51
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Van Vactor D, Sigrist SJ. Presynaptic morphogenesis, active zone organization and structural plasticity in Drosophila. Curr Opin Neurobiol 2017; 43:119-129. [PMID: 28388491 DOI: 10.1016/j.conb.2017.03.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 03/06/2017] [Accepted: 03/08/2017] [Indexed: 12/31/2022]
Abstract
Effective adaptation of neural circuit function to a changing environment requires many forms of plasticity. Among these, structural plasticity is one of the most durable, and is also an intrinsic part of the developmental logic for the formation and refinement of synaptic connectivity. Structural plasticity of presynaptic sites can involve the addition, remodeling, or removal of pre- and post-synaptic elements. However, this requires coordination of morphogenesis and assembly of the subcellular machinery for neurotransmitter release within the presynaptic neuron, as well as coordination of these events with the postsynaptic cell. While much progress has been made in revealing the cell biological mechanisms of postsynaptic structural plasticity, our understanding of presynaptic mechanisms is less complete.
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Affiliation(s)
- David Van Vactor
- Department of Cell Biology and Program in Neuroscience, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA; Okinawa Institute of Science and Technology, Graduate University, Tancha 1919-1, Onna-son, Okinawa, Japan.
| | - Stephan J Sigrist
- Institut für Biologie/Genetik and NeuroCure, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany.
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52
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Newman ZL, Hoagland A, Aghi K, Worden K, Levy SL, Son JH, Lee LP, Isacoff EY. Input-Specific Plasticity and Homeostasis at the Drosophila Larval Neuromuscular Junction. Neuron 2017; 93:1388-1404.e10. [PMID: 28285823 DOI: 10.1016/j.neuron.2017.02.028] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/18/2016] [Accepted: 02/15/2017] [Indexed: 11/28/2022]
Abstract
Synaptic connections undergo activity-dependent plasticity during development and learning, as well as homeostatic re-adjustment to ensure stability. Little is known about the relationship between these processes, particularly in vivo. We addressed this with novel quantal resolution imaging of transmission during locomotive behavior at glutamatergic synapses of the Drosophila larval neuromuscular junction. We find that two motor input types, Ib and Is, provide distinct forms of excitatory drive during crawling and differ in key transmission properties. Although both inputs vary in transmission probability, active Is synapses are more reliable. High-frequency firing "wakes up" silent Ib synapses and depresses Is synapses. Strikingly, homeostatic compensation in presynaptic strength only occurs at Ib synapses. This specialization is associated with distinct regulation of postsynaptic CaMKII. Thus, basal synaptic strength, short-term plasticity, and homeostasis are determined input-specifically, generating a functional diversity that sculpts excitatory transmission and behavioral function.
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Affiliation(s)
- Zachary L Newman
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Adam Hoagland
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Krishan Aghi
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Kurtresha Worden
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Sabrina L Levy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jun Ho Son
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA; Berkeley Sensor and Actuator Center, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Luke P Lee
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA; Berkeley Sensor and Actuator Center, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA 94720, USA; Biomedical Institute for Global Health Research and Technology, National University of Singapore, 119077 Singapore, Singapore
| | - Ehud Y Isacoff
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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53
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Steuer Costa W, Yu SC, Liewald JF, Gottschalk A. Fast cAMP Modulation of Neurotransmission via Neuropeptide Signals and Vesicle Loading. Curr Biol 2017; 27:495-507. [PMID: 28162892 DOI: 10.1016/j.cub.2016.12.055] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 12/06/2016] [Accepted: 12/27/2016] [Indexed: 02/02/2023]
Abstract
Cyclic AMP (cAMP) signaling augments synaptic transmission, but because many targets of cAMP and protein kinase A (PKA) may be involved, mechanisms underlying this pathway remain unclear. To probe this mechanism, we used optogenetic stimulation of cAMP signaling by Beggiatoa-photoactivated adenylyl cyclase (bPAC) in Caenorhabditis elegans motor neurons. Behavioral, electron microscopy (EM), and electrophysiology analyses revealed cAMP effects on both the rate and on quantal size of transmitter release and led to the identification of a neuropeptidergic pathway affecting quantal size. cAMP enhanced synaptic vesicle (SV) fusion by increasing mobilization and docking/priming. cAMP further evoked dense core vesicle (DCV) release of neuropeptides, in contrast to channelrhodopsin (ChR2) stimulation. cAMP-evoked DCV release required UNC-31/Ca2+-dependent activator protein for secretion (CAPS). Thus, DCVs accumulated in unc-31 mutant synapses. bPAC-induced neuropeptide signaling acts presynaptically to enhance vAChT-dependent SV loading with acetylcholine, thus causing increased miniature postsynaptic current amplitudes (mPSCs) and significantly enlarged SVs.
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Affiliation(s)
- Wagner Steuer Costa
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt, Germany; Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
| | - Szi-Chieh Yu
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt, Germany; Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
| | - Jana F Liewald
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt, Germany; Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt, Germany; Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany.
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54
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Cortactin Is a Regulator of Activity-Dependent Synaptic Plasticity Controlled by Wingless. J Neurosci 2017; 37:2203-2215. [PMID: 28123080 DOI: 10.1523/jneurosci.1375-16.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 12/05/2016] [Accepted: 01/17/2017] [Indexed: 01/07/2023] Open
Abstract
Major signaling molecules initially characterized as key early developmental regulators are also essential for the plasticity of the nervous system. Previously, the Wingless (Wg)/Wnt pathway was shown to underlie the structural and electrophysiological changes during activity-dependent synaptic plasticity at the Drosophila neuromuscular junction. A challenge remains to understand how this signal mediates the cellular changes underlying this plasticity. Here, we focus on the actin regulator Cortactin, a major organizer of protrusion, membrane mobility, and invasiveness, and define its new role in synaptic plasticity. We show that Cortactin is present presynaptically and postsynaptically at the Drosophila NMJ and that it is a presynaptic regulator of rapid activity-dependent modifications in synaptic structure. Furthermore, animals lacking presynaptic Cortactin show a decrease in spontaneous release frequency, and presynaptic Cortactin is necessary for the rapid potentiation of spontaneous release frequency that takes place during activity-dependent plasticity. Most interestingly, Cortactin levels increase at stimulated synaptic terminals and this increase requires neuronal activity, de novo transcription and depends on Wg/Wnt expression. Because it is not simply the presence of Cortactin in the presynaptic terminal but its increase that is necessary for the full range of activity-dependent plasticity, we conclude that it probably plays a direct and important role in the regulation of this process.SIGNIFICANCE STATEMENT In the nervous system, changes in activity that lead to modifications in synaptic structure and function are referred to as synaptic plasticity and are thought to be the basis of learning and memory. The secreted Wingless/Wnt molecule is a potent regulator of synaptic plasticity in both vertebrates and invertebrates. Understanding the molecular mechanisms that underlie these plastic changes is a major gap in our knowledge. Here, we identify a presynaptic effector molecule of the Wingless/Wnt signal, Cortactin. We show that this molecule is a potent regulator of modifications in synaptic structure and is necessary for the electrophysiological changes taking place during synaptic plasticity.
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55
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Chen J, Wang Z, Zhang S, Ai Q, Chu S, Chen NH. Possible target-related proteins of stress-resistant rats suggested by label-free proteomic analysis. RSC Adv 2017. [DOI: 10.1039/c7ra04212d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Stress plays a crucial role in the development of major depressive disorder, but the molecular mechanism underlying the susceptibility vs. resilience to stress remains unclear.
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Affiliation(s)
- Jiao Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica & Neuroscience Center
- Chinese Academy of Medical Sciences and Peking Union Medical College
- Beijing 100050
- China
| | - Zhenzhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica & Neuroscience Center
- Chinese Academy of Medical Sciences and Peking Union Medical College
- Beijing 100050
- China
| | - Shuai Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica & Neuroscience Center
- Chinese Academy of Medical Sciences and Peking Union Medical College
- Beijing 100050
- China
| | - Qidi Ai
- Hunan University of Chinese Medicine
- Changsha
- China
| | - Shifeng Chu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica & Neuroscience Center
- Chinese Academy of Medical Sciences and Peking Union Medical College
- Beijing 100050
- China
| | - Nai-hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines
- Institute of Materia Medica & Neuroscience Center
- Chinese Academy of Medical Sciences and Peking Union Medical College
- Beijing 100050
- China
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56
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Vasin A, Volfson D, Littleton JT, Bykhovskaia M. Interaction of the Complexin Accessory Helix with Synaptobrevin Regulates Spontaneous Fusion. Biophys J 2016; 111:1954-1964. [PMID: 27806277 PMCID: PMC5102999 DOI: 10.1016/j.bpj.2016.09.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 09/13/2016] [Accepted: 09/15/2016] [Indexed: 11/30/2022] Open
Abstract
Neuronal transmitters are released from nerve terminals via the fusion of synaptic vesicles with the plasma membrane. Vesicles attach to membranes via a specialized protein machinery composed of membrane-attached (t-SNARE) and vesicle-attached (v-SNARE) proteins that zipper together to form a coiled-coil SNARE bundle that brings the two fusing membranes into close proximity. Neurotransmitter release may occur either in response to an action potential or through spontaneous fusion. A cytosolic protein, Complexin (Cpx), binds the SNARE complex and restricts spontaneous exocytosis by acting as a fusion clamp. We previously proposed a model in which the interaction between Cpx and the v-SNARE serves as a spring to prevent premature zippering of the SNARE complex, thereby reducing the likelihood of fusion. To test this model, we combined molecular-dynamics (MD) simulations and site-directed mutagenesis of Cpx and SNAREs in Drosophila. MD simulations of the Drosophila Cpx-SNARE complex demonstrated that Cpx's interaction with the v-SNARE promotes unraveling of the v-SNARE off the core SNARE bundle. We investigated clamping properties in the syx3-69 paralytic mutant, which has a single-point mutation in the t-SNARE and displays enhanced spontaneous release. MD simulations demonstrated an altered interaction of Cpx with the SNARE bundle that hindered v-SNARE unraveling by Cpx, thus compromising clamping. We used our model to predict mutations that should enhance the ability of Cpx to prevent full assembly of the SNARE complex. MD simulations predicted that a weakened interaction between the Cpx accessory helix and the v-SNARE would enhance Cpx flexibility and thus promote separation of SNAREs, reducing spontaneous fusion. We generated transgenic Drosophila with mutations in Cpx and the v-SNARE that disrupted a salt bridge between these two proteins. As predicted, both lines demonstrated a selective inhibition in spontaneous release, suggesting that Cpx acts as a fusion clamp that restricts full SNARE zippering.
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Affiliation(s)
- Alexander Vasin
- Department of Neurology, Wayne State University, Detroit, Michigan
| | - Dina Volfson
- Massachusetts Institute of Technology, Cambridge, Massachusetts
| | | | - Maria Bykhovskaia
- Department of Neurology, Wayne State University, Detroit, Michigan; Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan.
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57
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Wierenga CJ. Live imaging of inhibitory axons: Synapse formation as a dynamic trial-and-error process. Brain Res Bull 2016; 129:43-49. [PMID: 27720814 DOI: 10.1016/j.brainresbull.2016.09.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 09/20/2016] [Accepted: 09/29/2016] [Indexed: 02/07/2023]
Abstract
In this review I discuss recent live imaging studies that demonstrate that synapses, and in particular inhibitory synapses, are highly dynamic structures. The ongoing changes of presynaptic boutons within axons emphasize the stochastic aspect of inhibitory synapse formation and paint a picture of a dynamic trial-and-error process. Furthermore, I discuss recent and previous insights in the molecular and mechanistic pathways that underlie synapse formation, with a specific focus on the formation of inhibitory presynaptic boutons.
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Affiliation(s)
- Corette J Wierenga
- Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
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58
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Li XW, Cao L, Wang F, Yang QG, Tong JJ, Li XY, Chen GH. Maternal inflammation linearly exacerbates offspring age-related changes of spatial learning and memory, and neurobiology until senectitude. Behav Brain Res 2016; 306:178-96. [PMID: 26992827 DOI: 10.1016/j.bbr.2016.03.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 03/01/2016] [Accepted: 03/05/2016] [Indexed: 01/06/2023]
Abstract
Maternal inflammation during pregnancy can elevate the risk of neurodegenerative disorders in offspring. However, how it affects age-related impairments of spatial learning and memory and changes in the neurobiological indictors in the offspring in later adulthood is still elusive. In this study, the CD-1 mice with maternal gestational inflammation due to receiving lipopolysaccharide (LPS, i.p. 50 or 25μg/kg) were divided into 3-, 12-, 18-, and 22-month-old groups. The spatial learning and memory were evaluated using a six-radial arm water maze and the levels of presynaptic proteins (synaptotagmin-1 and syntaxin-1) and histone acetylation (H3K9ac and H4K8ac) in the dorsal hippocampus were detected using the immunohistochemical method. The results indicated that there were significant age-related impairments of spatial learning and memory, decreased levels of H4K8ac, H3K9ac, and syntaxin-1, and increased levels of synaptotagmin-1 in the offspring mice from 12 months old to 22 months old compared to the same-age controls. Maternal LPS treatment significantly exacerbated the offspring impairments of spatial learning and memory, the reduction of H3K9ac, H4K8ac, and syntaxin-1, and the increment of synaptotagmin-1 from 12 months old to 22 months old compared to the same-age control groups. The changes in the neurobiological indicators significantly correlated with the impairments of spatial learning and memory. Furthermore, this correlation, besides the age and LPS-treatment effects, also showed a dose-dependent effect. Our results suggest that maternal inflammation during pregnancy could exacerbate age-related impairments of spatial learning and memory, and neurobiochemical indicators in the offspring CD-1 mice from midlife to senectitude.
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Affiliation(s)
- Xue-Wei Li
- Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui Province, PR China
| | - Lei Cao
- Department of Neurology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601, Anhui, PR China
| | - Fang Wang
- Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui Province, PR China
| | - Qi-Gang Yang
- Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui Province, PR China
| | - Jing-Jing Tong
- Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui Province, PR China
| | - Xue-Yan Li
- Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui Province, PR China; Department of Neurology, the Affiliated Chaohu Hospital of Anhui Medical University, and the Center of Anhui Province in Psychologic Medicine, Chaohu, Hefei 238000, Anhui Province, PR China
| | - Gui-Hai Chen
- Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui Province, PR China; Department of Neurology, the Affiliated Chaohu Hospital of Anhui Medical University, and the Center of Anhui Province in Psychologic Medicine, Chaohu, Hefei 238000, Anhui Province, PR China; Department of Neurology, the First People's Hospital of Chenzhou, Chenzhou 423000, Hunan Province, PR China.
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