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Perry S, Han Y, Qiu C, Chien C, Goel P, Nishimura S, Sajnani M, Schmid A, Sigrist SJ, Dickman D. A glutamate receptor C-tail recruits CaMKII to suppress retrograde homeostatic signaling. Nat Commun 2022; 13:7656. [PMID: 36496500 PMCID: PMC9741633 DOI: 10.1038/s41467-022-35417-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
Presynaptic homeostatic plasticity (PHP) adaptively enhances neurotransmitter release following diminished postsynaptic glutamate receptor (GluR) functionality to maintain synaptic strength. While much is known about PHP expression mechanisms, postsynaptic induction remains enigmatic. For over 20 years, diminished postsynaptic Ca2+ influx was hypothesized to reduce CaMKII activity and enable retrograde PHP signaling at the Drosophila neuromuscular junction. Here, we have interrogated inductive signaling and find that active CaMKII colocalizes with and requires the GluRIIA receptor subunit. Next, we generated Ca2+-impermeable GluRs to reveal that both CaMKII activity and PHP induction are Ca2+-insensitive. Rather, a GluRIIA C-tail domain is necessary and sufficient to recruit active CaMKII. Finally, chimeric receptors demonstrate that the GluRIIA tail constitutively occludes retrograde homeostatic signaling by stabilizing active CaMKII. Thus, the physical loss of the GluRIIA tail is sensed, rather than reduced Ca2+, to enable retrograde PHP signaling, highlighting a unique, Ca2+-independent control mechanism for CaMKII in gating homeostatic plasticity.
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Affiliation(s)
- Sarah Perry
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Yifu Han
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Chengjie Qiu
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Chun Chien
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Samantha Nishimura
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Manisha Sajnani
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA
| | - Andreas Schmid
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195, Berlin, Germany
- Faculty of Life Sciences, Albstadt-Sigmaringen University, Sigmaringen, Germany
| | - Stephan J Sigrist
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117, Berlin, Germany
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA, USA.
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2
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Presynaptic Homeostasis Opposes Disease Progression in Mouse Models of ALS-Like Degeneration: Evidence for Homeostatic Neuroprotection. Neuron 2020; 107:95-111.e6. [PMID: 32380032 DOI: 10.1016/j.neuron.2020.04.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/06/2020] [Accepted: 04/06/2020] [Indexed: 12/11/2022]
Abstract
Progressive synapse loss is an inevitable and insidious part of age-related neurodegenerative disease. Typically, synapse loss precedes symptoms of cognitive and motor decline. This suggests the existence of compensatory mechanisms that can temporarily counteract the effects of ongoing neurodegeneration. Here, we demonstrate that presynaptic homeostatic plasticity (PHP) is induced at degenerating neuromuscular junctions, mediated by an evolutionarily conserved activity of presynaptic ENaC channels in both Drosophila and mouse. To assess the consequence of eliminating PHP in a mouse model of ALS-like degeneration, we generated a motoneuron-specific deletion of Scnn1a, encoding the ENaC channel alpha subunit. We show that Scnn1a is essential for PHP without adversely affecting baseline neural function or lifespan. However, Scnn1a knockout in a degeneration-causing mutant background accelerated motoneuron loss and disease progression to twice the rate observed in littermate controls with intact PHP. We propose a model of neuroprotective homeostatic plasticity, extending organismal lifespan and health span.
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Held A, Major P, Sahin A, Reenan RA, Lipscombe D, Wharton KA. Circuit Dysfunction in SOD1-ALS Model First Detected in Sensory Feedback Prior to Motor Neuron Degeneration Is Alleviated by BMP Signaling. J Neurosci 2019; 39:2347-2364. [PMID: 30659087 PMCID: PMC6433758 DOI: 10.1523/jneurosci.1771-18.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 12/24/2018] [Accepted: 01/10/2019] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease for which the origin and underlying cellular defects are not fully understood. Although motor neuron degeneration is the signature feature of ALS, it is not clear whether motor neurons or other cells of the motor circuit are the site of disease initiation. To better understand the contribution of multiple cell types in ALS, we made use of a Drosophila Sod1G85R knock-in model, in which all cells harbor the disease allele. End-stage dSod1G85R animals of both sexes exhibit severe motor deficits with clear degeneration of motor neurons. Interestingly, earlier in dSod1G85R larvae, motor function is also compromised, but their motor neurons exhibit only subtle morphological and electrophysiological changes that are unlikely to cause the observed decrease in locomotion. We analyzed the intact motor circuit and identified a defect in sensory feedback that likely accounts for the altered motor activity of dSod1G85R We found cell-autonomous activation of bone morphogenetic protein signaling in proprioceptor sensory neurons which are critical for the relay of the contractile status of muscles back to the central nerve cord, completely rescues early-stage motor defects and partially rescue late-stage motor function to extend lifespan. Identification of a defect in sensory feedback as a potential initiating event in ALS motor dysfunction, coupled with the ability of modified proprioceptors to alleviate such motor deficits, underscores the critical role that nonmotor neurons play in disease progression and highlights their potential as a site to identify early-stage ALS biomarkers and for therapeutic intervention.SIGNIFICANCE STATEMENT At diagnosis, many cellular processes are already disrupted in the amyotrophic lateral sclerosis (ALS) patient. Identifying the initiating cellular events is critical for achieving an earlier diagnosis to slow or prevent disease progression. Our findings indicate that neurons relaying sensory information underlie early stage motor deficits in a Drosophila knock-in model of ALS that best replicates gene dosage in familial ALS (fALS). Importantly, studies on intact motor circuits revealed defects in sensory feedback before evidence of motor neuron degeneration. These findings strengthen our understanding of how neural circuit dysfunctions lead to neurodegeneration and, coupled with our demonstration that the activation of bone morphogenetic protein signaling in proprioceptors alleviates both early and late motor dysfunction, underscores the importance of considering nonmotor neurons as therapeutic targets.
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Affiliation(s)
- Aaron Held
- Department of Molecular Biology, Cell Biology and Biochemistry
- The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912
| | - Paxton Major
- Department of Molecular Biology, Cell Biology and Biochemistry
| | - Asli Sahin
- Department of Molecular Biology, Cell Biology and Biochemistry
| | - Robert A Reenan
- Department of Molecular Biology, Cell Biology and Biochemistry
| | - Diane Lipscombe
- Department of Neuroscience, and
- The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912
| | - Kristi A Wharton
- Department of Molecular Biology, Cell Biology and Biochemistry,
- The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912
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4
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Oswald MC, Brooks PS, Zwart MF, Mukherjee A, West RJ, Giachello CN, Morarach K, Baines RA, Sweeney ST, Landgraf M. Reactive oxygen species regulate activity-dependent neuronal plasticity in Drosophila. eLife 2018; 7:39393. [PMID: 30540251 PMCID: PMC6307858 DOI: 10.7554/elife.39393] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 12/12/2018] [Indexed: 12/11/2022] Open
Abstract
Reactive oxygen species (ROS) have been extensively studied as damaging agents associated with ageing and neurodegenerative conditions. Their role in the nervous system under non-pathological conditions has remained poorly understood. Working with the Drosophila larval locomotor network, we show that in neurons ROS act as obligate signals required for neuronal activity-dependent structural plasticity, of both pre- and postsynaptic terminals. ROS signaling is also necessary for maintaining evoked synaptic transmission at the neuromuscular junction, and for activity-regulated homeostatic adjustment of motor network output, as measured by larval crawling behavior. We identified the highly conserved Parkinson’s disease-linked protein DJ-1β as a redox sensor in neurons where it regulates structural plasticity, in part via modulation of the PTEN-PI3Kinase pathway. This study provides a new conceptual framework of neuronal ROS as second messengers required for neuronal plasticity and for network tuning, whose dysregulation in the ageing brain and under neurodegenerative conditions may contribute to synaptic dysfunction.
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Affiliation(s)
- Matthew Cw Oswald
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Paul S Brooks
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | | | - Amrita Mukherjee
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Ryan Jh West
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Department of Biology, University of York, York, United Kingdom
| | - Carlo Ng Giachello
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Khomgrit Morarach
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Richard A Baines
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Sean T Sweeney
- Department of Biology, University of York, York, United Kingdom
| | - Matthias Landgraf
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
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Jones RA, Reich CD, Dissanayake KN, Kristmundsdottir F, Findlater GS, Ribchester RR, Simmen MW, Gillingwater TH. NMJ-morph reveals principal components of synaptic morphology influencing structure-function relationships at the neuromuscular junction. Open Biol 2016; 6:160240. [PMID: 27927794 PMCID: PMC5204123 DOI: 10.1098/rsob.160240] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/09/2016] [Indexed: 01/10/2023] Open
Abstract
The ability to form synapses is one of the fundamental properties required by the mammalian nervous system to generate network connectivity. Structural and functional diversity among synaptic populations is a key hallmark of network diversity, and yet we know comparatively little about the morphological principles that govern variability in the size, shape and strength of synapses. Using the mouse neuromuscular junction (NMJ) as an experimentally accessible model synapse, we report on the development of a robust, standardized methodology to facilitate comparative morphometric analysis of synapses ('NMJ-morph'). We used NMJ-morph to generate baseline morphological reference data for 21 separate pre- and post-synaptic variables from 2160 individual NMJs belonging to nine anatomically distinct populations of synapses, revealing systematic differences in NMJ morphology between defined synaptic populations. Principal components analysis revealed that overall NMJ size and the degree of synaptic fragmentation, alongside pre-synaptic axon diameter, were the most critical parameters in defining synaptic morphology. 'Average' synaptic morphology was remarkably conserved between comparable synapses from the left and right sides of the body. Systematic differences in synaptic morphology predicted corresponding differences in synaptic function that were supported by physiological recordings, confirming the robust relationship between synaptic size and strength.
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Affiliation(s)
- Ross A Jones
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
- Centre for Integrative Physiology, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
- Anatomy, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
| | - Caitlan D Reich
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
- Centre for Integrative Physiology, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
- Anatomy, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
| | - Kosala N Dissanayake
- Centre for Integrative Physiology, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
| | - Fanney Kristmundsdottir
- Anatomy, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
| | - Gordon S Findlater
- Anatomy, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
| | - Richard R Ribchester
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
- Centre for Integrative Physiology, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
| | - Martin W Simmen
- Centre for Integrative Physiology, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
| | - Thomas H Gillingwater
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
- Centre for Integrative Physiology, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
- Anatomy, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9XD, UK
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Rawson JM, Kreko T, Davison H, Mahoney R, Bokov A, Chang L, Gelfond J, Macleod GT, Eaton BA. Effects of diet on synaptic vesicle release in dynactin complex mutants: a mechanism for improved vitality during motor disease. Aging Cell 2012; 11:418-27. [PMID: 22268717 PMCID: PMC3350605 DOI: 10.1111/j.1474-9726.2012.00799.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Synaptic dysfunction is considered the primary substrate for the functional declines observed within the nervous system during age-related neurodegenerative disease. Dietary restriction (DR), which extends lifespan in numerous species, has been shown to have beneficial effects on many neurodegenerative disease models. Existing data sets suggest that the effects of DR during disease include the amelioration of synaptic dysfunction but evidence of the beneficial effects of diet on the synapse is lacking. Dynactin mutant flies have significant increases in mortality rates and exhibit progressive loss of motor function. Using a novel fly motor disease model, we demonstrate that mutant flies raised on a low calorie diet have enhanced motor function and improved survival compared to flies on a high calorie diet. Neurodegeneration in this model is characterized by an early impairment of neurotransmission that precedes the deterioration of neuromuscular junction (NMJ) morphology. In mutant flies, low calorie diet increases neurotransmission, but has little effect on morphology, supporting the hypothesis that enhanced neurotransmission contributes to the effects of diet on motor function. Importantly, the effects of diet on the synapse are not because of the reduction of mutant pathologies, but by the increased release of synaptic vesicles during activity. The generality of this effect is demonstrated by the observation that diet can also increase synaptic vesicle release at wild-type NMJs. These studies reveal a novel presynaptic mechanism of diet that may contribute to the improved vigor observed in mutant flies raised on low calorie diet.
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Affiliation(s)
- Joel M Rawson
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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7
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Paterson BA, Anikin IM, Krans JL. Hysteresis in the production of force by larval Dipteran muscle. J Exp Biol 2010; 213:2483-93. [DOI: 10.1242/jeb.043026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
We describe neuromuscular hysteresis – the dependence of muscle force on recent motoneuron activity – in the body wall muscles of larval Sarcophaga bullata and Drosophila melanogaster. In semi-intact preparations, isometric force produced by a train of nerve impulses at a constant rate was significantly less than that produced by the same train of stimuli with a brief (200 ms) high-frequency burst of impulses interspersed. Elevated force did not decay back to predicted values after the burst but instead remained high throughout the duration of the stimulus train. The increased force was not due to a change in excitatory junction potentials (EJPs); EJP voltage and time course before and after the high-frequency burst were not statistically different. Single muscle and semi-intact preparations exhibited hysteresis similarly, suggesting that connective tissues of the origin or insertion are not crucial to the mechanism of hysteresis. Hysteresis was greatest at low motoneuron rates – yielding a ~100% increase over predicted values based on constant-rate stimulation alone – and decreased as impulse rate increased. We modulated motoneuron frequency rhythmically across rates and cycle periods similar to those observed during kinematic analysis of larval crawling. Positive force hysteresis was also evident within these more physiological activation parameters.
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Affiliation(s)
- Bethany A. Paterson
- Department of Biological Science, Mount Holyoke College, South Hadley, MA 01075, USA
| | - Ilya Marko Anikin
- Department of Biology, Central Connecticut State University, New Britain, CT 06050, USA
| | - Jacob L. Krans
- Department of Biology, Central Connecticut State University, New Britain, CT 06050, USA
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8
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Krans JL, Parfitt KD, Gawera KD, Rivlin PK, Hoy RR. The resting membrane potential of Drosophila melanogaster larval muscle depends strongly on external calcium concentration. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:304-313. [PMID: 19913024 DOI: 10.1016/j.jinsphys.2009.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 11/02/2009] [Accepted: 11/03/2009] [Indexed: 05/28/2023]
Abstract
The resting membrane potential (RMP) of most cells is not greatly influenced by the transmembrane calcium gradient because at rest, the membrane has very low permeability to calcium. We have observed, however, that the resting membrane potential of muscle cells in the larval bodywall of Drosophila melanogaster varies widely as the external calcium concentration is modified. The RMP depolarized as much as 21.8 mV/mM calcium at low concentrations, and on average, about 10 mV/mM across a range typical of neurophysiological investigations. The extent to which muscle RMP varies has important implications for the measurement of synaptic potentials as well. Two parameters of excitatory junctional potential (EJP) voltage were compared across a range of RMPs. EJP amplitude (DeltaV) and peak voltage (maxima) change as a function of RMP; on average, a 10 mV change in RMP elicits a 4-5 mV change in EJP amplitude and peak voltage. The influence of the calcium gradient on resting and synaptic membrane potentials led us to investigate the endogenous ion concentrations of larval hemolymph. In addition to the major monovalent ions and calcium, we report the first voltammetric analysis of magnesium concentration in larval fruit fly hemolymph.
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Affiliation(s)
- Jacob L Krans
- Biological Sciences, Mount Holyoke College, South Hadley, MA 01075, United States.
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Frank CA, Kennedy MJ, Goold CP, Marek KW, Davis GW. Mechanisms underlying the rapid induction and sustained expression of synaptic homeostasis. Neuron 2007; 52:663-77. [PMID: 17114050 PMCID: PMC2673733 DOI: 10.1016/j.neuron.2006.09.029] [Citation(s) in RCA: 285] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 07/27/2006] [Accepted: 09/14/2006] [Indexed: 11/22/2022]
Abstract
Homeostatic signaling systems are thought to interface with the mechanisms of neural plasticity to achieve stable yet flexible neural circuitry. However, the time course, molecular design, and implementation of homeostatic signaling remain poorly defined. Here we demonstrate that a homeostatic increase in presynaptic neurotransmitter release can be induced within minutes following postsynaptic glutamate receptor blockade. The rapid induction of synaptic homeostasis is independent of new protein synthesis and does not require evoked neurotransmission, indicating that a change in the efficacy of spontaneous quantal release events is sufficient to trigger the induction of synaptic homeostasis. Finally, both the rapid induction and the sustained expression of synaptic homeostasis are blocked by mutations that disrupt the pore-forming subunit of the presynaptic Ca(V)2.1 calcium channel encoded by cacophony. These data confirm the presynaptic expression of synaptic homeostasis and implicate presynaptic Ca(V)2.1 in a homeostatic retrograde signaling system.
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Affiliation(s)
- C Andrew Frank
- Department of Biochemistry and Biophysics, Neuroscience Program, University of California, San Francisco, 1550 4th Street, Rock Hall 4th Floor North, San Francisco, California 94158, USA
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DiAntonio A. Glutamate Receptors At The Drosophila Neuromuscular Junction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2006; 75:165-79. [PMID: 17137928 DOI: 10.1016/s0074-7742(06)75008-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Aaron DiAntonio
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, Saint Louis, Missouri 63110, USA
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