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González-Hernández A, Marichal-Cancino BA, MaassenVanDenBrink A, Villalón CM. Serotonergic Modulation of Neurovascular Transmission: A Focus on Prejunctional 5-HT Receptors/Mechanisms. Biomedicines 2023; 11:1864. [PMID: 37509503 PMCID: PMC10377335 DOI: 10.3390/biomedicines11071864] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/17/2023] [Accepted: 06/23/2023] [Indexed: 07/30/2023] Open
Abstract
5-Hydroxytryptamine (5-HT), or serotonin, plays a crucial role as a neuromodulator and/or neurotransmitter of several nervous system functions. Its actions are complex, and depend on multiple factors, including the type of effector or receptor activated. Briefly, 5-HT can activate: (i) metabotropic (G-protein-coupled) receptors to promote inhibition (5-HT1, 5-HT5) or activation (5-HT4, 5-HT6, 5-HT7) of adenylate cyclase, as well as activation (5-HT2) of phospholipase C; and (ii) ionotropic receptor (5-HT3), a ligand-gated Na+/K+ channel. Regarding blood pressure regulation (and beyond the intricacy of central 5-HT effects), this monoamine also exerts direct postjunctional (on vascular smooth muscle and endothelium) or indirect prejunctional (on autonomic and sensory perivascular nerves) effects. At the prejunctional level, 5-HT can facilitate or preclude the release of autonomic (e.g., noradrenaline and acetylcholine) or sensory (e.g., calcitonin gene-related peptide) neurotransmitters facilitating hypertensive or hypotensive effects. Hence, we cannot formulate a specific impact of 5-HT on blood pressure level, since an increase or decrease in neurotransmitter release would be favoured, depending on the type of prejunctional receptor involved. This review summarizes and discusses the current knowledge on the prejunctional mechanisms involved in blood pressure regulation by 5-HT and its impact on some vascular-related diseases.
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Affiliation(s)
- Abimael González-Hernández
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Queretaro 76230, Mexico
| | - Bruno A Marichal-Cancino
- Departamento de Fisiología y Farmacología, Universidad Autónoma de Aguascalientes, Mexico City 20100, Mexico
| | - Antoinette MaassenVanDenBrink
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, 3000 CA Rotterdam, The Netherlands
| | - Carlos M Villalón
- Departamento de Farmacobiología, Cinvestav-Coapa, Calzada de los Tenorios 235, Colonia Granjas-Coapa, Delegación Tlalpan, Mexico City 14330, Mexico
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Bodzęta A, Berger F, MacGillavry HD. Subsynaptic mobility of presynaptic mGluR types is differentially regulated by intra- and extracellular interactions. Mol Biol Cell 2022; 33:ar66. [PMID: 35511883 PMCID: PMC9635276 DOI: 10.1091/mbc.e21-10-0484] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Presynaptic metabotropic glutamate receptors (mGluRs) are essential for the control of synaptic transmission. However, how the subsynaptic dynamics of these receptors is controlled and contributes to synaptic signaling remain poorly understood quantitatively. Particularly, since the affinity of individual mGluR subtypes for glutamate differs considerably, the activation of mGluR subtypes critically depends on their precise subsynaptic distribution. Here, using superresolution microscopy and single-molecule tracking, we unravel novel molecular mechanisms that control the nanoscale distribution and mobility of presynaptic mGluRs in hippocampal neurons. We demonstrate that the high-affinity group II receptor mGluR2 localizes diffusely along the axon, and is highly mobile, while the low-affinity group III receptor mGluR7 is stably anchored at the active zone. We demonstrate that intracellular interactions modulate surface diffusion of mGluR2, while immobilization of mGluR7 at the active zone relies on its extracellular domain. Receptor activation or increases in synaptic activity do not alter the surface mobility of presynaptic mGluRs. Finally, computational modeling of presynaptic mGluR activity revealed that this particular nanoscale arrangement directly impacts their ability to modulate neurotransmitter release. Altogether, this study demonstrates that distinct mechanisms control surface mobility of presynaptic mGluRs to contribute differentially to glutamatergic synaptic transmission.
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Affiliation(s)
- Anna Bodzęta
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, The Netherlands
| | - Florian Berger
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, The Netherlands
| | - Harold D MacGillavry
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, The Netherlands
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García-Pedraza JÁ, Fernández-González JF, López C, Martín ML, Alarcón-Torrecillas C, Rodríguez-Barbero A, Morán A, García-Domingo M. Oral fluoxetine treatment changes serotonergic sympatho-regulation in experimental type 1 diabetes. Life Sci 2022; 293:120335. [PMID: 35051421 DOI: 10.1016/j.lfs.2022.120335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/14/2022] [Accepted: 01/14/2022] [Indexed: 11/28/2022]
Abstract
AIMS This study investigated whether fluoxetine treatment changes the 5-HT regulation on vascular sympathetic neurotransmission in type 1 diabetes. MAIN METHODS Four-week diabetes was obtained by a single alloxan s.c. administration in male Wistar rats, administering fluoxetine for 14 days (10 mg/kg/day; p.o.). Systolic blood pressure, heart rate, glycaemia, body weight (BW) evolution, creatinine, and blood urea nitrogen (BUN) were monitored. Afterward, rats were pithed to perform the vascular sympathetic stimulation. 5-HT1A/1D/2A receptors expression was analysed by Western blot in thoracic aorta. Both i.v. norepinephrine and the electrical stimulation of the spinal sympathetic drive evoked vasoconstrictor responses. KEY FINDINGS Fluoxetine treatment significantly reduced the BW gain, hyperglycaemia, creatinine, and BUN in diabetic rats. The electrical-produced vasopressor responses were greater in untreated than in fluoxetine-treated diabetic rats. 5-HT decreased the sympathetic-produced vasopressor responses. While 5-CT, 8-OH-DPAT and L-694,247 (5-HT1/7, 5-HT1A and 5-HT1D agonists, respectively) reproduced 5-HT-evoked inhibition, the 5-HT2 activation by α-methyl-5-HT augmented the vasoconstrictions. The 5-CT sympatho-inhibition was reversed by 5-HT1A plus 5-HT1D antagonists (WAY-100,635 and LY310762, respectively), whereas ritanserin (5-HT2A antagonist) blocked the α-methyl-5-HT potentiating effect. Norepinephrine-generated vasoconstrictions were increased or diminished by α-methyl-5-HT or 5-CT, respectively. 5-HT1A/1D/2A receptors were expressed at vascular level, being 5-HT1A expression increased by fluoxetine in diabetic rats. SIGNIFICANCE Our findings suggest that fluoxetine improves metabolic and renal profiles, changes the vasopressor responses, and 5-HT receptors modulating sympathetic activity in diabetic rats: 5-HT1A/1D are involved in the sympatho-inhibition, while 5-HT2A is implicated in the sympatho-potentiation, being both effects pre and/or postjunctional in nature.
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Affiliation(s)
- José Ángel García-Pedraza
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007 Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007 Salamanca, Spain
| | - Juan Francisco Fernández-González
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007 Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007 Salamanca, Spain
| | - Cristina López
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007 Salamanca, Spain
| | - María Luisa Martín
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007 Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007 Salamanca, Spain
| | - Claudia Alarcón-Torrecillas
- Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007 Salamanca, Spain; Unit of Cardiovascular and Renal Pathophysiology, Research Institute of Nephrology "Reina Sofía", Department of Physiology and Pharmacology, University of Salamanca, 37007 Salamanca, Spain
| | - Alicia Rodríguez-Barbero
- Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007 Salamanca, Spain; Unit of Cardiovascular and Renal Pathophysiology, Research Institute of Nephrology "Reina Sofía", Department of Physiology and Pharmacology, University of Salamanca, 37007 Salamanca, Spain
| | - Asunción Morán
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007 Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007 Salamanca, Spain
| | - Mónica García-Domingo
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007 Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007 Salamanca, Spain.
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Membrane trafficking and positioning of mGluRs at presynaptic and postsynaptic sites of excitatory synapses. Neuropharmacology 2021; 200:108799. [PMID: 34592242 DOI: 10.1016/j.neuropharm.2021.108799] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/31/2021] [Accepted: 09/17/2021] [Indexed: 01/21/2023]
Abstract
The plethora of functions of glutamate in the brain are mediated by the complementary actions of ionotropic and metabotropic glutamate receptors (mGluRs). The ionotropic glutamate receptors carry most of the fast excitatory transmission, while mGluRs modulate transmission on longer timescales by triggering multiple intracellular signaling pathways. As such, mGluRs mediate critical aspects of synaptic transmission and plasticity. Interestingly, at synapses, mGluRs operate at both sides of the cleft, and thus bidirectionally exert the effects of glutamate. At postsynaptic sites, group I mGluRs act to modulate excitability and plasticity. At presynaptic sites, group II and III mGluRs act as auto-receptors, modulating release properties in an activity-dependent manner. Thus, synaptic mGluRs are essential signal integrators that functionally couple presynaptic and postsynaptic mechanisms of transmission and plasticity. Understanding how these receptors reach the membrane and are positioned relative to the presynaptic glutamate release site are therefore important aspects of synapse biology. In this review, we will discuss the currently known mechanisms underlying the trafficking and positioning of mGluRs at and around synapses, and how these mechanisms contribute to synaptic functioning. We will highlight outstanding questions and present an outlook on how recent technological developments will move this exciting research field forward.
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García-Pedraza JÁ, López C, Fernández-González JF, Martín ML, Morán A, García-Domingo M. Vascular sympathetic neurotransmission and its serotonergic regulation are modified by chronic fluoxetine treatment. J Pharmacol Sci 2021; 147:48-57. [PMID: 34294372 DOI: 10.1016/j.jphs.2021.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/07/2021] [Accepted: 05/17/2021] [Indexed: 11/23/2022] Open
Abstract
Given the interconnection between depressive and cardiovascular disorders, we investigated whether antidepressant treatment (fluoxetine) modifies the serotonergic influence on rat vascular noradrenergic outflow. Twelve-week-old male Wistar rats received fluoxetine treatment (10 mg/kg/day; p.o.) for 14 days; then, they were pithed and prepared for sympathetic stimulation. Vasopressor responses were obtained by electrical stimulation of the sympathetic outflow (0.1, 0.5, 1, and 5 Hz) or i.v. noradrenaline (NA; 0.01, 0.05, 0.1, and 0.5 μg/kg). In fluoxetine-treated group, the electrical-induced vasoconstrictions were lower compared to non-treated rats. Intravenous infusion of 5-HT (10 μg/kg/min) inhibited the sympathetically-induced vasoconstrictions. Only 5-CT, 8-OH-DPAT and L-694,247 (5-HT1/7, 5-HT1A and 5-HT1D agonists, respectively) mimicked 5-HT-induced inhibition, while α-methyl-5-HT (5-HT2 agonist) increased the vasopressor responses. The inhibitory effect of 5-HT was: a) no modified by SB269970 (5-HT7 antagonist); b) abolished by WAY-100,635 (5-HT1A antagonist) plus LY310762 (5-HT1D antagonist); and c) potentiated by ritanserin (5-HT2A receptor antagonist). The vasoconstrictions induced by exogenous NA were not modified by 5-CT but were increased by α-methyl-5-HT. Our results suggest that fluoxetine treatment decreases NA release at vascular level and changes 5-HT modulation on rat vascular noradrenergic neurotransmission, inducing sympatho-inhibition via prejunctional 5-HT1A/1D receptors, and sympatho-potentiation via pre and/or postjunctional 5-HT2A receptors.
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Affiliation(s)
- José Ángel García-Pedraza
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007, Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007, Salamanca, Spain
| | - Cristina López
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007, Salamanca, Spain
| | - Juan Francisco Fernández-González
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007, Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007, Salamanca, Spain
| | - María Luisa Martín
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007, Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007, Salamanca, Spain
| | - Asunción Morán
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007, Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007, Salamanca, Spain
| | - Mónica García-Domingo
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, 37007, Salamanca, Spain; Research Institute of Salamanca (IBSAL), Paseo San Vicente 58-182, 37007, Salamanca, Spain.
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Emperador-Melero J, Wong MY, Wang SSH, de Nola G, Nyitrai H, Kirchhausen T, Kaeser PS. PKC-phosphorylation of Liprin-α3 triggers phase separation and controls presynaptic active zone structure. Nat Commun 2021; 12:3057. [PMID: 34031393 PMCID: PMC8144191 DOI: 10.1038/s41467-021-23116-w] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 04/16/2021] [Indexed: 01/24/2023] Open
Abstract
The active zone of a presynaptic nerve terminal defines sites for neurotransmitter release. Its protein machinery may be organized through liquid-liquid phase separation, a mechanism for the formation of membrane-less subcellular compartments. Here, we show that the active zone protein Liprin-α3 rapidly and reversibly undergoes phase separation in transfected HEK293T cells. Condensate formation is triggered by Liprin-α3 PKC-phosphorylation at serine-760, and RIM and Munc13 are co-recruited into membrane-attached condensates. Phospho-specific antibodies establish phosphorylation of Liprin-α3 serine-760 in transfected cells and mouse brain tissue. In primary hippocampal neurons of newly generated Liprin-α2/α3 double knockout mice, synaptic levels of RIM and Munc13 are reduced and the pool of releasable vesicles is decreased. Re-expression of Liprin-α3 restored these presynaptic defects, while mutating the Liprin-α3 phosphorylation site to abolish phase condensation prevented this rescue. Finally, PKC activation in these neurons acutely increased RIM, Munc13 and neurotransmitter release, which depended on the presence of phosphorylatable Liprin-α3. Our findings indicate that PKC-mediated phosphorylation of Liprin-α3 triggers its phase separation and modulates active zone structure and function.
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Affiliation(s)
| | - Man Yan Wong
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Shan Shan H Wang
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Giovanni de Nola
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Hajnalka Nyitrai
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.,VIB-KU Leuven Center for Brain and Disease Research, Campus Gasthuisberg, Leuven, Belgium
| | - Tom Kirchhausen
- Departments of Cell Biology and Pediatrics, Harvard Medical School and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
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Role of peripheral 5-HT5A receptors in 5-HT-induced cardiac sympatho-inhibition in type 1 diabetic rats. Sci Rep 2020. [DOI: 10.1155/2013/313917] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Abstract5-HT inhibits cardiac sympathetic neurotransmission in normoglycaemic rats, via 5-HT1B, 5-HT1Dand 5-HT5Areceptor activation. Since type 1 diabetes impairs the cardiac sympathetic innervation leading to cardiopathies, this study aimed to investigate whether the serotonergic influence on cardiac noradrenergic control is altered in type 1 diabetic rats. Diabetes was induced in male Wistar rats by streptozotocin (50 mg/kg, i.p.). Four weeks later, the rats were anaesthetized, pithed and prepared for producing tachycardic responses by electrical preganglionic stimulation (C7-T1) of the cardioaccelerator sympathetic outflow or i.v. noradrenaline bolus injections. Immunohistochemistry was performed to study 5-HT1B, 5-HT1Dand 5-HT5Areceptor expression in the stellate ganglion from normoglycaemic and diabetic rats. In the diabetic group, i) i.v. continuous infusions of 5-HT induced a cardiac sympatho-inhibition that was mimicked by the 5-HT1/5Aagonist 5-carboxamidotryptamine (without modifying noradrenaline-induced tachycardia), but not by the agonists indorenate (5-HT1A), CP 93,129 (5-HT1B), PNU 142633 (5-HT1D), or LY344864 (5-HT1F); ii) SB 699551 (5-HT5Aantagonist; i.v.) completely reversed 5-CT-induced cardiac sympatho-inhibition; and iii) 5-HT5Areceptors were more expressed in the stellate ganglion compared to normoglycaemic rats. These results show the prominent role of the peripheral 5-HT5Areceptors prejunctionally inhibiting the cardiac sympathetic drive in type 1 diabetic rats.
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García-Pedraza JÁ, Hernández-Abreu O, Morán A, Carretero J, García-Domingo M, Villalón CM. Role of peripheral 5-HT 5A receptors in 5-HT-induced cardiac sympatho-inhibition in type 1 diabetic rats. Sci Rep 2020; 10:19358. [PMID: 33168874 PMCID: PMC7652863 DOI: 10.1038/s41598-020-76298-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/16/2020] [Indexed: 01/15/2023] Open
Abstract
5-HT inhibits cardiac sympathetic neurotransmission in normoglycaemic rats, via 5-HT1B, 5-HT1D and 5-HT5A receptor activation. Since type 1 diabetes impairs the cardiac sympathetic innervation leading to cardiopathies, this study aimed to investigate whether the serotonergic influence on cardiac noradrenergic control is altered in type 1 diabetic rats. Diabetes was induced in male Wistar rats by streptozotocin (50 mg/kg, i.p.). Four weeks later, the rats were anaesthetized, pithed and prepared for producing tachycardic responses by electrical preganglionic stimulation (C7-T1) of the cardioaccelerator sympathetic outflow or i.v. noradrenaline bolus injections. Immunohistochemistry was performed to study 5-HT1B, 5-HT1D and 5-HT5A receptor expression in the stellate ganglion from normoglycaemic and diabetic rats. In the diabetic group, i) i.v. continuous infusions of 5-HT induced a cardiac sympatho-inhibition that was mimicked by the 5-HT1/5A agonist 5-carboxamidotryptamine (without modifying noradrenaline-induced tachycardia), but not by the agonists indorenate (5-HT1A), CP 93,129 (5-HT1B), PNU 142633 (5-HT1D), or LY344864 (5-HT1F); ii) SB 699551 (5-HT5A antagonist; i.v.) completely reversed 5-CT-induced cardiac sympatho-inhibition; and iii) 5-HT5A receptors were more expressed in the stellate ganglion compared to normoglycaemic rats. These results show the prominent role of the peripheral 5-HT5A receptors prejunctionally inhibiting the cardiac sympathetic drive in type 1 diabetic rats.
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Affiliation(s)
- José Ángel García-Pedraza
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, Biomedical Research Institute of Salamanca (IBSAL), 37007, Salamanca, Spain
| | - Oswaldo Hernández-Abreu
- Department of Pharmacobiology, Cinvestav-Coapa, Czda. Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, C.P. 14330, Mexico City, Mexico
| | - Asunción Morán
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, Biomedical Research Institute of Salamanca (IBSAL), 37007, Salamanca, Spain
| | - José Carretero
- Laboratory of Neuroendocrinology, Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Neurosciences Institute of Castilla y León (INCyL), Salamanca, Spain.,Laboratory of Neuroendocrinology and Obesity, IBSAL, Salamanca, Spain
| | - Mónica García-Domingo
- Laboratory of Pharmacology, Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, Biomedical Research Institute of Salamanca (IBSAL), 37007, Salamanca, Spain
| | - Carlos M Villalón
- Department of Pharmacobiology, Cinvestav-Coapa, Czda. Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, C.P. 14330, Mexico City, Mexico.
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BDNF Activates Postsynaptic TrkB Receptors to Induce Endocannabinoid Release and Inhibit Presynaptic Calcium Influx at a Calyx-Type Synapse. J Neurosci 2020; 40:8070-8087. [PMID: 32948677 PMCID: PMC7574661 DOI: 10.1523/jneurosci.2838-19.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 09/03/2020] [Accepted: 09/13/2020] [Indexed: 12/26/2022] Open
Abstract
Brain-derived neurotropic factor (BDNF) has been shown to play critical roles in neural development, plasticity, and neurodegenerative diseases. The main function of BDNF in the brain is widely accepted to be synaptic regulation. However, how BDNF modulates synaptic transmission, especially the underlying signaling cascades between presynaptic and postsynaptic neurons, remains controversial. Brain-derived neurotropic factor (BDNF) has been shown to play critical roles in neural development, plasticity, and neurodegenerative diseases. The main function of BDNF in the brain is widely accepted to be synaptic regulation. However, how BDNF modulates synaptic transmission, especially the underlying signaling cascades between presynaptic and postsynaptic neurons, remains controversial. In the present study, we investigated the actions of BDNF at rat calyx-type synapses of either sex by measuring the excitatory postsynaptic current (EPSC) and presynaptic calcium current and capacitance changes. We found that BDNF inhibits the EPSC, presynaptic calcium influx, and exocytosis/endocytosis via activation of the presynaptic cannabinoid Type 1 receptors (CB1Rs). Inhibition of the CB1Rs abolished the BDNF-induced presynaptic inhibition, whereas CB1R agonist mimicked the effect of BDNF. Exploring the underlying signaling cascade, we found that BDNF specifically activates the postsynaptic TrkB receptors, inducing the release of endocannabinoids via the PLCγ/DGL pathway and retrogradely activating presynaptic CB1Rs. We also reported the involvement of AC/PKA in modulating vesicle endocytosis, which may account for the BDNF-induced calcium-dependent and -independent regulation of endocytosis. Thus, our study provides new insights into the BDNF/endocannabinoid-associated modulation of neurotransmission in physiological and pathologic processes. SIGNIFICANCE STATEMENT BDNF plays critical roles in the modulation of synaptic strength. However, how BDNF regulates synaptic transmission and its underlying signaling cascade(s) remains elusive. By measuring EPSC and the presynaptic calcium current and capacitance changes at rat calyces, we found that BDNF inhibits synaptic transmission via BDNF-TrkB-eCB signaling pathway. Activation of postsynaptic TrkB receptors induces endocannabinoid release via the PLCγ/DGL pathway, retrogradely activating the presynaptic CB1Rs, inhibiting the AC/PKA, and suppressing calcium influx. Our findings provide a comprehensive understanding of BDNF/endocannabinoid-associated modulation of neuronal activities.
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Huson V, Meijer M, Dekker R, Ter Veer M, Ruiter M, van Weering JR, Verhage M, Cornelisse LN. Post-tetanic potentiation lowers the energy barrier for synaptic vesicle fusion independently of Synaptotagmin-1. eLife 2020; 9:55713. [PMID: 32831174 PMCID: PMC7500951 DOI: 10.7554/elife.55713] [Citation(s) in RCA: 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: 02/12/2020] [Accepted: 08/23/2020] [Indexed: 11/13/2022] Open
Abstract
Previously, we showed that modulation of the energy barrier for synaptic vesicle fusion boosts release rates supralinearly (Schotten, 2015). Here we show that mouse hippocampal synapses employ this principle to trigger Ca2+-dependent vesicle release and post-tetanic potentiation (PTP). We assess energy barrier changes by fitting release kinetics in response to hypertonic sucrose. Mimicking activation of the C2A domain of the Ca2+-sensor Synaptotagmin-1 (Syt1), by adding a positive charge (Syt1D232N) or increasing its hydrophobicity (Syt14W), lowers the energy barrier. Removing Syt1 or impairing its release inhibitory function (Syt19Pro) increases spontaneous release without affecting the fusion barrier. Both phorbol esters and tetanic stimulation potentiate synaptic strength, and lower the energy barrier equally well in the presence and absence of Syt1. We propose a model where tetanic stimulation activates Syt1-independent mechanisms that lower the energy barrier and act additively with Syt1-dependent mechanisms to produce PTP by exerting multiplicative effects on release rates.
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Affiliation(s)
- Vincent Huson
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Marieke Meijer
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Rien Dekker
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Mirelle Ter Veer
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Marvin Ruiter
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Jan Rt van Weering
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Lennart Niels Cornelisse
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
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11
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García-Pedraza JÁ, Morán A, Martín ML, Ollauri-Ibáñez C, Rodríguez-Barbero A, Villalón CM, García-Domingo M. Dopamine D 4 receptor subtype activation reduces the rat cardiac parasympathetic discharge. Pflugers Arch 2020; 472:1693-1703. [PMID: 32820344 DOI: 10.1007/s00424-020-02452-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/31/2020] [Accepted: 08/14/2020] [Indexed: 12/19/2022]
Abstract
The dopaminergic system influences the heart rhythm by inhibiting the rat cardiac sympathetic and parasympathetic neurotransmissions through activation of D2-like receptors (encompassing the D2, D3, and D4 subtypes). Whereas D2 receptor subtype activation results in cardiac sympatho-inhibition, the dopamine receptor subtypes involved in rat cardiac vago-inhibition remain unknown. Hence, this study investigated the specific functional role of the D2-like receptor subtypes (D2, D3, and/or D4) inhibiting the rat heart cholinergic drive. For this purpose, male Wistar rats were pithed and prepared for cardiac vagal stimulation. Bradycardic responses were obtained by electrical stimulation of vagal fibres (3, 6, 9 Hz; n = 100) or i.v. acetylcholine (ACh; 1, 5, 10 μg/kg; n = 15). Expression of D2, D3, and D4 receptors was studied in left and right atrium samples by PCR (n = 4). Intravenous injections of quinpirole (D2-like agonist; 1-30 μg/kg), but not of SFK-38393 (D1-like agonist; 1-30 μg/kg), dose-dependently inhibited the vagally induced bradycardia. The vago-inhibition induced by quinpirole (which failed to affect the bradycardia to i.v. ACh) was unchanged after i.v. injections of the antagonists L-741,626 (D2; 100 μg/kg) or SB-277011-A (D3; 100 μg/kg), but it was abolished by L-745,870 (D4; 100 μg/kg). mRNA levels of D2, D3, and D4 receptor subtype were detected in the left and right rat atria. Our results suggest that the quinpirole-induced vagolytic effect involves prejunctional D4 receptor subtypes, located in the left and right atria. This provides new evidence on the relevance of D4 receptor modulating the heart parasympathetic control.
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Affiliation(s)
- José Ángel García-Pedraza
- Laboratorio de Farmacología, Dep. de Fisiología y Farmacología, Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, 37007, Salamanca, Spain
| | - Asunción Morán
- Laboratorio de Farmacología, Dep. de Fisiología y Farmacología, Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, 37007, Salamanca, Spain
| | - María Luisa Martín
- Laboratorio de Farmacología, Dep. de Fisiología y Farmacología, Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, 37007, Salamanca, Spain
| | - Claudia Ollauri-Ibáñez
- Unidad de Fisiopatología Renal y Cardiovascular, Instituto Reina Sofía de Investigación Nefrológica, Dep. de Fisiología y Farmacología, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, 37007, Salamanca, Spain
| | - Alicia Rodríguez-Barbero
- Unidad de Fisiopatología Renal y Cardiovascular, Instituto Reina Sofía de Investigación Nefrológica, Dep. de Fisiología y Farmacología, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, 37007, Salamanca, Spain
| | - Carlos M Villalón
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330, Mexico City, Mexico
| | - Mónica García-Domingo
- Laboratorio de Farmacología, Dep. de Fisiología y Farmacología, Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, 37007, Salamanca, Spain.
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12
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Classen J, Saarloos I, Meijer M, Sullivan PF, Verhage M. A Munc18-1 mutant mimicking phosphorylation by Down Syndrome-related kinase Dyrk1a supports normal synaptic transmission and promotes recovery after intense activity. Sci Rep 2020; 10:3181. [PMID: 32081899 PMCID: PMC7035266 DOI: 10.1038/s41598-020-59757-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 01/31/2020] [Indexed: 11/24/2022] Open
Abstract
Phosphorylation of Munc18-1 (Stxbp1), a presynaptic organizer of synaptic vesicle fusion, is a powerful mechanism to regulate synaptic strength. Munc18-1 is a proposed substrate for the Down Syndrome-related kinase dual-specificity tyrosine phosphorylation-regulate kinase 1a (Dyrk1a) and mutations in both genes cause intellectual disability. However, the functional consequences of Dyrk1a-dependent phosphorylation of Munc18-1 for synapse function are unknown. Here, we show that the proposed Munc18-1 phosphorylation site, T479, is among the highly constrained phosphorylation sites in the coding regions of the gene and is also located within a larger constrained coding region. We confirm that Dyrk1a phosphorylates Munc18-1 at T479. Patch-clamp physiology in conditional null mutant hippocampal neurons expressing Cre and either wildtype, or mutants mimicking or preventing phosphorylation, revealed that synaptic transmission is similar among the three groups: frequency/amplitude of mEPSCs, evoked EPSCs, paired pulse plasticity, rundown kinetics upon intense activity and the readily releasable pool. However, synapses expressing the phosphomimic mutant responded to intense activity with more pronounced facilitation. These data indicate that Dyrk1a-dependent Munc18-1 phosphorylation has a minor impact on synaptic transmission, only after intense activity, and that the role of genetic variation in both genes in intellectual disability may be through different mechanisms.
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Affiliation(s)
- Jessica Classen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, 1081, HV, Amsterdam, The Netherlands
| | - Ingrid Saarloos
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, 1081, HV, Amsterdam, The Netherlands
| | - Marieke Meijer
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, 1081, HV, Amsterdam, The Netherlands
| | - Patrick F Sullivan
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobels väg 12A, PO Box 281, 171 77, Stockholm, Sweden
- Departments of Genetics and Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, 1081, HV, Amsterdam, The Netherlands.
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13
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van Huijstee AN, Kessels HW. Variance analysis as a tool to predict the mechanism underlying synaptic plasticity. J Neurosci Methods 2020; 331:108526. [PMID: 31756397 DOI: 10.1016/j.jneumeth.2019.108526] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/31/2019] [Accepted: 11/18/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND The strength of synaptic transmission onto a neuron depends on the number of functional vesicle release sites (N), the probability of vesicle release (Pr), and the quantal size (Q). Statistical tools based on the quantal model of synaptic transmission can be used to acquire information on which of these parameters is the source of plasticity. However, quantal analysis depends on assumptions that may not be met at central synapses. NEW METHOD We examined the merit of quantal analysis to extract the mechanisms underlying synaptic plasticity by applying binomial statistics on the variance in amplitude of postsynaptic currents evoked at Schaffer collateral-CA1 (Sc-CA1) synapses in mouse hippocampal slices. We extend this analysis by combining the conventional inverse square of the coefficient of variation (1/CV2) with the variance-to-mean ratio (VMR). RESULTS This method can be used to assess the relative, but not absolute, contribution of N, Pr and Q to synaptic plasticity. The changes in 1/CV2 and VMR values correctly reflect experimental modifications of N, Pr and Q at Sc-CA1 synapses. COMPARISON WITH EXISTING METHODS While the 1/CV2 depends on N and Pr, but is independent of Q, the VMR is dependent on Pr and Q, but not on N. Combining both allows for a rapid assessment of the mechanism underlying synaptic plasticity without the need for additional electrophysiological experiments. CONCLUSION Combining the 1/CV2 with the VMR allows for a reliable prediction of the relative contribution of changes in N, Pr and Q to synaptic plasticity.
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Affiliation(s)
- Aile N van Huijstee
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands.
| | - Helmut W Kessels
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands.
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14
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Hernández-Abreu OI, García-Pedraza JÁ, Rivera-Mancilla E, Villanueva-Castillo B, Morán A, García-Domingo M, Manrique-Maldonado G, Altamirano-Espinoza AH, Villalón CM. Blockade of 5-HT 2 receptors with sarpogrelate uncovers 5-HT 7 receptors inhibiting the tachycardic sympathetic drive in pithed rats. Clin Exp Pharmacol Physiol 2019; 47:403-411. [PMID: 31846086 DOI: 10.1111/1440-1681.13227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/22/2019] [Accepted: 12/10/2019] [Indexed: 11/30/2022]
Abstract
Our group has previously shown in pithed rats that the cardiac sympathetic drive, which produces tachycardic responses, is inhibited by 5-HT via the activation of prejunctional 5-HT1B/1D/5 receptors. Interestingly, when 5-HT2 receptors are chronically blocked with sarpogrelate, the additional role of cardiac sympatho-inhibitory 5-HT1F receptors is unmasked. Although 5-HT2 receptors mediate tachycardia in rats, and the chronic blockade of 5-HT2 receptors unmasked 5-HT7 receptors mediating cardiac vagal inhibition, the role of 5-HT7 receptors in the modulation of the cardiac sympathetic tone remains virtually unexplored. On this basis, male Wistar rats were pretreated during 14 days with sarpogrelate (a 5-HT2 receptor antagonist) in drinking water (30 mg/kg/day; sarpogrelate-pretreated group) or equivalent volumes of drinking water (control group). Subsequently, the rats were pithed to produce increases in heart rate by either electrical preganglionic spinal (C7 -T1 ) stimulation of the cardiac sympathetic drive or iv administration of exogenous noradrenaline. The iv continuous infusion of AS-19 (a 5-HT7 receptor agonist; 10 µg/kg/min) (i) inhibited the tachycardic responses to sympathetic stimulation, but not those to exogenous noradrenaline only in sarpogrelate-pretreated rats. This inhibition was completely reversed by SB258719 (a selective 5-HT7 receptor antagonist; 1 mg/kg, iv) or glibenclamide (an ATP-sensitive K+ channel blocker; 20 mg/kg, iv). These results suggest that chronic 5-HT2 receptor blockade uncovers a cardiac sympatho-inhibitory mechanism mediated by 5-HT7 receptors, involving a hyperpolarization due to the opening of ATP-sensitive K+ channels. Thus, these findings support the role of 5-HT7 receptors in the modulation of the cardiac sympathetic neurotransmission.
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Affiliation(s)
| | - José Á García-Pedraza
- Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, Salamanca, Spain
| | | | | | - Asunción Morán
- Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, Salamanca, Spain
| | - Mónica García-Domingo
- Department of Physiology and Pharmacology, Faculty of Pharmacy, University of Salamanca, Salamanca, Spain
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15
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Ruiter M, Houy S, Engholm-Keller K, Graham ME, Sørensen JB. SNAP-25 phosphorylation at Ser187 is not involved in Ca 2+ or phorbolester-dependent potentiation of synaptic release. Mol Cell Neurosci 2019; 102:103452. [PMID: 31794878 DOI: 10.1016/j.mcn.2019.103452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/13/2019] [Accepted: 11/29/2019] [Indexed: 11/25/2022] Open
Abstract
SNAP-25, one of the three SNARE-proteins responsible for synaptic release, can be phosphorylated by Protein Kinase C on Ser-187, close to the fusion pore. In neuroendocrine cells, this phosphorylation event potentiates vesicle recruitment into releasable pools, whereas the consequences of phosphorylation for synaptic release remain unclear. We mutated Ser-187 and expressed two mutants (S187C and S187E) in the context of the SNAP-25B-isoform in SNAP-25 knockout glutamatergic autaptic neurons. Whole-cell patch clamp recordings were performed to assess the effect of Ser-187 phosphorylation on synaptic transmission. Blocking phosphorylation by expressing the S187C mutant did not affect synapse density, basic evoked or spontaneous neurotransmission, the readily-releasable pool size or its Ca2+-independent or Ca2+-dependent replenishment. Furthermore, it did not affect the response to phorbol esters, which activate PKC. Expressing S187C in the context of the SNAP-25A isoform also did not affect synaptic transmission. Strikingly, the - potentially phosphomimetic - mutant S187E reduced spontaneous release and release probability, with the largest effect seen in the SNAP-25B isoform, showing that a negative charge in this position is detrimental for neurotransmission, in agreement with electrostatic fusion triggering. During the course of our experiments, we found that higher SNAP-25B expression levels led to decreased paired pulse potentiation, probably due to higher release probabilities. Under these conditions, the potentiation of evoked EPSCs by phorbol esters was followed by a persistent down-regulation, probably due to a ceiling effect. In conclusion, our results indicate that phosphorylation of Ser-187 in SNAP-25 is not involved in modulation of synaptic release by Ca2+ or phorbol esters.
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Affiliation(s)
- Marvin Ruiter
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3C, 2200 Copenhagen N, Denmark
| | - Sébastien Houy
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3C, 2200 Copenhagen N, Denmark
| | - Kasper Engholm-Keller
- Synapse Proteomics Group, Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead NSW 2145, New South Wales, Australia; Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Mark E Graham
- Synapse Proteomics Group, Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead NSW 2145, New South Wales, Australia
| | - Jakob B Sørensen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3C, 2200 Copenhagen N, Denmark.
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16
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Manrique-Maldonado G, Altamirano-Espinoza AH, Rivera-Mancilla E, Hernández-Abreu O, Villalón CM. Activation of Dopamine D 3 Receptor Subtypes Inhibits the Neurogenic Systemic Vasodilation Induced by Stimulation of the Perivascular CGRPergic Discharge. ACS Chem Neurosci 2019; 10:3751-3757. [PMID: 31343160 DOI: 10.1021/acschemneuro.9b00277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The sensory nervous system controls cardiovascular homeostasis via capsaicin-sensitive neurons that release calcitonin gene-related peptide (CGRP), which subsequently activates CGRP receptors. How this perivascular CGRPergic discharge is modulated, nevertheless, remains unclear. In pithed rats, systemic vasodilation induced by CGRPergic discharge stimulation results in diastolic blood pressure (BP) decrements that are inhibited by the dopamine D2-like receptor agonist quinpirole. Since this inhibition is mediated by raclopride- or haloperidol-sensitive D2-like receptors (comprising the D2, D3, and D4 subtypes), the present study pharmacologically investigated the specific contribution of these subtypes to the modulation of the systemic CGRPergic vasodilation, using highly specific antagonists. To that end, 55 male Wistar rats were pithed for thoracic (T9-T12) spinal stimulation of the perivascular CGRPergic discharge. The resulting frequency-dependent decrements in diastolic BP were inhibited by quinpirole, and this sensory-inhibition was (a) unchanged after i.v. injections of the antagonists L-741,626 (D2) or L-745,870 (D4) and (b) completely blocked by SB-277011-A (D3). Accordingly, we suggest the main role of the D3 receptor subtypes in the inhibition by quinpirole of the neurogenic CGRPergic systemic vasodilation. These findings contribute to a better understanding of the dopaminergic modulation of the rat perivascular CGRPergic discharge producing systemic vasodilation.
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Affiliation(s)
- Guadalupe Manrique-Maldonado
- Department of Pharmacobiology, Cinvestav-Coapa, Czda. Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 Mexico City, Mexico
| | - Alain H. Altamirano-Espinoza
- Department of Pharmacobiology, Cinvestav-Coapa, Czda. Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 Mexico City, Mexico
| | - Eduardo Rivera-Mancilla
- Department of Pharmacobiology, Cinvestav-Coapa, Czda. Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 Mexico City, Mexico
| | - Oswaldo Hernández-Abreu
- Department of Pharmacobiology, Cinvestav-Coapa, Czda. Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 Mexico City, Mexico
| | - Carlos M. Villalón
- Department of Pharmacobiology, Cinvestav-Coapa, Czda. Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 Mexico City, Mexico
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17
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Fawley JA, Andresen MC. Distinct Calcium Sources Define Compartmentalized Synaptic Signaling Domains. Neuroscientist 2019; 25:408-419. [PMID: 31375041 DOI: 10.1177/1073858419863771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Nervous system communication relies on neurotransmitter release for synaptic transmission between neurons. Neurotransmitter is contained within vesicles in presynaptic terminals and intraterminal calcium governs the fundamental step of their release into the synaptic cleft. Despite a common dependence on calcium, synaptic transmission and its modulation varies highly across the nervous system. The precise mechanisms that underlie this heterogeneity, however, remain unclear. The present review highlights recent data that reveal vesicles sourced from separate pools define discrete modes of release. A rich diversity of regulatory machinery may further distinguish the different forms of vesicle release, including presynaptic proteins involved in trafficking, alignment, and exocytosis. These multiple vesicle release mechanisms and vesicle pools likely depend on the arrangement of vesicles in relation to specific calcium entry pathways that create compartmentalized spheres of calcium influence (i.e., domains). This diversity permits release specialization. This review details examples of how individual neurons rely on multiple calcium sources and unique regulatory schemes to provide differential release and discrete modulation of neurotransmitter release from specific vesicle pools-as part of network signal integration.
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Affiliation(s)
- Jessica A Fawley
- Department of Physiology & Pharmacology, Oregon Health & Science University, Portland, OR, USA
| | - Michael C Andresen
- Department of Physiology & Pharmacology, Oregon Health & Science University, Portland, OR, USA
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18
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González-Hernández A, Marichal-Cancino BA, Lozano-Cuenca J, MaassenVanDenBrink A, Villalón CM. Functional Characterization of the Prejunctional Receptors Mediating the Inhibition by Ergotamine of the Rat Perivascular Sensory Peptidergic Drive. ACS Chem Neurosci 2019; 10:3173-3182. [PMID: 30695640 DOI: 10.1021/acschemneuro.8b00611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Calcitonin gene-related peptide (α-CGRP) released from perivascular sensory nerves induces decreases in diastolic blood pressure (DBP). Experimentally, this can be shown by spinal thoracic (T9-T12) electrical stimulation of these afferent fibers. Because ergotamine inhibits these neurogenic vascular responses and displays affinity for monoaminergic receptors that inhibit neurotransmitter release, we investigated whether this ergotamine-induced inhibition results from activation of serotonin 5-HT1B/1D, dopamine D2-like, and α2-adrenergic receptors. Wistar rats were pithed and, under autonomic ganglion blockade, received intravenous infusions of methoxamine followed by ergotamine (0.1-3.1 μg kg-1 min-1). Thoracic T9-T12 electrical stimulation or an intravenous bolus of α-CGRP resulted in decreases in DBP. Ergotamine inhibited the electrically induced, but not α-CGRP-induced, responses. The vasodilator sensory inhibition by 3.1 μg of ergotamine kg-1 min-1 was resistant to simultaneous blockade of 5-HT1B/1D, D2-like, and α2-adrenergic receptors upon addition of antagonists GR127935, haloperidol, and rauwolscine. Moreover, the inhibition by 0.31 μg of ergotamine kg-1 min-1 was unaltered by GR127935 and haloperidol, partly blocked by GR127935 and rauwolscine or rauwolscine and haloperidol, and abolished by GR127935, haloperidol, and rauwolscine. These findings imply that prejunctional 5-HT1B/1D, D2-like, and α2-adrenergic receptors mediate the sensory inhibition induced by 0.31 μg of ergotamine kg-1 min-1, whereas larger doses may involve other receptors. Thus, ergotamine's ability to inhibit the perivascular sensory peptidergic drive may result in facilitation of its systemic vasoconstrictor properties.
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Affiliation(s)
- Abimael González-Hernández
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de los Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Boulevard Juriquilla 3001, Juriquilla, 76230 Querétaro, Mexico
| | - Bruno A. Marichal-Cancino
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de los Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico
- Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria, 20131 Aguascalientes, Ags., Mexico
| | - Jair Lozano-Cuenca
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de los Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico
| | - Antoinette MaassenVanDenBrink
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, P.O. Box
2040, 3000 CA Rotterdam, The Netherlands
| | - Carlos M. Villalón
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de los Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico
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19
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King CR, A A Quadros AR, Chazeau A, Saarloos I, van der Graaf AJ, Verhage M, Toonen RF. Fbxo41 Promotes Disassembly of Neuronal Primary Cilia. Sci Rep 2019; 9:8179. [PMID: 31160656 PMCID: PMC6546786 DOI: 10.1038/s41598-019-44589-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/20/2019] [Indexed: 01/02/2023] Open
Abstract
Neuronal primary cilia are signaling organelles with crucial roles in brain development and disease. Cilia structure is decisive for their signaling capacities but the mechanisms regulating it are poorly understood. We identify Fbxo41 as a novel Skp1/Cullin1/F-box (SCF) E3-ligase complex subunit that targets to neuronal centrioles where its accumulation promotes disassembly of primary cilia, and affects sonic hedgehog signaling, a canonical ciliary pathway. Fbxo41 targeting to centrioles requires its Coiled-coil and F-box domains. Levels of Fbxo41 at the centrioles inversely correlate with neuronal cilia length, and mutations that disrupt Fbxo41 targeting or assembly into SCF-complexes also disturb its function in cilia disassembly and signaling. Fbxo41 dependent cilia disassembly in mitotic and post-mitotic cells requires rearrangements of the actin-cytoskeleton, but requires Aurora A kinase activation only in mitotic cells, highlighting important mechanistical differences controlling cilia size between mitotic and post-mitotic cells. Phorbol esters induce recruitment of overexpressed Fbxo41 to centrioles and cilia disassembly in neurons, but disassembly can also occur in absence of Fbxo41. We propose that Fbxo41 targeting to centrosomes regulates neuronal cilia structure and signaling capacity in addition to Fbxo41-independent pathways controlling cilia size.
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Affiliation(s)
- Cillian R King
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Ana R A A Quadros
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Anaël Chazeau
- Cell Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Ingrid Saarloos
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands.,Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Anne Jolien van der Graaf
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands.,Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands.
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20
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Jiao J, He M, Port SA, Baker RW, Xu Y, Qu H, Xiong Y, Wang Y, Jin H, Eisemann TJ, Hughson FM, Zhang Y. Munc18-1 catalyzes neuronal SNARE assembly by templating SNARE association. eLife 2018; 7:41771. [PMID: 30540253 PMCID: PMC6320071 DOI: 10.7554/elife.41771] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/11/2018] [Indexed: 01/16/2023] Open
Abstract
Sec1/Munc18-family (SM) proteins are required for SNARE-mediated membrane fusion, but their mechanism(s) of action remain controversial. Using single-molecule force spectroscopy, we found that the SM protein Munc18-1 catalyzes step-wise zippering of three synaptic SNAREs (syntaxin, VAMP2, and SNAP-25) into a four-helix bundle. Catalysis requires formation of an intermediate template complex in which Munc18-1 juxtaposes the N-terminal regions of the SNARE motifs of syntaxin and VAMP2, while keeping their C-terminal regions separated. SNAP-25 binds the templated SNAREs to induce full SNARE zippering. Munc18-1 mutations modulate the stability of the template complex in a manner consistent with their effects on membrane fusion, indicating that chaperoned SNARE assembly is essential for exocytosis. Two other SM proteins, Munc18-3 and Vps33, similarly chaperone SNARE assembly via a template complex, suggesting that SM protein mechanism is conserved.
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Affiliation(s)
- Junyi Jiao
- Department of Cell Biology, Yale University School of Medicine, New Haven, United States
| | - Mengze He
- Department of Cell Biology, Yale University School of Medicine, New Haven, United States
| | - Sarah A Port
- Department of Molecular Biology, Princeton University, Princeton, United States
| | - Richard W Baker
- Department of Molecular Biology, Princeton University, Princeton, United States.,Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, United States
| | - Yonggang Xu
- Department of Cell Biology, Yale University School of Medicine, New Haven, United States
| | - Hong Qu
- Department of Cell Biology, Yale University School of Medicine, New Haven, United States
| | - Yujian Xiong
- Department of Cell Biology, Yale University School of Medicine, New Haven, United States
| | - Yukun Wang
- Department of Cell Biology, Yale University School of Medicine, New Haven, United States
| | - Huaizhou Jin
- Department of Cell Biology, Yale University School of Medicine, New Haven, United States
| | - Travis J Eisemann
- Department of Molecular Biology, Princeton University, Princeton, United States
| | - Frederick M Hughson
- Department of Molecular Biology, Princeton University, Princeton, United States
| | - Yongli Zhang
- Department of Cell Biology, Yale University School of Medicine, New Haven, United States
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21
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Tarasova EO, Gaydukov AE, Balezina OP. Calcineurin and Its Role in Synaptic Transmission. BIOCHEMISTRY (MOSCOW) 2018; 83:674-689. [PMID: 30195324 DOI: 10.1134/s0006297918060056] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Calcineurin (CaN) is a serine/threonine phosphatase widely expressed in different cell types and structures including neurons and synapses. The most studied role of CaN is its involvement in the functioning of postsynaptic structures of central synapses. The role of CaN in the presynaptic structures of central and peripheral synapses is less understood, although it has generated a considerable interest and is a subject of a growing number of studies. The regulatory role of CaN in synaptic vesicle endocytosis in the synapse terminals is actively studied. In recent years, new targets of CaN have been identified and its role in the regulation of enzymes and neurotransmitter secretion in peripheral neuromuscular junctions has been revealed. CaN is the only phosphatase that requires calcium and calmodulin for activation. In this review, we present details of CaN molecular structure and give a detailed description of possible mechanisms of CaN activation involving calcium, enzymes, and endogenous and exogenous inhibitors. Known and newly discovered CaN targets at pre- and postsynaptic levels are described. CaN activity in synaptic structures is discussed in terms of functional involvement of this phosphatase in synaptic transmission and neurotransmitter release.
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Affiliation(s)
- E O Tarasova
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
| | - A E Gaydukov
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia. .,Pirogov Russian National Research Medical University, Moscow, 117997, Russia
| | - O P Balezina
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
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22
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Rivera-Mancilla E, Altamirano-Espinoza AH, Manrique-Maldonado G, Villanueva-Castillo B, Villalón CM. Differential cardiac sympatho-inhibitory responses produced by the agonists B-HT 933, quinpirole and immepip in normoglycaemic and diabetic pithed rats. Clin Exp Pharmacol Physiol 2018; 45:767-778. [PMID: 29675928 DOI: 10.1111/1440-1681.12949] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 03/22/2018] [Accepted: 04/10/2018] [Indexed: 01/24/2023]
Abstract
This study compared the cardiac sympatho-inhibitory responses produced by agonists at α2 -adrenergic (B-HT 933), dopamine D2 -like (quinpirole) and histamine H3 /H4 (immepip) receptors between normoglycaemic and streptozotocin-pretreated (diabetic) pithed rats. Intravenous (i.v.) continuous infusions of B-HT 933, quinpirole or immepip were used in normoglycaemic and diabetic pithed rats to analyse their sympatho-inhibitory effects on the electrically-stimulated cardioaccelerator sympathetic outflow. Both in normoglycaemic and diabetic animals, B-HT 933 (until 100 μg/kg per minute) and quinpirole (until 10 μg/kg per minute) inhibited the tachycardic responses to electrical sympathetic stimulation, but not those to i.v. bolus of exogenous noradrenaline. These sympatho-inhibitory responses were more pronounced in diabetic than in normoglycaemic animals. Accordingly, the areas under the curve for 100 μg/kg per minute B-HT 933 and 10 μg/kg per minute quinpirole in diabetic rats (1065 ± 70 and 920 ± 35, respectively) were significantly smaller (P < .05) than those in normoglycaemic rats (1220 ± 45 and 1360 ± 42, respectively). In contrast, immepip infusions produced cardiac sympatho-inhibition in normoglycaemic (until 10 μg/kg per minute), but not in diabetic (until 100 μg/kg per minute) animals. Our results suggest that in diabetic pithed rats: (i) the more pronounced cardiac sympatho-inhibition to B-HT 933 and quinpirole may be probably due to up-regulation of α2 -adrenergic and dopamine D2 -like receptors, respectively; (ii) the histamine H3 /H4 receptors do not seem to play a sympatho-inhibitory role; and (iii) there is a differential participation of α2 -adrenergic and dopamine D2 -like receptors, which may certainly represent therapeutic targets for the treatment of diabetic complications such as cardiovascular autonomic neuropathy.
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23
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González-Hernández A, Lozano-Cuenca J, Marichal-Cancino BA, MaassenVanDenBrink A, Villalón CM. Dihydroergotamine inhibits the vasodepressor sensory CGRPergic outflow by prejunctional activation of α 2-adrenoceptors and 5-HT 1 receptors. J Headache Pain 2018; 19:40. [PMID: 29802544 PMCID: PMC5970131 DOI: 10.1186/s10194-018-0869-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/14/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Dihydroergotamine (DHE) is an antimigraine drug that produces cranial vasoconstriction and inhibits trigeminal CGRP release; furthermore, it inhibits the vasodepressor sensory CGRPergic outflow, but the receptors involved remain unknown. Prejunctional activation of α2A/2C-adrenergic, serotonin 5-HT1B/1F, or dopamine D2-like receptors results in inhibition of this CGRPergic outflow. Since DHE displays affinity for these receptors, this study investigated the pharmacological profile of DHE-induced inhibition of the vasodepressor sensory CGRPergic outflow. METHODS Pithed rats were pretreated i.v. with hexamethonium (2 mg/kg·min) followed by continuous infusions of methoxamine (20 μg/kg·min) and DHE (3.1 μg/kg·min). Then, stimulus-response curves (spinal electrical stimulation; T9-T12) or dose-response curves (i.v. injections of α-CGRP) resulted in frequency-dependent or dose-dependent decreases in diastolic blood pressure. RESULTS DHE inhibited the vasodepressor responses to electrical stimulation (0.56-5.6 Hz), without affecting those to i.v. α-CGRP (0.1-1 μg/kg). This inhibition by DHE (not produced by the methoxamine infusions): (i) was abolished by pretreatment with the combination of the antagonists rauwolscine (α2-adrenoceptor; 310 μg/kg) plus GR127935 (5-HT1B/1D; 31 μg/kg); and (ii) remained unaffected after rauwolscine (310 μg/kg), GR127935 (31 μg/kg) or haloperidol (D2-like; 310 μg/kg) given alone, or after the combination of rauwolscine plus haloperidol or GR127935 plus haloperidol at the aforementioned doses. CONCLUSION DHE-induced inhibition of the vasodepressor sensory CGRPergic outflow is mainly mediated by prejunctional rauwolscine-sensitive α2-adrenoceptors and GR127935-sensitive 5-HT1B/1D receptors, which correlate with α2A/2C-adrenoceptors and 5-HT1B receptors, respectively. These findings suggest that DHE-induced inhibition of the perivascular sensory CGRPergic outflow may facilitate DHE's vasoconstrictor properties resulting in an increased vascular resistance.
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Affiliation(s)
- Abimael González-Hernández
- Departamento de Farmacobiología, Cinvestav-Coapa, Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330, Ciudad de México, México.,Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM, Juriquilla, México
| | - Jair Lozano-Cuenca
- Departamento de Farmacobiología, Cinvestav-Coapa, Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330, Ciudad de México, México
| | - Bruno A Marichal-Cancino
- Departamento de Farmacobiología, Cinvestav-Coapa, Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330, Ciudad de México, México.,Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria, 20131, Aguascalientes, Ags, México
| | - Antoinette MaassenVanDenBrink
- Division of Vascular Medicine and Pharmacology, Erasmus University Medical Center, P.O. Box 2040, 3000, CA, Rotterdam, The Netherlands
| | - Carlos M Villalón
- Departamento de Farmacobiología, Cinvestav-Coapa, Tenorios 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330, Ciudad de México, México.
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24
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Persistent but Labile Synaptic Plasticity at Excitatory Synapses. J Neurosci 2018; 38:5750-5758. [PMID: 29802202 DOI: 10.1523/jneurosci.2772-17.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 04/11/2018] [Accepted: 04/19/2018] [Indexed: 11/21/2022] Open
Abstract
Short-term synaptic plasticity contributes to many computations in the brain and allows synapses to keep a finite record of recent activity. Here we have investigated the mechanisms underlying an intriguing form of short-term plasticity termed labile LTP, at hippocampal and PFC synapses in male rats and male and female mice. In the hippocampus, labile LTP is triggered by high-frequency activation of presynaptic axons and is rapidly discharged with further activation of those axons. However, if the synapses are quiescent, they remain potentiated until further presynaptic activation. To distinguish labile LTP from NMDAR-dependent forms of potentiation, we blocked NMDARs in all experiments. Labile LTP was synapse-specific and was accompanied by a decreased paired pulse ratio, consistent with an increased release probability. Presynaptic Ca2+ and protein kinase activation during the tetanus appeared to be required for its initiation. Labile LTP was not reversed by a PKC inhibitor and did not require either RIM1α or synaptotagmin-7, proteins implicated in other forms of presynaptic short-term plasticity. Similar NMDAR-independent potentiation could be elicited at synapses in mPFC. Labile LTP allows for rapid information storage that is erased under controlled circumstances and could have a role in a variety of hippocampal and prefrontal cortical computations related to short-term memory.SIGNIFICANCE STATEMENT Changes in synaptic strength are thought to represent information storage relevant to particular nervous system tasks. A single synapse can exhibit multiple overlapping forms of plasticity that shape information transfer from presynaptic to postsynaptic neurons. Here we investigate the mechanisms underlying labile LTP, an NMDAR-independent form of plasticity induced at hippocampal synapses. The potentiation is maintained for long periods as long as the synapses are infrequently active, but with regular activation, the synapses are depotentiated. Similar NMDAR-independent potentiation can also be induced at L2/3-to-L5 synapses in mPFC. Labile LTP requires a rise in presynaptic Ca2+ and protein kinase activation but is unaffected in RIM1α or synaptotagmin-7 mutant mice. Labile LTP may contribute to short-term or working memory in hippocampus and mPFC.
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Meijer M, Dörr B, Lammertse HC, Blithikioti C, van Weering JR, Toonen RF, Söllner TH, Verhage M. Tyrosine phosphorylation of Munc18-1 inhibits synaptic transmission by preventing SNARE assembly. EMBO J 2017; 37:300-320. [PMID: 29150433 PMCID: PMC5770875 DOI: 10.15252/embj.201796484] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 10/12/2017] [Accepted: 10/16/2017] [Indexed: 11/17/2022] Open
Abstract
Tyrosine kinases are important regulators of synaptic strength. Here, we describe a key component of the synaptic vesicle release machinery, Munc18‐1, as a phosphorylation target for neuronal Src family kinases (SFKs). Phosphomimetic Y473D mutation of a SFK phosphorylation site previously identified by brain phospho‐proteomics abolished the stimulatory effect of Munc18‐1 on SNARE complex formation (“SNARE‐templating”) and membrane fusion in vitro. Furthermore, priming but not docking of synaptic vesicles was disrupted in hippocampal munc18‐1‐null neurons expressing Munc18‐1Y473D. Synaptic transmission was temporarily restored by high‐frequency stimulation, as well as by a Munc18‐1 mutation that results in helix 12 extension, a critical conformational step in vesicle priming. On the other hand, expression of non‐phosphorylatable Munc18‐1 supported normal synaptic transmission. We propose that SFK‐dependent Munc18‐1 phosphorylation may constitute a potent, previously unknown mechanism to shut down synaptic transmission, via direct occlusion of a Synaptobrevin/VAMP2 binding groove and subsequent hindrance of conformational changes in domain 3a responsible for vesicle priming. This would strongly interfere with the essential post‐docking SNARE‐templating role of Munc18‐1, resulting in a largely abolished pool of releasable synaptic vesicles.
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Affiliation(s)
- Marieke Meijer
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam (NCA) VU University Medical Center, Amsterdam, The Netherlands
| | - Bernhard Dörr
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Hanna Ca Lammertse
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam (NCA) VU University Amsterdam, Amsterdam, The Netherlands
| | - Chrysanthi Blithikioti
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam (NCA) VU University Amsterdam, Amsterdam, The Netherlands
| | - Jan Rt van Weering
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam (NCA) VU University Medical Center, Amsterdam, The Netherlands
| | - Ruud Fg Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam (NCA) VU University Amsterdam, Amsterdam, The Netherlands
| | - Thomas H Söllner
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Matthijs Verhage
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam (NCA) VU University Medical Center, Amsterdam, The Netherlands .,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam (NCA) VU University Amsterdam, Amsterdam, The Netherlands
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Neher E. Some Subtle Lessons from the Calyx of Held Synapse. Biophys J 2017; 112:215-223. [PMID: 28122210 PMCID: PMC5266140 DOI: 10.1016/j.bpj.2016.12.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/29/2016] [Accepted: 12/09/2016] [Indexed: 12/12/2022] Open
Abstract
The calyx of Held is a giant nerve terminal that forms a glutamatergic synapse in the auditory pathway. Due to its large size, it offers a number of advantages for biophysical studies, including voltage-clamp of both pre- and postsynaptic compartments and the loading with indicator dyes and caged compounds. Three aspects of recent findings on the calyx are reviewed here, each of which seems to have only subtle consequences for nerve-evoked excitatory postsynaptic currents: vesicle heterogeneity, refractoriness of release sites, and superpriming. Together, they determine short-term plasticity features that are superficially similar to those expected for a simple vesicle pool model. However, detailed consideration of these aspects may be required for the correct mechanistic interpretation of data from synapses with normal and perturbed function, as well as for modeling the dynamics of short-term plasticity.
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Affiliation(s)
- Erwin Neher
- Membrane Biophysics Laboratory, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
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27
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Abstract
Synaptic transmission requires a stable pool of release-ready (primed) vesicles. Here we show that two molecules involved in SNARE-complex assembly, Munc13-1 and Munc18-1, together stabilize release-ready vesicles by preventing de-priming. Replacing neuronal Munc18-1 by a non-neuronal isoform Munc18-2 (Munc18-1/2SWAP) supports activity-dependent priming, but primed vesicles fall back into a non-releasable state (de-prime) within seconds. Munc13-1 deficiency produces a similar defect. Inhibitors of N-ethylmaleimide sensitive factor (NSF), N-ethylmaleimide (NEM) or interfering peptides, prevent de-priming in munc18-1/2SWAP or munc13-1 null synapses, but not in CAPS-1/2 null, another priming-deficient mutant. NEM rescues synaptic transmission in munc13-1 null and munc18-1/2SWAP synapses, in acute munc13-1 null slices and even partially in munc13-1/2 double null synapses. Together these data indicate that Munc13-1 and Munc18-1, but not CAPS-1/2, stabilize primed synaptic vesicles by preventing NSF-dependent de-priming. The molecular mechanism underlying the generation and maintenance of the readily releasable pool composed of primed synaptic vesicles is only partially known. Here the authors show that in mouse primary neurons, Munc13-1 and Munc18-1 stabilize primed synaptic vesicles by preventing NSF-dependent de-priming.
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Heteroreceptors Modulating CGRP Release at Neurovascular Junction: Potential Therapeutic Implications on Some Vascular-Related Diseases. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2056786. [PMID: 28116293 PMCID: PMC5223010 DOI: 10.1155/2016/2056786] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 11/12/2016] [Accepted: 11/27/2016] [Indexed: 01/23/2023]
Abstract
Calcitonin gene-related peptide (CGRP) is a 37-amino-acid neuropeptide belonging to the calcitonin gene peptide superfamily. CGRP is a potent vasodilator with potential therapeutic usefulness for treating vascular-related disease. This peptide is primarily located on C- and Aδ-fibers, which have extensive perivascular presence and a dual sensory-efferent function. Although CGRP has two major isoforms (α-CGRP and β-CGRP), the α-CGRP is the isoform related to vascular actions. Release of CGRP from afferent perivascular nerve terminals has been shown to result in vasodilatation, an effect mediated by at least one receptor (the CGRP receptor). This receptor is an atypical G-protein coupled receptor (GPCR) composed of three functional proteins: (i) the calcitonin receptor-like receptor (CRLR; a seven-transmembrane protein), (ii) the activity-modifying protein type 1 (RAMP1), and (iii) a receptor component protein (RCP). Although under physiological conditions, CGRP seems not to play an important role in vascular tone regulation, this peptide has been strongly related as a key player in migraine and other vascular-related disorders (e.g., hypertension and preeclampsia). The present review aims at providing an overview on the role of sensory fibers and CGRP release on the modulation of vascular tone.
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Superpriming of synaptic vesicles as a common basis for intersynapse variability and modulation of synaptic strength. Proc Natl Acad Sci U S A 2016; 113:E4548-57. [PMID: 27432975 DOI: 10.1073/pnas.1606383113] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Glutamatergic synapses show large variations in strength and short-term plasticity (STP). We show here that synapses displaying an increased strength either after posttetanic potentiation (PTP) or through activation of the phospholipase-C-diacylglycerol pathway share characteristic properties with intrinsically strong synapses, such as (i) pronounced short-term depression (STD) during high-frequency stimulation; (ii) a conversion of that STD into a sequence of facilitation followed by STD after a few conditioning stimuli at low frequency; (iii) an equalizing effect of such conditioning stimulation, which reduces differences among synapses and abolishes potentiation; and (iv) a requirement of long periods of rest for reconstitution of the original STP pattern. These phenomena are quantitatively described by assuming that a small fraction of "superprimed" synaptic vesicles are in a state of elevated release probability (p ∼ 0.5). This fraction is variable in size among synapses (typically about 30%), but increases after application of phorbol ester or during PTP. The majority of vesicles, released during repetitive stimulation, have low release probability (p ∼ 0.1), are relatively uniform in number across synapses, and are rapidly recruited. In contrast, superprimed vesicles need several seconds to be regenerated. They mediate enhanced synaptic strength at the onset of burst-like activity, the impact of which is subject to modulation by slow modulatory transmitter systems.
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Phosphorylation of synaptotagmin-1 controls a post-priming step in PKC-dependent presynaptic plasticity. Proc Natl Acad Sci U S A 2016; 113:5095-100. [PMID: 27091977 DOI: 10.1073/pnas.1522927113] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Presynaptic activation of the diacylglycerol (DAG)/protein kinase C (PKC) pathway is a central event in short-term synaptic plasticity. Two substrates, Munc13-1 and Munc18-1, are essential for DAG-induced potentiation of vesicle priming, but the role of most presynaptic PKC substrates is not understood. Here, we show that a mutation in synaptotagmin-1 (Syt1(T112A)), which prevents its PKC-dependent phosphorylation, abolishes DAG-induced potentiation of synaptic transmission in hippocampal neurons. This mutant also reduces potentiation of spontaneous release, but only if alternative Ca(2+) sensors, Doc2A/B proteins, are absent. However, unlike mutations in Munc13-1 or Munc18-1 that prevent DAG-induced potentiation, the synaptotagmin-1 mutation does not affect paired-pulse facilitation. Furthermore, experiments to probe vesicle priming (recovery after train stimulation and dual application of hypertonic solutions) also reveal no abnormalities. Expression of synaptotagmin-2, which lacks a seven amino acid sequence that contains the phosphorylation site in synaptotagmin-1, or a synaptotagmin-1 variant with these seven residues removed (Syt1(Δ109-116)), supports normal DAG-induced potentiation. These data suggest that this seven residue sequence in synaptotagmin-1 situated in the linker between the transmembrane and C2A domains is inhibitory in the unphosphorylated state and becomes permissive of potentiation upon phosphorylation. We conclude that synaptotagmin-1 phosphorylation is an essential step in PKC-dependent potentiation of synaptic transmission, acting downstream of the two other essential DAG/PKC substrates, Munc13-1 and Munc18-1.
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Pinacho-García M, Marichal-Cancino BA, Villalón CM. Further evidence for the role of histamine H3, but not H1, H2 or H4, receptors in immepip-induced inhibition of the rat cardioaccelerator sympathetic outflow. Eur J Pharmacol 2016; 773:85-92. [PMID: 26826593 DOI: 10.1016/j.ejphar.2016.01.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 12/03/2015] [Accepted: 01/26/2016] [Indexed: 11/25/2022]
Abstract
Since histamine H3 and H4 receptors are coupled to heterotrimeric Gi/o proteins, a signal transduction pathway associated with inhibition of neurotransmitter release, the present study has investigated the inhibition of the rat cardioaccelerator sympathetic outflow induced by the H3/H4 receptor agonist immepip by using antagonists for histamine H1 (ketotifen), H2 (ranitidine), H3 (thioperamide) and H4 (JNJ7777120) receptors. For this purpose, 102 male Wistar rats were pithed, artificially ventilated and prepared for either preganglionic spinal (C7-T1) stimulation of the cardioaccelerator sympathetic outflow (n=90) or i.v. bolus injections of noradrenaline (n=12). This approach resulted in frequency-dependent and dose-dependent tachycardic responses, respectively. I.v. continuous infusions of immepip (3 and 10 μg/kg min), but not of saline (0.02 ml/min), dose-dependently inhibited the sympathetically-induced tachycardic responses. Moreover, the cardiac sympatho-inhibition induced by 10 μg/kg min immepip (which failed to affect the tachycardic responses to i.v. noradrenaline) was: (i) unaltered after i.v. treatment with 1 ml/kg vehicle, 100 μg/kg ketotifen, 3000 μg/kg ranitidine, 30 μg/kg thioperamide or 300 μg/kg JNJ7777120; and (ii) abolished after 100 μg/kg thioperamide (i.v.). These doses of antagonists, which did not affect per se the sympathetically-induced tachycardic responses, were high enough to block their respective receptors. In conclusion, the cardiac sympatho-inhibition induced by 10 μg/kg.min immepip involves histamine H3 receptors, with further pharmacological evidence excluding the involvement of H1, H2 and H4 receptors.
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Affiliation(s)
- Manuel Pinacho-García
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de los Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., México.
| | - Bruno A Marichal-Cancino
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de los Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., México.
| | - Carlos M Villalón
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de los Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., México.
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García M, García-Pedraza JÁ, Villalón CM, Morán A. Pharmacological Evidence that Histamine H3Receptors Mediate Histamine-Induced Inhibition of the Vagal Bradycardic Out-flow in Pithed Rats. Basic Clin Pharmacol Toxicol 2015; 118:113-21. [DOI: 10.1111/bcpt.12475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 08/13/2015] [Indexed: 01/05/2023]
Affiliation(s)
- Mónica García
- Laboratory of Pharmacology; Department of Physiology and Pharmacology; Faculty of Pharmacy; University of Salamanca; Salamanca Spain
| | - José Ángel García-Pedraza
- Laboratory of Pharmacology; Department of Physiology and Pharmacology; Faculty of Pharmacy; University of Salamanca; Salamanca Spain
| | | | - Asunción Morán
- Laboratory of Pharmacology; Department of Physiology and Pharmacology; Faculty of Pharmacy; University of Salamanca; Salamanca Spain
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33
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Zhou H, Liu G. Regulation of density of functional presynaptic terminals by local energy supply. Mol Brain 2015; 8:42. [PMID: 26184109 PMCID: PMC4504454 DOI: 10.1186/s13041-015-0132-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/22/2015] [Indexed: 01/12/2023] Open
Abstract
Background The density of functional synapses is an important parameter in determining the efficacy of synaptic transmission. However, how functional presynaptic terminal density is regulated under natural physiological conditions is still poorly understood. Results We studied the factors controlling the density of presynaptic functional terminals at single dendritic branches of hippocampal neurons and found that elevation of intracellular Mg2+ concentration was effective in increasing the density of functional terminals. Interestingly, the upregulation was not due to synaptogenesis, but to the conversion of a considerable proportion of presynaptic terminals from nonfunctional to functional. Mechanistic studies revealed that the nonfunctional terminals had inadequate Ca2+-sensitivity-related proteins, resulting in very low Ca2+ sensitivity within their vesicle release machinery. We identified energy-dependent axonal transport as a primary factor controlling the amount of Ca2+-sensitivity-related proteins in terminals. The elevation of intracellular Mg2+ enhanced local energy supply and promoted the increase of Ca2+-sensitivity-related proteins in terminals, leading to increased functional terminal density. Conclusions Our study suggests that local energy supply plays a critical role in controlling the density of functional presynaptic terminals, demonstrating the link between energy supply and efficacy of synaptic transmission. Electronic supplementary material The online version of this article (doi:10.1186/s13041-015-0132-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hang Zhou
- Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing, China.
| | - Guosong Liu
- Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing, China.
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34
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Giniatullina A, Maroteaux G, Geerts CJ, Koopmans B, Loos M, Klaassen R, Chen N, van der Schors RC, van Nierop P, Li KW, de Jong J, Altrock WD, Cornelisse LN, Toonen RF, van der Sluis S, Sullivan PF, Stiedl O, Posthuma D, Smit AB, Groffen AJ, Verhage M. Functional characterization of the PCLO p.Ser4814Ala variant associated with major depressive disorder reveals cellular but not behavioral differences. Neuroscience 2015; 300:518-38. [PMID: 26045179 DOI: 10.1016/j.neuroscience.2015.05.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 05/17/2015] [Accepted: 05/20/2015] [Indexed: 12/14/2022]
Abstract
Genome-wide association studies have suggested a role for a genetic variation in the presynaptic gene PCLO in major depressive disorder (MDD). As with many complex traits, the PCLO variant has a small contribution to the overall heritability and the association does not always replicate. One variant (rs2522833, p.Ser4814Ala) is of particular interest given that it is a common, nonsynonymous exon variant near a calcium-sensing part of PCLO. It has been suggested that the molecular effects of such variations penetrate to a variable extent in the population due to phenotypic and genotypic heterogeneity at the population level. More robust effects may be exposed by studying such variations in isolation, in a more homogeneous context. We tested this idea by modeling PCLO variation in a mouse knock-in model expressing the Pclo(SA)(/)(SA) variant. In the highly homogeneous background of inbred mice, two functional effects of the SA-variation were observed at the cellular level: increased synaptic Piccolo levels, and 30% increased excitatory synaptic transmission in cultured neurons. Other aspects of Piccolo function were unaltered: calcium-dependent phospholipid binding, synapse formation in vitro, and synaptic accumulation of synaptic vesicles. Moreover, anxiety, cognition and depressive-like behavior were normal in Pclo(SA)(/)(SA) mice. We conclude that the PCLO p.Ser4814Ala missense variant produces mild cellular phenotypes, which do not translate into behavioral phenotypes. We propose a model explaining how (subtle) cellular phenotypes do not penetrate to the mouse behavioral level but, due to genetic and phenotypic heterogeneity and non-linearity, can produce association signals in human population studies.
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Affiliation(s)
- A Giniatullina
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - G Maroteaux
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - C J Geerts
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - B Koopmans
- Sylics (Synaptologics BV), Amsterdam, The Netherlands
| | - M Loos
- Sylics (Synaptologics BV), Amsterdam, The Netherlands
| | - R Klaassen
- Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - N Chen
- Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - R C van der Schors
- Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - P van Nierop
- Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - K W Li
- Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - J de Jong
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - W D Altrock
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - L N Cornelisse
- Department of Clinical Genetics, Section Complex Trait Genetics, VU University Medical Center, Amsterdam, The Netherlands
| | - R F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - S van der Sluis
- Department of Clinical Genetics, Section Complex Trait Genetics, VU University Medical Center, Amsterdam, The Netherlands
| | - P F Sullivan
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - O Stiedl
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands; Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - D Posthuma
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - A B Smit
- Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands
| | - A J Groffen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - M Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, The Netherlands; Department of Clinical Genetics, Section Complex Trait Genetics, VU University Medical Center, Amsterdam, The Netherlands.
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35
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Lenkey N, Kirizs T, Holderith N, Máté Z, Szabó G, Vizi ES, Hájos N, Nusser Z. Tonic endocannabinoid-mediated modulation of GABA release is independent of the CB1 content of axon terminals. Nat Commun 2015; 6:6557. [PMID: 25891347 PMCID: PMC4413030 DOI: 10.1038/ncomms7557] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/06/2015] [Indexed: 12/28/2022] Open
Abstract
The release of GABA from cholecystokinin-containing interneurons is modulated by type-1 cannabinoid receptors (CB1). Here we tested the hypothesis that the strength of CB1-mediated modulation of GABA release is related to the CB1 content of axon terminals. Basket cell boutons have on average 78% higher CB1 content than those of dendritic-layer-innervating (DLI) cells, a consequence of larger bouton surface and higher CB1 density. The CB1 antagonist AM251 caused a 54% increase in action potential-evoked [Ca(2+)] in boutons of basket cells, but not in DLI cells. However, the effect of AM251 did not correlate with CB1 immunoreactivity of individual boutons. Moreover, a CB1 agonist decreased [Ca(2+)] in a cell type- and CB1-content-independent manner. Replica immunogold labelling demonstrated the colocalization of CB1 with the Cav2.2 Ca(2+) channel subunit. Our data suggest that only a subpopulation of CB1s, within nanometre distances from their target Cav2.2 channels, are responsible for endocannabinoid-mediated modulation of GABA release.
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Affiliation(s)
- Nora Lenkey
- Lendület Laboratory of Cellular Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Budapest
H1083, Hungary
| | - Tekla Kirizs
- Lendület Laboratory of Cellular Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Budapest
H1083, Hungary
- János Szentágothai School of
Neurosciences, Semmelweis University, Budapest H1085,
Hungary
| | - Noemi Holderith
- Lendület Laboratory of Cellular Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Budapest
H1083, Hungary
| | - Zoltán Máté
- Division of Medical Gene Technology, Institute of
Experimental Medicine, Hungarian Academy of Sciences, Budapest
H1083, Hungary
| | - Gábor Szabó
- Division of Medical Gene Technology, Institute of
Experimental Medicine, Hungarian Academy of Sciences, Budapest
H1083, Hungary
| | - E. Sylvester Vizi
- Laboratory of Drug Research, Institute of Experimental
Medicine, Hungarian Academy of Sciences, Budapest H1083,
Hungary
| | - Norbert Hájos
- Lendület Laboratory of Network Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Szigony street 43, Budapest
H1083, Hungary
| | - Zoltan Nusser
- Lendület Laboratory of Cellular Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Budapest
H1083, Hungary
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36
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Schotten S, Meijer M, Walter AM, Huson V, Mamer L, Kalogreades L, ter Veer M, Ruiter M, Brose N, Rosenmund C, Sørensen JB, Verhage M, Cornelisse LN. Additive effects on the energy barrier for synaptic vesicle fusion cause supralinear effects on the vesicle fusion rate. eLife 2015; 4:e05531. [PMID: 25871846 PMCID: PMC4426983 DOI: 10.7554/elife.05531] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 04/13/2015] [Indexed: 01/08/2023] Open
Abstract
The energy required to fuse synaptic vesicles with the plasma membrane
(‘activation energy’) is considered a major determinant in synaptic
efficacy. From reaction rate theory, we predict that a class of modulations exists,
which utilize linear modulation of the energy barrier for fusion to achieve
supralinear effects on the fusion rate. To test this prediction experimentally, we
developed a method to assess the number of releasable vesicles, rate constants for
vesicle priming, unpriming, and fusion, and the activation energy for fusion by
fitting a vesicle state model to synaptic responses induced by hypertonic solutions.
We show that complexinI/II deficiency or phorbol ester stimulation indeed affects
responses to hypertonic solution in a supralinear manner. An additive vs
multiplicative relationship between activation energy and fusion rate provides a
novel explanation for previously observed non-linear effects of
genetic/pharmacological perturbations on synaptic transmission and a novel
interpretation of the cooperative nature of Ca2+-dependent
release. DOI:http://dx.doi.org/10.7554/eLife.05531.001 Information is carried around our nervous system by cells called neurons, which are
connected to each other by junctions known as synapses. Within the neurons, there are
many small compartments known as synaptic vesicles that are essential to the transfer
of information from one neuron to the next. When one neuron is activated, the
synaptic vesicles fuse with the membrane surrounding the cell to release molecules
called neurotransmitters, which cross the synapse and activate the next neuron.
Vesicle fusion is carefully regulated to control the speed and amount of
neurotransmitter release, which determines the level of activation of the next
neuron. Vesicle fusion requires energy, much of which is provided by a set of proteins found
in the synapse. The minimum amount of energy required—called the activation
energy—is influenced by many factors, including the shape of the cell's
membrane at the synapse. It is thought that altering the activation energy required
for fusion may control the activity of synapses, but it is not possible to directly
measure this in living cells. To bypass this problem, Schotten, Meijer, Walter et al. established a new method to
study vesicle fusion. This method combines a mathematical model with experimental
data of the activity of synapses. First, the neurons were placed in a solution
containing the sugar sucrose, which triggered vesicle fusion by lowering the
activation energy. The increase in vesicle fusion was smaller in neurons that lacked
two proteins called complexin I and complexin II—which control vesicle
fusion—than in the normal neurons. A molecule called phorbol ester is also able to activate the release of
neurotransmitters. When cells were treated with both sucrose and phorbol ester, the
speed of vesicle fusion was greater. The experiments show that the effects of
sucrose, phorbol ester, and the complexins multiply together to dramatically alter
vesicle fusion. Schotten, Meijer, Walter et al. suggest a new model for how the activation energy of
vesicle fusion controls the transfer of information across synapses. This might shed
new light on how the efficiency of vesicle fusion is altered when neurons are highly
active, which is thought to have strong implications for how information is processed
in the brain. DOI:http://dx.doi.org/10.7554/eLife.05531.002
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Affiliation(s)
- Sebastiaan Schotten
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
| | - Marieke Meijer
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
| | - Alexander Matthias Walter
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
| | - Vincent Huson
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
| | - Lauren Mamer
- NeuroCure Cluster of Excellence, Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Lawrence Kalogreades
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
| | - Mirelle ter Veer
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
| | - Marvin Ruiter
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Christian Rosenmund
- NeuroCure Cluster of Excellence, Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jakob Balslev Sørensen
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
| | - Lennart Niels Cornelisse
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Medical Center, Amsterdam, Netherlands
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37
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Deviance detection in auditory subcortical structures: what can we learn from neurochemistry and neural connectivity? Cell Tissue Res 2015; 361:215-32. [DOI: 10.1007/s00441-015-2134-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/22/2015] [Indexed: 12/18/2022]
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38
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Manrique-Maldonado G, Altamirano-Espinoza AH, Marichal-Cancino BA, Rivera-Mancilla E, Avilés-Rosas V, Villalón CM. Pharmacological evidence that histamine H3 receptors inhibit the vasodepressor responses by selective stimulation of the rat perivascular sensory CGRPergic outflow. Eur J Pharmacol 2015; 754:25-31. [PMID: 25704614 DOI: 10.1016/j.ejphar.2015.02.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 02/05/2015] [Accepted: 02/11/2015] [Indexed: 10/24/2022]
Abstract
This study has investigated whether pharmacological activation of Gi/o coupled histamine H3/H4 receptors inhibits the rat vasodepressor sensory outflow. For this purpose, 100 male Wistar rats were pithed, artificially ventilated and pretreated (i.v.) with: 25mg/kg gallamine, 2mg/kg/min hexamethonium and 20μg/kg/min methoxamine, followed by i.v. continuous infusions of physiological saline (0.02ml/min) or immepip (3.1, 10 or 31μg/kg/min; a histamine H3/H4 receptor agonist). Under these conditions, electrical stimulation (0.56-5.6Hz; 50V and 2ms) of the spinal cord (T9-T12) resulted in frequency-dependent vasodepressor responses, which were: (i) unchanged during the infusions of saline or immepip (3.1μg/kg/min); and (ii) significantly but, surprisingly, not dose-dependently inhibited by 10 and 31μg/kg/min immepip. Moreover, the sensory-inhibition by 10μg/kg/min immepip (which failed to inhibit the vasodepressor responses by i.v. bolus injections of α-CGRP; 0.1-1µg/kg) was: (i) essentially unaltered after i.v. administration of saline (1ml/kg) or blocking doses of the antagonists ketotifen (100μg/kg; H1), ranitidine (1000μg/kg; H2) or JNJ7777120 (310μg/kg; H4); and (ii) abolished after i.v. thioperamide (310µg/kg; H3). In conclusion, our results suggest that immepip-induced inhibition of the vasodepressor sensory outflow is mainly mediated by prejunctional activation of histamine H3 receptors.
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Affiliation(s)
- Guadalupe Manrique-Maldonado
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico.
| | - Alain H Altamirano-Espinoza
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico.
| | - Bruno A Marichal-Cancino
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico.
| | - Eduardo Rivera-Mancilla
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico.
| | - Victor Avilés-Rosas
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico.
| | - Carlos M Villalón
- Departamento de Farmacobiología, Cinvestav-Coapa, Czda. Tenorios No. 235, Col. Granjas-Coapa, Deleg. Tlalpan, 14330 México D.F., Mexico.
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39
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de Jong APH, Fioravante D. Translating neuronal activity at the synapse: presynaptic calcium sensors in short-term plasticity. Front Cell Neurosci 2014; 8:356. [PMID: 25400547 PMCID: PMC4212674 DOI: 10.3389/fncel.2014.00356] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 10/09/2014] [Indexed: 01/03/2023] Open
Abstract
The complex manner in which patterns of presynaptic neural activity are translated into short-term plasticity (STP) suggests the existence of multiple presynaptic calcium (Ca(2+)) sensors, which regulate the amplitude and time-course of STP and are the focus of this review. We describe two canonical Ca(2+)-binding protein domains (C2 domains and EF-hands) and define criteria that need to be met for a protein to qualify as a Ca(2+) sensor mediating STP. With these criteria in mind, we discuss various forms of STP and identify established and putative Ca(2+) sensors. We find that despite the multitude of proposed sensors, only three are well established in STP: Munc13, protein kinase C (PKC) and synaptotagmin-7. For putative sensors, we pinpoint open questions and potential pitfalls. Finally, we discuss how the molecular properties and modes of action of Ca(2+) sensors can explain their differential involvement in STP and shape net synaptic output.
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Affiliation(s)
| | - Diasynou Fioravante
- Department of Neurobiology, Physiology and Behavior, Center for Neuroscience, University of California Davis Davis, CA, USA
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40
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Role of 5-HT7 receptors in the inhibition of the vasodepressor sensory CGRPergic outflow in pithed rats. Vascul Pharmacol 2014; 63:4-12. [DOI: 10.1016/j.vph.2014.06.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/05/2014] [Accepted: 06/26/2014] [Indexed: 01/03/2023]
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41
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Fioravante D, Chu Y, de Jong AP, Leitges M, Kaeser PS, Regehr WG. Protein kinase C is a calcium sensor for presynaptic short-term plasticity. eLife 2014; 3:e03011. [PMID: 25097249 PMCID: PMC5841930 DOI: 10.7554/elife.03011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 06/24/2014] [Indexed: 01/02/2023] Open
Abstract
In presynaptic boutons, calcium (Ca(2+)) triggers both neurotransmitter release and short-term synaptic plasticity. Whereas synaptotagmins are known to mediate vesicle fusion through binding of high local Ca(2+) to their C2 domains, the proteins that sense smaller global Ca(2+) increases to produce short-term plasticity have remained elusive. Here, we identify a Ca(2+) sensor for post-tetanic potentiation (PTP), a form of plasticity thought to underlie short-term memory. We find that at the functionally mature calyx of Held synapse the Ca(2+)-dependent protein kinase C isoforms α and β are necessary for PTP, and the expression of PKCβ in PKCαβ double knockout mice rescues PTP. Disruption of Ca(2+) binding to the PKCβ C2 domain specifically prevents PTP without impairing other PKCβ-dependent forms of synaptic enhancement. We conclude that different C2-domain-containing presynaptic proteins are engaged by different Ca(2+) signals, and that Ca(2+) increases evoked by tetanic stimulation are sensed by PKCβ to produce PTP.DOI: http://dx.doi.org/10.7554/eLife.03011.001.
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Affiliation(s)
- Diasynou Fioravante
- Department of Neurobiology, Harvard Medical School, Boston, United States Center for Neuroscience, University of California, Davis, Davis, United States
| | - YunXiang Chu
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Arthur Ph de Jong
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Michael Leitges
- The Biotechnology Center of Oslo, University of Oslo, Oslo, Norway
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston, United States
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42
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Presynaptic calcium channel inhibition underlies CB₁ cannabinoid receptor-mediated suppression of GABA release. J Neurosci 2014; 34:7958-63. [PMID: 24899717 DOI: 10.1523/jneurosci.0247-14.2014] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
CB1 cannabinoid receptors (CB1) are located at axon terminals and effectively control synaptic communication and thereby circuit operation widespread in the CNS. Although it is partially uncovered how CB1 activation leads to the reduction of synaptic excitation, the mechanisms of the decrease of GABA release upon activation of these cannabinoid receptors remain elusive. To determine the mechanisms underlying the suppression of synaptic transmission by CB1 at GABAergic synapses, we recorded unitary IPSCs (uIPSCs) at cholecystokinin-expressing interneuron-pyramidal cell connections and imaged presynaptic [Ca(2+)] transients in mouse hippocampal slices. Our results reveal a power function with an exponent of 2.2 between the amplitude of uIPSCs and intrabouton [Ca(2+)]. Altering CB1 function by either increasing endocannabinoid production or removing its tonic activity allowed us to demonstrate that CB1 controls GABA release by inhibiting Ca(2+) entry into presynaptic axon terminals via N-type (Cav2.2) Ca(2+) channels. These results provide evidence for modulation of intrabouton Ca(2+) influx into GABAergic axon terminals by CB1, leading to the effective suppression of synaptic inhibition.
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43
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Hammerschlag AR, Polderman TJC, de Leeuw C, Tiemeier H, White T, Smit AB, Verhage M, Posthuma D. Functional gene-set analysis does not support a major role for synaptic function in attention deficit/hyperactivity disorder (ADHD). Genes (Basel) 2014; 5:604-14. [PMID: 25055203 PMCID: PMC4198920 DOI: 10.3390/genes5030604] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 07/04/2014] [Accepted: 07/10/2014] [Indexed: 12/15/2022] Open
Abstract
Attention Deficit/Hyperactivity Disorder (ADHD) is one of the most common childhood-onset neuropsychiatric disorders. Despite high heritability estimates, genome-wide association studies (GWAS) have failed to find significant genetic associations, likely due to the polygenic character of ADHD. Nevertheless, genetic studies suggested the involvement of several processes important for synaptic function. Therefore, we applied a functional gene-set analysis to formally test whether synaptic functions are associated with ADHD. Gene-set analysis tests the joint effect of multiple genetic variants in groups of functionally related genes. This method provides increased statistical power compared to conventional GWAS. We used data from the Psychiatric Genomics Consortium including 896 ADHD cases and 2455 controls, and 2064 parent-affected offspring trios, providing sufficient statistical power to detect gene sets representing a genotype relative risk of at least 1.17. Although all synaptic genes together showed a significant association with ADHD, this association was not stronger than that of randomly generated gene sets matched for same number of genes. Further analyses showed no association of specific synaptic function categories with ADHD after correction for multiple testing. Given current sample size and gene sets based on current knowledge of genes related to synaptic function, our results do not support a major role for common genetic variants in synaptic genes in the etiology of ADHD.
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Affiliation(s)
- Anke R Hammerschlag
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - Tinca J C Polderman
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - Christiaan de Leeuw
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - Henning Tiemeier
- Department of Child and Adolescent Psychiatry, Erasmus University Medical Center and Sophia Children's Hospital, P.O. Box 2060, 3000 CB Rotterdam, The Netherlands.
| | - Tonya White
- Department of Child and Adolescent Psychiatry, Erasmus University Medical Center and Sophia Children's Hospital, P.O. Box 2060, 3000 CB Rotterdam, The Netherlands.
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - Danielle Posthuma
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
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44
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Stachniak TJ, Ghosh A, Sternson SM. Chemogenetic synaptic silencing of neural circuits localizes a hypothalamus→midbrain pathway for feeding behavior. Neuron 2014; 82:797-808. [PMID: 24768300 PMCID: PMC4306349 DOI: 10.1016/j.neuron.2014.04.008] [Citation(s) in RCA: 302] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2014] [Indexed: 12/28/2022]
Abstract
Brain function is mediated by neural circuit connectivity, and elucidating the role of connections is aided by techniques to block their output. We developed cell-type-selective, reversible synaptic inhibition tools for mammalian neural circuits by leveraging G protein signaling pathways to suppress synaptic vesicle release. Here, we find that the pharmacologically selective designer Gi-protein-coupled receptor hM4D is a presynaptic silencer in the presence of its cognate ligand clozapine-N-oxide (CNO). Activation of hM4D signaling sharply reduced synaptic release probability and synaptic current amplitude. To demonstrate the utility of this tool for neural circuit perturbations, we developed an axon-selective hM4D-neurexin variant and used spatially targeted intracranial CNO injections to localize circuit connections from the hypothalamus to the midbrain responsible for feeding behavior. This synaptic silencing approach is broadly applicable for cell-type-specific and axon projection-selective functional analysis of diverse neural circuits.
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Affiliation(s)
- Tevye J Stachniak
- Janelia Farm Research Campus, HHMI, 19700 Helix Drive, Ashburn, VA 20147, USA; Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Anirvan Ghosh
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Neuroscience Discovery and Translation Area, Pharma Research and Development, F. Hoffmann-La Roche, 4070 Basel, Switzerland
| | - Scott M Sternson
- Janelia Farm Research Campus, HHMI, 19700 Helix Drive, Ashburn, VA 20147, USA.
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Modulation of neurotransmission by GPCRs is dependent upon the microarchitecture of the primed vesicle complex. J Neurosci 2014; 34:260-74. [PMID: 24381287 DOI: 10.1523/jneurosci.3633-12.2014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
G(i/o)-protein-coupled receptors (GPCRs) ubiquitously inhibit neurotransmission, principally via Gβγ, which acts via a number of possible effectors. GPCR effector specificity has traditionally been attributed to Gα, based on Gα's preferential effector targeting in vitro compared with Gβγ's promiscuous targeting of various effectors. In synapses, however, Gβγ clearly targets unique effectors in a receptor-dependent way to modulate synaptic transmission. It remains unknown whether Gβγ specificity in vivo is due to specific Gβγ isoform-receptor associations or to spatial separation of distinct Gβγ pathways through macromolecular interactions. We thus sought to determine how Gβγ signaling pathways within axons remain distinct from one another. In rat hippocampal CA1 axons, GABA(B) receptors (GABA(B)Rs) inhibit presynaptic Ca(2+) entry, and we have now demonstrated that 5-HT(1B) receptors (5-HT(1B)Rs) liberate Gβγ to interact with SNARE complex C terminals with no effect on Ca(2+) entry. Both GABA(B)Rs and 5-HT(1B)Rs inhibit Ca(2+)-evoked neurotransmitter release, but 5-HT(1B)Rs have no effect on Sr(2+)-evoked release. Sr(2+), unlike Ca(2+), does not cause synaptotagmin to compete with Gβγ binding to SNARE complexes. 5-HT(1B)Rs also fail to inhibit release following cleavage of the C terminus of the SNARE complex protein SNAP-25 with botulinum A toxin. Thus, GABA(B)Rs and 5-HT(1B)Rs both localize to presynaptic terminals, but target distinct effectors. We demonstrate that disruption of SNARE complexes and vesicle priming with botulinum C toxin eliminates this selectivity, allowing 5-HT(1B)R inhibition of Ca(2+) entry. We conclude that receptor-effector specificity requires a microarchitecture provided by the SNARE complex during vesicle priming.
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Etherington SJ, Johnstone VPA, Everett AW. Modulation of synaptic vesicle exocytosis in muscle-dependent long-term depression at the amphibian neuromuscular junction. PLoS One 2014; 9:e87174. [PMID: 24489862 PMCID: PMC3904971 DOI: 10.1371/journal.pone.0087174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 12/20/2013] [Indexed: 11/24/2022] Open
Abstract
We have labeled recycling synaptic vesicles at the somatic Bufo marinus neuromuscular junction with the styryl dye FM2-10 and provide direct evidence for refractoriness of exocytosis associated with a muscle activity-dependent form of long-term depression (LTD) at this synapse. FM2-10 dye unloading experiments demonstrated that the rate of vesicle exocytosis from the release ready pool (RRP) of vesicles was more than halved in the LTD (induced by 20 min of low frequency stimulation). Recovery from LTD, observed as a partial recovery of nerve-evoked muscle twitch amplitude, was accompanied by partial recovery of the refractoriness of RRP exocytosis. Unexpectedly, paired pulse plasticity, another routinely used indicator of presynaptic forms of synaptic plasticity, was unchanged in the LTD. We conclude that the LTD induces refractoriness of the neuromuscular vesicle release machinery downstream of presynaptic calcium entry.
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Affiliation(s)
- Sarah J. Etherington
- School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Perth, Western Australia, Australia
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
- * E-mail:
| | - Victoria P. A. Johnstone
- School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Perth, Western Australia, Australia
- Department of Physiology, Monash University, Clayton, Victoria, Australia
| | - Alan W. Everett
- School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Perth, Western Australia, Australia
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A polarized Ca2+, diacylglycerol and STIM1 signalling system regulates directed cell migration. Nat Cell Biol 2014; 16:133-44. [PMID: 24463606 PMCID: PMC3953390 DOI: 10.1038/ncb2906] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 12/10/2013] [Indexed: 12/16/2022]
Abstract
Ca(2+) signals control cell migration by regulating forward movement and cell adhesion. However, it is not well understood how Ca(2+)-regulatory proteins and second messengers are spatially organized in migrating cells. Here we show that receptor tyrosine kinase and phospholipase C signalling are restricted to the front of migrating endothelial leader cells, triggering local Ca(2+) pulses, local depletion of Ca(2+) in the endoplasmic reticulum and local activation of STIM1, supporting pulsatile front retraction and adhesion. At the same time, the mediator of store-operated Ca(2+) influx, STIM1, is transported by microtubule plus ends to the front. Furthermore, higher Ca(2+) pump rates in the front relative to the back of the plasma membrane enable effective local Ca(2+) signalling by locally decreasing basal Ca(2+). Finally, polarized phospholipase C signalling generates a diacylglycerol gradient towards the front that promotes persistent forward migration. Thus, cells employ an integrated Ca(2+) control system with polarized Ca(2+) signalling proteins and second messengers to synergistically promote directed cell migration.
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Marichal-Cancino BA, Manrique-Maldonado G, Altamirano-Espinoza AH, Ruiz-Salinas I, González-Hernández A, MaassenVanDenBrink A, Villalón CM. Analysis of anandamide- and lysophosphatidylinositol-induced inhibition of the vasopressor responses produced by sympathetic stimulation or noradrenaline in pithed rats. Eur J Pharmacol 2013; 721:168-77. [DOI: 10.1016/j.ejphar.2013.09.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 08/09/2013] [Accepted: 09/08/2013] [Indexed: 12/28/2022]
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Altamirano-Espinoza AH, González-Hernández A, Manrique-Maldonado G, Marichal-Cancino BA, Ruiz-Salinas I, Villalón CM. The role of dopamine D2, but not D3 or D4, receptor subtypes, in quinpirole-induced inhibition of the cardioaccelerator sympathetic outflow in pithed rats. Br J Pharmacol 2013; 170:1102-11. [PMID: 24032529 PMCID: PMC3949657 DOI: 10.1111/bph.12358] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 07/26/2013] [Accepted: 08/13/2013] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND PURPOSE Quinpirole (a dopamine D2-like receptor agonist) inhibits the cardioaccelerator sympathetic outflow in pithed rats by sympathoinhibitory D2-like receptors. The present study was designed to identify pharmacologically the specific D2-like receptor subtypes (i.e. D2 , D3 and D4) involved in this sympathoinhibition by quinpirole. EXPERIMENTAL APPROACH One hundred fourteen male Wistar rats were pithed, artificially ventilated with room air and prepared for either preganglionic spinal (C7-T1) stimulation of the cardioaccelerator sympathetic outflow (n = 102) or i.v. bolus injections of exogenous noradrenaline (n = 12). This approach resulted in frequency-dependent and dose-dependent tachycardic responses, respectively, as previously reported by our group. KEY RESULTS I.v. continuous infusions of quinpirole (0.1-10 μg kg(-1) min(-1)), but not of saline (0.02 mL min(-1)), dose-dependently inhibited the sympathetically induced tachycardic responses. Moreover, the cardiac sympathoinhibition induced by 3 μg kg(-1) min(-1) quinpirole (which failed to affect the tachycardic responses to i.v. noradrenaline) was: (i) unchanged after i.v. injections of the antagonists SB-277011-A (D3 ; 100-300 μg kg(-1)) or L-745,870 (D4 ; 30-100 μg kg(-1)); and (ii) markedly blocked and abolished by, respectively, 100 and 300 μg kg(-1) of the D2 preferring receptor subtype antagonist L-741,626. These doses of antagonists, which did not affect per se the sympathetically induced tachycardic responses, were high enough to completely block their respective receptors. CONCLUSIONS AND IMPLICATIONS The cardiac sympathoinhibition induced by 3 μg kg(-1) min(-1) quinpirole involves the dopamine D2 receptor subtype, with no evidence for the involvement of the D3 or D4 subtypes. This provides new evidence for understanding the modulation of the cardioaccelerator sympathetic outflow.
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MESH Headings
- Animals
- Decerebrate State
- Dopamine Agonists/administration & dosage
- Dopamine Agonists/pharmacology
- Dopamine Antagonists/administration & dosage
- Dose-Response Relationship, Drug
- Electric Stimulation
- Heart/innervation
- Heart Rate/drug effects
- Infusions, Intravenous
- Injections, Intravenous
- Male
- Norepinephrine/administration & dosage
- Quinpirole/administration & dosage
- Quinpirole/pharmacology
- Rats
- Rats, Wistar
- Receptors, Dopamine D2/drug effects
- Receptors, Dopamine D2/metabolism
- Receptors, Dopamine D3/drug effects
- Receptors, Dopamine D3/metabolism
- Receptors, Dopamine D4/drug effects
- Receptors, Dopamine D4/metabolism
- Sympathetic Nervous System/drug effects
- Sympathetic Nervous System/metabolism
- Sympathomimetics/administration & dosage
- Time Factors
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Affiliation(s)
| | | | | | | | - I Ruiz-Salinas
- Departamento de Farmacobiología, Cinvestav-CoapaMéxico D.F., México
| | - C M Villalón
- Departamento de Farmacobiología, Cinvestav-CoapaMéxico D.F., México
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Manrique-Maldonado G, González-Hernández A, Altamirano-Espinoza AH, Marichal-Cancino BA, Ruiz-Salinas I, Villalón CM. The role of pre-junctional D2 -like receptors mediating quinpirole-induced inhibition of the vasodepressor sensory CGRPergic out-flow in pithed rats. Basic Clin Pharmacol Toxicol 2013; 114:174-80. [PMID: 23964609 DOI: 10.1111/bcpt.12122] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 08/06/2013] [Indexed: 01/11/2023]
Abstract
Calcitonin gene-related peptide (CGRP) released from perivascular sensory nerves plays a role in the regulation of vascular tone. Indeed, electrical stimulation of the perivascular sensory out-flow in pithed rats produces vasodepressor responses, which are mainly mediated by CGRP release. This study investigated the potential role of dopamine D1 -like and D2 -like receptors in the inhibition of these vasodepressor responses. For this purpose, male Wistar pithed rats (pre-treated i.v. with 25 mg/kg gallamine and 2 mg/kg min. hexamethonium) received i.v. continuous infusions of methoxamine (20 μg/kg min.) followed by physiological saline (0.02 ml/min.), the D1 -like receptor agonist SKF-38393 (0.1-1 μg/kg min.) or the D2 -like receptor agonist quinpirole (0.03-10 μg/kg min.). Under these conditions, electrical stimulation (0.56-5.6 Hz; 50 V and 2 ms) of the thoracic spinal cord (T9 -T12 ) resulted in frequency-dependent vasodepressor responses which were (i) unchanged during the infusions of saline or SKF-38393 and (ii) inhibited during the infusions of quinpirole (except at 0.03 μg/kg min.). Moreover, the inhibition induced by 0.1 μg/kg min. quinpirole (which failed to inhibit the vasodepressor responses elicited by i.v. bolus injections of exogenous α-CGRP; 0.1-1 μg/kg) was (i) unaltered after i.v. treatment with 1 ml/kg of either saline or 5% ascorbic acid and (ii) abolished after 300 μg/kg (i.v.) of the D2 -like receptor antagonists haloperidol or raclopride. These doses of antagonists (enough to completely block D2 -like receptors) essentially failed to modify per se the electrically induced vasodepressor responses. In conclusion, our results suggest that quinpirole-induced inhibition of the vasodepressor sensory CGRPergic out-flow is mainly mediated by pre-junctional D2 -like receptors.
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