1
|
Caya-Bissonnette L, Béïque JC. Half a century legacy of long-term potentiation. Curr Biol 2024; 34:R640-R662. [PMID: 38981433 DOI: 10.1016/j.cub.2024.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
In 1973, two papers from Bliss and Lømo and from Bliss and Gardner-Medwin reported that high-frequency synaptic stimulation in the dentate gyrus of rabbits resulted in a long-lasting increase in synaptic strength. This form of synaptic plasticity, commonly referred to as long-term potentiation (LTP), was immediately considered as an attractive mechanism accounting for the ability of the brain to store information. In this historical piece looking back over the past 50 years, we discuss how these two landmark contributions directly motivated a colossal research effort and detail some of the resulting milestones that have shaped our evolving understanding of the molecular and cellular underpinnings of LTP. We highlight the main features of LTP, cover key experiments that defined its induction and expression mechanisms, and outline the evidence supporting a potential role of LTP in learning and memory. We also briefly explore some ramifications of LTP on network stability, consider current limitations of LTP as a model of associative memory, and entertain future research orientations.
Collapse
Affiliation(s)
- Léa Caya-Bissonnette
- Graduate Program in Neuroscience, University of Ottawa, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada; Brain and Mind Research Institute's Centre for Neural Dynamics and Artificial Intelligence, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada
| | - Jean-Claude Béïque
- Brain and Mind Research Institute's Centre for Neural Dynamics and Artificial Intelligence, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada.
| |
Collapse
|
2
|
Rao S, Liang F, Herring BE. RhoGEF Tiam2 Regulates Glutamatergic Synaptic Transmission in Hippocampal CA1 Pyramidal Neurons. eNeuro 2024; 11:ENEURO.0500-21.2024. [PMID: 38871458 PMCID: PMC11262554 DOI: 10.1523/eneuro.0500-21.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 03/29/2024] [Accepted: 05/23/2024] [Indexed: 06/15/2024] Open
Abstract
Glutamatergic synapses exhibit significant molecular diversity, but circuit-specific mechanisms that underlie synaptic regulation are not well characterized. Prior reports show that Rho-guanine nucleotide exchange factor (RhoGEF) Tiam1 regulates perforant path→dentate gyrus granule neuron synapses. In the present study, we report Tiam1's homolog Tiam2 is implicated in glutamatergic neurotransmission in CA1 pyramidal neurons. We find that Tiam2 regulates evoked excitatory glutamatergic currents via a postsynaptic mechanism mediated by the catalytic Dbl-homology domain. Overall, we present evidence for RhoGEF Tiam2's role in glutamatergic synapse function at Schaffer collateral→CA1 pyramidal neuron synapses.
Collapse
Affiliation(s)
- Sadhna Rao
- Department of Biological Sciences, Neurobiology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California 90089
| | - Feng Liang
- Department of Biological Sciences, Neurobiology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California 90089
| | - Bruce E Herring
- Department of Biological Sciences, Neurobiology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California 90089
| |
Collapse
|
3
|
Noriega-Prieto JA, Maglio LE, Perez-Domper P, Dávila JC, Gutiérrez A, Torres-Alemán I, Fernández de Sevilla D. Bidirectional modulation of synaptic transmission by insulin-like growth factor-I. Front Cell Neurosci 2024; 18:1390663. [PMID: 38910964 PMCID: PMC11193368 DOI: 10.3389/fncel.2024.1390663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/29/2024] [Indexed: 06/25/2024] Open
Abstract
Insulin-like growth factor-I (IGF-I) plays a key role in the modulation of synaptic plasticity and is an essential factor in learning and memory processes. However, during aging, IGF-I levels are decreased, and the effect of this decrease in the induction of synaptic plasticity remains unknown. Here we show that the induction of N-methyl-D-aspartate receptor (NMDAR)-dependent long-term potentiation (LTP) at layer 2/3 pyramidal neurons (PNs) of the mouse barrel cortex is favored or prevented by IGF-I (10 nM) or IGF-I (7 nM), respectively, when IGF-I is applied 1 h before the induction of Hebbian LTP. Analyzing the cellular basis of this bidirectional control of synaptic plasticity, we observed that while 10 nM IGF-I generates LTP (LTPIGF-I) of the post-synaptic potentials (PSPs) by inducing long-term depression (LTD) of the inhibitory post-synaptic currents (IPSCs), 7 nM IGF-I generates LTD of the PSPs (LTDIGF-I) by inducing LTD of the excitatory post-synaptic currents (EPSCs). This bidirectional effect of IGF-I is supported by the observation of IGF-IR immunoreactivity at both excitatory and inhibitory synapses. Therefore, IGF-I controls the induction of Hebbian NMDAR-dependent plasticity depending on its concentration, revealing novel cellular mechanisms of IGF-I on synaptic plasticity and in the learning and memory machinery of the brain.
Collapse
Affiliation(s)
- José Antonio Noriega-Prieto
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Laura Eva Maglio
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paloma Perez-Domper
- Centro de Investigaciones Biomédicas en Red Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Instituto Cajal (CSIC), Madrid, Spain
| | - José Carlos Dávila
- Centro de Investigaciones Biomédicas en Red Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Departamento Biología Celular, Genética y Fisiología. Facultad de Ciencias, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Málaga, Spain
| | - Antonia Gutiérrez
- Centro de Investigaciones Biomédicas en Red Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Departamento Biología Celular, Genética y Fisiología. Facultad de Ciencias, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Málaga, Spain
| | - Ignacio Torres-Alemán
- Centro de Investigaciones Biomédicas en Red Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Ikerbasque Science Foundation, Bilbao, Spain
| | - David Fernández de Sevilla
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
4
|
Rijal K, Müller NIC, Friauf E, Singh A, Prasad A, Das D. Exact Distribution of the Quantal Content in Synaptic Transmission. PHYSICAL REVIEW LETTERS 2024; 132:228401. [PMID: 38877921 DOI: 10.1103/physrevlett.132.228401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 01/26/2024] [Accepted: 04/25/2024] [Indexed: 08/23/2024]
Abstract
During electrochemical signal transmission through synapses, triggered by an action potential (AP), a stochastic number of synaptic vesicles (SVs), called the "quantal content," release neurotransmitters in the synaptic cleft. It is widely accepted that the quantal content probability distribution is a binomial based on the number of ready-release SVs in the presynaptic terminal. But the latter number itself fluctuates due to its stochastic replenishment, hence the actual distribution of quantal content is unknown. We show that exact distribution of quantal content can be derived for general stochastic AP inputs in the steady state. For fixed interval AP train, we prove that the distribution is a binomial, and corroborate our predictions by comparison with electrophysiological recordings from MNTB-LSO synapses of juvenile mice. For a Poisson train, we show that the distribution is nonbinomial. Moreover, we find exact moments of the quantal content in the Poisson and other general cases, which may be used to obtain the model parameters from experiments.
Collapse
Affiliation(s)
- Krishna Rijal
- Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Nicolas I C Müller
- Animal Physiology Group, Department of Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Eckhard Friauf
- Animal Physiology Group, Department of Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Abhyudai Singh
- Departments of Electrical and Computer Engineering, Biomedical Engineering and Mathematical Sciences, University of Delaware, Newark, Delaware 19716, USA
| | - Ashok Prasad
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado, USA
| | - Dibyendu Das
- Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| |
Collapse
|
5
|
Khodaie B, Edelmann E, Leßmann V. Distinct GABAergic modulation of timing-dependent LTP in CA1 pyramidal neurons along the longitudinal axis of the mouse hippocampus. iScience 2024; 27:109320. [PMID: 38487018 PMCID: PMC10937841 DOI: 10.1016/j.isci.2024.109320] [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: 04/07/2023] [Revised: 01/25/2024] [Accepted: 02/20/2024] [Indexed: 03/17/2024] Open
Abstract
Synaptic plasticity in the hippocampus underlies episodic memory formation, with dorsal hippocampus being instrumental for spatial memory whereas ventral hippocampus is crucial for emotional learning. Here, we studied how GABAergic inhibition regulates physiologically relevant low repeat spike timing-dependent LTP (t-LTP) at Schaffer collateral-CA1 synapses along the dorsoventral hippocampal axis. We used two t-LTP protocols relying on only 6 repeats of paired spike-firing in pre- and postsynaptic cells within 10 s that differ in postsynaptic firing patterns. GABAA receptor mechanisms played a greater role in blocking 6× 1:1 t-LTP that recruits single postsynaptic action potentials. 6× 1:4 t-LTP that depends on postsynaptic burst-firing unexpectedly required intact GABAB receptor signaling. The magnitude of both t-LTP-forms decreased along the dorsoventral axis, despite increasing excitability and basal synaptic strength in this direction. This suggests that GABAergic inhibition contributes to the distinct roles of dorsal and ventral hippocampus in memory formation.
Collapse
Affiliation(s)
- Babak Khodaie
- Institut für Physiologie, Otto-von-Guericke-Universität (OVGU), Medizinische Fakultät, 39120 Magdeburg, Germany
- OVGU International ESF-funded Graduate School ABINEP, 39104 Magdeburg, Germany
| | - Elke Edelmann
- Institut für Physiologie, Otto-von-Guericke-Universität (OVGU), Medizinische Fakultät, 39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences, 39104 Magdeburg, Germany
- OVGU International ESF-funded Graduate School ABINEP, 39104 Magdeburg, Germany
| | - Volkmar Leßmann
- Institut für Physiologie, Otto-von-Guericke-Universität (OVGU), Medizinische Fakultät, 39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences, 39104 Magdeburg, Germany
- OVGU International ESF-funded Graduate School ABINEP, 39104 Magdeburg, Germany
- DZPG (German Center of Mental Health), partner site Halle/Jena/Magdeburg (CIRC), Magdeburg, Germany
| |
Collapse
|
6
|
Zhang T, Dolga AM, Eisel ULM, Schmidt M. Novel crosstalk mechanisms between GluA3 and Epac2 in synaptic plasticity and memory in Alzheimer's disease. Neurobiol Dis 2024; 191:106389. [PMID: 38142840 DOI: 10.1016/j.nbd.2023.106389] [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: 11/23/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease which accounts for the most cases of dementia worldwide. Impaired memory, including acquisition, consolidation, and retrieval, is one of the hallmarks in AD. At the cellular level, dysregulated synaptic plasticity partly due to reduced long-term potentiation (LTP) and enhanced long-term depression (LTD) underlies the memory deficits in AD. GluA3 containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are one of key receptors involved in rapid neurotransmission and synaptic plasticity. Recent studies revealed a novel form of GluA3 involved in neuronal plasticity that is dependent on cyclic adenosine monophosphate (cAMP), rather than N-methyl-d-aspartate (NMDA). However, this cAMP-dependent GluA3 pathway is specifically and significantly impaired by amyloid beta (Aβ), a pathological marker of AD. cAMP is a key second messenger that plays an important role in modulating memory and synaptic plasticity. We previously reported that exchange protein directly activated by cAMP 2 (Epac2), acting as a main cAMP effector, plays a specific and time-limited role in memory retrieval. From electrophysiological perspective, Epac2 facilities the maintenance of LTP, a cellular event closely associated with memory retrieval. Additionally, Epac2 was found to be involved in the GluA3-mediated plasticity. In this review, we comprehensively summarize current knowledge regarding the specific roles of GluA3 and Epac2 in synaptic plasticity and memory, and their potential association with AD.
Collapse
Affiliation(s)
- Tong Zhang
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747 AG, Netherlands
| | - Amalia M Dolga
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Ulrich L M Eisel
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747 AG, Netherlands
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, the Netherlands; Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| |
Collapse
|
7
|
Souza JR, Lima-Silveira L, Accorsi-Mendonça D, Machado BH. Enhancement of the Evoked Excitatory Transmission in the Nucleus Tractus Solitarius Neurons after Sustained Hypoxia in Mice Depends on A 2A Receptors. Neuroscience 2024; 536:57-71. [PMID: 37979842 DOI: 10.1016/j.neuroscience.2023.11.010] [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: 08/11/2023] [Revised: 11/06/2023] [Accepted: 11/11/2023] [Indexed: 11/20/2023]
Abstract
The first synapses of the afferents of peripheral chemoreceptors are located in the Nucleus Tractus Solitarius (NTS) and there is evidence that short-term sustained hypoxia (SH - 24 h, FiO2 0.1) facilitates glutamatergic transmission in NTS neurons of rats. Adenosine is an important neuromodulator of synaptic transmission and hypoxia contributes to increase its extracellular concentration. The A2A receptors mediate the excitatory actions of adenosine and are active players in the modulation of neuronal networks in the NTS. Herein, we used knockout mice for A2A receptors (A2AKO) and electrophysiological recordings of NTS neurons were performed to evaluate the contribution of these receptors in the changes in synaptic transmission in NTS neurons of mice submitted to SH. The membrane passive properties and excitability of NTS neurons were not affected by SH and were similar between A2AKO and wild-type mice. The overall amplitude of spontaneous glutamatergic currents in NTS neurons of A2AKO mice was lower than in Balb/c WT mice. SH increased the amplitude of evoked glutamatergic currents of NTS neurons from WT mice by a non-presynaptic mechanism, but this enhancement was not observed in NTS neurons of A2AKO mice. Under normoxia, the amplitude of evoked glutamatergic currents was similar between WT and A2AKO mice. The data indicate that A2A receptors (a) modulate spontaneous glutamatergic currents, (b) do not modulate the evoked glutamatergic transmission in the NTS neurons under control conditions, and (c) are required for the enhancement of glutamatergic transmission observed in the NTS neurons of mice submitted to SH.
Collapse
Affiliation(s)
- Juliana R Souza
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil
| | - Ludmila Lima-Silveira
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil
| | - Daniela Accorsi-Mendonça
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil
| | - Benedito H Machado
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil.
| |
Collapse
|
8
|
Pushkin AN, Kay Y, Herring BE. Protein 4.1N Plays a Cell Type-Specific Role in Hippocampal Glutamatergic Synapse Regulation. J Neurosci 2023; 43:8336-8347. [PMID: 37845032 PMCID: PMC10711697 DOI: 10.1523/jneurosci.0185-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 09/14/2023] [Accepted: 10/02/2023] [Indexed: 10/18/2023] Open
Abstract
Many glutamatergic synapse proteins contain a 4.1N protein binding domain. However, a role for 4.1N in the regulation of glutamatergic neurotransmission has been controversial. Here, we observe significantly higher expression of protein 4.1N in granule neurons of the dentate gyrus (DG granule neurons) compared with other hippocampal regions. We discover that reducing 4.1N expression in rat DG granule neurons of either sex results in a significant reduction in glutamatergic synapse function that is caused by a decrease in the number of glutamatergic synapses. By contrast, we find reduction of 4.1N expression in hippocampal CA1 pyramidal neurons has no impact on basal glutamatergic neurotransmission. We also find 4.1N's C-terminal domain (CTD) to be nonessential to its role in the regulation of glutamatergic synapses of DG granule neurons. Instead, we show that 4.1N's four-point-one, ezrin, radixin, and moesin (FERM) domain is essential for supporting synaptic AMPA receptor (AMPAR) function in these neurons. Altogether, this work demonstrates a novel, cell type-specific role for protein 4.1N in governing glutamatergic synapse function.SIGNIFICANCE STATEMENT Glutamatergic synapses exhibit immense molecular diversity. In comparison to heavily studied Schaffer collateral, CA1 glutamatergic synapses, significantly less is known about perforant path-dentate gyrus (DG) synapses. Our data demonstrate that compromising 4.1N function in CA1 pyramidal neurons produces no alteration in basal glutamatergic synaptic transmission. However, in DG granule neurons, compromising 4.1N function leads to a significant decrease in the strength of glutamatergic neurotransmission at perforant pathway synapses. Together, our data identifies 4.1N as a cell type-specific regulator of synaptic transmission within the hippocampus and reveals a unique molecular program that governs perforant pathway synapse function.
Collapse
Affiliation(s)
- Anna N Pushkin
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California 90089
| | - Yuni Kay
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California 90089
| | - Bruce E Herring
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California 90089
- Department of Biological Sciences, Neurobiology Section, Dornslife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, California 90089
| |
Collapse
|
9
|
Chikamoto A, Tochinai R, Sekizawa SI, Kuwahara M. Plasticity occurs in a specific phenotype of neurons in the nucleus tractus solitarius of dystrophin gene-mutated rats. Eur J Neurosci 2023; 58:4282-4297. [PMID: 37933572 DOI: 10.1111/ejn.16179] [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: 02/07/2023] [Revised: 10/03/2023] [Accepted: 10/09/2023] [Indexed: 11/08/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a severe progressive neuromuscular disorder that causes cardiac and respiratory failure. Patients with DMD have tachycardia and autonomic nervous dysfunction at a young age, which can potentially worsen cardiorespiratory function. Therefore, we hypothesised that plasticity occurs in neurons of the cardiorespiratory brainstem nucleus (nucleus tractus solitarius [NTS]) due to DMD, thus affecting neuronal regulation because afferent information from cardiorespiratory organs changes with disease progression. Patch-clamp experiments were performed on second-order NTS neurons from Dmd-mutated (Dm) rats that showed no functional dystrophin protein expression, as confirmed by immunohistochemistry. NTS neurons are classified into two electrophysiological phenotypes: one showing a delayed onset of spiking from hyperpolarised membrane potentials, namely, delayed-onset spiking (DS)-type neurons, and the other showing a rapid onset, namely, rapid-onset spiking-type neurons. Neuroplasticity mainly occurs in DS-type neurons in Dm rats and is characterised by blunted neuronal excitability accompanied by reduced outward currents and a facilitatory effect on synaptic transmission, that is, an increased frequency of spontaneous and miniature excitatory postsynaptic currents (EPSCs) without changes in the amplitude and an increased amplitude of tractus solitarius-evoked EPSCs without changes in the paired-pulse ratio. Although we cannot rule out the possibility that the neuroplastic changes observed in Dm rats were caused by dystrophin deficiency in the neurons themselves, the plasticity could be caused by cardiorespiratory deterioration and/or adaptation in DMD patients.
Collapse
Affiliation(s)
- Akitoshi Chikamoto
- Laboratory of Veterinary Pathophysiology and Animal Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Ryota Tochinai
- Laboratory of Veterinary Pathophysiology and Animal Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Shin-Ichi Sekizawa
- Laboratory of Veterinary Pathophysiology and Animal Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Masayoshi Kuwahara
- Laboratory of Veterinary Pathophysiology and Animal Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
10
|
Weichard I, Taschenberger H, Gsell F, Bornschein G, Ritzau-Jost A, Schmidt H, Kittel RJ, Eilers J, Neher E, Hallermann S, Nerlich J. Fully-primed slowly-recovering vesicles mediate presynaptic LTP at neocortical neurons. Proc Natl Acad Sci U S A 2023; 120:e2305460120. [PMID: 37856547 PMCID: PMC10614622 DOI: 10.1073/pnas.2305460120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/26/2023] [Indexed: 10/21/2023] Open
Abstract
Pre- and postsynaptic forms of long-term potentiation (LTP) are candidate synaptic mechanisms underlying learning and memory. At layer 5 pyramidal neurons, LTP increases the initial synaptic strength but also short-term depression during high-frequency transmission. This classical form of presynaptic LTP has been referred to as redistribution of synaptic efficacy. However, the underlying mechanisms remain unclear. We therefore performed whole-cell recordings from layer 5 pyramidal neurons in acute cortical slices of rats and analyzed presynaptic function before and after LTP induction by paired pre- and postsynaptic neuronal activity. LTP was successfully induced in about half of the synaptic connections tested and resulted in increased synaptic short-term depression during high-frequency transmission and a decelerated recovery from short-term depression due to an increased fraction of a slow recovery component. Analysis with a recently established sequential two-step vesicle priming model indicates an increase in the abundance of fully-primed and slowly-recovering vesicles. A systematic analysis of short-term plasticity and synapse-to-synapse variability of synaptic strength at various types of synapses revealed that stronger synapses generally recover more slowly from synaptic short-term depression. Finally, pharmacological stimulation of the cyclic adenosine monophosphate and diacylglycerol signaling pathways, which are both known to promote synaptic vesicle priming, mimicked LTP and slowed the recovery from short-term depression. Our data thus demonstrate that LTP at layer 5 pyramidal neurons increases synaptic strength primarily by enlarging a subpool of fully-primed slowly-recovering vesicles.
Collapse
Affiliation(s)
- Iron Weichard
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig04103, Germany
| | - Holger Taschenberger
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen37075, Germany
| | - Felix Gsell
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig04103, Germany
| | - Grit Bornschein
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig04103, Germany
| | - Andreas Ritzau-Jost
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig04103, Germany
| | - Hartmut Schmidt
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig04103, Germany
| | - Robert J. Kittel
- Department of Animal Physiology, Institute of Biology, Leipzig University, Leipzig04103, Germany
| | - Jens Eilers
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig04103, Germany
| | - Erwin Neher
- Emeritus Laboratory of Membrane Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen37070, Germany
- Cluster of Excellence “Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells”, University of Göttingen, Göttingen37073, Germany
| | - Stefan Hallermann
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig04103, Germany
| | - Jana Nerlich
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig04103, Germany
| |
Collapse
|
11
|
Werynska K, Neumann E, Cramer T, Ganley RP, Gingras J, Zeilhofer HU. A phospho-deficient α3 glycine receptor mutation alters synaptic glycine and GABA release in mouse spinal dorsal horn neurons. J Physiol 2023; 601:4121-4133. [PMID: 37598301 DOI: 10.1113/jp284589] [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: 02/25/2023] [Accepted: 08/03/2023] [Indexed: 08/21/2023] Open
Abstract
Glycine receptors (GlyRs), together with GABAA receptors, mediate postsynaptic inhibition in most spinal cord and hindbrain neurons. In several CNS regions, GlyRs are also expressed in presynaptic terminals. Here, we analysed the effects of a phospho-deficient mutation (S346A) in GlyR α3 subunits on inhibitory synaptic transmission in superficial spinal dorsal horn neurons, where this subunit is abundantly expressed. Unexpectedly, we found that not only were the amplitudes of evoked glycinergic inhibitory postsynaptic currents (IPSCs) significantly larger in GlyRα3(S346A) mice than in mice expressing wild-type α3GlyRs (GlyRα3(WT) mice), but so were those of GABAergic IPSCs. Decreased frequencies of spontaneously occurring glycinergic and GABAergic miniature IPSCs (mIPSCs) with no accompanying change in mIPSC amplitudes suggested a change in presynaptic transmitter release. Paired-pulse experiments on glycinergic IPSCs revealed an increased paired-pulse ratio and a smaller coefficient of variation in GlyRα3(S346A) mice, which together indicate a reduction in transmitter release probability and an increase in the number of releasable vesicles. Paired-pulse ratios of GABAergic IPSCs recorded in the presence of strychnine were not different between genotypes, while the coefficient of variation was smaller in GlyRα3(S346A) mice, demonstrating that the decrease in release probability was readily reversible by GlyR blockade, while the difference in the size of the pool of releasable vesicles remained. Taken together, our results suggest that presynaptic α3 GlyRs regulate synaptic glycine and GABA release in superficial dorsal horn neurons, and that this effect is potentially regulated by their phosphorylation status. KEY POINTS: A serine-to-alanine point mutation was introduced into the glycine receptor α3 subunit of mice. This point mutation renders α3 glycine receptors resistant to protein kinase A mediated phosphorylation but has otherwise only small effects on receptor function. Patch-clamp recordings from neurons in mouse spinal cord slices revealed an unexpected increase in the amplitudes of both glycinergic and GABAergic evoked inhibitory postsynaptic currents (IPSCs). Miniature IPSCs, paired-pulse ratios and synaptic variation analyses indicate a change in synaptic glycine and GABA release. The results strongly suggest that α3 subunit-containing glycine receptors are expressed on presynaptic terminals of inhibitory dorsal horn neurons where they regulate transmitter release.
Collapse
Affiliation(s)
- Karolina Werynska
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Drug Discovery Network Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Elena Neumann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Teresa Cramer
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Robert P Ganley
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | | | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Drug Discovery Network Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| |
Collapse
|
12
|
Lumeij LB, van Huijstee AN, Cappaert NLM, Kessels HW. Variance analysis as a method to predict the locus of plasticity at populations of non-uniform synapses. Front Cell Neurosci 2023; 17:1232541. [PMID: 37528963 PMCID: PMC10388551 DOI: 10.3389/fncel.2023.1232541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 06/30/2023] [Indexed: 08/03/2023] Open
Abstract
Our knowledge on synaptic transmission in the central nervous system has often been obtained by evoking synaptic responses to populations of synapses. Analysis of the variance in synaptic responses can be applied as a method to predict whether a change in synaptic responses is a consequence of altered presynaptic neurotransmitter release or postsynaptic receptors. However, variance analysis is based on binomial statistics, which assumes that synapses are uniform. In reality, synapses are far from uniform, which questions the reliability of variance analysis when applying this method to populations of synapses. To address this, we used an in silico model for evoked synaptic responses and compared variance analysis outcomes between populations of uniform versus non-uniform synapses. This simulation revealed that variance analysis produces similar results irrespectively of the grade of uniformity of synapses. We put this variance analysis to the test with an electrophysiology experiment using a model system for which the loci of plasticity are well established: the effect of amyloid-β on synapses. Variance analysis correctly predicted that postsynaptically produced amyloid-β triggered predominantly a loss of synapses and a minor reduction of postsynaptic currents in remaining synapses with little effect on presynaptic release probability. We propose that variance analysis can be reliably used to predict the locus of synaptic changes for populations of non-uniform synapses.
Collapse
|
13
|
Sheu ML, Pan LY, Yang CN, Sheehan J, Pan LY, You WC, Wang CC, Pan HC. Thrombin-Induced Microglia Activation Modulated through Aryl Hydrocarbon Receptors. Int J Mol Sci 2023; 24:11416. [PMID: 37511175 PMCID: PMC10380349 DOI: 10.3390/ijms241411416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/01/2023] [Accepted: 07/03/2023] [Indexed: 07/30/2023] Open
Abstract
Thrombin is a multifunctional serine protein which is closely related to neurodegenerative disorders. The Aryl hydrocarbon receptor (AhR) is well expressed in microglia cells involving inflammatory disorders of the brain. However, it remains unclear as to how modulation of AhR expression by thrombin is related to the development of neurodegeneration disorders. In this study, we investigated the role of AhR in the development of thrombin-induced neurodegenerative processes, especially those concerning microglia. The primary culture of either wild type or AhR deleted microglia, as well as BV-2 cell lines, was used for an in vitro study. Hippocampal slice culture and animals with either wild type or with AhR deleted were used for the ex vivo and in vivo studies. Simulations of ligand protein docking showed a strong integration between the thrombin and AhR. In thrombin-triggered microglia cells, deleting AhR escalated both the NO release and iNOS expression. Such effects were abolished by the administration of the AhR agonist. In thrombin-activated microglia cells, downregulating AhR increased the following: vascular permeability, pro-inflammatory genetic expression, MMP-9 activity, and the ratio of M1/M2 phenotype. In the in vivo study, thrombin induced the activation of microglia and their volume, thereby contributing to the deterioration of neurobehavior. Deleting AhR furthermore aggravated the response in terms of impaired neurobehavior, increasing brain edema, aggregating microglia, and increasing neuronal death. In conclusion, thrombin caused the activation of microglia through increased vessel permeability, expression of inflammatory response, and phenotype of M1 microglia, as well the MMP activity. Deleting AhR augmented the above detrimental effects. These findings indicate that the modulation of AhR is essential for the regulation of thrombin-induced brain damages and that the AhR agonist may harbor the potentially therapeutic effect in thrombin-induced neurodegenerative disorder.
Collapse
Affiliation(s)
- Meei-Ling Sheu
- Institute of Biomedical Sciences, National Chung-Hsing University, Taichung 40227, Taiwan;
- Department of Medical Research, Taichung Veterans General Hospital, Taichung 40210, Taiwan
- Ph.D. Program in Translational Medicine, Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Liang-Yi Pan
- Faculty of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Cheng-Ning Yang
- Department of Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei 106319, Taiwan;
| | - Jason Sheehan
- Department of Neurosurgery, University of Virginia, Charlottesville, VA 22904, USA;
| | - Liang-Yu Pan
- Faculty of Medicine, Poznan University of Medical Sciences, 61-701 Poznań, Poland;
| | - Weir-Chiang You
- Department of Radiation Oncology, Taichung Veterans General Hospital, Taichung 40210, Taiwan;
| | - Chien-Chia Wang
- Department of Life Sciences, National Central University, Taoyuan 32001, Taiwan;
| | - Hung-Chuan Pan
- Department of Medical Research, Taichung Veterans General Hospital, Taichung 40210, Taiwan
- Ph.D. Program in Translational Medicine, Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 40227, Taiwan
- Department of Neurosurgery, Taichung Veterans General Hospital, Taichung 40210, Taiwan
| |
Collapse
|
14
|
Huang M, Bin NR, Rai J, Ma K, Chow CH, Eide S, Harada H, Xiao J, Feng D, Sun HS, Feng ZP, Gaisano HY, Pessin JE, Monnier PP, Okamoto K, Zhang L, Sugita S. Neuronal SNAP-23 is critical for synaptic plasticity and spatial memory independently of NMDA receptor regulation. iScience 2023; 26:106664. [PMID: 37168570 PMCID: PMC10165271 DOI: 10.1016/j.isci.2023.106664] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/30/2023] [Accepted: 04/06/2023] [Indexed: 05/13/2023] Open
Abstract
SNARE-mediated membrane fusion plays a crucial role in presynaptic vesicle exocytosis and also in postsynaptic receptor delivery. The latter is considered particularly important for synaptic plasticity and learning and memory, yet the identity of the key SNARE proteins remains elusive. Here, we investigate the role of neuronal synaptosomal-associated protein-23 (SNAP-23) by analyzing pyramidal-neuron specific SNAP-23 conditional knockout (cKO) mice. Electrophysiological analysis of SNAP-23 deficient neurons using acute hippocampal slices showed normal basal neurotransmission in CA3-CA1 synapses with unchanged AMPA and NMDA currents. Nevertheless, we found theta-burst stimulation-induced long-term potentiation (LTP) was vastly diminished in SNAP-23 cKO slices. Moreover, unlike syntaxin-4 cKO mice where both basal neurotransmission and LTP decrease manifested changes in a broad set of behavioral tasks, deficits of SNAP-23 cKO are more limited to spatial memory. Our data reveal that neuronal SNAP-23 is selectively crucial for synaptic plasticity and spatial memory without affecting basal glutamate receptor function.
Collapse
Affiliation(s)
- Mengjia Huang
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Na-Ryum Bin
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Jayant Rai
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G1X5, Canada
- Department of Molecular Genetics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Ke Ma
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Department of Pediatrics, The First Hospital of Jilin University, Changchun 130021, China
| | - Chun Hin Chow
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Sarah Eide
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Hidekiyo Harada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON M5T 0S8, Canada
| | - Jianbing Xiao
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Anatomy, Harbin Medical University, Harbin 150081, China
| | - Daorong Feng
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Hong-Shuo Sun
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Anatomy, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Zhong-Ping Feng
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Herbert Y. Gaisano
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2C4, Canada
- Department of Medicine, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Jeffrey E. Pessin
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Philippe P. Monnier
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Kenichi Okamoto
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G1X5, Canada
- Department of Molecular Genetics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Liang Zhang
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Department of Medicine, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Shuzo Sugita
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| |
Collapse
|
15
|
Groisman AI, Aguilar-Arredondo A, Giacomini D, Schinder AF. Neuroligin-2 controls the establishment of fast GABAergic transmission in adult-born granule cells. Hippocampus 2023; 33:424-441. [PMID: 36709408 PMCID: PMC11342305 DOI: 10.1002/hipo.23505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 12/19/2022] [Accepted: 01/13/2023] [Indexed: 01/30/2023]
Abstract
GABAergic inhibition is critical for the precision of neuronal spiking and the homeostatic regulation of network activity in the brain. Adult neurogenesis challenges network homeostasis because new granule cells (GCs) integrate continuously in the functional dentate gyrus. While developing, adult-born GCs undergo a transient state of enhanced excitability due to the delayed maturation of perisomatic GABAergic inhibition by parvalbumin interneurons (PV-INs). The mechanisms underlying this delayed synaptic maturation remain unknown. We examined the morphology and function of synapses formed by PV-INs onto new GCs over a 2-month interval in young adult mice, and investigated the influence of the synaptic adhesion molecule neuroligin-2 (NL2). Perisomatic appositions of PV-IN terminals onto new GCs were conspicuous at 2 weeks and continued to grow in size to reach a plateau over the fourth week. Postsynaptic knockdown of NL2 by expression of a short-hairpin RNA (shNL2) in new GCs resulted in smaller size of synaptic contacts, reduced area of perisomatic appositions of the vesicular GABA transporter VGAT, and the number of presynaptic active sites. GCs expressing shNL2 displayed spontaneous GABAergic responses with decreased frequency and amplitude, as well as slower kinetics compared to control GCs. In addition, postsynaptic responses evoked by optogenetic stimulation of PV-INs exhibited slow kinetics, increased paired-pulse ratio and coefficient of variation in GCs with NL2 knockdown, suggesting a reduction in the number of active synapses as well as in the probability of neurotransmitter release (Pr ). Our results demonstrate that synapses formed by PV-INs on adult-born GCs continue to develop beyond the point of anatomical growth, and require NL2 for the structural and functional maturation that accompanies the conversion into fast GABAergic transmission.
Collapse
Affiliation(s)
- Ayelén I Groisman
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | | | - Damiana Giacomini
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| |
Collapse
|
16
|
Kudryashova I. Presynaptic Plasticity Is Associated with Actin Polymerization. BIOCHEMISTRY (MOSCOW) 2023; 88:392-403. [PMID: 37076285 DOI: 10.1134/s0006297923030082] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Modulation of presynaptic short-term plasticity induced by actin polymerization was studied in rat hippocampal slices using the paired-pulse paradigm. Schaffer collaterals were stimulated with paired pulses with a 70-ms interstimulus interval every 30 s before and during perfusion with jasplakinolide, an activator of actin polymerization. Jasplakinolide application resulted in the increase in the amplitudes of CA3-CA1 responses (potentiation) accompanied by a decrease in the paired-pulse facilitation, suggesting induction of presynaptic modifications. Jasplakinolide-induced potentiation depended on the initial paired-pulse rate. These data indicate that the jasplakinolide-mediated changes in actin polymerization increased the probability of neurotransmitter release. Less typical for CA3-CA1 synapses responses, such as a very low paired-pulse ratio (close to 1 or even lower) or even paired-pulse depression, were affected differently. Thus, jasplakinolide caused potentiation of the second, but not the first response to the paired stimulus, which increased the paired-pulse ratio from 0.8 to 1.0 on average, suggesting a negative impact of jasplakinolide on the mechanisms promoting paired-pulse depression. In general, actin polymerization facilitated potentiation, although the patterns of potentiation differed depending on the initial synapse characteristics. We conclude that in addition to the increase in the neurotransmitter release probability, jasplakinolide induced other actin polymerization-dependent mechanisms, including those involved in the paired-pulse depression.
Collapse
Affiliation(s)
- Irina Kudryashova
- Laboratory of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 119991, Russia.
| |
Collapse
|
17
|
Álvarez-Ferradas C, Wellmann M, Morales K, Fuenzalida M, Cerpa W, Inestrosa NC, Bonansco C. Wnt-5a induces the conversion of silent to functional synapses in the hippocampus. Front Mol Neurosci 2022; 15:1024034. [DOI: 10.3389/fnmol.2022.1024034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 10/04/2022] [Indexed: 11/13/2022] Open
Abstract
Synapse unsilencing is an essential mechanism for experience-dependent plasticity. Here, we showed that the application of the ligand Wnt-5a converts glutamatergic silent synapses into functional ones by increasing both α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) currents (IAMPA and INMDA, respectively). These effects were mimicked by the hexapeptide Foxy-5 and inhibited by secreted frizzled-related protein sFRP-2. INMDA potentiation was produced by increased synaptic potency, followed by an increase in the probability of release (Pr), even in the presence of 7-nitro-2,3-dioxo-1,4-dihydroquinoxaline-6-carbonitrile (CNQX). At a longer time of Wnt-5a exposure, the Pr increments were higher in INMDA than in IAMPA. In the presence of NMDAR inhibitors, Wnt-5a-induced conversion was fully inhibited in 69.0% of silent synapses, whereas in the remaining synapses were converted into functional one. Our study findings showed that the Wnt-5a-activated pathway triggers AMPAR insertion into mammalian glutamatergic synapses, unsilencing non-functional synapses and promoting the formation of nascent synapses during the early postnatal development of the brain circuits.
Collapse
|
18
|
Midorikawa M. Developmental and activity-dependent modulation of coupling distance between release site and Ca2+ channel. Front Cell Neurosci 2022; 16:1037721. [DOI: 10.3389/fncel.2022.1037721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Synapses are junctions between a presynaptic neuron and a postsynaptic cell specialized for fast and precise information transfer. The presynaptic terminal secretes neurotransmitters via exocytosis of synaptic vesicles. Exocytosis is a tightly regulated reaction that occurs within a millisecond of the arrival of an action potential. One crucial parameter in determining the characteristics of the transmitter release kinetics is the coupling distance between the release site and the Ca2+ channel. Still, the technical limitations have hindered detailed analysis from addressing how the coupling distance is regulated depending on the development or activity of the synapse. However, recent technical advances in electrophysiology and imaging are unveiling their different configurations in different conditions. Here, I will summarize developmental- and activity-dependent changes in the coupling distances revealed by recent studies.
Collapse
|
19
|
Chipman PH, Fetter RD, Panzera LC, Bergerson SJ, Karmelic D, Yokoyama S, Hoppa MB, Davis GW. NMDAR-dependent presynaptic homeostasis in adult hippocampus: Synapse growth and cross-modal inhibitory plasticity. Neuron 2022; 110:3302-3317.e7. [PMID: 36070750 PMCID: PMC9588671 DOI: 10.1016/j.neuron.2022.08.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/11/2022] [Accepted: 08/10/2022] [Indexed: 11/25/2022]
Abstract
Homeostatic plasticity (HP) encompasses a suite of compensatory physiological processes that counteract neuronal perturbations, enabling brain resilience. Currently, we lack a complete description of the homeostatic processes that operate within the mammalian brain. Here, we demonstrate that acute, partial AMPAR-specific antagonism induces potentiation of presynaptic neurotransmitter release in adult hippocampus, a form of compensatory plasticity that is consistent with the expression of presynaptic homeostatic plasticity (PHP) documented at peripheral synapses. We show that this compensatory plasticity can be induced within minutes, requires postsynaptic NMDARs, and is expressed via correlated increases in dendritic spine volume, active zone area, and docked vesicle number. Further, simultaneous postsynaptic genetic reduction of GluA1, GluA2, and GluA3 in triple heterozygous knockouts induces potentiation of presynaptic release. Finally, induction of compensatory plasticity at excitatory synapses induces a parallel, NMDAR-dependent potentiation of inhibitory transmission, a cross-modal effect consistent with the anti-epileptic activity of AMPAR-specific antagonists used in humans.
Collapse
Affiliation(s)
- Peter H Chipman
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94941, USA
| | - Richard D Fetter
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94941, USA
| | - Lauren C Panzera
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Samuel J Bergerson
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Daniel Karmelic
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94941, USA
| | - Sae Yokoyama
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94941, USA
| | - Michael B Hoppa
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Graeme W Davis
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94941, USA.
| |
Collapse
|
20
|
Tanimura A, Shen W, Wokosin D, Surmeier DJ. Pathway-Specific Remodeling of Thalamostriatal Synapses in a Mouse Model of Parkinson's Disease. Mov Disord 2022; 37:1164-1174. [PMID: 35485341 PMCID: PMC9232945 DOI: 10.1002/mds.29030] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 03/21/2022] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The network pathophysiology underlying the motor symptoms of Parkinson's disease (PD) is poorly understood. In models of late-stage PD, there is significant cell-specific remodeling of corticostriatal, axospinous glutamatergic synapses on principal spiny projection neurons (SPNs). Neurons in the centrolateral nucleus (CLN) of the thalamus that relay cerebellar activity to the striatum also make axospinous synapses on SPNs, but the extent to which they are affected in PD has not been definitively characterized. OBJECTIVE To fill this gap, transgenic mice in which CLN neurons express Cre recombinase were used in conjunction with optogenetic and circuit mapping approaches to determine changes in the CLN projection to SPNs in a unilateral 6-hydroxydopamine (6-OHDA) model of late-stage PD. METHODS Adeno-associated virus vectors carrying Cre-dependent opsin expression constructs were stereotaxically injected into the CLN of Grp-KH288 mice in which CLN, but not parafascicular nucleus neurons, expressed Cre recombinase. The properties of this projection to identify direct pathway spiny projection neurons (dSPNs) and indirect pathway spiny projection neurons (iSPNs) were then studied in ex vivo brain slices of the dorsolateral striatum from control and 6-OHDA lesioned mice using anatomic, optogenetic, and electrophysiological approaches. RESULTS Optogenetically evoked excitatory synaptic currents in both iSPNs and dSPNs were reduced in lesioned mice; however, the reduction was significantly greater in dSPNs. In iSPNs, the reduction in evoked responses was attributable to synaptic pruning, because synaptic channelrhodopsin assisted circuit mapping (sCRACm) revealed fewer synapses per cell after lesioning. In contrast, sCRACm mapping of CLN inputs to dSPNs failed to detect any change in synapse abundance in lesioned mice. However, the ratio of currents through α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors to those through N-methyl-D-aspartate receptors was significantly reduced in dSPNs. Moreover, the distribution of currents evoked by optical stimulation of individual synapses shifted toward smaller amplitudes by lesioning, suggesting that they had undergone long-term depression. CONCLUSIONS Taken together, our results demonstrate that the CLN projection to the striatum undergoes a pathway-specific remodeling that could contribute to the circuit imbalance thought to drive the hypokinetic features of PD. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Asami Tanimura
- Department of Neuroscience, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
- Department of BiomedicineAarhus UniversityAarhusDenmark
| | - Weixing Shen
- Department of Neuroscience, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - David Wokosin
- Department of Neuroscience, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - D. James Surmeier
- Department of Neuroscience, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| |
Collapse
|
21
|
Bardoni R. Experimental Protocols and Analytical Procedures for Studying Synaptic Transmission in Rodent Spinal Cord Dorsal Horn. Curr Protoc 2022; 2:e409. [PMID: 35435326 DOI: 10.1002/cpz1.409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Synaptic modulation and plasticity are key mechanisms underlying pain transmission in the spinal cord and supra-spinal centers. The study and understanding of these phenomena are fundamental to investigating both acute nociception and maladaptive changes occurring in chronic pain. This article describes experimental protocols and analytical methods utilized in electrophysiological studies to investigate synaptic modulation and plasticity at the first station of somatosensory processing, the spinal cord dorsal horn. Protocols useful for characterizing the nature of synaptic inputs, the site of modulation (pre- versus postsynaptic), and the presence of short-term synaptic plasticity are presented. These methods can be employed to study the physiology of acute nociception, the pathological mechanisms of persistent inflammatory and neuropathic pain, and the pharmacology of receptors and channels involved in pain transmission. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Spinal cord dissection and acute slice preparation Basic Protocol 2: Stimulation of the dorsal root and extracellular recording (compound action potentials and field potentials) Basic Protocol 3: Patch-clamp recording from dorsal horn neurons: action potential firing patterns and evoked synaptic inputs Basic Protocol 4: Analysis of parameters responsible for changes in synaptic efficacy Basic Protocol 5: Recording and analysis of currents mediated by astrocytic glutamate.
Collapse
Affiliation(s)
- Rita Bardoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Campi, Modena, Italy
| |
Collapse
|
22
|
Kay Y, Tsan L, Davis EA, Tian C, Décarie-Spain L, Sadybekov A, Pushkin AN, Katritch V, Kanoski SE, Herring BE. Schizophrenia-associated SAP97 mutations increase glutamatergic synapse strength in the dentate gyrus and impair contextual episodic memory in rats. Nat Commun 2022; 13:798. [PMID: 35145085 PMCID: PMC8831576 DOI: 10.1038/s41467-022-28430-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 01/05/2022] [Indexed: 12/24/2022] Open
Abstract
Mutations in the putative glutamatergic synapse scaffolding protein SAP97 are associated with the development of schizophrenia in humans. However, the role of SAP97 in synaptic regulation is unclear. Here we show that SAP97 is expressed in the dendrites of granule neurons in the dentate gyrus but not in the dendrites of other hippocampal neurons. Schizophrenia-related perturbations of SAP97 did not affect CA1 pyramidal neuron synapse function. Conversely, these perturbations produce dramatic augmentation of glutamatergic neurotransmission in granule neurons that can be attributed to a release of perisynaptic GluA1-containing AMPA receptors into the postsynaptic densities of perforant pathway synapses. Furthermore, inhibiting SAP97 function in the dentate gyrus was sufficient to impair contextual episodic memory. Together, our results identify a cell-type-specific synaptic regulatory mechanism in the dentate gyrus that, when disrupted, impairs contextual information processing in rats. The effects of SAP97 mutations associated with schizophrenia on synaptic function are unclear. Here, the authors show that schizophrenia-related SAP97 mutations enhance glutamatergic synapse strength in the dentate gyrus, impairing contextual episodic memory in rats.
Collapse
Affiliation(s)
- Yuni Kay
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Linda Tsan
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Elizabeth A Davis
- Department of Biological Sciences, Human and Evolutionary Biology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Chen Tian
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Léa Décarie-Spain
- Department of Biological Sciences, Human and Evolutionary Biology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Anastasiia Sadybekov
- Department of Chemistry, University of Southern California, Los Angeles, CA, 90089, USA
| | - Anna N Pushkin
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Vsevolod Katritch
- Department of Chemistry, University of Southern California, Los Angeles, CA, 90089, USA.,Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Scott E Kanoski
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA.,Department of Biological Sciences, Human and Evolutionary Biology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Bruce E Herring
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA. .,Department of Biological Sciences, Neurobiology Section, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
| |
Collapse
|
23
|
France G, Volianskis R, Ingram R, Bannister N, Rothärmel R, Irvine MW, Fang G, Burnell ES, Sapkota K, Costa BM, Chopra DA, Dravid SM, Michael-Titus AT, Monaghan DT, Georgiou J, Bortolotto ZA, Jane DE, Collingridge GL, Volianskis A. Differential regulation of STP, LTP and LTD by structurally diverse NMDA receptor subunit-specific positive allosteric modulators. Neuropharmacology 2022; 202:108840. [PMID: 34678377 PMCID: PMC8803579 DOI: 10.1016/j.neuropharm.2021.108840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 11/30/2022]
Abstract
Different types of memory are thought to rely on different types of synaptic plasticity, many of which depend on the activation of the N-Methyl-D Aspartate (NMDA) subtype of glutamate receptors. Accordingly, there is considerable interest in the possibility of using positive allosteric modulators (PAMs) of NMDA receptors (NMDARs) as cognitive enhancers. Here we firstly review the evidence that NMDA receptor-dependent forms of synaptic plasticity: short-term potentiation (STP), long-term potentiation (LTP) and long-term depression (LTD) can be pharmacologically differentiated by using NMDAR ligands. These observations suggest that PAMs of NMDAR function, depending on their subtype selectivity, might differentially regulate STP, LTP and LTD. To test this hypothesis, we secondly performed experiments in rodent hippocampal slices with UBP714 (a GluN2A/2B preferring PAM), CIQ (a GluN2C/D selective PAM) and UBP709 (a pan-PAM that potentiates all GluN2 subunits). We report here, for the first time, that: (i) UBP714 potentiates sub-maximal LTP and reduces LTD; (ii) CIQ potentiates STP without affecting LTP; (iii) UBP709 enhances LTD and decreases LTP. We conclude that PAMs can differentially regulate distinct forms of NMDAR-dependent synaptic plasticity due to their subtype selectivity. This article is part of the Neuropharmacology Special Issue on ‘Glutamate Receptors – NMDA receptors’. NMDAR-dependent STP, LTP and LTD can be dissociated pharmacologically GluN2A/2B PAM UBP714 potentiates LTP and reduces LTD GluN2C/D PAM CIQ potentiates STP without affecting LTP NMDAR pan-PAM UBP709 potentiates LTD and reduces LTP
Collapse
Affiliation(s)
- G France
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - R Volianskis
- Department of Physiology, University of Toronto, Toronto, ON, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
| | - R Ingram
- Centre for Neuroscience, Surgery and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - N Bannister
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - R Rothärmel
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - M W Irvine
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - G Fang
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - E S Burnell
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK; University of Exeter, St Luke's Campus, Heavitree Road, Exeter, UK
| | - K Sapkota
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - B M Costa
- Edward Via College of Osteopathic Medicine, Blacksburg, VA, USA & Center for One Health Research, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - D A Chopra
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - S M Dravid
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - A T Michael-Titus
- Centre for Neuroscience, Surgery and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - D T Monaghan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - J Georgiou
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
| | - Z A Bortolotto
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - D E Jane
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - G L Collingridge
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK; Department of Physiology, University of Toronto, Toronto, ON, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada; TANZ Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - A Volianskis
- Schools of Clinical Sciences and Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK; Centre for Neuroscience, Surgery and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK; School of Biosciences, Museum Avenue, Cardiff University, Cardiff, CF10 3AX, UK.
| |
Collapse
|
24
|
Chipman PH, Fung CCA, Pazo Fernandez A, Sawant A, Tedoldi A, Kawai A, Ghimire Gautam S, Kurosawa M, Abe M, Sakimura K, Fukai T, Goda Y. Astrocyte GluN2C NMDA receptors control basal synaptic strengths of hippocampal CA1 pyramidal neurons in the stratum radiatum. eLife 2021; 10:70818. [PMID: 34693906 PMCID: PMC8594917 DOI: 10.7554/elife.70818] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 10/22/2021] [Indexed: 12/12/2022] Open
Abstract
Experience-dependent plasticity is a key feature of brain synapses for which neuronal N-Methyl-D-Aspartate receptors (NMDARs) play a major role, from developmental circuit refinement to learning and memory. Astrocytes also express NMDARs, although their exact function has remained controversial. Here, we identify in mouse hippocampus, a circuit function for GluN2C NMDAR, a subtype highly expressed in astrocytes, in layer-specific tuning of synaptic strengths in CA1 pyramidal neurons. Interfering with astrocyte NMDAR or GluN2C NMDAR activity reduces the range of presynaptic strength distribution specifically in the stratum radiatum inputs without an appreciable change in the mean presynaptic strength. Mathematical modeling shows that narrowing of the width of presynaptic release probability distribution compromises the expression of long-term synaptic plasticity. Our findings suggest a novel feedback signaling system that uses astrocyte GluN2C NMDARs to adjust basal synaptic weight distribution of Schaffer collateral inputs, which in turn impacts computations performed by the CA1 pyramidal neuron.
Collapse
Affiliation(s)
| | - Chi Chung Alan Fung
- Neural Coding and Brain Computing Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Japan
| | | | | | - Angelo Tedoldi
- RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Atsushi Kawai
- RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | | | | | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, Japan
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, Japan
| | - Tomoki Fukai
- Neural Coding and Brain Computing Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Japan
| | - Yukiko Goda
- RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| |
Collapse
|
25
|
Kudryashova IV. The Reorganization of the Actin Matrix as a Factor of Presynaptic Plasticity. NEUROCHEM J+ 2021. [DOI: 10.1134/s1819712421030089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
26
|
Prieto ML, Firouzi K, Khuri-Yakub BT, Madison DV, Maduke M. Spike frequency-dependent inhibition and excitation of neural activity by high-frequency ultrasound. J Gen Physiol 2021; 152:182190. [PMID: 33074301 PMCID: PMC7534904 DOI: 10.1085/jgp.202012672] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/14/2020] [Indexed: 01/09/2023] Open
Abstract
Ultrasound can modulate action potential firing in vivo and in vitro, but the mechanistic basis of this phenomenon is not well understood. To address this problem, we used patch-clamp recording to quantify the effects of focused, high-frequency (43 MHz) ultrasound on evoked action potential firing in CA1 pyramidal neurons in acute rodent hippocampal brain slices. We find that ultrasound can either inhibit or potentiate firing in a spike frequency–dependent manner: at low (near-threshold) input currents and low firing frequencies, ultrasound inhibits firing, while at higher input currents and higher firing frequencies, ultrasound potentiates firing. The net result of these two competing effects is that ultrasound increases the threshold current for action potential firing, the slope of frequency-input curves, and the maximum firing frequency. In addition, ultrasound slightly hyperpolarizes the resting membrane potential, decreases action potential width, and increases the depth of the after-hyperpolarization. All of these results can be explained by the hypothesis that ultrasound activates a sustained potassium conductance. According to this hypothesis, increased outward potassium currents hyperpolarize the resting membrane potential and inhibit firing at near-threshold input currents but potentiate firing in response to higher-input currents by limiting inactivation of voltage-dependent sodium channels during the action potential. This latter effect is a consequence of faster action potential repolarization, which limits inactivation of voltage-dependent sodium channels, and deeper (more negative) after-hyperpolarization, which increases the rate of recovery from inactivation. Based on these results, we propose that ultrasound activates thermosensitive and mechanosensitive two-pore-domain potassium (K2P) channels through heating or mechanical effects of acoustic radiation force. Finite-element modeling of the effects of ultrasound on brain tissue suggests that the effects of ultrasound on firing frequency are caused by a small (<2°C) increase in temperature, with possible additional contributions from mechanical effects.
Collapse
Affiliation(s)
- Martin Loynaz Prieto
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
| | - Kamyar Firouzi
- E.L. Ginzton Laboratory, Stanford University, Stanford, CA
| | | | - Daniel V Madison
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
| | - Merritt Maduke
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
| |
Collapse
|
27
|
Sun Y, Smirnov M, Kamasawa N, Yasuda R. Rapid Ultrastructural Changes in the PSD and Surrounding Membrane after Induction of Structural LTP in Single Dendritic Spines. J Neurosci 2021; 41:7003-7014. [PMID: 34266899 PMCID: PMC8372018 DOI: 10.1523/jneurosci.1964-20.2021] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 06/05/2021] [Accepted: 06/10/2021] [Indexed: 11/21/2022] Open
Abstract
The structural plasticity of dendritic spines is considered to be an important basis of synaptic plasticity, learning, and memory. Here, we induced input-specific structural LTP (sLTP) in single dendritic spines in organotypic hippocampal slices from mice of either sex and performed ultrastructural analyses of the spines using efficient correlative light and electron microscopy. We observed reorganization of the PSD nanostructure, such as perforation and segmentation, at 2-3, 20, and 120 min after sLTP induction. In addition, PSD and nonsynaptic axon-spine interface (nsASI) membrane expanded unevenly during sLTP. Specifically, the PSD area showed a transient increase at 2-3 min after sLTP induction. The PSD growth was to a degree less than spine volume growth at 2-3 min and 20 min after sLTP induction but became similar at 120 min. On the other hand, the nsASI area showed a profound and lasting expansion, to a degree similar to spine volume growth throughout the process. These rapid ultrastructural changes in PSD and surrounding membrane may contribute to rapid electrophysiological plasticity during sLTP.SIGNIFICANCE STATEMENT To understand the ultrastructural changes during synaptic plasticity, it is desired to efficiently image single dendritic spines that underwent structural plasticity in electron microscopy. We induced structural long-term potentiation (sLTP) in single dendritic spines by two-photon glutamate uncaging. We then identified the same spines at different phases of sLTP and performed ultrastructural analysis by using an efficient correlative light and electron microscopy method. We found that postsynaptic density undergoes dramatic modification in its structural complexity immediately after sLTP induction. Meanwhile, the nonsynaptic axon-spine interface area shows a rapid and sustained increase throughout sLTP. Our results indicate that the uneven modification of synaptic and nonsynaptic postsynaptic membrane might contribute to rapid electrophysiological plasticity during sLTP.
Collapse
Affiliation(s)
- Ye Sun
- Neuronal Signal Transduction Group, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
- Integrative Biology and Neuroscience Graduate Program, Florida Atlantic University, Jupiter, Florida 33458
- International Max Planck Research School for Brain and Behavior, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Michael Smirnov
- Neuronal Signal Transduction Group, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Naomi Kamasawa
- Electron Microscopy Core Facility, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
- International Max Planck Research School for Brain and Behavior, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Ryohei Yasuda
- Neuronal Signal Transduction Group, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
- Integrative Biology and Neuroscience Graduate Program, Florida Atlantic University, Jupiter, Florida 33458
- International Max Planck Research School for Brain and Behavior, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| |
Collapse
|
28
|
Hayashi Y. Molecular mechanism of hippocampal long-term potentiation - Towards multiscale understanding of learning and memory. Neurosci Res 2021; 175:3-15. [PMID: 34375719 DOI: 10.1016/j.neures.2021.08.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022]
Abstract
Long-term potentiation (LTP) of synaptic transmission is considered to be a cellular counterpart of learning and memory. Activation of postsynaptic NMDA type glutamate receptor (NMDA-R) induces trafficking of AMPA type glutamate receptors (AMPA-R) and other proteins to the synapse in sequential fashion. At the same time, the dendritic spine expands for long-term and modulation of actin underlies this (structural LTP or sLTP). How these changes persist despite constant diffusion and turnover of the component proteins have been the central focus of the current LTP research. Signaling triggered by Ca2+-influx via NMDA-R triggers kinase including Ca2+/calmodulin-dependent protein kinase II (CaMKII). CaMKII can sustain longer-term biochemical signaling by forming a reciprocally-activating kinase-effector complex with its substrate proteins including Tiam1, thereby regulating persistence of the downstream signaling. Furthermore, activated CaMKII can condense at the synapse through the mechanism of liquid-liquid phase separation (LLPS). This increases the binding capacity at the synapse, thereby contributing to the maintenance of enlarged protein complexes. It may also serve as the synapse tag, which captures newly synthesized proteins.
Collapse
Affiliation(s)
- Yasunori Hayashi
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.
| |
Collapse
|
29
|
Metabotropic actions of kainate receptors modulating glutamate release. Neuropharmacology 2021; 197:108696. [PMID: 34274351 DOI: 10.1016/j.neuropharm.2021.108696] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 12/06/2022]
Abstract
Presynaptic kainate (KA) receptors (KARs) modulate GABA and glutamate release in the central nervous system of mammals. While some of the actions of KARs are ionotropic, metabotropic actions for these receptors have also been seen to modulate both GABA and glutamate release. In general, presynaptic KARs modulate glutamate release through their metabotropic actions in a biphasic manner, with low KA concentrations producing an increase in glutamate release and higher concentrations of KA driving weaker release of this neurotransmitter. Different molecular mechanisms are involved in this modulation of glutamate release, with a G-protein independent, Ca2+-calmodulin adenylate cyclase (AC) and protein kinase A (PKA) dependent mechanism facilitating glutamate release, and a G-protein, AC and PKA dependent mechanism mediating the decrease in neurotransmitter release. Here, we describe the events underlying the KAR modulation of glutamatergic transmission in different brain regions, addressing the possible functions of this modulation and proposing future research lines in this field.
Collapse
|
30
|
Adoff MD, Climer JR, Davoudi H, Marvin JS, Looger LL, Dombeck DA. The functional organization of excitatory synaptic input to place cells. Nat Commun 2021; 12:3558. [PMID: 34117238 PMCID: PMC8196201 DOI: 10.1038/s41467-021-23829-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/19/2021] [Indexed: 12/23/2022] Open
Abstract
Hippocampal place cells contribute to mammalian spatial navigation and memory formation. Numerous models have been proposed to explain the location-specific firing of this cognitive representation, but the pattern of excitatory synaptic input leading to place firing is unknown, leaving no synaptic-scale explanation of place coding. Here we used resonant scanning two-photon microscopy to establish the pattern of synaptic glutamate input received by CA1 place cells in behaving mice. During traversals of the somatic place field, we found increased excitatory dendritic input, mainly arising from inputs with spatial tuning overlapping the somatic field, and functional clustering of this input along the dendrites over ~10 µm. These results implicate increases in total excitatory input and co-activation of anatomically clustered synaptic input in place firing. Since they largely inherit their fields from upstream synaptic partners with similar fields, many CA1 place cells appear to be part of multi-brain-region cell assemblies forming representations of specific locations.
Collapse
Affiliation(s)
- Michael D Adoff
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Jason R Climer
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Heydar Davoudi
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Jonathan S Marvin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Daniel A Dombeck
- Department of Neurobiology, Northwestern University, Evanston, IL, USA.
| |
Collapse
|
31
|
Modelling and Refining Neuronal Circuits with Guidance Cues: Involvement of Semaphorins. Int J Mol Sci 2021; 22:ijms22116111. [PMID: 34204060 PMCID: PMC8201269 DOI: 10.3390/ijms22116111] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 12/17/2022] Open
Abstract
The establishment of neuronal circuits requires neurons to develop and maintain appropriate connections with cellular partners in and out the central nervous system. These phenomena include elaboration of dendritic arborization and formation of synaptic contacts, initially made in excess. Subsequently, refinement occurs, and pruning takes places both at axonal and synaptic level, defining a homeostatic balance maintained throughout the lifespan. All these events require genetic regulations which happens cell-autonomously and are strongly influenced by environmental factors. This review aims to discuss the involvement of guidance cues from the Semaphorin family.
Collapse
|
32
|
Orlando M, Dvorzhak A, Bruentgens F, Maglione M, Rost BR, Sigrist SJ, Breustedt J, Schmitz D. Recruitment of release sites underlies chemical presynaptic potentiation at hippocampal mossy fiber boutons. PLoS Biol 2021; 19:e3001149. [PMID: 34153028 PMCID: PMC8216508 DOI: 10.1371/journal.pbio.3001149] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 02/17/2021] [Indexed: 01/14/2023] Open
Abstract
Synaptic plasticity is a cellular model for learning and memory. However, the expression mechanisms underlying presynaptic forms of plasticity are not well understood. Here, we investigate functional and structural correlates of presynaptic potentiation at large hippocampal mossy fiber boutons induced by the adenylyl cyclase activator forskolin. We performed 2-photon imaging of the genetically encoded glutamate sensor iGluu that revealed an increase in the surface area used for glutamate release at potentiated terminals. Time-gated stimulated emission depletion microscopy revealed no change in the coupling distance between P/Q-type calcium channels and release sites mapped by Munc13-1 cluster position. Finally, by high-pressure freezing and transmission electron microscopy analysis, we found a fast remodeling of synaptic ultrastructure at potentiated boutons: Synaptic vesicles dispersed in the terminal and accumulated at the active zones, while active zone density and synaptic complexity increased. We suggest that these rapid and early structural rearrangements might enable long-term increase in synaptic strength.
Collapse
Affiliation(s)
- Marta Orlando
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
| | - Anton Dvorzhak
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
| | - Felicitas Bruentgens
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
| | - Marta Maglione
- NeuroCure Cluster of Excellence, Berlin, Germany
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Benjamin R. Rost
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- German Center for Neurodegenerative Diseases, Berlin, Germany
| | - Stephan J. Sigrist
- NeuroCure Cluster of Excellence, Berlin, Germany
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Berlin, Germany
- German Center for Neurodegenerative Diseases, Berlin, Germany
| | - Jörg Breustedt
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
| | - Dietmar Schmitz
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
- German Center for Neurodegenerative Diseases, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- Einstein Center for Neurosciences Berlin, Berlin, Germany
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| |
Collapse
|
33
|
Abstract
Membrane potential (Vmem) is a fundamental biophysical signal present in all cells. Vmem signals range in time from milliseconds to days, and they span lengths from microns to centimeters. Vmem affects many cellular processes, ranging from neurotransmitter release to cell cycle control to tissue patterning. However, existing tools are not suitable for Vmem quantification in many of these areas. In this review, we outline the diverse biology of Vmem, drafting a wish list of features for a Vmem sensing platform. We then use these guidelines to discuss electrode-based and optical platforms for interrogating Vmem. On the one hand, electrode-based strategies exhibit excellent quantification but are most effective in short-term, cellular recordings. On the other hand, optical strategies provide easier access to diverse samples but generally only detect relative changes in Vmem. By combining the respective strengths of these technologies, recent advances in optical quantification of absolute Vmem enable new inquiries into Vmem biology.
Collapse
Affiliation(s)
- Julia R Lazzari-Dean
- Department of Chemistry, University of California, Berkeley, California 94720, USA; ,
| | - Anneliese M M Gest
- Department of Chemistry, University of California, Berkeley, California 94720, USA; ,
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, California 94720, USA; ,
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA
| |
Collapse
|
34
|
Shortened tethering filaments stabilize presynaptic vesicles in support of elevated release probability during LTP in rat hippocampus. Proc Natl Acad Sci U S A 2021; 118:2018653118. [PMID: 33875591 DOI: 10.1073/pnas.2018653118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Long-term potentiation (LTP) is a cellular mechanism of learning and memory that results in a sustained increase in the probability of vesicular release of neurotransmitter. However, previous work in hippocampal area CA1 of the adult rat revealed that the total number of vesicles per synapse decreases following LTP, seemingly inconsistent with the elevated release probability. Here, electron-microscopic tomography (EMT) was used to assess whether changes in vesicle density or structure of vesicle tethering filaments at the active zone might explain the enhanced release probability following LTP. The spatial relationship of vesicles to the active zone varies with functional status. Tightly docked vesicles contact the presynaptic membrane, have partially formed SNARE complexes, and are primed for release of neurotransmitter upon the next action potential. Loosely docked vesicles are located within 8 nm of the presynaptic membrane where SNARE complexes begin to form. Nondocked vesicles comprise recycling and reserve pools. Vesicles are tethered to the active zone via filaments composed of molecules engaged in docking and release processes. The density of tightly docked vesicles was increased 2 h following LTP compared to control stimulation, whereas the densities of loosely docked or nondocked vesicles congregating within 45 nm above the active zones were unchanged. The tethering filaments on all vesicles were shorter and their attachment sites shifted closer to the active zone. These findings suggest that tethering filaments stabilize more vesicles in the primed state. Such changes would facilitate the long-lasting increase in release probability following LTP.
Collapse
|
35
|
Banks PJ, Warburton EC, Bashir ZI. Plasticity in Prefrontal Cortex Induced by Coordinated Synaptic Transmission Arising from Reuniens/Rhomboid Nuclei and Hippocampus. Cereb Cortex Commun 2021; 2:tgab029. [PMID: 34296174 PMCID: PMC8152950 DOI: 10.1093/texcom/tgab029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/24/2021] [Accepted: 04/06/2021] [Indexed: 11/12/2022] Open
Abstract
The nucleus reuniens and rhomboid nuclei of the thalamus (ReRh) are reciprocally connected to a range of higher order cortices including hippocampus (HPC) and medial prefrontal cortex (mPFC). The physiological function of ReRh is well predicted by requirement for interactions between mPFC and HPC, including associative recognition memory, spatial navigation, and working memory. Although anatomical and electrophysiological evidence suggests ReRh makes excitatory synapses in mPFC there is little data on the physiological properties of these projections, or whether ReRh and HPC target overlapping cell populations and, if so, how they interact. We demonstrate in ex vivo mPFC slices that ReRh and HPC afferent inputs converge onto more than two-thirds of layer 5 pyramidal neurons, show that ReRh, but not HPC, undergoes marked short-term plasticity during theta frequency transmission, and that HPC, but not ReRh, afferents are subject to neuromodulation by acetylcholine acting via muscarinic receptor M2. Finally, we demonstrate that pairing HPC followed by ReRh (but not pairing ReRh followed by HPC) at theta frequency induces associative, NMDA receptor dependent synaptic plasticity in both inputs to mPFC. These data provide vital physiological phenotypes of the synapses of this circuit and provide a novel mechanism for HPC-ReRh-mPFC encoding.
Collapse
Affiliation(s)
- Paul J Banks
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - E Clea Warburton
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Zafar I Bashir
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| |
Collapse
|
36
|
Manz KM, Siemann JK, McMahon DG, Grueter BA. Patch-clamp and multi-electrode array electrophysiological analysis in acute mouse brain slices. STAR Protoc 2021; 2:100442. [PMID: 33899023 PMCID: PMC8056272 DOI: 10.1016/j.xpro.2021.100442] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Patch-clamp and multi-electrode array electrophysiology techniques are used to measure dynamic functional properties of neurons. Whole-cell and cell-attached patch-clamp recordings in brain slices can be performed in voltage-clamp and current-clamp configuration to reveal cell-type-specific synaptic and cellular parameters governing neurotransmission. Multi-electrode array electrophysiology can provide spike activity recordings from multiple neurons, enabling larger sample sizes, and long-term recordings. We provide our guide to preparing acute rodent brain slices with example experiments and analyses intended for novice and expert electrophysiologists. For complete details on the use and execution of this protocol, please refer to Manz et al. (2020b). Viable and efficient preparation of mouse brain tissue Comprehensive material source for acute brain slice electrophysiology Detailed approach to whole-cell patch-clamp recording of neurons Utility and application of multi-electrode array electrophysiology in mouse brain
Collapse
Affiliation(s)
- Kevin M Manz
- Medical Scientist Training Program, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Justin K Siemann
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Department of Biological Sciences, Vanderbilt University, Nashville, TN 3732, USA
| | - Douglas G McMahon
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Department of Biological Sciences, Vanderbilt University, Nashville, TN 3732, USA.,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Brad A Grueter
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA.,Anesthesiology Research Division, Vanderbilt University School of Medicine, 2213 Garland Avenue, P435H MRB IV, Nashville, TN 37232-0413, USA
| |
Collapse
|
37
|
Davenport CM, Rajappa R, Katchan L, Taylor CR, Tsai MC, Smith CM, de Jong JW, Arnold DB, Lammel S, Kramer RH. Relocation of an Extrasynaptic GABA A Receptor to Inhibitory Synapses Freezes Excitatory Synaptic Strength and Preserves Memory. Neuron 2021; 109:123-134.e4. [PMID: 33096025 PMCID: PMC7790995 DOI: 10.1016/j.neuron.2020.09.037] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/21/2020] [Accepted: 09/25/2020] [Indexed: 11/27/2022]
Abstract
The excitatory synapse between hippocampal CA3 and CA1 pyramidal neurons exhibits long-term potentiation (LTP), a positive feedback process implicated in learning and memory in which postsynaptic depolarization strengthens synapses, promoting further depolarization. Without mechanisms for interrupting positive feedback, excitatory synapses could strengthen inexorably, corrupting memory storage. Here, we reveal a hidden form of inhibitory synaptic plasticity that prevents accumulation of excitatory LTP. We developed a knockin mouse that allows optical control of endogenous α5-subunit-containing γ-aminobutyric acid (GABA)A receptors (α5-GABARs). Induction of excitatory LTP relocates α5-GABARs, which are ordinarily extrasynaptic, to inhibitory synapses, quashing further NMDA receptor activation necessary for inducing more excitatory LTP. Blockade of α5-GABARs accelerates reversal learning, a behavioral test for cognitive flexibility dependent on repeated LTP. Hence, inhibitory synaptic plasticity occurs in parallel with excitatory synaptic plasticity, with the ensuing interruption of the positive feedback cycle of LTP serving as a possible critical early step in preserving memory.
Collapse
Affiliation(s)
- Christopher M Davenport
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Rajit Rajappa
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ljudmila Katchan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Charlotte R Taylor
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ming-Chi Tsai
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Caleb M Smith
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Johannes W de Jong
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Don B Arnold
- Department of Biology, Section of Molecular and Computational Biology, University of Southern California, Los Angeles, Los Angeles, CA 90089, USA
| | - Stephan Lammel
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Richard H Kramer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
| |
Collapse
|
38
|
Agahari FA, Stricker C. Serotonergic Modulation of Spontaneous and Evoked Transmitter Release in Layer II Pyramidal Cells of Rat Somatosensory Cortex. Cereb Cortex 2021; 31:1182-1200. [PMID: 33063109 DOI: 10.1093/cercor/bhaa285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
As axons from the raphe nuclei densely innervate the somatosensory cortex, we investigated how serotonin (5-HT) modulates transmitter release in layer II pyramidal cells of rat barrel cortex. In the presence of tetrodotoxin and gabazine, 10 μM 5-HT caused a waxing and waning in the frequency of miniature excitatory postsynaptic currents (mEPSC) with no effect on amplitude. Specifically, within 15 min of recording the mEPSC frequency initially increased by 28 ± 7%, then dropped to below control (-15 ± 3%), before resurging back to 27 ± 7% larger than control. These changes were seen in 47% of pyramidal cells (responders) and were mediated by 5-HT2C receptors (5-HT2CR). Waxing resulted from phospholipase C activation, IP3 production, and Ca2+ release from presynaptic stores. Waning was prevented if PKC was blocked. In contrast, in paired recordings, the unitary EPSC amplitude was reduced by 50 ± 3% after 5-HT exposure in almost all cases with no significant effect on paired-pulse ratio and synaptic dynamics. This sustained EPSC reduction was also caused by 5-HT2R, but was mediated by presynaptic Gβγ subunits likely limiting influx through CaV2 channels. EPSC reduction, together with enhanced spontaneous noise in a restricted subset of inputs, could temporarily diminish the signal-to-noise ratio and affect the computation in the neocortical microcircuit.
Collapse
Affiliation(s)
- Fransiscus Adrian Agahari
- Neuronal Network Laboratory, Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Acton ACT 2601, Australia.,Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8787, Japan.,Brain Science Institute, Tamagawa University, Tokyo 194-8610, Japan
| | - Christian Stricker
- Neuronal Network Laboratory, Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Acton ACT 2601, Australia
| |
Collapse
|
39
|
Bertrand C, Deschamps C, Rabiant K, Peineau S, Antol J, Martinetti M, Naassila M, Vilpoux C, Pierrefiche O. Patch-Clamp Recording of Low Frequency Stimulation-induced Long-Term Synaptic Depression in Rat Hippocampus Slices During Early and Late Neurodevelopment. Alcohol Clin Exp Res 2020; 45:351-364. [PMID: 33196109 DOI: 10.1111/acer.14516] [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: 07/17/2020] [Accepted: 11/05/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Studying synaptic plasticity in the rat hippocampus slice is a well-established way to analyze cellular mechanisms related to learning and memory. Different modes of recording can be used, such as extracellular field excitatory post-synaptic potential (EPSP) and diverse patch-clamp methods. However, most studies using these methods have examined only up to the juvenile stage of brain maturation, which is known to terminate during late adolescence/early adulthood. Moreover, several animal models of human diseases have been developed at this late stage of brain development. To study the vulnerability of adolescent rat to the cognitive impairment of alcohol, we developed a model of binge-like exposure in which ethanol selectively abolishes low frequency stimulation (LFS)-induced, field EPSP long-term depression (LTD) in the rat hippocampus slice. METHODS In the present study, we sought to use whole-cell patch-clamp recording in the voltage-clamp mode to further investigate the mechanisms involved in the abolition of LFS-induced LTD in our model of binge-like exposure in adolescent rat hippocampus slices. In addition, we investigated LFS-induced NMDAR-LTD and mGluR-LTD at different ages and changed several parameters to improve the recordings. RESULTS Using patch-clamp recording, LFS-induced NMDAR-LTD and mGluR-LTD could be measured until 4 weeks of age, but not in older animals. Similarly, chemical mGluR-LTD and a combined LFS-LTD involving both N-Methyl-D-Aspartate Receptor (NMDAR) and mGluR were not measured in older animals. The absence of LFS-LTD was not due to the loss of a diffusible intracellular agent nor the voltage mode of recording or intracellular blockade of either sodium or potassium currents. In contrast to voltage-clamp recordings, LFS-induced LTD tested with field recordings was measured at all ages and the effects of EtOH were visible in all cases. CONCLUSIONS We concluded that whole-cell patch-clamp recordings are not suitable for studying synaptic LFS-induced LTD in rats older than 4 weeks of age and therefore cannot be used to explore electrophysiological disturbances, such as those induced by alcohol binge drinking during adolescence, which constitutes a late period of brain maturation.
Collapse
Affiliation(s)
- Cédric Bertrand
- UMR1247 INSERM, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | - Chloé Deschamps
- UMR1247 INSERM, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | - Kevin Rabiant
- UMR1247 INSERM, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | - Stéphane Peineau
- UMR1247 INSERM, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | - Johann Antol
- UMR1247 INSERM, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | | | - Mickael Naassila
- UMR1247 INSERM, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | - Catherine Vilpoux
- UMR1247 INSERM, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | - Olivier Pierrefiche
- UMR1247 INSERM, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| |
Collapse
|
40
|
Lima-Silveira L, Martinez D, Hasser EM, Kline DD. Mechanisms Underlying Neuroplasticity in the Nucleus Tractus Solitarii Following Hindlimb Unloading in Rats. Neuroscience 2020; 449:214-227. [PMID: 33039526 DOI: 10.1016/j.neuroscience.2020.09.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/15/2020] [Accepted: 09/20/2020] [Indexed: 12/11/2022]
Abstract
Hindlimb unloading (HU) in rats induces cardiovascular deconditioning (CVD) analogous to that observed in individuals exposed to microgravity or bed rest. Among other physiological changes, HU rats exhibit autonomic imbalance and altered baroreflex function. Lack of change in visceral afferent activity that projects to the brainstem in HU rats suggests that neuronal plasticity within central nuclei processing cardiovascular afferents may be responsible for these changes in CVD and HU. The nucleus tractus solitarii (nTS) is a critical brainstem region for autonomic control and integration of cardiovascular reflexes. In this study, we used patch electrophysiology, live-cell calcium imaging and molecular methods to investigate the effects of HU on glutamatergic synaptic transmission and intrinsic properties of nTS neurons. HU increased the amplitude of monosynaptic excitatory postsynaptic currents and presynaptic calcium entry evoked by afferent tractus solitarii stimulus (TS-EPSC); spontaneous (s) EPSCs were unaffected. The addition of a NMDA receptor antagonist (AP5) reduced TS-EPSC amplitude and sEPSC frequency in HU but not control. Despite the increase in glutamatergic inputs, HU neurons were more hyperpolarized and exhibited intrinsic decreased excitability compared to controls. After block of ionotropic glutamatergic and GABAergic synaptic transmission (NBQX, AP5, Gabazine), HU neuronal membrane potential depolarized and neuronal excitability was comparable to controls. These data demonstrate that HU increases presynaptic release and TS-EPSC amplitude, which includes a NMDA receptor component. Furthermore, the decreased excitability and hyperpolarized membrane after HU are associated with enhanced GABAergic modulation. This functional neuroplasticity in the nTS may underly the CVD induced by HU.
Collapse
Affiliation(s)
- Ludmila Lima-Silveira
- Department of Biomedical Sciences, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA; Dalton Cardiovascular Research Center, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA.
| | - Diana Martinez
- Department of Biomedical Sciences, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA; Dalton Cardiovascular Research Center, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA.
| | - Eileen M Hasser
- Department of Biomedical Sciences, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA; Department of Medical Pharmacology and Physiology, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA; Dalton Cardiovascular Research Center, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA.
| | - David D Kline
- Department of Biomedical Sciences, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA; Dalton Cardiovascular Research Center, University of Missouri, 134 Research Park Dr., Columbia, MO 65211, USA.
| |
Collapse
|
41
|
Astrocyte-mediated switch in spike timing-dependent plasticity during hippocampal development. Nat Commun 2020; 11:4388. [PMID: 32873805 PMCID: PMC7463247 DOI: 10.1038/s41467-020-18024-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 07/31/2020] [Indexed: 01/31/2023] Open
Abstract
Presynaptic spike timing-dependent long-term depression (t-LTD) at hippocampal CA3-CA1 synapses is evident until the 3rd postnatal week in mice, disappearing during the 4th week. At more mature stages, we found that the protocol that induced t-LTD induced t-LTP. We characterized this form of t-LTP and the mechanisms involved in its induction, as well as that driving this switch from t-LTD to t-LTP. We found that this t-LTP is expressed presynaptically at CA3-CA1 synapses, as witnessed by coefficient of variation, number of failures, paired-pulse ratio and miniature responses analysis. Additionally, this form of presynaptic t-LTP does not require NMDARs but the activation of mGluRs and the entry of Ca2+ into the postsynaptic neuron through L-type voltage-dependent Ca2+ channels and the release of Ca2+ from intracellular stores. Nitric oxide is also required as a messenger from the postsynaptic neuron. Crucially, the release of adenosine and glutamate by astrocytes is required for t-LTP induction and for the switch from t-LTD to t-LTP. Thus, we have discovered a developmental switch of synaptic transmission from t-LTD to t-LTP at hippocampal CA3-CA1 synapses in which astrocytes play a central role and revealed a form of presynaptic LTP and the rules for its induction. Presynaptic spike timing-dependent long-term depression at hippocampal CA3-CA1 synapses is evident until the third postnatal week in mice. The authors show that maturation beyond four weeks is associated with a switch to long-term potentiation in which astrocytes play a central role.
Collapse
|
42
|
A Slow Short-Term Depression at Purkinje to Deep Cerebellar Nuclear Neuron Synapses Supports Gain-Control and Linear Encoding over Second-Long Time Windows. J Neurosci 2020; 40:5937-5953. [PMID: 32554551 DOI: 10.1523/jneurosci.2078-19.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 04/21/2020] [Accepted: 05/23/2020] [Indexed: 11/21/2022] Open
Abstract
Modifications in the sensitivity of neural elements allow the brain to adapt its functions to varying demands. Frequency-dependent short-term synaptic depression (STD) provides a dynamic gain-control mechanism enabling adaptation to different background conditions alongside enhanced sensitivity to input-driven changes in activity. In contrast, synapses displaying frequency-invariant transmission can faithfully transfer ongoing presynaptic rates enabling linear processing, deemed critical for many functions. However, rigid frequency-invariant transmission may lead to runaway dynamics and low sensitivity to changes in rate. Here, I investigated the Purkinje cell to deep cerebellar nuclei neuron synapses (PC_DCNs), which display frequency invariance, and yet, PCs maintain background activity at disparate rates, even at rest. Using protracted PC_DCN activation (120 s) to mimic background activity in cerebellar slices from mature mice of both sexes, I identified a previously unrecognized, frequency-dependent, slow STD (S-STD), adapting IPSC amplitudes in tens of seconds to minutes. However, after changes in activation rates, over a behavior-relevant second-long time window, S-STD enabled scaled linear encoding of PC rates in synaptic charge transfer and DCN spiking activity. Combined electrophysiology, optogenetics, and statistical analysis suggested that S-STD mechanism is input-specific, involving decreased ready-to-release quanta, and distinct from faster short-term plasticity (f-STP). Accordingly, an S-STD component with a scaling effect (i.e., activity-dependent release sites inactivation), extending a model explaining PC_DCN release on shorter timescales using balanced f-STP, reproduced the experimental results. Thus, these results elucidates a novel slow gain-control mechanism able to support linear transfer of behavior-driven/learned PC rates concurrently with background activity adaptation, and furthermore, provides an alternative pathway to refine PC output.SIGNIFICANCE STATEMENT The brain can adapt to varying demands by dynamically changing the gain of its synapses; however, some tasks require ongoing linear transfer of presynaptic rates, seemingly incompatible with nonlinear gain adaptation. Here, I report a novel slow gain-control mechanism enabling scaled linear encoding of presynaptic rates over behavior-relevant time windows, and adaptation to background activity at the Purkinje to deep cerebellar nuclear neurons synapses (PC_DCNs). A previously unrecognized PC_DCNs slow and frequency-dependent short-term synaptic depression (S-STD) mediates this process. Experimental evidence and simulations suggested that scaled linear encoding emerges from the combination of S-STD slow dynamics and frequency-invariant transmission at faster timescales. These results demonstrate a mechanism reconciling rate code with background activity adaptation and suitable for flexibly tuning PCs output via background activity modulation.
Collapse
|
43
|
Cheyne JE, Montgomery JM. The cellular and molecular basis of in vivo synaptic plasticity in rodents. Am J Physiol Cell Physiol 2020; 318:C1264-C1283. [PMID: 32320288 DOI: 10.1152/ajpcell.00416.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Plasticity within the neuronal networks of the brain underlies the ability to learn and retain new information. The initial discovery of synaptic plasticity occurred by measuring synaptic strength in vivo, applying external stimulation and observing an increase in synaptic strength termed long-term potentiation (LTP). Many of the molecular pathways involved in LTP and other forms of synaptic plasticity were subsequently uncovered in vitro. Over the last few decades, technological advances in recording and imaging in live animals have seen many of these molecular mechanisms confirmed in vivo, including structural changes both pre- and postsynaptically, changes in synaptic strength, and changes in neuronal excitability. A well-studied aspect of neuronal plasticity is the capacity of the brain to adapt to its environment, gained by comparing the brains of deprived and experienced animals in vivo, and in direct response to sensory stimuli. Multiple in vivo studies have also strongly linked plastic changes to memory by interfering with the expression of plasticity and by manipulating memory engrams. Plasticity in vivo also occurs in the absence of any form of external stimulation, i.e., during spontaneous network activity occurring with brain development. However, there is still much to learn about how plasticity is induced during natural learning and how this is altered in neurological disorders.
Collapse
Affiliation(s)
- Juliette E Cheyne
- Department of Physiology and Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Johanna M Montgomery
- Department of Physiology and Centre for Brain Research, University of Auckland, Auckland, New Zealand
| |
Collapse
|
44
|
Brock JA, Thomazeau A, Watanabe A, Li SSY, Sjöström PJ. A Practical Guide to Using CV Analysis for Determining the Locus of Synaptic Plasticity. Front Synaptic Neurosci 2020; 12:11. [PMID: 32292337 PMCID: PMC7118219 DOI: 10.3389/fnsyn.2020.00011] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/04/2020] [Indexed: 01/17/2023] Open
Abstract
Long-term synaptic plasticity is widely believed to underlie learning and memory in the brain. Whether plasticity is primarily expressed pre- or postsynaptically has been the subject of considerable debate for many decades. More recently, it is generally agreed that the locus of plasticity depends on a number of factors, such as developmental stage, induction protocol, and synapse type. Since presynaptic expression alters not just the gain but also the short-term dynamics of a synapse, whereas postsynaptic expression only modifies the gain, the locus has fundamental implications for circuits dynamics and computations in the brain. It therefore remains crucial for our understanding of neuronal circuits to know the locus of expression of long-term plasticity. One classical method for elucidating whether plasticity is pre- or postsynaptically expressed is based on analysis of the coefficient of variation (CV), which serves as a measure of noise levels of synaptic neurotransmission. Here, we provide a practical guide to using CV analysis for the purposes of exploring the locus of expression of long-term plasticity, primarily aimed at beginners in the field. We provide relatively simple intuitive background to an otherwise theoretically complex approach as well as simple mathematical derivations for key parametric relationships. We list important pitfalls of the method, accompanied by accessible computer simulations to better illustrate the problems (downloadable from GitHub), and we provide straightforward solutions for these issues.
Collapse
Affiliation(s)
- Jennifer A Brock
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Aurore Thomazeau
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
| | - Airi Watanabe
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Sally Si Ying Li
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
| |
Collapse
|
45
|
Qi G, Yang D, Ding C, Feldmeyer D. Unveiling the Synaptic Function and Structure Using Paired Recordings From Synaptically Coupled Neurons. Front Synaptic Neurosci 2020; 12:5. [PMID: 32116641 PMCID: PMC7026682 DOI: 10.3389/fnsyn.2020.00005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/22/2020] [Indexed: 11/24/2022] Open
Abstract
Synaptic transmission between neurons is the basic mechanism for information processing in cortical microcircuits. To date, paired recording from synaptically coupled neurons is the most widely used method which allows a detailed functional characterization of unitary synaptic transmission at the cellular and synaptic level in combination with a structural characterization of both pre- and postsynaptic neurons at the light and electron microscopic level. In this review, we will summarize the many applications of paired recordings to investigate synaptic function and structure. Paired recordings have been used to study the detailed electrophysiological and anatomical properties of synaptically coupled cell pairs within a synaptic microcircuit; this is critical in order to understand the connectivity rules and dynamic properties of synaptic transmission. Paired recordings can also be adopted for quantal analysis of an identified synaptic connection and to study the regulation of synaptic transmission by neuromodulators such as acetylcholine, the monoamines, neuropeptides, and adenosine etc. Taken together, paired recordings from synaptically coupled neurons will remain a very useful approach for a detailed characterization of synaptic transmission not only in the rodent brain but also that of other species including humans.
Collapse
Affiliation(s)
- Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-10, Jülich Research Centre, Jülich, Germany
| | - Danqing Yang
- Institute of Neuroscience and Medicine, INM-10, Jülich Research Centre, Jülich, Germany
| | - Chao Ding
- Institute of Neuroscience and Medicine, INM-10, Jülich Research Centre, Jülich, Germany
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-10, Jülich Research Centre, Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University Hospital, Aachen, Germany.,Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
| |
Collapse
|
46
|
van Huijstee AN, Kessels HW. Variance analysis as a tool to predict the mechanism underlying synaptic plasticity. J Neurosci Methods 2020; 331:108526. [PMID: 31756397 DOI: 10.1016/j.jneumeth.2019.108526] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/31/2019] [Accepted: 11/18/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND The strength of synaptic transmission onto a neuron depends on the number of functional vesicle release sites (N), the probability of vesicle release (Pr), and the quantal size (Q). Statistical tools based on the quantal model of synaptic transmission can be used to acquire information on which of these parameters is the source of plasticity. However, quantal analysis depends on assumptions that may not be met at central synapses. NEW METHOD We examined the merit of quantal analysis to extract the mechanisms underlying synaptic plasticity by applying binomial statistics on the variance in amplitude of postsynaptic currents evoked at Schaffer collateral-CA1 (Sc-CA1) synapses in mouse hippocampal slices. We extend this analysis by combining the conventional inverse square of the coefficient of variation (1/CV2) with the variance-to-mean ratio (VMR). RESULTS This method can be used to assess the relative, but not absolute, contribution of N, Pr and Q to synaptic plasticity. The changes in 1/CV2 and VMR values correctly reflect experimental modifications of N, Pr and Q at Sc-CA1 synapses. COMPARISON WITH EXISTING METHODS While the 1/CV2 depends on N and Pr, but is independent of Q, the VMR is dependent on Pr and Q, but not on N. Combining both allows for a rapid assessment of the mechanism underlying synaptic plasticity without the need for additional electrophysiological experiments. CONCLUSION Combining the 1/CV2 with the VMR allows for a reliable prediction of the relative contribution of changes in N, Pr and Q to synaptic plasticity.
Collapse
Affiliation(s)
- Aile N van Huijstee
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands.
| | - Helmut W Kessels
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands.
| |
Collapse
|
47
|
Wang K, Xu F, Campbell SP, Hart KD, Durham T, Maylie J, Xu J. Rapid actions of anti-Müllerian hormone in regulating synaptic transmission and long-term synaptic plasticity in the hippocampus. FASEB J 2019; 34:706-719. [PMID: 31914642 DOI: 10.1096/fj.201902217r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/19/2019] [Accepted: 10/23/2019] [Indexed: 12/25/2022]
Abstract
Anti-Müllerian hormone (Amh) is a peptide factor that is known to regulate sexual differentiation and gonadal function in mammals. Although Amh is also suggested to be associated with cognitive development and function in the postnatal brain, little is known about its expression or direct effects on neuronal activities in the hippocampus. Therefore, we assessed Amh and its receptor expression in the hippocampus of male and female mice using PCR, Western blot, and immunofluorescence staining. While Amh-specific receptor expression was comparable between males and females, mRNA and protein levels of Amh were higher in females than those of males. Electrophysiological recordings on acute hippocampal slices showed that exogenous Amh protein addition increased synaptic transmission and long-term synaptic plasticity at the Cornu Ammonis (CA) 3-CA1 synapses. Amh exposure also increased the excitatory postsynaptic potential at CA1 synapses. Our findings support direct and rapid actions of Amh as a paracrine and/or autocrine factor in regulating hippocampal neuronal activities. Data provide functional evidence of Amh-mediated postsynaptic modulation of synaptic transmission and Amh-regulated long-term synaptic plasticity in the hippocampus. These results suggest a potential role of Amh in learning and memory, and a possible cause of the sex differences in cognitive development and function.
Collapse
Affiliation(s)
- Kang Wang
- School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Fuhua Xu
- School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Shawn P Campbell
- School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Kyle D Hart
- School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Tyler Durham
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | - James Maylie
- School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Jing Xu
- School of Medicine, Oregon Health & Science University, Portland, OR, USA.,Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| |
Collapse
|
48
|
Kruijssen DLH, Wierenga CJ. Single Synapse LTP: A Matter of Context? Front Cell Neurosci 2019; 13:496. [PMID: 31780899 PMCID: PMC6861208 DOI: 10.3389/fncel.2019.00496] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 10/21/2019] [Indexed: 12/18/2022] Open
Abstract
The most commonly studied form of synaptic plasticity is long-term potentiation (LTP). Over the last 15 years, it has been possible to induce structural and functional LTP in dendritic spines using two-photon glutamate uncaging, allowing for studying the signaling mechanisms of LTP with single synapse resolution. In this review, we compare different stimulation methods to induce single synapse LTP and discuss how LTP is expressed. We summarize the underlying signaling mechanisms that have been studied with high spatiotemporal resolution. Finally, we discuss how LTP in a single synapse can be affected by excitatory and inhibitory synapses nearby. We argue that single synapse LTP is highly dependent on context: the choice of induction method, the history of the dendritic spine and the dendritic vicinity crucially affect signaling pathways and expression of single synapse LTP.
Collapse
Affiliation(s)
- Dennis L H Kruijssen
- Department of Biology, Science for Life, Utrecht University, Utrecht, Netherlands
| | - Corette J Wierenga
- Department of Biology, Science for Life, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
49
|
Frau R, Miczán V, Traccis F, Aroni S, Pongor CI, Saba P, Serra V, Sagheddu C, Fanni S, Congiu M, Devoto P, Cheer JF, Katona I, Melis M. Prenatal THC exposure produces a hyperdopaminergic phenotype rescued by pregnenolone. Nat Neurosci 2019; 22:1975-1985. [PMID: 31611707 PMCID: PMC6884689 DOI: 10.1038/s41593-019-0512-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 09/11/2019] [Indexed: 12/21/2022]
Abstract
Increased legal availability of cannabis has led to a common misconception that it is a safe natural remedy for, amongst others, pregnancy-related ailments like morning sickness. Emerging clinical evidence, however, indicates that prenatal cannabis exposure (PCE) predisposes offspring to various neuropsychiatric disorders linked to aberrant dopaminergic function. Yet, our knowledge of how cannabis exposure affects the maturation of this neuromodulatory system remains limited. Here, we show that male, but not female, offspring of Δ9-tetrahydrocannabinol (THC)-exposed dams, a rat PCE model, exhibit extensive molecular and synaptic changes in dopaminergic neurons of the ventral tegmental area, including altered excitatory-to-inhibitory balance and switched polarity of long-term synaptic plasticity. The resulting hyperdopaminergic state leads to increased behavioral sensitivity to acute THC during pre-adolescence. The FDA-approved neurosteroid pregnenolone rescues synaptic defects and normalizes dopaminergic activity and behavior in PCE offspring, suggesting a therapeutic approach for offspring exposed to cannabis during pregnancy.
Collapse
Affiliation(s)
- Roberto Frau
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Vivien Miczán
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.,Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Francesco Traccis
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Sonia Aroni
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Csaba I Pongor
- Nikon Center of Excellence for Neuronal Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Pierluigi Saba
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Valeria Serra
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Claudia Sagheddu
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Silvia Fanni
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Mauro Congiu
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Paola Devoto
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Joseph F Cheer
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - István Katona
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Miriam Melis
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, Monserrato, Italy.
| |
Collapse
|
50
|
Linking Nanoscale Dynamics of AMPA Receptor Organization to Plasticity of Excitatory Synapses and Learning. J Neurosci 2019; 38:9318-9329. [PMID: 30381423 DOI: 10.1523/jneurosci.2119-18.2018] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/21/2018] [Accepted: 09/21/2018] [Indexed: 11/21/2022] Open
Abstract
The spatiotemporal organization of neurotransmitter receptors in the postsynaptic membrane is a fundamental determinant of synaptic transmission and thus of information processing by the brain. The ionotropic AMPA subtype of glutamate receptors (AMPARs) mediate fast excitatory synaptic transmission in the CNS. The number of AMPARs located en face presynaptic glutamate release sites sets the efficacy of synaptic transmission. Understanding how this number is set and regulated has been the topic of intense research in the last two decades. We showed that AMPARs are not stable in the synapse as initially thought. They continuously enter and exit the postsynaptic density by lateral diffusion, and they exchange between the neuronal surface and intracellular compartments by endocytosis and exocytosis at extrasynaptic sites. Regulation of these various trafficking pathways has emerged as a key mechanism for activity-dependent plasticity of synaptic transmission, a process important for learning and memory. I here present my view of these findings. In particular, the advent of super-resolution microscopy and single-molecule tracking has helped to uncover the intricacy of AMPARs' dynamic organization at the nanoscale. In addition, AMPAR surface diffusion is highly regulated by a variety of factors, including neuronal activity, stress hormones, and neurodegeneration, suggesting that AMPAR diffusion-trapping may play a central role in synapse function. Using innovative tools to understand further the link between receptor dynamics and synapse plasticity is now unveiling new molecular mechanisms of learning. Modifying AMPAR dynamics may emerge as a new target to correct synapse dysfunction in the diseased brain.
Collapse
|