1
|
Yao J, Chen SRW. RyR2-dependent modulation of neuronal hyperactivity: A potential therapeutic target for treating Alzheimer's disease. J Physiol 2024; 602:1509-1518. [PMID: 36866974 DOI: 10.1113/jp283824] [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: 11/29/2022] [Accepted: 02/27/2023] [Indexed: 03/04/2023] Open
Abstract
Increasing evidence suggests that simply reducing β-amyloid (Aβ) plaques may not significantly affect the progression of Alzheimer's disease (AD). There is also increasing evidence indicating that AD progression is driven by a vicious cycle of soluble Aβ-induced neuronal hyperactivity. In support of this, it has recently been shown that genetically and pharmacologically limiting ryanodine receptor 2 (RyR2) open time prevents neuronal hyperactivity, memory impairment, dendritic spine loss and neuronal cell death in AD mouse models. By contrast, increased RyR2 open probability (Po) exacerbates the onset of familial AD-associated neuronal dysfunction and induces AD-like defects in the absence of AD-causing gene mutations. Thus, RyR2-dependent modulation of neuronal hyperactivity represents a promising new target for combating AD.
Collapse
Affiliation(s)
- Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
2
|
Moldwin T, Kalmenson M, Segev I. Asymmetric Voltage Attenuation in Dendrites Can Enable Hierarchical Heterosynaptic Plasticity. eNeuro 2023; 10:ENEURO.0014-23.2023. [PMID: 37414554 PMCID: PMC10354808 DOI: 10.1523/eneuro.0014-23.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 05/16/2023] [Accepted: 06/14/2023] [Indexed: 07/08/2023] Open
Abstract
Long-term synaptic plasticity is mediated via cytosolic calcium concentrations ([Ca2+]). Using a synaptic model that implements calcium-based long-term plasticity via two sources of Ca2+ - NMDA receptors and voltage-gated calcium channels (VGCCs) - we show in dendritic cable simulations that the interplay between these two calcium sources can result in a diverse array of heterosynaptic effects. When spatially clustered synaptic input produces a local NMDA spike, the resulting dendritic depolarization can activate VGCCs at nonactivated spines, resulting in heterosynaptic plasticity. NMDA spike activation at a given dendritic location will tend to depolarize dendritic regions that are located distally to the input site more than dendritic sites that are proximal to it. This asymmetry can produce a hierarchical effect in branching dendrites, where an NMDA spike at a proximal branch can induce heterosynaptic plasticity primarily at branches that are distal to it. We also explored how simultaneously activated synaptic clusters located at different dendritic locations synergistically affect the plasticity at the active synapses, as well as the heterosynaptic plasticity of an inactive synapse "sandwiched" between them. We conclude that the inherent electrical asymmetry of dendritic trees enables sophisticated schemes for spatially targeted supervision of heterosynaptic plasticity.
Collapse
Affiliation(s)
| | - Menachem Kalmenson
- Department of Neurobiology, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - Idan Segev
- Edmond and Lily Safra Center for Brain Sciences
- Department of Neurobiology, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| |
Collapse
|
3
|
Chiantia G, Hidisoglu E, Marcantoni A. The Role of Ryanodine Receptors in Regulating Neuronal Activity and Its Connection to the Development of Alzheimer's Disease. Cells 2023; 12:cells12091236. [PMID: 37174636 PMCID: PMC10177020 DOI: 10.3390/cells12091236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Research into the early impacts of Alzheimer's disease (AD) on synapse function is one of the most promising approaches to finding a treatment. In this context, we have recently demonstrated that the Abeta42 peptide, which builds up in the brain during the processing of the amyloid precursor protein (APP), targets the ryanodine receptors (RyRs) of mouse hippocampal neurons and potentiates calcium (Ca2+) release from the endoplasmic reticulum (ER). The uncontrolled increase in intracellular calcium concentration ([Ca2+]i), leading to the development of Ca2+ dysregulation events and related excitable and synaptic dysfunctions, is a consolidated hallmark of AD onset and possibly other neurodegenerative diseases. Since RyRs contribute to increasing [Ca2+]i and are thought to be a promising target for AD treatment, the goal of this review is to summarize the current level of knowledge regarding the involvement of RyRs in governing neuronal function both in physiological conditions and during the onset of AD.
Collapse
Affiliation(s)
| | - Enis Hidisoglu
- Department of Drug and Science Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy
| | - Andrea Marcantoni
- Department of Drug and Science Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy
- N.I.S. Center, University of Torino, 10125 Turin, Italy
| |
Collapse
|
4
|
Martinez Damonte V, Pomrenze MB, Manning CE, Casper C, Wolfden AL, Malenka RC, Kauer JA. Somatodendritic Release of Cholecystokinin Potentiates GABAergic Synapses Onto Ventral Tegmental Area Dopamine Cells. Biol Psychiatry 2023; 93:197-208. [PMID: 35961792 PMCID: PMC9976994 DOI: 10.1016/j.biopsych.2022.06.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/01/2022] [Accepted: 06/10/2022] [Indexed: 11/02/2022]
Abstract
BACKGROUND Neuropeptides are contained in nearly every neuron in the central nervous system and can be released not only from nerve terminals but also from somatodendritic sites. Cholecystokinin (CCK), among the most abundant neuropeptides in the brain, is expressed in the majority of midbrain dopamine neurons. Despite this high expression, CCK function within the ventral tegmental area (VTA) is not well understood. METHODS We confirmed CCK expression in VTA dopamine neurons through immunohistochemistry and in situ hybridization and detected optogenetically induced CCK release using an enzyme-linked immunosorbent assay. To investigate whether CCK modulates VTA circuit activity, we used whole-cell patch clamp recordings in mouse brain slices. We infused CCK locally in vivo and tested food intake and locomotion in fasted mice. We also used in vivo fiber photometry to measure Ca2+ transients in dopamine neurons during feeding. RESULTS Here we report that VTA dopamine neurons release CCK from somatodendritic regions, where it triggers long-term potentiation of GABAergic (gamma-aminobutyric acidergic) synapses. The somatodendritic release occurs during trains of optogenetic stimuli or prolonged but modest depolarization and is dependent on synaptotagmin-7 and T-type Ca2+ channels. Depolarization-induced long-term potentiation is blocked by a CCK2 receptor antagonist and mimicked by exogenous CCK. Local infusion of CCK in vivo inhibits food consumption and decreases distance traveled in an open field test. Furthermore, intra-VTA-infused CCK reduced dopamine cell Ca2+ signals during food consumption after an overnight fast and was correlated with reduced food intake. CONCLUSIONS Our experiments introduce somatodendritic neuropeptide release as a previously unknown feedback regulator of VTA dopamine cell excitability and dopamine-related behaviors.
Collapse
|
5
|
Nabi SU, Rehman MU, Arafah A, Taifa S, Khan IS, Khan A, Rashid S, Jan F, Wani HA, Ahmad SF. Treatment of Autism Spectrum Disorders by Mitochondrial-targeted Drug: Future of Neurological Diseases Therapeutics. Curr Neuropharmacol 2023; 21:1042-1064. [PMID: 36411568 PMCID: PMC10286588 DOI: 10.2174/1570159x21666221121095618] [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: 08/16/2022] [Revised: 10/09/2022] [Accepted: 10/11/2022] [Indexed: 11/23/2022] Open
Abstract
Autism is a neurodevelopmental disorder with a complex etiology that might involve environmental and genetic variables. Recently, some epidemiological studies conducted in various parts of the world have estimated a significant increase in the prevalence of autism, with 1 in every 59 children having some degree of autism. Since autism has been associated with other clinical abnormalities, there is every possibility that a sub-cellular component may be involved in the progression of autism. The organelle remains a focus based on mitochondria's functionality and metabolic role in cells. Furthermore, the mitochondrial genome is inherited maternally and has its DNA and organelle that remain actively involved during embryonic development; these characteristics have linked mitochondrial dysfunction to autism. Although rapid stride has been made in autism research, there are limited studies that have made particular emphasis on mitochondrial dysfunction and autism. Accumulating evidence from studies conducted at cellular and sub-cellular levels has indicated that mitochondrial dysfunction's role in autism is more than expected. The present review has attempted to describe the risk factors of autism, the role of mitochondria in the progression of the disease, oxidative damage as a trigger point to initiate mitochondrial damage, genetic determinants of the disease, possible pathogenic pathways and therapeutic regimen in vogue and the developmental stage. Furthermore, in the present review, an attempt has been made to include the novel therapeutic regimens under investigation at different clinical trial stages and their potential possibility to emerge as promising drugs against ASD.
Collapse
Affiliation(s)
- Showkat Ul Nabi
- Large Animal Diagnostic Laboratory, Department of Clinical Veterinary Medicine, Ethics & Jurisprudence, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology (SKUAST-K), Srinagar J&K, 190006, India
| | - Muneeb U. Rehman
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Azher Arafah
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Syed Taifa
- Large Animal Diagnostic Laboratory, Department of Clinical Veterinary Medicine, Ethics & Jurisprudence, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology (SKUAST-K), Srinagar J&K, 190006, India
| | - Iqra Shafi Khan
- Large Animal Diagnostic Laboratory, Department of Clinical Veterinary Medicine, Ethics & Jurisprudence, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology (SKUAST-K), Srinagar J&K, 190006, India
| | - Andleeb Khan
- Department of Pharmacology and Toxicology, College of Pharmacy, Jazan University, Jazan, 45142, Saudi Arabia
| | - Summya Rashid
- Department of Pharmacology & Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, P.O. Box 173, Al-Kharj, 11942, Saudi Arabia
| | - Fatimah Jan
- Department of Pharmaceutical Sciences, CT University, Ludhiana, Ferozepur Road, Punjab, 142024, India
| | - Hilal Ahmad Wani
- Department of Biochemistry, Government Degree College Sumbal, Bandipora, J&K, India
| | - Sheikh Fayaz Ahmad
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, 11451, Saudi Arabia
| |
Collapse
|
6
|
Shkryl VM. The spatio-temporal properties of calcium transients in hippocampal pyramidal neurons in vitro. Front Cell Neurosci 2022; 16:1054950. [PMID: 36589284 PMCID: PMC9795003 DOI: 10.3389/fncel.2022.1054950] [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: 09/28/2022] [Accepted: 11/24/2022] [Indexed: 12/15/2022] Open
Abstract
The spatio-temporal properties of calcium signals were studied in cultured pyramidal neurons of the hippocampus using two-dimensional fluorescence microscopy and ratiometric dye Fura-2. Depolarization-induced Ca2+ transients revealed an asynchronous delayed increase in free Ca2+ concentration. We found that the level of free resting calcium in the cell nucleus is significantly lower compared to the soma, sub-membrane, and dendritic tree regions. Calcium release from the endoplasmic reticulum under the action of several stimuli (field stimulation, high K+ levels, and caffeine) occurs in all areas studied. Under depolarization, calcium signals developed faster in the dendrites than in other areas, while their amplitude was significantly lower since larger and slower responses inside the soma. The peak value of the calcium response to the application of 10 mM caffeine, ryanodine receptors (RyRs) agonist, does not differ in the sub-membrane zone, central region, and nucleus but significantly decreases in the dendrites. In the presence of caffeine, the delay of Ca2+ signals between various areas under depolarization significantly declined. Thirty percentage of the peak amplitude of Ca2+ transients at prolonged electric field stimulation corresponded to calcium release from the ER store by RyRs, while short-term stimulation did not depend on them. 20 μM dantrolene, RyRs inhibitor, significantly reduces Ca2+ transient under high K+ levels depolarization of the neuron. RyRs-mediated enhancement of the Ca2+ signal is more pronounced in the central part and nucleus compared to the sub-membrane or dendrites regions of the neuron. In summary, using the ratiometric imaging allowed us to obtain additional information about the involvement of RyRs in the intracellular dynamics of Ca2+ signals induced by depolarization or electrical stimulation train, with an underlying change in Ca2+ concentration in various regions of interest in hippocampal pyramidal neurons.
Collapse
|
7
|
O’Hare JK, Gonzalez KC, Herrlinger SA, Hirabayashi Y, Hewitt VL, Blockus H, Szoboszlay M, Rolotti SV, Geiller TC, Negrean A, Chelur V, Polleux F, Losonczy A. Compartment-specific tuning of dendritic feature selectivity by intracellular Ca 2+ release. Science 2022; 375:eabm1670. [PMID: 35298275 PMCID: PMC9667905 DOI: 10.1126/science.abm1670] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dendritic calcium signaling is central to neural plasticity mechanisms that allow animals to adapt to the environment. Intracellular calcium release (ICR) from the endoplasmic reticulum has long been thought to shape these mechanisms. However, ICR has not been investigated in mammalian neurons in vivo. We combined electroporation of single CA1 pyramidal neurons, simultaneous imaging of dendritic and somatic activity during spatial navigation, optogenetic place field induction, and acute genetic augmentation of ICR cytosolic impact to reveal that ICR supports the establishment of dendritic feature selectivity and shapes integrative properties determining output-level receptive fields. This role for ICR was more prominent in apical than in basal dendrites. Thus, ICR cooperates with circuit-level architecture in vivo to promote the emergence of behaviorally relevant plasticity in a compartment-specific manner.
Collapse
Affiliation(s)
- Justin K. O’Hare
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Kevin C. Gonzalez
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Stephanie A. Herrlinger
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Yusuke Hirabayashi
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo; Tokyo, Japan
| | - Victoria L. Hewitt
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Heike Blockus
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Miklos Szoboszlay
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Sebi V. Rolotti
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Tristan C. Geiller
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Adrian Negrean
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
| | - Vikas Chelur
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
| | - Franck Polleux
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
- Kavli Institute for Brain Science, Columbia University; New York, NY, 10027, United States
| | - Attila Losonczy
- Department of Neuroscience, Columbia University; New York, NY, 10027, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, United States
- Kavli Institute for Brain Science, Columbia University; New York, NY, 10027, United States
| |
Collapse
|
8
|
Genetic determinants of autism spectrum disorders - a review. CURRENT PROBLEMS OF PSYCHIATRY 2021. [DOI: 10.2478/cpp-2021-0011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Abstract
Introduction: It is estimated that various types of abnormalities from the autistic spectrum disorder occur in up to 2% of the population. These include difficulties in maintaining relationships, communication, and repetitive behaviours. Literature describes them quite well, in contrast to the causes of these disorders, which include both environmental factors and a very long list of genetic aberrations.
Materials and methods: The papers available on the PubMed platform and other sources were reviewed to describe the most important genetic factors responsible for the development of autism spectrum disorders.
Results: There are many genes and their mutations associated with the prevalence of autism spectrum disorders in patients. One of the main factors is the SHANK gene family, with the type and degree of abnormality in patients depending on the damage to particular genes: SHANK1-SHANK3. Research also shows the potential of targeted symptom-relieving therapies in patients with SHANK3 mutations. A correlation with the occurrence of autism has also been demonstrated for genes responsible for calcium signaling - especially the group of IP3R calcium channels. Their calcium transmission is abnormal in the majority of patients with autism spectrum disorders. A number of mutations in the 7q region were discovered - including the AUTS2, GNAI1, RELN, KMT2E, BRAF genes - the occurrence of which is associated with the presence of symptoms of autism. Autism spectrum disorders occur in about 10% of patients suffering from monogenic syndromes such as fragile X chromosome syndrome, Timothy syndrome, tuberous sclerosis, Rett syndrome or hamartomatic tumor syndrome.
Conclusions: Research shows that many mutations can contribute to the development of autism spectrum disorders. Further studies are necessary to discover their therapeutic and diagnostic potential for autism.
Collapse
|
9
|
Leleo EG, Segev I. Burst control: Synaptic conditions for burst generation in cortical layer 5 pyramidal neurons. PLoS Comput Biol 2021; 17:e1009558. [PMID: 34727124 PMCID: PMC8589150 DOI: 10.1371/journal.pcbi.1009558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 11/12/2021] [Accepted: 10/12/2021] [Indexed: 11/30/2022] Open
Abstract
The output of neocortical layer 5 pyramidal cells (L5PCs) is expressed by a train of single spikes with intermittent bursts of multiple spikes at high frequencies. The bursts are the result of nonlinear dendritic properties, including Na+, Ca2+, and NMDA spikes, that interact with the ~10,000 synapses impinging on the neuron's dendrites. Output spike bursts are thought to implement key dendritic computations, such as coincidence detection of bottom-up inputs (arriving mostly at the basal tree) and top-down inputs (arriving mostly at the apical tree). In this study we used a detailed nonlinear model of L5PC receiving excitatory and inhibitory synaptic inputs to explore the conditions for generating bursts and for modulating their properties. We established the excitatory input conditions on the basal versus the apical tree that favor burst and show that there are two distinct types of bursts. Bursts consisting of 3 or more spikes firing at < 200 Hz, which are generated by stronger excitatory input to the basal versus the apical tree, and bursts of ~2-spikes at ~250 Hz, generated by prominent apical tuft excitation. Localized and well-timed dendritic inhibition on the apical tree differentially modulates Na+, Ca2+, and NMDA spikes and, consequently, finely controls the burst output. Finally, we explored the implications of different burst classes and respective dendritic inhibition for regulating synaptic plasticity.
Collapse
Affiliation(s)
- Eilam Goldenberg Leleo
- The Edmond and Lily Safra Center for Brain Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Idan Segev
- The Edmond and Lily Safra Center for Brain Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Neurobiology, the Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
10
|
Stochastic reaction-diffusion modeling of calcium dynamics in 3D dendritic spines of Purkinje cells. Biophys J 2021; 120:2112-2123. [PMID: 33887224 PMCID: PMC8390834 DOI: 10.1016/j.bpj.2021.03.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 02/22/2021] [Accepted: 03/18/2021] [Indexed: 02/07/2023] Open
Abstract
Calcium (Ca2+) is a second messenger assumed to control changes in synaptic strength in the form of both long-term depression and long-term potentiation at Purkinje cell dendritic spine synapses via inositol trisphosphate (IP3)-induced Ca2+ release. These Ca2+ transients happen in response to stimuli from parallel fibers (PFs) from granule cells and climbing fibers (CFs) from the inferior olivary nucleus. These events occur at low numbers of free Ca2+, requiring stochastic single-particle methods when modeling them. We use the stochastic particle simulation program MCell to simulate Ca2+ transients within a three-dimensional Purkinje cell dendritic spine. The model spine includes the endoplasmic reticulum, several Ca2+ transporters, and endogenous buffer molecules. Our simulations successfully reproduce properties of Ca2+ transients in different dynamical situations. We test two different models of the IP3 receptor (IP3R). The model with nonlinear concentration response of binding of activating Ca2+ reproduces experimental results better than the model with linear response because of the filtering of noise. Our results also suggest that Ca2+-dependent inhibition of the IP3R needs to be slow to reproduce experimental results. Simulations suggest the experimentally observed optimal timing window of CF stimuli arises from the relative timing of CF influx of Ca2+ and IP3 production sensitizing IP3R for Ca2+-induced Ca2+ release. We also model ataxia, a loss of fine motor control assumed to be the result of malfunctioning information transmission at the granule to Purkinje cell synapse, resulting in a decrease or loss of Ca2+ transients. Finally, we propose possible ways of recovering Ca2+ transients under ataxia.
Collapse
|
11
|
Maneshi MM, Toth AB, Ishii T, Hori K, Tsujikawa S, Shum AK, Shrestha N, Yamashita M, Miller RJ, Radulovic J, Swanson GT, Prakriya M. Orai1 Channels Are Essential for Amplification of Glutamate-Evoked Ca 2+ Signals in Dendritic Spines to Regulate Working and Associative Memory. Cell Rep 2020; 33:108464. [PMID: 33264616 PMCID: PMC7832685 DOI: 10.1016/j.celrep.2020.108464] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/14/2020] [Accepted: 11/10/2020] [Indexed: 11/18/2022] Open
Abstract
Store-operated Orai1 calcium channels function as highly Ca2+-selective ion channels and are broadly expressed in many tissues including the central nervous system, but their contributions to cognitive processing are largely unknown. Here, we report that many measures of synaptic, cellular, and behavioral models of learning are markedly attenuated in mice lacking Orai1 in forebrain excitatory neurons. Results with focal glutamate uncaging in hippocampal neurons support an essential role of Orai1 channels in amplifying NMDA-receptor-induced dendritic Ca2+ transients that drive activity-dependent spine morphogenesis and long-term potentiation at Schaffer collateral-CA1 synapses. Consistent with these signaling roles, mice lacking Orai1 in pyramidal neurons (but not interneurons) exhibit striking deficits in working and associative memory tasks. These findings identify Orai1 channels as essential regulators of dendritic spine Ca2+ signaling, synaptic plasticity, and cognition.
Collapse
Affiliation(s)
- Mohammad Mehdi Maneshi
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Anna B Toth
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Toshiyuki Ishii
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Kotaro Hori
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Shogo Tsujikawa
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Andrew K Shum
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Nisha Shrestha
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Megumi Yamashita
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Richard J Miller
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Jelena Radulovic
- Department of Psychiatry, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Geoffrey T Swanson
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Murali Prakriya
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| |
Collapse
|
12
|
Influence of spatially segregated IP 3-producing pathways on spike generation and transmitter release in Purkinje cell axons. Proc Natl Acad Sci U S A 2020; 117:11097-11108. [PMID: 32358199 DOI: 10.1073/pnas.2000148117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
It has been known for a long time that inositol-trisphosphate (IP3) receptors are present in the axon of certain types of mammalian neurons, but their functional role has remained unexplored. Here we show that localized photolysis of IP3 induces spatially constrained calcium rises in Purkinje cell axons. Confocal immunohistology reveals that the axon initial segment (AIS), as well as terminals onto deep cerebellar cells, express specific subtypes of Gα/q and phospholipase C (PLC) molecules, together with the upstream purinergic receptor P2Y1. By contrast, intermediate parts of the axon express another set of Gα/q and PLC molecules, indicating two spatially segregated signaling cascades linked to IP3 generation. This prompted a search for distinct actions of IP3 in different parts of Purkinje cell axons. In the AIS, we found that local applications of the specific P2Y1R agonist MRS2365 led to calcium elevation, and that IP3 photolysis led to inhibition of action potential firing. In synaptic terminals on deep cerebellar nuclei neurons, we found that photolysis of both IP3 and ATP led to GABA release. We propose that axonal IP3 receptors can inhibit action potential firing and increase neurotransmitter release, and that these effects are likely controlled by purinergic receptors. Altogether our results suggest a rich and diverse functional role of IP3 receptors in axons of mammalian neurons.
Collapse
|
13
|
Furlan S, Campione M, Murgia M, Mosole S, Argenton F, Volpe P, Nori A. Calsequestrins New Calcium Store Markers of Adult Zebrafish Cerebellum and Optic Tectum. Front Neuroanat 2020; 14:15. [PMID: 32372920 PMCID: PMC7188384 DOI: 10.3389/fnana.2020.00015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/18/2020] [Indexed: 12/26/2022] Open
Abstract
Calcium stores in neurons are heterogeneous in compartmentalization and molecular composition. Danio rerio (zebrafish) is an animal model with a simply folded cerebellum similar in cellular organization to that of mammals. The aim of the study was to identify new endoplasmic reticulum (ER) calcium store markers in zebrafish adult brain with emphasis on cerebellum and optic tectum. By quantitative polymerase chain reaction, we found three RNA transcripts coding for the intra-ER calcium binding protein calsequestrin: casq1a, casq1b, and casq2. In brain homogenates, two isoforms were detected by mass spectrometry and western blotting. Fractionation experiments of whole brain revealed that Casq1a and Casq2 were enriched in a heavy fraction containing ER microsomes and synaptic membranes. By in situ hybridization, we found the heterogeneous expression of casq1a and casq2 mRNA to be compatible with the cellular localization of calsequestrins investigated by immunofluorescence. Casq1 was expressed in neurogenic differentiation 1 expressing the granule cells of the cerebellum and the periventricular zone of the optic tectum. Casq2 was concentrated in parvalbumin expressing Purkinje cells. At a subcellular level, Casq1 was restricted to granular cell bodies, and Casq2 was localized in cell bodies, dendrites, and axons. Data are discussed in relation to the differential cellular and subcellular distribution of other cerebellum calcium store markers and are evaluated with respect to the putative relevance of calsequestrins in the neuron-specific functional activity.
Collapse
Affiliation(s)
- Sandra Furlan
- Consiglio Nazionale delle Ricerche, Institute of Neuroscience, Padova, Italy
| | - Marina Campione
- Consiglio Nazionale delle Ricerche, Institute of Neuroscience, Padova, Italy
| | - Marta Murgia
- Department of Biomedical Sciences, University of Padova, Istituto Interuniversitario di Miologia, Padova, Italy.,Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Simone Mosole
- Institute of Oncology Research (IOR), Bellinzona, Switzerland
| | | | - Pompeo Volpe
- Department of Biomedical Sciences, University of Padova, Istituto Interuniversitario di Miologia, Padova, Italy
| | - Alessandra Nori
- Department of Biomedical Sciences, University of Padova, Istituto Interuniversitario di Miologia, Padova, Italy
| |
Collapse
|
14
|
Fernández de Sevilla D, Núñez A, Buño W. Muscarinic Receptors, from Synaptic Plasticity to its Role in Network Activity. Neuroscience 2020; 456:60-70. [PMID: 32278062 DOI: 10.1016/j.neuroscience.2020.04.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 12/13/2022]
Abstract
Acetylcholine acting via metabotropic receptors plays a key role in learning and memory by regulating synaptic plasticity and circuit activity. However, a recent overall view of the effects of muscarinic acetylcholine receptors (mAChRs) on excitatory and inhibitory long-term synaptic plasticity and on circuit activity is lacking. This review focusses on specific aspects of the regulation of synaptic plasticity and circuit activity by mAChRs in the hippocampus and cortex. Acetylcholine increases the excitability of pyramidal neurons, facilitating the generation of dendritic Ca2+-spikes, NMDA-spikes and action potential bursts which provide the main source of Ca2+ influx necessary to induce synaptic plasticity. The activation of mAChRs induced Ca2+ release from intracellular IP3-sensitive stores is a major player in the induction of a NMDA independent long-term potentiation (LTP) caused by an increased expression of AMPA receptors in hippocampal pyramidal neuron dendritic spines. In the neocortex, activation of mAChRs also induces a long-term enhancement of excitatory postsynaptic currents. In addition to effects on excitatory synapses, a single brief activation of mAChRs together with short repeated membrane depolarization can induce a long-term enhancement of GABA A type (GABAA) inhibition through an increased expression of GABAA receptors in hippocampal pyramidal neurons. By contrast, a long term depression of GABAA inhibition (iLTD) is induced by muscarinic receptor activation in the absence of postsynaptic depolarizations. This iLTD is caused by an endocannabinoid-mediated presynaptic inhibition that reduces the GABA release probability at the terminals of inhibitory interneurons. This bidirectional long-term plasticity of inhibition may dynamically regulate the excitatory/inhibitory balance depending on the quiescent or active state of the postsynaptic pyramidal neurons. Therefore, acetylcholine can induce varied effects on neuronal activity and circuit behavior that can enhance sensory detection and processing through the modification of circuit activity leading to learning, memory and behavior.
Collapse
Affiliation(s)
- D Fernández de Sevilla
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain.
| | - A Núñez
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain
| | - W Buño
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid 28029, Spain
| |
Collapse
|
15
|
Neuromodulators and Long-Term Synaptic Plasticity in Learning and Memory: A Steered-Glutamatergic Perspective. Brain Sci 2019; 9:brainsci9110300. [PMID: 31683595 PMCID: PMC6896105 DOI: 10.3390/brainsci9110300] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/24/2019] [Accepted: 10/29/2019] [Indexed: 12/19/2022] Open
Abstract
The molecular pathways underlying the induction and maintenance of long-term synaptic plasticity have been extensively investigated revealing various mechanisms by which neurons control their synaptic strength. The dynamic nature of neuronal connections combined with plasticity-mediated long-lasting structural and functional alterations provide valuable insights into neuronal encoding processes as molecular substrates of not only learning and memory but potentially other sensory, motor and behavioural functions that reflect previous experience. However, one key element receiving little attention in the study of synaptic plasticity is the role of neuromodulators, which are known to orchestrate neuronal activity on brain-wide, network and synaptic scales. We aim to review current evidence on the mechanisms by which certain modulators, namely dopamine, acetylcholine, noradrenaline and serotonin, control synaptic plasticity induction through corresponding metabotropic receptors in a pathway-specific manner. Lastly, we propose that neuromodulators control plasticity outcomes through steering glutamatergic transmission, thereby gating its induction and maintenance.
Collapse
|
16
|
Sather WA, Dittmer PJ. Regulation of voltage-gated calcium channels by the ER calcium sensor STIM1. Curr Opin Neurobiol 2019; 57:186-191. [PMID: 31260893 DOI: 10.1016/j.conb.2019.01.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 01/21/2019] [Indexed: 01/13/2023]
Abstract
The endoplasmic reticulum (ER) Ca2+ sensor STIM1, best-known for its essential role in triggering influx of extracellular Ca2+ via Ca2+-release-activated channels when ER stores become depleted, unexpectedly also regulates Ca2+ entry through voltage-gated Ca2+ channels. In response to a drop in ER luminal Ca2+ level, this ER membrane-spanning sensor can contact voltage-gated Ca2+ channels in the plasma membrane and thereby inhibit Ca2+ influx through them. This previously unappreciated, interaction between ER Ca2+ level and magnitude of Ca2+ influx via voltage-gated Ca2+ channels may turn out to powerfully impact Ca2+ signaling in excitable cells, including neurotransmitter release, structural and functional postsynaptic plasticity, and transcription factor translocation.
Collapse
Affiliation(s)
- William A Sather
- Department of Pharmacology, University of Colorado School of Medicine, 12800 E. 19th Avenue, Aurora, CO 80045, USA.
| | - Philip J Dittmer
- Department of Pharmacology, University of Colorado School of Medicine, 12800 E. 19th Avenue, Aurora, CO 80045, USA
| |
Collapse
|
17
|
Mahajan G, Nadkarni S. Intracellular calcium stores mediate metaplasticity at hippocampal dendritic spines. J Physiol 2019; 597:3473-3502. [PMID: 31099020 PMCID: PMC6636706 DOI: 10.1113/jp277726] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 05/16/2019] [Indexed: 12/21/2022] Open
Abstract
Key points Calcium (Ca2+) entry mediated by NMDA receptors is considered central to the induction of activity‐dependent synaptic plasticity in hippocampal area CA1; this description does not, however, take into account the potential contribution of endoplasmic reticulum (ER) Ca2+ stores. The ER has a heterogeneous distribution in CA1 dendritic spines, and may introduce localized functional differences in Ca2+ signalling between synapses, as suggested by experiments on metabotropic receptor‐dependent long‐term depression. A physiologically detailed computational model of Ca2+ dynamics at a CA3–CA1 excitatory synapse characterizes the contribution of spine ER via metabotropic signalling during plasticity induction protocols. ER Ca2+ release via IP3 receptors modulates NMDA receptor‐dependent plasticity in a graded manner, to selectively promote synaptic depression with relatively diminished effect on LTP induction; this may temper further strengthening at the stronger synapses which are preferentially associated with ER‐containing spines. Acquisition of spine ER may thus represent a local, biophysically plausible ‘metaplastic switch’ at potentiated CA1 synapses, contributing to the plasticity–stability balance in neural circuits.
Abstract Long‐term plasticity mediated by NMDA receptors supports input‐specific, Hebbian forms of learning at excitatory CA3–CA1 connections in the hippocampus. There exists an additional layer of stabilizing mechanisms that act globally as well as locally over multiple time scales to ensure that plasticity occurs in a constrained manner. Here, we investigated the role of calcium (Ca2+) stores associated with the endoplasmic reticulum (ER) in the local regulation of plasticity at individual CA1 synapses. Our study was spurred by (1) the curious observation that ER is sparsely distributed in dendritic spines, but over‐represented in larger spines that are likely to have undergone activity‐dependent strengthening, and (2) evidence suggesting that ER motility at synapses can be rapid, and accompany activity‐regulated spine remodelling. We constructed a physiologically realistic computational model of an ER‐bearing CA1 spine, and examined how IP3‐sensitive Ca2+ stores affect spine Ca2+ dynamics during activity patterns mimicking the induction of long‐term potentiation and long‐term depression (LTD). Our results suggest that the presence of ER modulates NMDA receptor‐dependent plasticity in a graded manner that selectively enhances LTD induction. We propose that ER may locally tune Ca2+‐based plasticity, providing a braking mechanism to mitigate runaway strengthening at potentiated synapses. Our study provides a biophysically accurate description of postsynaptic Ca2+ regulation, and suggests that ER in the spine may promote the re‐use of hippocampal synapses with saturated strengths. Calcium (Ca2+) entry mediated by NMDA receptors is considered central to the induction of activity‐dependent synaptic plasticity in hippocampal area CA1; this description does not, however, take into account the potential contribution of endoplasmic reticulum (ER) Ca2+ stores. The ER has a heterogeneous distribution in CA1 dendritic spines, and may introduce localized functional differences in Ca2+ signalling between synapses, as suggested by experiments on metabotropic receptor‐dependent long‐term depression. A physiologically detailed computational model of Ca2+ dynamics at a CA3–CA1 excitatory synapse characterizes the contribution of spine ER via metabotropic signalling during plasticity induction protocols. ER Ca2+ release via IP3 receptors modulates NMDA receptor‐dependent plasticity in a graded manner, to selectively promote synaptic depression with relatively diminished effect on LTP induction; this may temper further strengthening at the stronger synapses which are preferentially associated with ER‐containing spines. Acquisition of spine ER may thus represent a local, biophysically plausible ‘metaplastic switch’ at potentiated CA1 synapses, contributing to the plasticity–stability balance in neural circuits.
Collapse
Affiliation(s)
- Gaurang Mahajan
- Indian Institute of Science Education and Research, Pune, 411 008, India
| | - Suhita Nadkarni
- Indian Institute of Science Education and Research, Pune, 411 008, India
| |
Collapse
|
18
|
Glovaci I, Chapman CA. Dopamine induces release of calcium from internal stores in layer II lateral entorhinal cortex fan cells. Cell Calcium 2019; 80:103-111. [PMID: 30999216 DOI: 10.1016/j.ceca.2019.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 04/03/2019] [Accepted: 04/08/2019] [Indexed: 11/16/2022]
Abstract
The entorhinal cortex plays an important role in temporal lobe processes including learning and memory, object recognition, and contextual information processing. The alteration of the strength of synaptic inputs to the lateral entorhinal cortex may therefore contribute substantially to sensory and mnemonic functions. The neuromodulatory transmitter dopamine exerts powerful effects on excitatory glutamatergic synaptic transmission in the entorhinal cortex. Interestingly, inputs from midbrain dopamine neurons appear to specifically target clusters of excitatory cells located in the superficial layers of the entorhinal cortex. We have previously demonstrated that dopamine facilitates synaptic transmission through the activation of D1-like receptors. This facilitation of synaptic transmission is dependent on both activation of classical D1-like-receptors, and upon activation of dopamine receptors linked to increases in phospholipase C, inositol triphosphate (IP3), and intracellular calcium. In the present study we combined electrophysiological recordings of evoked excitatory postsynaptic currents with imaging of intracellular calcium using the fluorescent indicator fluo-4 to monitor calcium transients evoked by dopamine in electrophysiologically identified putative fan and pyramidal cells of the lateral entorhinal cortex. Bath application of dopamine (1 μM), or the phosphatidylinositol (PI)-linked D1-like-receptor agonist SKF83959 (5 μM), induced reliable and reversible increases in fluo-4 fluorescence and excitatory postsynaptic currents in fan cells, but not in pyramidal cells. In contrast, application of the classical D1-like-receptor agonist SKF38393 (10 μM) did not result in significant increases in fluorescence. Blocking release of calcium from internal stores by loading cells with the IP3 receptor blocker heparin (1 mM) or the ryanodine receptor blocker dantrolene (20 μM) abolished both the calcium transients and the facilitation of evoked synaptic currents induced by dopamine. Dopamine also induced calcium transients in fan cells when calcium was excluded from the extracellular medium, further indicating that the calcium transients are linked to release from internal stores. These results indicate that following D1-like-receptor binding, dopamine selectively induces transient elevations in intracellular calcium via activation of IP3 and ryanodine receptors, and that these elevations are linked to the facilitation of synaptic responses in putative layer II entorhinal cortex fan cells.
Collapse
Affiliation(s)
- Iulia Glovaci
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, H4B 1R6, Canada
| | - C Andrew Chapman
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, H4B 1R6, Canada.
| |
Collapse
|
19
|
Chirillo MA, Waters MS, Lindsey LF, Bourne JN, Harris KM. Local resources of polyribosomes and SER promote synapse enlargement and spine clustering after long-term potentiation in adult rat hippocampus. Sci Rep 2019; 9:3861. [PMID: 30846859 PMCID: PMC6405867 DOI: 10.1038/s41598-019-40520-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 02/07/2019] [Indexed: 12/11/2022] Open
Abstract
Synapse clustering facilitates circuit integration, learning, and memory. Long-term potentiation (LTP) of mature neurons produces synapse enlargement balanced by fewer spines, raising the question of how clusters form despite this homeostatic regulation of total synaptic weight. Three-dimensional reconstruction from serial section electron microscopy (3DEM) revealed the shapes and distributions of smooth endoplasmic reticulum (SER) and polyribosomes, subcellular resources important for synapse enlargement and spine outgrowth. Compared to control stimulation, synapses were enlarged two hours after LTP on resource-rich spines containing polyribosomes (4% larger than control) or SER (15% larger). SER in spines shifted from a single tubule to complex spine apparatus after LTP. Negligible synapse enlargement (0.6%) occurred on resource-poor spines lacking SER and polyribosomes. Dendrites were divided into discrete synaptic clusters surrounded by asynaptic segments. Spine density was lowest in clusters having only resource-poor spines, especially following LTP. In contrast, resource-rich spines preserved neighboring resource-poor spines and formed larger clusters with elevated total synaptic weight following LTP. These clusters also had more shaft SER branches, which could sequester cargo locally to support synapse growth and spinogenesis. Thus, resources appear to be redistributed to synaptic clusters with LTP-related synapse enlargement while homeostatic regulation suppressed spine outgrowth in resource-poor synaptic clusters.
Collapse
Affiliation(s)
- Michael A Chirillo
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.,Fulbright U.S. Scholar Program, University of Belgrade, Studentski trg 1, Belgrade, 11000, Serbia
| | - Mikayla S Waters
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.,McGovern Medical School in Houston, 6431 Fannin St., Houston, TX, 77030, USA
| | - Laurence F Lindsey
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.,Google Seattle, Seattle, Washington, 98103, USA
| | - Jennifer N Bourne
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.,Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Kristen M Harris
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.
| |
Collapse
|
20
|
Breit M, Kessler M, Stepniewski M, Vlachos A, Queisser G. Spine-to-Dendrite Calcium Modeling Discloses Relevance for Precise Positioning of Ryanodine Receptor-Containing Spine Endoplasmic Reticulum. Sci Rep 2018; 8:15624. [PMID: 30353066 PMCID: PMC6199256 DOI: 10.1038/s41598-018-33343-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 09/18/2018] [Indexed: 12/15/2022] Open
Abstract
The endoplasmic reticulum (ER) forms a complex endomembrane network that reaches into the cellular compartments of a neuron, including dendritic spines. Recent work discloses that the spine ER is a dynamic structure that enters and leaves spines. While evidence exists that ER Ca2+ release is involved in synaptic plasticity, the role of spine ER morphology remains unknown. Combining a new 3D spine generator with 3D Ca2+ modeling, we addressed the relevance of ER positioning on spine-to-dendrite Ca2+ signaling. Our simulations, which account for Ca2+ exchange on the plasma membrane and ER, show that spine ER needs to be present in distinct morphological conformations in order to overcome a barrier between the spine and dendritic shaft. We demonstrate that RyR-carrying spine ER promotes spine-to-dendrite Ca2+ signals in a position-dependent manner. Our simulations indicate that RyR-carrying ER can initiate time-delayed Ca2+ reverberation, depending on the precise position of the spine ER. Upon spine growth, structural reorganization of the ER restores spine-to-dendrite Ca2+ communication, while maintaining aspects of Ca2+ homeostasis in the spine head. Our work emphasizes the relevance of precise positioning of RyR-containing spine ER in regulating the strength and timing of spine Ca2+ signaling, which could play an important role in tuning spine-to-dendrite Ca2+ communication and homeostasis.
Collapse
Affiliation(s)
- Markus Breit
- Goethe Center for Scientific Computing, Computational Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Marcus Kessler
- Goethe Center for Scientific Computing, Computational Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Martin Stepniewski
- Goethe Center for Scientific Computing, Computational Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, 79104, Germany. .,Bernstein Center Freiburg, University of Freiburg, Freiburg, 79104, Germany.
| | - Gillian Queisser
- Department of Mathematics, Temple University, Philadelphia, USA.
| |
Collapse
|
21
|
A Multicomponent Neuronal Response Encodes the Larval Decision to Pupariate upon Amino Acid Starvation. J Neurosci 2018; 38:10202-10219. [PMID: 30301757 PMCID: PMC6246885 DOI: 10.1523/jneurosci.1163-18.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 09/21/2018] [Accepted: 09/24/2018] [Indexed: 12/12/2022] Open
Abstract
Organisms need to coordinate growth with development, particularly in the context of nutrient availability. Thus, multiple ways have evolved to survive extrinsic nutrient deprivation during development. In Drosophila, growth occurs during larval development. Larvae are thus critically dependent on nutritional inputs; but after critical weight, they pupariate even when starved. How nutrient availability is coupled to the internal metabolic state for the decision to pupariate needs better understanding. We had earlier identified glutamatergic interneurons in the ventral ganglion that regulate pupariation on a protein-deficient diet. Here we report that Drosophila third instar larvae (either sex) sense arginine to evaluate their nutrient environment using an amino acid transporter Slimfast. The glutamatergic interneurons integrate external protein availability with internal metabolic state through neuropeptide signals. IP3-mediated calcium release and store-operated calcium entry are essential in these glutamatergic neurons for such integration and alter neuronal function by reducing the expression of multiple ion channels. SIGNIFICANCE STATEMENT Coordinating growth with development, in the context of nutrient availability is a challenge for all organisms in nature. After attainment of “critical weight,” insect larvae can pupariate, even in the absence of nutrition. Mechanism(s) that stimulate appropriate cellular responses and allow normal development on a nutritionally deficient diet remain to be understood. Here, we demonstrate that nutritional deprivation, in postcritical weight larvae, is sensed by special sensory neurons through an amino acid transporter that detects loss of environmental arginine. This information is integrated by glutamatergic interneurons with the internal metabolic state through neuropeptide signals. These glutamatergic interneurons require calcium-signaling-regulated expression of a host of neuronal channels to generate complex calcium signals essential for pupariation on a protein-deficient diet.
Collapse
|
22
|
Suenami S, Oya S, Kohno H, Kubo T. Kenyon Cell Subtypes/Populations in the Honeybee Mushroom Bodies: Possible Function Based on Their Gene Expression Profiles, Differentiation, Possible Evolution, and Application of Genome Editing. Front Psychol 2018; 9:1717. [PMID: 30333766 PMCID: PMC6176018 DOI: 10.3389/fpsyg.2018.01717] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 08/24/2018] [Indexed: 12/20/2022] Open
Abstract
Mushroom bodies (MBs), a higher-order center in the honeybee brain, comprise some subtypes/populations of interneurons termed as Kenyon cells (KCs), which are distinguished by their cell body size and location in the MBs, as well as their gene expression profiles. Although the role of MBs in learning ability has been studied extensively in the honeybee, the roles of each KC subtype and their evolution in hymenopteran insects remain mostly unknown. This mini-review describes recent progress in the analysis of gene/protein expression profiles and possible functions of KC subtypes/populations in the honeybee. Especially, the discovery of novel KC subtypes/populations, the “middle-type KCs” and “KC population expressing FoxP,” necessitated a redefinition of the KC subtype/population. Analysis of the effects of inhibiting gene function in a KC subtype-preferential manner revealed the function of the gene product as well as of the KC subtype where it is expressed. Genes expressed in a KC subtype/population-preferential manner can be used to trace the differentiation of KC subtypes during the honeybee ontogeny and the possible evolution of KC subtypes in hymenopteran insects. Current findings suggest that the three KC subtypes are unique characteristics to the aculeate hymenopteran insects. Finally, prospects regarding future application of genome editing for the study of KC subtype functions in the honeybee are described. Genes expressed in a KC subtype-preferential manner can be good candidate target genes for genome editing, because they are likely related to highly advanced brain functions and some of them are dispensable for normal development and sexual maturation in honeybees.
Collapse
Affiliation(s)
- Shota Suenami
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Satoyo Oya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Hiroki Kohno
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takeo Kubo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| |
Collapse
|
23
|
Nguyen RL, Medvedeva YV, Ayyagari TE, Schmunk G, Gargus JJ. Intracellular calcium dysregulation in autism spectrum disorder: An analysis of converging organelle signaling pathways. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1718-1732. [PMID: 30992134 DOI: 10.1016/j.bbamcr.2018.08.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/18/2018] [Accepted: 08/02/2018] [Indexed: 12/14/2022]
Abstract
Autism spectrum disorder (ASD) is a group of complex, neurological disorders that affect early cognitive, social, and verbal development. Our understanding of ASD has vastly improved with advances in genomic sequencing technology and genetic models that have identified >800 loci with variants that increase susceptibility to ASD. Although these findings have confirmed its high heritability, the underlying mechanisms by which these genes produce the ASD phenotypes have not been defined. Current efforts have begun to "functionalize" many of these variants and envisage how these susceptibility factors converge at key biochemical and biophysical pathways. In this review, we discuss recent work on intracellular calcium signaling in ASD, including our own work, which begins to suggest it as a compelling candidate mechanism in the pathophysiology of autism and a potential therapeutic target. We consider how known variants in the calcium signaling genomic architecture of ASD may exert their deleterious effects along pathways particularly involving organelle dysfunction including the endoplasmic reticulum (ER), a major calcium store, and the mitochondria, a major calcium ion buffer, and theorize how many of these pathways intersect.
Collapse
Affiliation(s)
- Rachel L Nguyen
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA; UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Yuliya V Medvedeva
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA; UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA; Department of Neurology, University of California, Irvine, Irvine, CA, USA
| | - Tejasvi E Ayyagari
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA; UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Galina Schmunk
- UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - John Jay Gargus
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA; UCI Center for Autism Research and Translation, School of Medicine, University of California, Irvine, Irvine, CA, USA; Department of Pediatrics, Section of Human Genetics and Genomics, University of California, Irvine, Irvine, CA, USA.
| |
Collapse
|
24
|
Calabrese EJ, Rubio-Casillas A. Biphasic effects of THC in memory and cognition. Eur J Clin Invest 2018; 48:e12920. [PMID: 29574698 DOI: 10.1111/eci.12920] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/11/2018] [Indexed: 12/20/2022]
Abstract
A generally undesired effect of cannabis smoking is a reversible disruption of short-term memory induced by delta-9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis. However, this paradigm has been recently challenged by a group of scientists who have shown that THC is also able to improve neurological function in old animals when chronically administered at low concentrations. Moreover, recent studies demonstrated that THC paradoxically promotes hippocampal neurogenesis, prevents neurodegenerative processes occurring in animal models of Alzheimer's disease, protects from inflammation-induced cognitive damage and restores memory and cognitive function in old mice. With the aim to reconcile these seemingly contradictory facts, this work will show that such paradox can be explained within the framework of hormesis, defined as a biphasic dose-response.
Collapse
Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, University of Massachusetts, Amherst, MA, USA
| | - Alberto Rubio-Casillas
- Laboratorio de Biologia, Escuela Preparatoria Regional de Autlán, Universidad de Guadalajara, Jalisco, México
| |
Collapse
|
25
|
Cobley JN, Fiorello ML, Bailey DM. 13 reasons why the brain is susceptible to oxidative stress. Redox Biol 2018; 15:490-503. [PMID: 29413961 PMCID: PMC5881419 DOI: 10.1016/j.redox.2018.01.008] [Citation(s) in RCA: 650] [Impact Index Per Article: 108.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 12/12/2022] Open
Abstract
The human brain consumes 20% of the total basal oxygen (O2) budget to support ATP intensive neuronal activity. Without sufficient O2 to support ATP demands, neuronal activity fails, such that, even transient ischemia is neurodegenerative. While the essentiality of O2 to brain function is clear, how oxidative stress causes neurodegeneration is ambiguous. Ambiguity exists because many of the reasons why the brain is susceptible to oxidative stress remain obscure. Many are erroneously understood as the deleterious result of adventitious O2 derived free radical and non-radical species generation. To understand how many reasons underpin oxidative stress, one must first re-cast free radical and non-radical species in a positive light because their deliberate generation enables the brain to achieve critical functions (e.g. synaptic plasticity) through redox signalling (i.e. positive functionality). Using free radicals and non-radical derivatives to signal sensitises the brain to oxidative stress when redox signalling goes awry (i.e. negative functionality). To advance mechanistic understanding, we rationalise 13 reasons why the brain is susceptible to oxidative stress. Key reasons include inter alia unsaturated lipid enrichment, mitochondria, calcium, glutamate, modest antioxidant defence, redox active transition metals and neurotransmitter auto-oxidation. We review RNA oxidation as an underappreciated cause of oxidative stress. The complex interplay between each reason dictates neuronal susceptibility to oxidative stress in a dynamic context and neural identity dependent manner. Our discourse sets the stage for investigators to interrogate the biochemical basis of oxidative stress in the brain in health and disease.
Collapse
Affiliation(s)
- James Nathan Cobley
- Free Radical Laboratory, Departments of Diabetes and Cardiovascular Sciences, Centre for Health Sciences, University of the Highlands and Islands, Inverness IV2 3HJ, UK.
| | - Maria Luisa Fiorello
- Free Radical Laboratory, Departments of Diabetes and Cardiovascular Sciences, Centre for Health Sciences, University of the Highlands and Islands, Inverness IV2 3HJ, UK
| | - Damian Miles Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, CF37 4AT, UK
| |
Collapse
|
26
|
Kucharz K, Lauritzen M. CaMKII-dependent endoplasmic reticulum fission by whisker stimulation and during cortical spreading depolarization. Brain 2018. [DOI: 10.1093/brain/awy036] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Krzysztof Kucharz
- Department of Neuroscience and Center for Healthy Aging, University of Copenhagen, Maersk Tower, Blegdamsvej 3, 2200 Copenhagen N, Denmark
| | - Martin Lauritzen
- Department of Neuroscience and Center for Healthy Aging, University of Copenhagen, Maersk Tower, Blegdamsvej 3, 2200 Copenhagen N, Denmark
- Department of Clinical Neurophysiology, Rigshospitalet, Nordre Ringvej 57, 2600 Glostrup, Denmark
| |
Collapse
|
27
|
Henry FE, Hockeimer W, Chen A, Mysore SP, Sutton MA. Mechanistic target of rapamycin is necessary for changes in dendritic spine morphology associated with long-term potentiation. Mol Brain 2017; 10:50. [PMID: 29084578 PMCID: PMC5663037 DOI: 10.1186/s13041-017-0330-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/18/2017] [Indexed: 11/10/2022] Open
Abstract
Alterations in the strength of excitatory synapses in the hippocampus is believed to serve a vital function in the storage and recall of new information in the mammalian brain. These alterations involve the regulation of both functional and morphological features of dendritic spines, the principal sites of excitatory synaptic contact. New protein synthesis has been implicated extensively in the functional changes observed following long-term potentiation (LTP), and changes to spine morphology have similarly been documented extensively following synaptic potentiation. However, mechanistic links between de novo translation and the structural changes of potentiated spines are less clear. Here, we assess explicitly the potential contribution of new protein translation under control of the mechanistic target of rapamycin (mTOR) to LTP-associated changes in spine morphology. Utilizing genetic and pharmacological manipulations of mTORC1 function in combination with confocal microscopy in live dissociated hippocampal cultures, we demonstrate that chemically-induced LTP (cLTP) requires do novo protein synthesis and intact mTORC1 signaling. We observed a striking diversity in response properties across morphological classes, with mushroom spines displaying a particular sensitivity to altered mTORC1 signaling across varied levels of synaptic activity. Notably, while pharmacological inhibition of mTORC1 signaling significantly diminished glycine-induced changes in spine morphology, transient genetic upregulation of mTORC1 signaling was insufficient to produce spine enlargements on its own. In contrast, genetic upregulation of mTORC1 signaling promoted rapid expansion in spine head diameter when combined with otherwise sub-threshold synaptic stimulation. These results suggest that synaptic activity-derived signaling pathways act in combination with mTORC1-dependent translational control mechanisms to ultimately regulate changes in spine morphology. As several monogenic neurodevelopmental disorders with links to Autism and Intellectual Disability share a common feature of dysregulated mTORC1 signaling, further understanding of the role of this signaling pathway in regulating synapse function and morphology will be essential in the development of novel therapeutic interventions.
Collapse
Affiliation(s)
- Fredrick E Henry
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, 48109, USA.,Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - William Hockeimer
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Alex Chen
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, 48109, USA.,Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Shreesh P Mysore
- Department of Pyschological and Brain Sciences, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Michael A Sutton
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, 48109, USA. .,Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, 48109, USA. .,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA. .,Molecular and Behavioral Neuroscience Institute, Department of Molecular and Integrative Physiology, University of Michigan, 5067 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.
| |
Collapse
|
28
|
STIM1 Ca 2+ Sensor Control of L-type Ca 2+-Channel-Dependent Dendritic Spine Structural Plasticity and Nuclear Signaling. Cell Rep 2017; 19:321-334. [PMID: 28402855 DOI: 10.1016/j.celrep.2017.03.056] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 11/07/2016] [Accepted: 03/17/2017] [Indexed: 12/23/2022] Open
Abstract
Potentiation of synaptic strength relies on postsynaptic Ca2+ signals, modification of dendritic spine structure, and changes in gene expression. One Ca2+ signaling pathway supporting these processes routes through L-type Ca2+ channels (LTCC), whose activity is subject to tuning by multiple mechanisms. Here, we show in hippocampal neurons that LTCC inhibition by the endoplasmic reticulum (ER) Ca2+ sensor, stromal interaction molecule 1 (STIM1), is engaged by the neurotransmitter glutamate, resulting in regulation of spine ER structure and nuclear signaling by the NFATc3 transcription factor. In this mechanism, depolarization by glutamate activates LTCC Ca2+ influx, releases Ca2+ from the ER, and consequently drives STIM1 aggregation and an inhibitory interaction with LTCCs that increases spine ER content but decreases NFATc3 nuclear translocation. These findings of negative feedback control of LTCC signaling by STIM1 reveal interplay between Ca2+ influx and release from stores that controls both postsynaptic structural plasticity and downstream nuclear signaling.
Collapse
|
29
|
Alteration of Neuronal Excitability and Short-Term Synaptic Plasticity in the Prefrontal Cortex of a Mouse Model of Mental Illness. J Neurosci 2017; 37:4158-4180. [PMID: 28283561 DOI: 10.1523/jneurosci.4345-15.2017] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 02/17/2017] [Accepted: 02/22/2017] [Indexed: 01/28/2023] Open
Abstract
Using a genetic mouse model that faithfully recapitulates a DISC1 genetic alteration strongly associated with schizophrenia and other psychiatric disorders, we examined the impact of this mutation within the prefrontal cortex. Although cortical layering, cytoarchitecture, and proteome were found to be largely unaffected, electrophysiological examination of the mPFC revealed both neuronal hyperexcitability and alterations in short-term synaptic plasticity consistent with enhanced neurotransmitter release. Increased excitability of layer II/III pyramidal neurons was accompanied by consistent reductions in voltage-activated potassium currents near the action potential threshold as well as by enhanced recruitment of inputs arising from superficial layers to layer V. We further observed reductions in both the paired-pulse ratios and the enhanced short-term depression of layer V synapses arising from superficial layers consistent with enhanced neurotransmitter release at these synapses. Recordings from layer II/III pyramidal neurons revealed action potential widening that could account for enhanced neurotransmitter release. Significantly, we found that reduced functional expression of the voltage-dependent potassium channel subunit Kv1.1 substantially contributes to both the excitability and short-term plasticity alterations that we observed. The underlying dysregulation of Kv1.1 expression was attributable to cAMP elevations in the PFC secondary to reduced phosphodiesterase 4 activity present in Disc1 deficiency and was rescued by pharmacological blockade of adenylate cyclase. Our results demonstrate a potentially devastating impact of Disc1 deficiency on neural circuit function, partly due to Kv1.1 dysregulation that leads to a dual dysfunction consisting of enhanced neuronal excitability and altered short-term synaptic plasticity.SIGNIFICANCE STATEMENT Schizophrenia is a profoundly disabling psychiatric illness with a devastating impact not only upon the afflicted but also upon their families and the broader society. Although the underlying causes of schizophrenia remain poorly understood, a growing body of studies has identified and strongly implicated various specific risk genes in schizophrenia pathogenesis. Here, using a genetic mouse model, we explored the impact of one of the most highly penetrant schizophrenia risk genes, DISC1, upon the medial prefrontal cortex, the region believed to be most prominently dysfunctional in schizophrenia. We found substantial derangements in both neuronal excitability and short-term synaptic plasticity-parameters that critically govern neural circuit information processing-suggesting that similar changes may critically, and more broadly, underlie the neural computational dysfunction prototypical of schizophrenia.
Collapse
|
30
|
Díez-García A, Barros-Zulaica N, Núñez Á, Buño W, Fernández de Sevilla D. Bidirectional Hebbian Plasticity Induced by Low-Frequency Stimulation in Basal Dendrites of Rat Barrel Cortex Layer 5 Pyramidal Neurons. Front Cell Neurosci 2017; 11:8. [PMID: 28203145 PMCID: PMC5285403 DOI: 10.3389/fncel.2017.00008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/12/2017] [Indexed: 11/15/2022] Open
Abstract
According to Hebb's original hypothesis (Hebb, 1949), synapses are reinforced when presynaptic activity triggers postsynaptic firing, resulting in long-term potentiation (LTP) of synaptic efficacy. Long-term depression (LTD) is a use-dependent decrease in synaptic strength that is thought to be due to synaptic input causing a weak postsynaptic effect. Although the mechanisms that mediate long-term synaptic plasticity have been investigated for at least three decades not all question have as yet been answered. Therefore, we aimed at determining the mechanisms that generate LTP or LTD with the simplest possible protocol. Low-frequency stimulation of basal dendrite inputs in Layer 5 pyramidal neurons of the rat barrel cortex induces LTP. This stimulation triggered an EPSP, an action potential (AP) burst, and a Ca2+ spike. The same stimulation induced LTD following manipulations that reduced the Ca2+ spike and Ca2+ signal or the AP burst. Low-frequency whisker deflections induced similar bidirectional plasticity of action potential evoked responses in anesthetized rats. These results suggest that both in vitro and in vivo similar mechanisms regulate the balance between LTP and LTD. This simple induction form of bidirectional hebbian plasticity could be present in the natural conditions to regulate the detection, flow, and storage of sensorimotor information.
Collapse
Affiliation(s)
- Andrea Díez-García
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Natali Barros-Zulaica
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Ángel Núñez
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Washington Buño
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC) Madrid, Spain
| | - David Fernández de Sevilla
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de MadridMadrid, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC)Madrid, Spain
| |
Collapse
|
31
|
Sexual Dimorphism in a Reciprocal Interaction of Ryanodine and IP 3 Receptors in the Induction of Hyperalgesic Priming. J Neurosci 2017; 37:2032-2044. [PMID: 28115480 DOI: 10.1523/jneurosci.2911-16.2017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 01/12/2017] [Accepted: 01/13/2017] [Indexed: 12/15/2022] Open
Abstract
Hyperalgesic priming, a model of pain chronification in the rat, is mediated by ryanodine receptor-dependent calcium release. Although ryanodine induces priming in both sexes, females are 5 orders of magnitude more sensitive, by an estrogen receptor α (EsRα)-dependent mechanism. An inositol 1,4,5-triphosphate (IP3) receptor inhibitor prevented the induction of priming by ryanodine. For IP3 induced priming, females were also more sensitive. IP3-induced priming was prevented by pretreatment with inhibitors of the sarcoendoplasmic reticulum calcium ATPase and ryanodine receptor. Antisense to EsRα prevented the induction of priming by low-dose IP3 in females. The induction of priming by an EsRα agonist was ryanodine receptor-dependent and prevented by the IP3 antagonist. Thus, an EsRα-dependent bidirectional interaction between endoplasmic reticulum IP3 and ryanodine receptor-mediated calcium signaling is present in the induction of hyperalgesic priming, in females. In cultured male DRG neurons, IP3 (100 μm) potentiated depolarization-induced transients produced by extracellular application of high-potassium solution (20 mm, K20), in nociceptors incubated with β-estradiol. This potentiation of depolarization-induced calcium transients was blocked by the IP3 antagonist, and not observed in the absence of IP3 IP3 potentiation was also blocked by ryanodine receptor antagonist. The application of ryanodine (2 nm), instead of IP3, also potentiated K20-induced calcium transients in the presence of β-estradiol, in an IP3 receptor-dependent manner. Our results point to an EsRα-dependent, reciprocal interaction between IP3 and ryanodine receptors that contributes to sex differences in hyperalgesic priming.SIGNIFICANCE STATEMENT The present study demonstrates a mechanism that plays a role in the marked sexual dimorphism observed in a model of the transition to chronic pain, hyperalgesic priming. This mechanism involves a reciprocal interaction between the endoplasmic reticulum receptors, IP3 and ryanodine, in the induction of priming, regulated by estrogen receptor α in the nociceptor of female rats. The presence of this signaling pathway modulating the susceptibility of nociceptors to develop plasticity may contribute to our understanding of sex differences observed clinically in chronic pain syndromes.
Collapse
|
32
|
Berridge MJ. The Inositol Trisphosphate/Calcium Signaling Pathway in Health and Disease. Physiol Rev 2016; 96:1261-96. [DOI: 10.1152/physrev.00006.2016] [Citation(s) in RCA: 377] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Many cellular functions are regulated by calcium (Ca2+) signals that are generated by different signaling pathways. One of these is the inositol 1,4,5-trisphosphate/calcium (InsP3/Ca2+) signaling pathway that operates through either primary or modulatory mechanisms. In its primary role, it generates the Ca2+ that acts directly to control processes such as metabolism, secretion, fertilization, proliferation, and smooth muscle contraction. Its modulatory role occurs in excitable cells where it modulates the primary Ca2+ signal generated by the entry of Ca2+ through voltage-operated channels that releases Ca2+ from ryanodine receptors (RYRs) on the internal stores. In carrying out this modulatory role, the InsP3/Ca2+ signaling pathway induces subtle changes in the generation and function of the voltage-dependent primary Ca2+ signal. Changes in the nature of both the primary and modulatory roles of InsP3/Ca2+ signaling are a contributory factor responsible for the onset of a large number human diseases.
Collapse
Affiliation(s)
- Michael J. Berridge
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, United Kingdom
| |
Collapse
|
33
|
Hanus C, Geptin H, Tushev G, Garg S, Alvarez-Castelao B, Sambandan S, Kochen L, Hafner AS, Langer JD, Schuman EM. Unconventional secretory processing diversifies neuronal ion channel properties. eLife 2016; 5:e20609. [PMID: 27677849 PMCID: PMC5077297 DOI: 10.7554/elife.20609] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 09/22/2016] [Indexed: 01/01/2023] Open
Abstract
N-glycosylation - the sequential addition of complex sugars to adhesion proteins, neurotransmitter receptors, ion channels and secreted trophic factors as they progress through the endoplasmic reticulum and the Golgi apparatus - is one of the most frequent protein modifications. In mammals, most organ-specific N-glycosylation events occur in the brain. Yet, little is known about the nature, function and regulation of N-glycosylation in neurons. Using imaging, quantitative immunoblotting and mass spectrometry, we show that hundreds of neuronal surface membrane proteins are core-glycosylated, resulting in the neuronal membrane displaying surprisingly high levels of glycosylation profiles that are classically associated with immature intracellular proteins. We report that while N-glycosylation is generally required for dendritic development and glutamate receptor surface expression, core-glycosylated proteins are sufficient to sustain these processes, and are thus functional. This atypical glycosylation of surface neuronal proteins can be attributed to a bypass or a hypo-function of the Golgi apparatus. Core-glycosylation is regulated by synaptic activity, modulates synaptic signaling and accelerates the turnover of GluA2-containing glutamate receptors, revealing a novel mechanism that controls the composition and sensing properties of the neuronal membrane.
Collapse
Affiliation(s)
- Cyril Hanus
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Helene Geptin
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Georgi Tushev
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Sakshi Garg
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | | | | | - Lisa Kochen
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | | | - Julian D Langer
- Max Planck Institute for Brain Research, Frankfurt, Germany
- Max Planck Institute for Biophysics, Frankfurt, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany
| |
Collapse
|
34
|
Li Y, Kulvicius T, Tetzlaff C. Induction and Consolidation of Calcium-Based Homo- and Heterosynaptic Potentiation and Depression. PLoS One 2016; 11:e0161679. [PMID: 27560350 PMCID: PMC4999190 DOI: 10.1371/journal.pone.0161679] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 08/10/2016] [Indexed: 11/19/2022] Open
Abstract
The adaptive mechanisms of homo- and heterosynaptic plasticity play an important role in learning and memory. In order to maintain plasticity-induced changes for longer time scales (up to several days), they have to be consolidated by transferring them from a short-lasting early-phase to a long-lasting late-phase state. The underlying processes of this synaptic consolidation are already well-known for homosynaptic plasticity, however, it is not clear whether the same processes also enable the induction and consolidation of heterosynaptic plasticity. In this study, by extending a generic calcium-based plasticity model with the processes of synaptic consolidation, we show in simulations that indeed heterosynaptic plasticity can be induced and, furthermore, consolidated by the same underlying processes as for homosynaptic plasticity. Furthermore, we show that by local diffusion processes the heterosynaptic effect can be restricted to a few synapses neighboring the homosynaptically changed ones. Taken together, this generic model reproduces many experimental results of synaptic tagging and consolidation, provides several predictions for heterosynaptic induction and consolidation, and yields insights into the complex interactions between homo- and heterosynaptic plasticity over a broad variety of time (minutes to days) and spatial scales (several micrometers).
Collapse
Affiliation(s)
- Yinyun Li
- III. Institute of Physics – Biophysics, Georg-August-University, 37077 Göttingen, Germany
- Bernstein Center for Computational Neuroscience, Georg-August-University, 37077 Göttingen, Germany
- School of System Science, Beijing Normal University, 100875 Beijing, China
- * E-mail:
| | - Tomas Kulvicius
- III. Institute of Physics – Biophysics, Georg-August-University, 37077 Göttingen, Germany
- Maersk Mc-Kinney Moller Institute, University of Southern Denmark, 5230 Odense, Denmark
| | - Christian Tetzlaff
- Bernstein Center for Computational Neuroscience, Georg-August-University, 37077 Göttingen, Germany
- Max Planck Institute for Dynamics and Self-Organization, 37077 Göttingen, Germany
- Department of Neurobiology, Weizmann Institute of Science, 76100 Rehovot, Israel
| |
Collapse
|
35
|
Emergence of ion channel modal gating from independent subunit kinetics. Proc Natl Acad Sci U S A 2016; 113:E5288-97. [PMID: 27551100 DOI: 10.1073/pnas.1604090113] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Many ion channels exhibit a slow stochastic switching between distinct modes of gating activity. This feature of channel behavior has pronounced implications for the dynamics of ionic currents and the signaling pathways that they regulate. A canonical example is the inositol 1,4,5-trisphosphate receptor (IP3R) channel, whose regulation of intracellular Ca(2+) concentration is essential for numerous cellular processes. However, the underlying biophysical mechanisms that give rise to modal gating in this and most other channels remain unknown. Although ion channels are composed of protein subunits, previous mathematical models of modal gating are coarse grained at the level of whole-channel states, limiting further dialogue between theory and experiment. Here we propose an origin for modal gating, by modeling the kinetics of ligand binding and conformational change in the IP3R at the subunit level. We find good agreement with experimental data over a wide range of ligand concentrations, accounting for equilibrium channel properties, transient responses to changing ligand conditions, and modal gating statistics. We show how this can be understood within a simple analytical framework and confirm our results with stochastic simulations. The model assumes that channel subunits are independent, demonstrating that cooperative binding or concerted conformational changes are not required for modal gating. Moreover, the model embodies a generally applicable principle: If a timescale separation exists in the kinetics of individual subunits, then modal gating can arise as an emergent property of channel behavior.
Collapse
|
36
|
Abstract
Ca2+ ions subserve complex signaling roles in neurons, regulating functions ranging from gene transcription to modulation of membrane excitability. Ca2+ ions enter the cytosol from extracellular sources, such as entry through voltage-gated channels, and by liberation from intracellular endoplasmic reticulum (ER) stores through inositol triphosphate (IP3) receptors and/or ryanodine (RyR) receptors. Disruptions of intracellular Ca2+ signaling are proposed to underlie the pathophysiology of Alzheimer’s disease (AD), and recent studies examining AD-linked mutations in the presenilin genes demonstrate enhanced ER Ca2+ release in a variety of cell types and model systems. The development of transgenic AD mouse models provides a means to study the mechanisms and downstream effects of neuronal ER Ca2+-signaling alterations on AD pathogenesis and offers insight into potential novel therapeutic strategies. The author discusses recent findings in both the physiological functioning of the IP3-signaling pathway in neurons and the involvement of ERCa2+ disruptions in the pathogenesis of AD.
Collapse
Affiliation(s)
- Grace E Stutzmann
- Department of Neurobiology and Behavior, 1146 McGaugh Hall, University of California-Irvine, Irvine, CA 92697, USA.
| |
Collapse
|
37
|
Suenami S, Paul RK, Takeuchi H, Okude G, Fujiyuki T, Shirai K, Kubo T. Analysis of the Differentiation of Kenyon Cell Subtypes Using Three Mushroom Body-Preferential Genes during Metamorphosis in the Honeybee (Apis mellifera L.). PLoS One 2016; 11:e0157841. [PMID: 27351839 PMCID: PMC4924639 DOI: 10.1371/journal.pone.0157841] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/06/2016] [Indexed: 01/29/2023] Open
Abstract
The adult honeybee (Apis mellifera L.) mushroom bodies (MBs, a higher center in the insect brain) comprise four subtypes of intrinsic neurons: the class-I large-, middle-, and small-type Kenyon cells (lKCs, mKCs, and sKCs, respectively), and class-II KCs. Analysis of the differentiation of KC subtypes during metamorphosis is important for the better understanding of the roles of KC subtypes related to the honeybee behaviors. In the present study, aiming at identifying marker genes for KC subtypes, we used a cDNA microarray to comprehensively search for genes expressed in an MB-preferential manner in the honeybee brain. Among the 18 genes identified, we further analyzed three genes whose expression was enriched in the MBs: phospholipase C epsilon (PLCe), synaptotagmin 14 (Syt14), and discs large homolog 5 (dlg5). Quantitative reverse transcription-polymerase chain reaction analysis revealed that expression of PLCe, Syt14, and dlg5 was more enriched in the MBs than in the other brain regions by approximately 31-, 6.8-, and 5.6-fold, respectively. In situ hybridization revealed that expression of both Syt14 and dlg5 was enriched in the lKCs but not in the mKCs and sKCs, whereas expression of PLCe was similar in all KC subtypes (the entire MBs) in the honeybee brain, suggesting that Syt14 and dlg5, and PLCe are available as marker genes for the lKCs, and all KC subtypes, respectively. In situ hybridization revealed that expression of PLCe is already detectable in the class-II KCs at the larval fifth instar feeding stage, indicating that PLCe expression is a characteristic common to the larval and adult MBs. In contrast, expression of both Syt14 and dlg5 became detectable at the day three pupa, indicating that Syt14 and dlg5 expressions are characteristic to the late pupal and adult MBs and the lKC specific molecular characteristics are established during the late pupal stages.
Collapse
Affiliation(s)
- Shota Suenami
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Rajib Kumar Paul
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Hideaki Takeuchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Genta Okude
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Tomoko Fujiyuki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Kenichi Shirai
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Takeo Kubo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113–0033, Japan
- * E-mail:
| |
Collapse
|
38
|
Neyer C, Herr D, Kohmann D, Budde T, Pape HC, Coulon P. mGluR-mediated calcium signalling in the thalamic reticular nucleus. Cell Calcium 2016; 59:312-23. [PMID: 27041217 DOI: 10.1016/j.ceca.2016.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 10/22/2022]
Abstract
The thalamic reticular nucleus (TRN) plays a major role in modulating the transfer of information from the thalamus to the cortex. GABAergic inhibition via the TRN is differentially regulated by metabotropic glutamate receptors (mGluRs) and the effect of mGluRs on the membrane potential, on ion channels, and on the plasticity of electrical coupling of TRN neurons has been studied previously. Although mGluRs are generally known to trigger Ca(2+) transients, mGluR-mediated Ca(2+)-transients in TRN neurons have not yet been investigated. In this study, we show that mGluRs can trigger Ca(2+)-transients in TRN neurons, that these transients depend on intracellular Ca(2+)-stores, and are mediated by IP3 receptors. Ca(2+) transients caused by the group I mGluR agonist DHPG elicit a current that is sensitive to flufenamic acid and has a reversal potential around -40mV. Our results add mGluR-mediated Ca(2+)-signalling in the TRN to the state-dependent modulators of the thalamocortical system.
Collapse
Affiliation(s)
- Christina Neyer
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - David Herr
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Denise Kohmann
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Philippe Coulon
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany; Center For Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA.
| |
Collapse
|
39
|
Hanus C, Ehlers MD. Specialization of biosynthetic membrane trafficking for neuronal form and function. Curr Opin Neurobiol 2016; 39:8-16. [PMID: 27010827 DOI: 10.1016/j.conb.2016.03.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 03/01/2016] [Accepted: 03/07/2016] [Indexed: 10/24/2022]
Abstract
Neuronal growth and synaptic transmission require the continuous production of adhesion molecules, neurotransmitter receptors, ion-channels, and secreted trophic factors, and thus critically relies on the secretory pathway-the series of intracellular organelles including the endoplasmic reticulum (ER) and the Golgi apparatus (GA), where membrane lipids and proteins are synthesized. Commensurate with the gigantic size of the neuronal membrane and its compartmentalization by thousands of synapses with distinct compositions and activities, the neuronal secretory pathway has evolved to both traffic synaptic components over very long distances, and locally control the composition of specified segments of dendrites. Here we review new insights into the distribution and dynamics of dendritic secretory organelles and their impact on postsynaptic compartments.
Collapse
Affiliation(s)
- Cyril Hanus
- Department of Synaptic Plasticity, Max Planck Institute for Brain Research, Frankfurt, Germany.
| | - Michael D Ehlers
- Neuroscience Research Unit, BioTherapeutics, Worldwide Research and Development, Pfizer Inc., Cambridge, MA, USA.
| |
Collapse
|
40
|
Kim S, Kim T, Lee HR, Jang EH, Ryu HH, Kang M, Rah SY, Yoo J, Lee B, Kim JI, Lim CS, Kim SJ, Kim UH, Lee YS, Kaang BK. Impaired learning and memory in CD38 null mutant mice. Mol Brain 2016; 9:16. [PMID: 26856703 PMCID: PMC4746819 DOI: 10.1186/s13041-016-0195-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/01/2016] [Indexed: 11/17/2022] Open
Abstract
CD38 is an enzyme that catalyzes the formation of cyclic ADP ribose and nicotinic acid adenine dinucleotide phosphate, both of which are involved in the mobilization of Ca2+ from intracellular stores. Recently, CD38 has been shown to regulate oxytocin release from hypothalamic neurons. Importantly, CD38 mutations are associated with autism spectrum disorders (ASD) and CD38 knockout (CD38−/−) mice display ASD-like behavioral phenotypes including deficient parental behavior and poor social recognition memory. Although ASD and learning deficits commonly co-occur, the role of CD38 in learning and memory has not been investigated. We report that CD38−/− mice show deficits in various learning and memory tasks such as the Morris water maze, contextual fear conditioning, and the object recognition test. However, either long-term potentiation or long-term depression is not impaired in the hippocampus of CD38−/− mice. Our results provide convincing evidence that CD38−/− mice show deficits in various learning and memory tasks including spatial and non-spatial memory tasks. Our data demonstrate that CD38 is critical for regulating hippocampus-dependent learning and memory without modulating synaptic plasticity.
Collapse
Affiliation(s)
- Somi Kim
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| | - TaeHyun Kim
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| | - Hye-Ryeon Lee
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| | - Eun-Hye Jang
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| | - Hyun-Hee Ryu
- Department of Life Science, Chung-Ang University, Seoul, 156-756, South Korea.
| | - Minkyung Kang
- Department of Life Science, Chung-Ang University, Seoul, 156-756, South Korea.
| | - So-Young Rah
- Departments of Biochemistry, Institute of Cardiovascular Research, Chonbuk National University Medical School, Jeonju, 561-182, South Korea.
| | - Juyoun Yoo
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| | - Bolam Lee
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| | - Jae-Ick Kim
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| | - Chae Seok Lim
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| | - Sang Jeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, 110-799, South Korea.
| | - Uh-Hyun Kim
- Departments of Biochemistry, Institute of Cardiovascular Research, Chonbuk National University Medical School, Jeonju, 561-182, South Korea.
| | - Yong-Seok Lee
- Department of Life Science, Chung-Ang University, Seoul, 156-756, South Korea.
| | - Bong-Kiun Kaang
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 08826, South Korea.
| |
Collapse
|
41
|
Segal M, Korkotian E. Roles of Calcium Stores and Store-Operated Channels in Plasticity of Dendritic Spines. Neuroscientist 2015; 22:477-85. [PMID: 26511041 DOI: 10.1177/1073858415613277] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Calcium stores in the endoplasmic reticulum play important roles in a variety of mammalian cellular functions. However, the multitude of calcium-handling machineries in neurons, including voltage- and ligand-gated channels, calcium-binding proteins, pumps, and transporters, as well as the rapid mobility of calcium ions among different cellular compartments hampered the singling out of calcium stores as a pivotal player in synaptic plasticity. Despite these methodological obstacles, novel molecular and imaging tools afforded a rapid progress in deciphering the role of specific calcium stores in neuronal functions. In the present review, we will address several key issues related to the involvement of ryanodine receptors and the calcium entry channel Orai1 in dendritic spine development and plasticity as well as their derailing in neurodegenerative diseases.
Collapse
Affiliation(s)
- Menahem Segal
- Department of Neurobiology, The Weizmann Institute, Rehovot, Israel
| | - Eduard Korkotian
- Department of Neurobiology, The Weizmann Institute, Rehovot, Israel
| |
Collapse
|
42
|
Futagi D, Kitano K. Ryanodine-receptor-driven intracellular calcium dynamics underlying spatial association of synaptic plasticity. J Comput Neurosci 2015; 39:329-47. [PMID: 26497496 PMCID: PMC4648987 DOI: 10.1007/s10827-015-0579-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 09/24/2015] [Accepted: 09/28/2015] [Indexed: 11/28/2022]
Abstract
Synaptic modifications induced at one synapse are accompanied by hetero-synaptic changes at neighboring sites. In addition, it is suggested that the mechanism of spatial association of synaptic plasticity is based on intracellular calcium signaling that is mainly regulated by two types of receptors of endoplasmic reticulum calcium store: the ryanodine receptor (RyR) and the inositol triphosphate receptor (IP3R). However, it is not clear how these types of receptors regulate intracellular calcium flux and contribute to the outcome of calcium-dependent synaptic change. To understand the relation between the synaptic association and store-regulated calcium dynamics, we focused on the function of RyR calcium regulation and simulated its behavior by using a computational neuron model. As a result, we observed that RyR-regulated calcium release depended on spike timings of pre- and postsynaptic neurons. From the induction site of calcium release, the chain activation of RyRs occurred, and spike-like calcium increase propagated along the dendrite. For calcium signaling, the propagated calcium increase did not tend to attenuate; these characteristics came from an all-or-none behavior of RyR-sensitive calcium store. Considering the role of calcium dependent synaptic plasticity, the results suggest that RyR-regulated calcium propagation induces a similar change at the synapses. However, according to the dependence of RyR calcium regulation on the model parameters, whether the chain activation of RyRs occurred, sensitively depended on spatial expression of RyR and nominal fluctuation of calcium flux. Therefore, calcium regulation of RyR helps initiate rather than relay calcium propagation.
Collapse
Affiliation(s)
- Daiki Futagi
- Graduate School of Information Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan.
| | - Katsunori Kitano
- Department of Human and Computer Intelligence, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
| |
Collapse
|
43
|
Henderson MJ, Baldwin HA, Werley CA, Boccardo S, Whitaker LR, Yan X, Holt GT, Schreiter ER, Looger LL, Cohen AE, Kim DS, Harvey BK. A Low Affinity GCaMP3 Variant (GCaMPer) for Imaging the Endoplasmic Reticulum Calcium Store. PLoS One 2015; 10:e0139273. [PMID: 26451944 PMCID: PMC4599735 DOI: 10.1371/journal.pone.0139273] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 09/09/2015] [Indexed: 12/22/2022] Open
Abstract
Endoplasmic reticulum calcium homeostasis is critical for cellular functions and is disrupted in diverse pathologies including neurodegeneration and cardiovascular disease. Owing to the high concentration of calcium within the ER, studying this subcellular compartment requires tools that are optimized for these conditions. To develop a single-fluorophore genetically encoded calcium indicator for this organelle, we targeted a low affinity variant of GCaMP3 to the ER lumen (GCaMPer (10.19)). A set of viral vectors was constructed to express GCaMPer in human neuroblastoma cells, rat primary cortical neurons, and human induced pluripotent stem cell-derived cardiomyocytes. We observed dynamic changes in GCaMPer (10.19) fluorescence in response to pharmacologic manipulations of the ER calcium store. Additionally, periodic calcium efflux from the ER was observed during spontaneous beating of cardiomyocytes. GCaMPer (10.19) has utility in imaging ER calcium in living cells and providing insight into luminal calcium dynamics under physiologic and pathologic states.
Collapse
Affiliation(s)
- Mark J. Henderson
- National Institute on Drug Abuse, National Institutes of Health, 251 Bayview Blvd, Baltimore, Maryland, 21224, United States of America
- * E-mail: (MJH); (BKH)
| | - Heather A. Baldwin
- National Institute on Drug Abuse, National Institutes of Health, 251 Bayview Blvd, Baltimore, Maryland, 21224, United States of America
| | - Christopher A. Werley
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States of America
| | - Stefano Boccardo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States of America
| | - Leslie R. Whitaker
- National Institute on Drug Abuse, National Institutes of Health, 251 Bayview Blvd, Baltimore, Maryland, 21224, United States of America
| | - Xiaokang Yan
- National Institute on Drug Abuse, National Institutes of Health, 251 Bayview Blvd, Baltimore, Maryland, 21224, United States of America
| | - Graham T. Holt
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia, 20147, United States of America
| | - Eric R. Schreiter
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia, 20147, United States of America
| | - Loren L. Looger
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia, 20147, United States of America
| | - Adam E. Cohen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States of America
- Department of Physics, Harvard University, Cambridge, Massachusetts, 02138, United States of America
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, 02138, United States of America
- Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts, 02138, United States of America
| | - Douglas S. Kim
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia, 20147, United States of America
| | - Brandon K. Harvey
- National Institute on Drug Abuse, National Institutes of Health, 251 Bayview Blvd, Baltimore, Maryland, 21224, United States of America
- * E-mail: (MJH); (BKH)
| |
Collapse
|
44
|
Schmunk G, Boubion BJ, Smith IF, Parker I, Gargus JJ. Shared functional defect in IP₃R-mediated calcium signaling in diverse monogenic autism syndromes. Transl Psychiatry 2015; 5:e643. [PMID: 26393489 PMCID: PMC5068815 DOI: 10.1038/tp.2015.123] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 07/13/2015] [Accepted: 07/27/2015] [Indexed: 01/03/2023] Open
Abstract
Autism spectrum disorder (ASD) affects 2% of children, and is characterized by impaired social and communication skills together with repetitive, stereotypic behavior. The pathophysiology of ASD is complex due to genetic and environmental heterogeneity, complicating the development of therapies and making diagnosis challenging. Growing genetic evidence supports a role of disrupted Ca(2+) signaling in ASD. Here, we report that patient-derived fibroblasts from three monogenic models of ASD-fragile X and tuberous sclerosis TSC1 and TSC2 syndromes-display depressed Ca(2+) release through inositol trisphosphate receptors (IP3Rs). This was apparent in Ca(2+) signals evoked by G protein-coupled receptors and by photoreleased IP3 at the levels of both global and local elementary Ca(2+) events, suggesting fundamental defects in IP3R channel activity in ASD. Given the ubiquitous involvement of IP3R-mediated Ca(2+) signaling in neuronal excitability, synaptic plasticity, gene expression and neurodevelopment, we propose dysregulated IP3R signaling as a nexus where genes altered in ASD converge to exert their deleterious effect. These findings highlight potential pharmaceutical targets, and identify Ca(2+) screening in skin fibroblasts as a promising technique for early detection of individuals susceptible to ASD.
Collapse
Affiliation(s)
- G Schmunk
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA,Center for Autism Research and Translation, University of California, Irvine, CA, USA
| | - B J Boubion
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California, Irvine, CA, USA
| | - I F Smith
- Center for Autism Research and Translation, University of California, Irvine, CA, USA,Department of Neurobiology and Behavior, School of Biological Sciences, University of California, Irvine, CA, USA
| | - I Parker
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA,Center for Autism Research and Translation, University of California, Irvine, CA, USA,Department of Neurobiology and Behavior, School of Biological Sciences, University of California, Irvine, CA, USA
| | - J J Gargus
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA,Center for Autism Research and Translation, University of California, Irvine, CA, USA,Division of Human Genetics & Genomics, Department of Pediatrics, School of Medicine, University of California, Irvine, CA, USA,Department of Physiology and Biophysics, School of Medicine, University of California, 2056 Hewitt Hall, 843 Health Sciences Road, Irvine, CA 92697-3940, USA. E-mail:
| |
Collapse
|
45
|
Activation of Phosphatidylinositol-Linked Dopamine Receptors Induces a Facilitation of Glutamate-Mediated Synaptic Transmission in the Lateral Entorhinal Cortex. PLoS One 2015; 10:e0131948. [PMID: 26133167 PMCID: PMC4489908 DOI: 10.1371/journal.pone.0131948] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/08/2015] [Indexed: 11/19/2022] Open
Abstract
The lateral entorhinal cortex receives strong inputs from midbrain dopamine neurons that can modulate its sensory and mnemonic function. We have previously demonstrated that 1 µM dopamine facilitates synaptic transmission in layer II entorhinal cortex cells via activation of D1-like receptors, increased cAMP-PKA activity, and a resulting enhancement of AMPA-receptor mediated currents. The present study assessed the contribution of phosphatidylinositol (PI)-linked D1 receptors to the dopaminergic facilitation of transmission in layer II of the rat entorhinal cortex, and the involvement of phospholipase C activity and release of calcium from internal stores. Whole-cell patch-clamp recordings of glutamate-mediated evoked excitatory postsynaptic currents were obtained from pyramidal and fan cells. Activation of D1-like receptors using SKF38393, SKF83959, or 1 µM dopamine induced a reversible facilitation of EPSCs which was abolished by loading cells with either the phospholipase C inhibitor U-73122 or the Ca2+ chelator BAPTA. Neither the L-type voltage-gated Ca2+ channel blocker nifedipine, nor the L/N-type channel blocker cilnidipine, blocked the facilitation of synaptic currents. However, the facilitation was blocked by blocking Ca2+ release from internal stores via inositol 1,4,5-trisphosphate (InsP3) receptors or ryanodine receptors. Follow-up studies demonstrated that inhibiting CaMKII activity with KN-93 failed to block the facilitation, but that application of the protein kinase C inhibitor PKC(19-36) completely blocked the dopamine-induced facilitation. Overall, in addition to our previous report indicating a role for the cAMP-PKA pathway in dopamine-induced facilitation of synaptic transmission, we demonstrate here that the dopaminergic facilitation of synaptic responses in layer II entorhinal neurons also relies on a signaling cascade dependent on PI-linked D1 receptors, PLC, release of Ca2+ from internal stores, and PKC activation which is likely dependent upon both DAG and enhanced intracellular Ca2+. These signaling pathways may collaborate to enhance sensory and mnemonic function in the entorhinal cortex during tonic release of dopamine.
Collapse
|
46
|
Ashhad S, Johnston D, Narayanan R. Activation of InsP₃ receptors is sufficient for inducing graded intrinsic plasticity in rat hippocampal pyramidal neurons. J Neurophysiol 2014; 113:2002-13. [PMID: 25552640 DOI: 10.1152/jn.00833.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 12/29/2014] [Indexed: 11/22/2022] Open
Abstract
The synaptic plasticity literature has focused on establishing necessity and sufficiency as two essential and distinct features in causally relating a signaling molecule to plasticity induction, an approach that has been surprisingly lacking in the intrinsic plasticity literature. In this study, we complemented the recently established necessity of inositol trisphosphate (InsP3) receptors (InsP3R) in a form of intrinsic plasticity by asking if InsP3R activation was sufficient to induce intrinsic plasticity in hippocampal neurons. Specifically, incorporation of d-myo-InsP3 in the recording pipette reduced input resistance, maximal impedance amplitude, and temporal summation but increased resonance frequency, resonance strength, sag ratio, and impedance phase lead. Strikingly, the magnitude of plasticity in all these measurements was dependent on InsP3 concentration, emphasizing the graded dependence of such plasticity on InsP3R activation. Mechanistically, we found that this InsP3-induced plasticity depended on hyperpolarization-activated cyclic nucleotide-gated channels. Moreover, this calcium-dependent form of plasticity was critically reliant on the release of calcium through InsP3Rs, the influx of calcium through N-methyl-d-aspartate receptors and voltage-gated calcium channels, and on the protein kinase A pathway. Our results delineate a causal role for InsP3Rs in graded adaptation of neuronal response dynamics, revealing novel regulatory roles for the endoplasmic reticulum in neural coding and homeostasis.
Collapse
Affiliation(s)
- Sufyan Ashhad
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India; and
| | - Daniel Johnston
- Center for Learning and Memory, The University of Texas at Austin, Austin, Texas
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India; and
| |
Collapse
|
47
|
Jong YJI, Sergin I, Purgert CA, O'Malley KL. Location-dependent signaling of the group 1 metabotropic glutamate receptor mGlu5. Mol Pharmacol 2014; 86:774-85. [PMID: 25326002 DOI: 10.1124/mol.114.094763] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although G protein-coupled receptors are primarily known for converting extracellular signals into intracellular responses, some receptors, such as the group 1 metabotropic glutamate receptor, mGlu5, are also localized on intracellular membranes where they can mediate both overlapping and unique signaling effects. Thus, besides "ligand bias," whereby a receptor's signaling modality can shift from G protein dependence to independence, canonical mGlu5 receptor signaling can also be influenced by "location bias" (i.e., the particular membrane and/or cell type from which it signals). Because mGlu5 receptors play important roles in both normal development and in disorders such as Fragile X syndrome, autism, epilepsy, addiction, anxiety, schizophrenia, pain, dyskinesias, and melanoma, a large number of drugs are being developed to allosterically target this receptor. Therefore, it is critical to understand how such drugs might be affecting mGlu5 receptor function on different membranes and in different brain regions. Further elucidation of the site(s) of action of these drugs may determine which signal pathways mediate therapeutic efficacy.
Collapse
Affiliation(s)
- Yuh-Jiin I Jong
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Ismail Sergin
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Carolyn A Purgert
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Karen L O'Malley
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| |
Collapse
|
48
|
Maggio N, Vlachos A. Synaptic plasticity at the interface of health and disease: New insights on the role of endoplasmic reticulum intracellular calcium stores. Neuroscience 2014; 281:135-46. [PMID: 25264032 DOI: 10.1016/j.neuroscience.2014.09.041] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/17/2014] [Accepted: 09/18/2014] [Indexed: 10/24/2022]
Abstract
Work from the past 40years has unraveled a wealth of information on the cellular and molecular mechanisms underlying synaptic plasticity and their relevance in physiological brain function. At the same time, it has been recognized that a broad range of neurological diseases may be accompanied by severe alterations in synaptic plasticity, i.e., 'maladaptive synaptic plasticity', which could initiate and sustain the remodeling of neuronal networks under pathological conditions. Nonetheless, our current knowledge on the specific contribution and interaction of distinct forms of synaptic plasticity (including metaplasticity and homeostatic plasticity) in the context of pathological brain states remains limited. This review focuses on recent experimental evidence, which highlights the fundamental role of endoplasmic reticulum-mediated Ca(2+) signals in modulating the duration, direction, extent and type of synaptic plasticity. We discuss the possibility that intracellular Ca(2+) stores may regulate synaptic plasticity and hence behavioral and cognitive functions at the interface between physiology and pathology.
Collapse
Affiliation(s)
- N Maggio
- Talpiot Medical Leadership Program, Department of Neurology, The Chaim Sheba Medical Center, 52621 Tel HaShomer, Israel
| | - A Vlachos
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, 60590 Frankfurt, Germany.
| |
Collapse
|
49
|
Abstract
Among the largest cells in the body, neurons possess an immense surface area and intricate geometry that poses many unique cell biological challenges. This morphological complexity is critical for neural circuit formation and enables neurons to compartmentalize cell-cell communication and local intracellular signalling to a degree that surpasses other cell types. The adaptive plastic properties of neurons, synapses and circuits have been classically studied by measurement of electrophysiological properties, ionic conductances and excitability. Over the last 15 years, the field of synaptic and neural electrophysiology has collided with neuronal cell biology to produce a more integrated understanding of how these remarkable highly differentiated cells utilize common eukaryotic cellular machinery to decode, integrate and propagate signals in the nervous system. The present article gives a very brief and personal overview of the organelles and trafficking machinery of neuronal dendrites and their role in dendritic and synaptic plasticity.
Collapse
|
50
|
Segal M, Korkotian E. Endoplasmic reticulum calcium stores in dendritic spines. Front Neuroanat 2014; 8:64. [PMID: 25071469 PMCID: PMC4089118 DOI: 10.3389/fnana.2014.00064] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 06/23/2014] [Indexed: 12/14/2022] Open
Abstract
Despite decades of research, the role of calcium stores in dendritic spines structure, function and plasticity is still debated. The reasons for this may have to do with the multitude of overlapping calcium handling machineries in the neuron, including stores, voltage and ligand gated channels, pumps and transporters. Also, different cells in the brain are endowed with calcium stores that are activated by different receptor types, and their differential compartmentalization in dendrites, spines and presynaptic terminals complicates their analysis. In the present review we address several key issues, including the role of calcium stores in synaptic plasticity, their role during development, in stress and in neurodegenerative diseases. Apparently, there is increasing evidence for a crucial role of calcium stores, especially of the ryanodine species, in synaptic plasticity and neuronal survival.
Collapse
Affiliation(s)
- Menahem Segal
- Department of Neurobiology, The Weizman Institute Rehovot, Israel
| | - Eduard Korkotian
- Department of Neurobiology, The Weizman Institute Rehovot, Israel
| |
Collapse
|