our understanding of the onset and progression of synaptic plasticity deficits in the HD brain is lacking. To better understand the time-course of synaptic plasticity deficits in HD, as well as the impact of heterozygous and homozygous huntingtin mutations, we quantified basal synaptic connectivity, presynaptic release probability, presynaptically mediated post-tetanic potentiation (PTP) and postsynaptically mediated LTP at presymptomatic, early symptomatic and late symptomatic ages in heterozygous and homozygous Q175FDN knock-in HD mice. Our results demonstrate clear age-dependent effects of the HD-causing mutation on both short and long-term plasticity that generally emerge earlier in homozygous mice. Interestingly, deficits in presynaptic short-term plasticity were more closely linked to disease progression than deficits in postsynaptic LTP, and heterozygous mice were more susceptible to an LTP deficit when induced by high frequency stimulation compared to theta burst stimulation. To the best of our knowledge, the present study represents the most thorough characterization to date of the onset and progression of hippocampal synaptic plasticity deficits in a mouse model of HD, and should prove valuable to future studies exploring cellular mechanisms underlying the debilitating cognitive decline in HD.
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Affiliation(s)
- Jade G Quirion
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Matthew P Parsons
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
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11
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Sun G, Chen H, Liang WZ, Jan CR. Exploration of the effect of the alkaloid colchicine on Ca2+ handling and its related physiology in human oral cancer cells. Arch Oral Biol 2019; 102:179-185. [DOI: 10.1016/j.archoralbio.2019.04.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/15/2019] [Accepted: 04/27/2019] [Indexed: 10/26/2022]
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12
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Chakroborty S, Hill ES, Christian DT, Helfrich R, Riley S, Schneider C, Kapecki N, Mustaly-Kalimi S, Seiler FA, Peterson DA, West AR, Vertel BM, Frost WN, Stutzmann GE. Reduced presynaptic vesicle stores mediate cellular and network plasticity defects in an early-stage mouse model of Alzheimer's disease. Mol Neurodegener 2019; 14:7. [PMID: 30670054 PMCID: PMC6343260 DOI: 10.1186/s13024-019-0307-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 01/13/2019] [Indexed: 01/27/2023] Open
Abstract
Background Identifying effective strategies to prevent memory loss in AD has eluded researchers to date, and likely reflects insufficient understanding of early pathogenic mechanisms directly affecting memory encoding. As synaptic loss best correlates with memory loss in AD, refocusing efforts to identify factors driving synaptic impairments may provide the critical insight needed to advance the field. In this study, we reveal a previously undescribed cascade of events underlying pre and postsynaptic hippocampal signaling deficits linked to cognitive decline in AD. These profound alterations in synaptic plasticity, intracellular Ca2+ signaling, and network propagation are observed in 3–4 month old 3xTg-AD mice, an age which does not yet show overt histopathology or major behavioral deficits. Methods In this study, we examined hippocampal synaptic structure and function from the ultrastructural level to the network level using a range of techniques including electron microscopy (EM), patch clamp and field potential electrophysiology, synaptic immunolabeling, spine morphology analyses, 2-photon Ca2+ imaging, and voltage-sensitive dye-based imaging of hippocampal network function in 3–4 month old 3xTg-AD and age/background strain control mice. Results In 3xTg-AD mice, short-term plasticity at the CA1-CA3 Schaffer collateral synapse is profoundly impaired; this has broader implications for setting long-term plasticity thresholds. Alterations in spontaneous vesicle release and paired-pulse facilitation implicated presynaptic signaling abnormalities, and EM analysis revealed a reduction in the ready-releasable and reserve pools of presynaptic vesicles in CA3 terminals; this is an entirely new finding in the field. Concurrently, increased synaptically-evoked Ca2+ in CA1 spines triggered by LTP-inducing tetani is further enhanced during PTP and E-LTP epochs, and is accompanied by impaired synaptic structure and spine morphology. Notably, vesicle stores, synaptic structure and short-term plasticity are restored by normalizing intracellular Ca2+ signaling in the AD mice. Conclusions These findings suggest the Ca2+ dyshomeostasis within synaptic compartments has an early and fundamental role in driving synaptic pathophysiology in early stages of AD, and may thus reflect a foundational disease feature driving later cognitive impairment. The overall significance is the identification of previously unidentified defects in pre and postsynaptic compartments affecting synaptic vesicle stores, synaptic plasticity, and network propagation, which directly impact memory encoding. Electronic supplementary material The online version of this article (10.1186/s13024-019-0307-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shreaya Chakroborty
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Evan S Hill
- Department of Cell Biology and Anatomy, The Chicago Medical School; Center for Brain Function and Repair, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Daniel T Christian
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Rosalind Helfrich
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Shannon Riley
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Corinne Schneider
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Nicolas Kapecki
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Sarah Mustaly-Kalimi
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Figen A Seiler
- Electron Microscopy Center, RFUMS, North Chicago, IL, 60064, USA
| | - Daniel A Peterson
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Anthony R West
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Barbara M Vertel
- Department of Cell Biology and Anatomy, The Chicago Medical School; Center for Brain Function and Repair, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA.,Electron Microscopy Center, RFUMS, North Chicago, IL, 60064, USA
| | - William N Frost
- Department of Cell Biology and Anatomy, The Chicago Medical School; Center for Brain Function and Repair, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA
| | - Grace E Stutzmann
- Department of Neuroscience, The Chicago Medical School; The Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd, North Chicago, IL, 60064, USA.
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13
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Cheng Q, Song SH, Augustine GJ. Molecular Mechanisms of Short-Term Plasticity: Role of Synapsin Phosphorylation in Augmentation and Potentiation of Spontaneous Glutamate Release. Front Synaptic Neurosci 2018; 10:33. [PMID: 30425632 PMCID: PMC6218601 DOI: 10.3389/fnsyn.2018.00033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/20/2018] [Indexed: 12/24/2022] Open
Abstract
We used genetic and pharmacological approaches to identify the signaling pathways involved in augmentation and potentiation, two forms of activity dependent, short-term synaptic plasticity that enhance neurotransmitter release. Trains of presynaptic action potentials produced a robust increase in the frequency of miniature excitatory postsynaptic currents (mEPSCs). Following the end of the stimulus, mEPSC frequency followed a bi-exponential decay back to basal levels. The time constants of decay identified these two exponential components as the decay of augmentation and potentiation, respectively. Augmentation increased mEPSC frequency by 9.3-fold, while potentiation increased mEPSC frequency by 2.4-fold. In synapsin triple-knockout (TKO) neurons, augmentation was reduced by 83% and potentiation was reduced by 74%, suggesting that synapsins are key signaling elements in both forms of plasticity. To examine the synapsin isoforms involved, we expressed individual synapsin isoforms in TKO neurons. While synapsin IIIa rescued both augmentation and potentiation, none of the other synapsin isoforms produced statistically significant amounts of rescue. To determine the involvement of protein kinases in these two forms of short-term plasticity, we examined the effects of inhibitors of protein kinases A (PKA) and C (PKC). While inhibition of PKC had little effect, PKA inhibition reduced augmentation by 76% and potentiation by 60%. Further, elevation of intracellular cAMP concentration, by either forskolin or IBMX, greatly increased mEPSC frequency and occluded the amount of augmentation and potentiation evoked by electrical stimulation. Finally, mutating a PKA phosphorylation site to non-phosphorylatable alanine largely abolished the ability of synapsin IIIa to rescue both augmentation and potentiation. Together, these results indicate that PKA activation is required for both augmentation and potentiation of spontaneous neurotransmitter release and that PKA-mediated phosphorylation of synapsin IIIa underlies both forms of presynaptic short-term plasticity.
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Affiliation(s)
- Qing Cheng
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Sang-Ho Song
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - George J Augustine
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Institute of Molecular and Cell Biology, Singapore, Singapore
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14
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Chen Q, Ren L, Min S, Hao X, Chen H, Deng J. Changes in synaptic plasticity are associated with electroconvulsive shock-induced learning and memory impairment in rats with depression-like behavior. Neuropsychiatr Dis Treat 2018; 14:1737-1746. [PMID: 29997435 PMCID: PMC6033087 DOI: 10.2147/ndt.s163756] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Accompanied with the effective antidepressant effect, electroconvulsive shock (ECS) can induce cognitive impairment, but the mechanism is unclear. Synaptic plasticity is the fundamental mechanism of learning and memory. This study aimed to investigate the effect of ECS on synaptic plasticity changes in rats with depression-like behavior. METHODS Chronic unpredictable mild stress procedure was conducted to establish a model of depression-like behavior. Rats were randomly divided into the following three groups: control group with healthy rats (group C), rats with depression-like behavior (group D), and rats with depression-like behavior undergoing ECS (group DE). Depression-like behavior and spatial learning and memory function were assessed by sucrose preference test and Morris water test, respectively. Synaptic plasticity changes in long-term potentiation (LTP), long-term depression (LTD), depotentiation, and post-tetanic potentiation (PTP) were tested by electrophysiological experiment. RESULTS ECS could exert antidepressant effect and also induced spatial learning and memory impairment in rats with depression-like behavior. And, data on electrophysiological experiment showed that ECS induced lower magnitude of LTP, higher magnitude of LTD, higher magnitude of depotentiation, and lower magnitude of PTP. CONCLUSION ECS-induced learning and memory impairment may be attributed to postsynaptic mechanism of LTP impairment, LTD and depotentiation enhancement, and presynaptic mechanism of PTP impairment.
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Affiliation(s)
- Qibin Chen
- Department of Anesthesiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing,
| | - Li Ren
- Department of Anesthesiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing,
| | - Su Min
- Department of Anesthesiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing,
| | - Xuechao Hao
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan
| | - Hengsheng Chen
- Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, People's Republic of China
| | - Jie Deng
- Department of Anesthesiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing,
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15
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Persistent but Labile Synaptic Plasticity at Excitatory Synapses. J Neurosci 2018; 38:5750-5758. [PMID: 29802202 DOI: 10.1523/jneurosci.2772-17.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 04/11/2018] [Accepted: 04/19/2018] [Indexed: 11/21/2022] Open
Abstract
Short-term synaptic plasticity contributes to many computations in the brain and allows synapses to keep a finite record of recent activity. Here we have investigated the mechanisms underlying an intriguing form of short-term plasticity termed labile LTP, at hippocampal and PFC synapses in male rats and male and female mice. In the hippocampus, labile LTP is triggered by high-frequency activation of presynaptic axons and is rapidly discharged with further activation of those axons. However, if the synapses are quiescent, they remain potentiated until further presynaptic activation. To distinguish labile LTP from NMDAR-dependent forms of potentiation, we blocked NMDARs in all experiments. Labile LTP was synapse-specific and was accompanied by a decreased paired pulse ratio, consistent with an increased release probability. Presynaptic Ca2+ and protein kinase activation during the tetanus appeared to be required for its initiation. Labile LTP was not reversed by a PKC inhibitor and did not require either RIM1α or synaptotagmin-7, proteins implicated in other forms of presynaptic short-term plasticity. Similar NMDAR-independent potentiation could be elicited at synapses in mPFC. Labile LTP allows for rapid information storage that is erased under controlled circumstances and could have a role in a variety of hippocampal and prefrontal cortical computations related to short-term memory.SIGNIFICANCE STATEMENT Changes in synaptic strength are thought to represent information storage relevant to particular nervous system tasks. A single synapse can exhibit multiple overlapping forms of plasticity that shape information transfer from presynaptic to postsynaptic neurons. Here we investigate the mechanisms underlying labile LTP, an NMDAR-independent form of plasticity induced at hippocampal synapses. The potentiation is maintained for long periods as long as the synapses are infrequently active, but with regular activation, the synapses are depotentiated. Similar NMDAR-independent potentiation can also be induced at L2/3-to-L5 synapses in mPFC. Labile LTP requires a rise in presynaptic Ca2+ and protein kinase activation but is unaffected in RIM1α or synaptotagmin-7 mutant mice. Labile LTP may contribute to short-term or working memory in hippocampus and mPFC.
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