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De Gasperi R, Gama Sosa MA, Perez Garcia G, Perez GM, Pryor D, Morrison CLA, Lind R, Abutarboush R, Kawoos U, Statz JK, Patterson J, Hof PR, Zhu CW, Ahlers ST, Cook DG, Elder GA. Metabotropic Glutamate Receptor 2 Expression Is Chronically Elevated in Male Rats With Post-Traumatic Stress Disorder Related Behavioral Traits Following Repetitive Low-Level Blast Exposure. J Neurotrauma 2024; 41:714-733. [PMID: 37917117 PMCID: PMC10902502 DOI: 10.1089/neu.2023.0252] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Many military veterans who experienced blast-related traumatic brain injuries in the conflicts in Iraq and Afghanistan currently suffer from chronic cognitive and mental health problems that include depression and post-traumatic stress disorder (PTSD). Male rats exposed to repetitive low-level blast develop cognitive and PTSD-related behavioral traits that are present for more than 1 year after exposure. We previously reported that a group II metabotropic receptor (mGluR2/3) antagonist reversed blast-induced behavioral traits. In this report, we explored mGluR2/3 expression following blast exposure in male rats. Western blotting revealed that mGluR2 protein (but not mGluR3) was increased in all brain regions studied (anterior cortex, hippocampus, and amygdala) at 43 or 52 weeks after blast exposure but not at 2 weeks or 6 weeks. mGluR2 RNA was elevated at 52 weeks while mGluR3 was not. Immunohistochemical staining revealed no changes in the principally presynaptic localization of mGluR2 by blast exposure. Administering the mGluR2/3 antagonist LY341495 after behavioral traits had emerged rapidly reversed blast-induced effects on novel object recognition and cued fear responses 10 months following blast exposure. These studies support alterations in mGluR2 receptors as a key pathophysiological event following blast exposure and provide further support for group II metabotropic receptors as therapeutic targets in the neurobehavioral effects that follow blast injury.
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Affiliation(s)
- Rita De Gasperi
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Miguel A. Gama Sosa
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- General Medical Research Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, USA
| | - Georgina Perez Garcia
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gissel M. Perez
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, USA
| | - Dylan Pryor
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, USA
| | - Chenel L-A. Morrison
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Northeast Regional Alliance Health Careers Opportunity Program, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Rachel Lind
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, USA
| | - Rania Abutarboush
- Department of Neurotrauma, Naval Medical Research Command, Silver Spring, Maryland, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, Maryland, USA
| | - Usmah Kawoos
- Department of Neurotrauma, Naval Medical Research Command, Silver Spring, Maryland, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, Maryland, USA
| | - Jonathan K. Statz
- Department of Neurotrauma, Naval Medical Research Command, Silver Spring, Maryland, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, Maryland, USA
| | - Jacob Patterson
- Department of Neurotrauma, Naval Medical Research Command, Silver Spring, Maryland, USA
| | - Patrick R. Hof
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Geriatrics and Palliative Care, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mount Sinai Alzheimer's Disease Research Center and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Carolyn W. Zhu
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Geriatrics and Palliative Care, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Stephen T. Ahlers
- Department of Neurotrauma, Naval Medical Research Command, Silver Spring, Maryland, USA
| | - David G. Cook
- Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, Washington, USA
- Department of Medicine, Pharmacology, and Psychiatry, University of Washington, Seattle, Washington, USA
- Department of Behavioral Sciences, University of Washington, Seattle, Washington, USA
| | - Gregory A. Elder
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mount Sinai Alzheimer's Disease Research Center and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Neurology Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, USA
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Kim YS, Lee CJ, Kim JH, Kim YB, Colwell CS, Kim YI. Activation of mGluR1 negatively modulates glutamate-induced phase shifts of the circadian pacemaker in the mouse suprachiasmatic nucleus. Neurobiol Sleep Circadian Rhythms 2023; 14:100089. [PMID: 36874931 PMCID: PMC9982032 DOI: 10.1016/j.nbscr.2023.100089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/25/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
In mammals, photic information delivered to the suprachiasmatic nucleus (SCN) via the retinohypothalamic tract (RHT) plays a crucial role in synchronizing the master circadian clock located in the SCN to the solar cycle. It is well known that glutamate released from the RHT terminals initiates the synchronizing process by activating ionotropic glutamate receptors (iGluRs) on retinorecipient SCN neurons. The potential role of metabotropic glutamate receptors (mGluRs) in modulating this signaling pathway has received less attention. In this study, using extracellular single-unit recordings in mouse SCN slices, we investigated the possible roles of the Gq/11 protein-coupled mGluRs, mGluR1 and mGluR5, in photic resetting. We found that mGluR1 activation in the early night produced phase advances in neural activity rhythms in the SCN, while activation in the late night produced phase delays. In contrast, mGluR5 activation had no significant effect on the phase of these rhythms. Interestingly, mGluR1 activation antagonized phase shifts induced by glutamate through a mechanism that was dependent upon CaV1.3 L-type voltage-gated Ca2+ channels (VGCCs). While both mGluR1-evoked phase delays and advances were inhibited by knockout (KO) of CaV1.3 L-type VGCCs, different signaling pathways appeared to be involved in mediating these effects, with mGluR1 working via protein kinase G in the early night and via protein kinase A signaling in the late night. We conclude that, in the mouse SCN, mGluR1s function to negatively modulate glutamate-evoked phase shifts.
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Affiliation(s)
- Yoon Sik Kim
- Department of Physiology and Neuroscience Research Institute, Korea University College of Medicine, Seoul, 136-705, Republic of Korea
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, Republic of Korea
| | - Ji-Hyeon Kim
- Department of Physiology and Neuroscience Research Institute, Korea University College of Medicine, Seoul, 136-705, Republic of Korea
| | - Young-Beom Kim
- Department of Physiology and Neuroscience Research Institute, Korea University College of Medicine, Seoul, 136-705, Republic of Korea
| | - Christopher S Colwell
- Department of Psychiatry & Biobehavioral Sciences, University of California-Los Angeles, 760 Westwood Plaza, Los Angeles, CA, 90024, USA
| | - Yang In Kim
- Department of Physiology and Neuroscience Research Institute, Korea University College of Medicine, Seoul, 136-705, Republic of Korea
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Group II metabotropic glutamate receptor activation suppresses ATP currents in rat dorsal root ganglion neurons. Neuropharmacology 2023; 227:109443. [PMID: 36709909 DOI: 10.1016/j.neuropharm.2023.109443] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 01/28/2023]
Abstract
P2X3 receptors and group II metabotropic glutamate receptors (mGluRs) have been found to be expressed in primary sensory neurons. P2X3 receptors participate in a variety of pain processes, while the activation of mGluRs has an analgesic effect. However, it's still unclear whether there is a link between them in pain. Herein, we reported that the group II mGluR activation inhibited the electrophysiological activity of P2X3 receptors in rat dorsal root ganglia (DRG) neurons. Group II mGluR agonist LY354740 concentration-dependently decreased P2X3 receptor-mediated and α,β-methylene-ATP (α,β-meATP)-evoked inward currents in DRG neurons. LY354740 significantly suppressed the maximum response of P2X3 receptor to α,β-meATP, but did not change their affinity. Inhibition of ATP currents by LY354740 was blocked by the group II mGluR antagonist LY341495, also prevented by the intracellular dialysis of either the Gi/o protein inhibitor pertussis toxin, the cAMP analog 8-Br-cAMP, or the protein kinase A (PKA) inhibitor H-89. Moreover, LY354740 decreased α,β-meATP-induced membrane potential depolarization and action potential bursts in DRG neurons. Finally, intraplantar injection of LY354740 also relieved α,β-meATP-induced spontaneous nociceptive behaviors and mechanical allodynia in rats by activating peripheral group Ⅱ mGluRs. These results indicated that peripheral group II mGluR activation inhibited the functional activity of P2X3 receptors via a Gi/o protein and cAMP/PKA signaling pathway in rat DRG neurons, which revealed a novel mechanism underlying analgesic effects of peripheral group II mGluRs. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
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Onisiforou A, Georgiou P, Zanos P. Role of group II metabotropic glutamate receptors in ketamine's antidepressant actions. Pharmacol Biochem Behav 2023; 223:173531. [PMID: 36841543 DOI: 10.1016/j.pbb.2023.173531] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/08/2023] [Accepted: 02/15/2023] [Indexed: 02/26/2023]
Abstract
Major Depressive Disorder (MDD) is a serious neuropsychiatric disorder afflicting around 16-17 % of the global population and is accompanied by recurrent episodes of low mood, hopelessness and suicidal thoughts. Current pharmacological interventions take several weeks to even months for an improvement in depressive symptoms to emerge, with a significant percentage of individuals not responding to these medications at all, thus highlighting the need for rapid and effective next-generation treatments for MDD. Pre-clinical studies in animals have demonstrated that antagonists of the metabotropic glutamate receptor subtype 2/3 (mGlu2/3 receptor) exert rapid antidepressant-like effects, comparable to the actions of ketamine. Therefore, it is possible that mGlu2 or mGlu3 receptors to have a regulatory role on the unique antidepressant properties of ketamine, or that convergent intracellular mechanisms exist between mGlu2/3 receptor signaling and ketamine's effects. Here, we provide a comprehensive and critical evaluation of the literature on these convergent processes underlying the antidepressant action of mGlu2/3 receptor inhibitors and ketamine. Importantly, combining sub-threshold doses of mGlu2/3 receptor inhibitors with sub-antidepressant ketamine doses induce synergistic antidepressant-relevant behavioral effects. We review the evidence supporting these combinatorial effects since sub-effective dosages of mGlu2/3 receptor antagonists and ketamine could reduce the risk for the emergence of significant adverse events compared with taking normal dosages. Overall, deconvolution of ketamine's pharmacological targets will give critical insights to influence the development of next-generation antidepressant treatments with rapid actions.
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Affiliation(s)
- Anna Onisiforou
- Department of Psychology, University of Cyprus, Nicosia 2109, Cyprus
| | - Polymnia Georgiou
- Department of Biological Sciences, University of Cyprus, Nicosia 2109, Cyprus; Department of Psychology, University of Wisconsin Milwaukee, WI 53211, USA
| | - Panos Zanos
- Department of Psychology, University of Cyprus, Nicosia 2109, Cyprus.
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Group II metabotropic glutamate receptor activation attenuates acid-sensing ion channel currents in rat primary sensory neurons. J Biol Chem 2023; 299:102953. [PMID: 36731795 PMCID: PMC9976456 DOI: 10.1016/j.jbc.2023.102953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 02/01/2023] Open
Abstract
Acid-sensing ion channels (ASICs) play an important role in pain associated with tissue acidification. Peripheral inhibitory group II metabotropic glutamate receptors (mGluRs) have analgesic effects in a variety of pain conditions. Whether there is a link between ASICs and mGluRs in pain processes is still unclear. Herein, we show that the group II mGluR agonist LY354740 inhibited acid-evoked ASIC currents and action potentials in rat dorsal root ganglia neurons. LY354740 reduced the maximum current response to protons, but it did not change the sensitivity of ASICs to protons. LY354740 inhibited ASIC currents by activating group II mGluRs. We found that the inhibitory effect of LY354740 was blocked by intracellular application of the Gi/o protein inhibitor pertussis toxin and the cAMP analogue 8-Br-cAMP and mimicked by the protein kinase A (PKA) inhibitor H-89. LY354740 also inhibited ASIC3 currents in CHO cells coexpressing mGluR2 and ASIC3 but not in cells expressing ASIC3 alone. In addition, intraplantar injection of LY354740 dose-dependently alleviated acid-induced nociceptive behavior in rats through local group II mGluRs. Together, these results suggested that activation of peripheral group II mGluRs inhibited the functional activity of ASICs through a mechanism that depended on Gi/o proteins and the intracellular cAMP/PKA signaling pathway in rat dorsal root ganglia neurons. We propose that peripheral group II mGluRs are an important therapeutic target for ASIC-mediated pain.
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de Lima IB, Ribeiro FM. The Implication of Glial Metabotropic Glutamate Receptors in Alzheimer's Disease. Curr Neuropharmacol 2023; 21:164-182. [PMID: 34951388 PMCID: PMC10190153 DOI: 10.2174/1570159x20666211223140303] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/05/2021] [Accepted: 12/16/2021] [Indexed: 11/22/2022] Open
Abstract
Alzheimer's disease (AD) was first identified more than 100 years ago, yet aspects pertaining to its origin and the mechanisms underlying disease progression are not well known. To this date, there is no therapeutic approach or disease-modifying drug that could halt or at least delay disease progression. Until recently, glial cells were seen as secondary actors in brain homeostasis. Although this view was gradually refuted and the relevance of glial cells for the most diverse brain functions such as synaptic plasticity and neurotransmission was vastly proved, many aspects of its functioning, as well as its role in pathological conditions, remain poorly understood. Metabotropic glutamate receptors (mGluRs) in glial cells were shown to be involved in neuroinflammation and neurotoxicity. Besides its relevance for glial function, glutamatergic receptors are also central in the pathology of AD, and recent studies have shown that glial mGluRs play a role in the establishment and progression of AD. AD-related alterations in Ca2+ signalling, APP processing, and Aβ load, as well as AD-related neurodegeneration, are influenced by glial mGluRs. However, different types of mGluRs play different roles, depending on the cell type and brain region that is being analysed. Therefore, in this review, we focus on the current understanding of glial mGluRs and their implication in AD, providing an insight for future therapeutics and identifying existing research gaps worth investigating.
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Affiliation(s)
- Izabella B.Q. de Lima
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Fabíola M. Ribeiro
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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The role of thalamic group II mGlu receptors in health and disease. Neuronal Signal 2022; 6:NS20210058. [PMID: 36561092 PMCID: PMC9760452 DOI: 10.1042/ns20210058] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 12/25/2022] Open
Abstract
The thalamus plays a pivotal role in the integration and processing of sensory, motor, and cognitive information. It is therefore important to understand how the thalamus operates in states of both health and disease. In the present review, we discuss the function of the Group II metabotropic glutamate (mGlu) receptors within thalamic circuitry, and how they may represent therapeutic targets in treating disease states associated with thalamic dysfunction.
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Li SH, Abd-Elrahman KS, Ferguson SS. Targeting mGluR2/3 for treatment of neurodegenerative and neuropsychiatric diseases. Pharmacol Ther 2022; 239:108275. [DOI: 10.1016/j.pharmthera.2022.108275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 10/15/2022]
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Tyler RE, Besheer J, Joffe ME. Advances in translating mGlu 2 and mGlu 3 receptor selective allosteric modulators as breakthrough treatments for affective disorders and alcohol use disorder. Pharmacol Biochem Behav 2022; 219:173450. [PMID: 35988792 PMCID: PMC10405528 DOI: 10.1016/j.pbb.2022.173450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/26/2022] [Accepted: 08/13/2022] [Indexed: 11/16/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are promising targets for the treatment of affective disorders and alcohol use disorder (AUD). Nonspecific ligands for Group II (mGlu2 and mGlu3) mGlu receptors have demonstrated consistent therapeutic potential for affective disorders in preclinical models. Disentangling the specific roles of mGlu2 versus mGlu3 receptors in these effects has persisted as a major challenge, in part due to pharmacological limitations. However, the recent development of highly specific allosteric modulators for both mGlu2 and mGlu3 receptors have enabled straightforward and rigorous investigations into the specific function of each receptor. Here, we review recent experiments using these compounds that have demonstrated both similar and distinct receptor functions in behavioral, molecular, and electrophysiological measures associated with basal function and preclinical models of affective disorders. Studies using these selective drugs have demonstrated that mGlu2 is the predominant receptor subclass involved in presynaptic neurotransmitter release in prefrontal cortex. By contrast, the activation of postsynaptic mGlu3 receptors induces a cascade of cellular changes that results in AMPA receptor internalization, producing long-term depression and diminishing excitatory drive. Acute stress decreases the mGlu3 receptor function and dynamically alters transcript expression for both mGlu2 (Grm2) and mGlu3 (Grm3) receptors in brain areas involved in reward and stress. Accordingly, both mGlu2 and mGlu3 negative allosteric modulators show acute antidepressant-like effects and potential prophylactic effects against acute and traumatic stressors. The wide array of effects displayed by these new allosteric modulators of mGlu2 and mGlu3 receptors suggest that these drugs may act through improving endophenotypes of symptoms observed across several neuropsychiatric disorders. Therefore, recently developed allosteric modulators selective for mGlu2 or mGlu3 receptors show promise as potential therapeutics for affective disorders and AUD.
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Affiliation(s)
- Ryan E Tyler
- Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Neuroscience Curriculum, University of North Carolina at Chapel Hill, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, USA
| | - Joyce Besheer
- Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Neuroscience Curriculum, University of North Carolina at Chapel Hill, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, USA
| | - Max E Joffe
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15219, USA; Translational Neuroscience Program, University of Pittsburgh, USA.
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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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Joffe ME, Santiago CI, Vermudez SAD, Fisher NM, Dogra S, Niswender CM, Jeffrey Conn P. Frontal cortex genetic ablation of metabotropic glutamate receptor subtype 3 (mGlu 3) impairs postsynaptic plasticity and modulates affective behaviors. Neuropsychopharmacology 2021; 46:2148-2157. [PMID: 34035469 PMCID: PMC8505649 DOI: 10.1038/s41386-021-01041-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/22/2021] [Accepted: 05/04/2021] [Indexed: 12/20/2022]
Abstract
Clinical and translational studies suggest that prefrontal cortex (PFC) dysregulation is a hallmark feature of several affective disorders. Thus, investigating the mechanisms involved in the regulation of PFC function and synaptic plasticity could aid in developing new medications. In recent years, the mGlu2 and mGlu3 subtypes of metabotropic glutamate (mGlu) receptors have emerged as exciting potential targets for the treatment of affective disorders, as mGlu2/3 antagonists exert antidepressant-like effects across many rodent models. Several recent studies suggest that presynaptic mGlu2 receptors may contribute to these effects by regulating excitatory transmission at synapses from the thalamus to the PFC. Interestingly, we found that mGlu3 receptors also inhibit excitatory drive to the PFC but act by inducing long-term depression (LTD) at amygdala-PFC synapses. It remains unclear, however, whether blockade of presynaptic, postsynaptic, or glial mGlu3 receptors contribute to long-term effects on PFC circuit function and antidepressant-like effects of mGlu2/3 antagonists. To address these outstanding questions, we leveraged transgenic Grm3fl/fl mice and viral-mediated gene transfer to genetically ablate mGlu3 receptors from pyramidal cells in the frontal cortex of adult mice of all sexes. Consistent with a role for mGlu3 in PFC pyramidal cells, mGlu3-dependent amygdala-cortical LTD was eliminated following mGlu3 receptor knockdown. Furthermore, knockdown mice displayed a modest, task-specific anxiolytic phenotype and decreased passive coping behaviors. These studies reveal that postsynaptic mGlu3 receptors are critical for mGlu3-dependent LTD and provide convergent genetic evidence suggesting that modulating cortical mGlu3 receptors may provide a promising new approach for the treatment of mood disorders.
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Affiliation(s)
- Max E Joffe
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, USA.
- Vanderbilt Center for Addiction Research, Nashville, TN, USA.
| | - Chiaki I Santiago
- Vanderbilt University, Nashville, TN, USA
- Division of Biological Sciences, Section of Neurobiology, Center for Neural Circuits and Behavior, University of California San Diego, San Diego, USA
| | - Sheryl Anne D Vermudez
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, USA
| | - Nicole M Fisher
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, USA
| | - Shalini Dogra
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, USA
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, USA
- Vanderbilt Kennedy Center, Nashville, TN, USA
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, USA.
- Vanderbilt Center for Addiction Research, Nashville, TN, USA.
- Vanderbilt University, Nashville, TN, USA.
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Liu X, Ying J, Wang X, Zheng Q, Zhao T, Yoon S, Yu W, Yang D, Fang Y, Hua F. Astrocytes in Neural Circuits: Key Factors in Synaptic Regulation and Potential Targets for Neurodevelopmental Disorders. Front Mol Neurosci 2021; 14:729273. [PMID: 34658786 PMCID: PMC8515196 DOI: 10.3389/fnmol.2021.729273] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/02/2021] [Indexed: 12/14/2022] Open
Abstract
Astrocytes are the major glial cells in the brain, which play a supporting role in the energy and nutritional supply of neurons. They were initially regarded as passive space-filling cells, but the latest progress in the study of the development and function of astrocytes highlights their active roles in regulating synaptic transmission, formation, and plasticity. In the concept of "tripartite synapse," the bidirectional influence between astrocytes and neurons, in addition to their steady-state and supporting function, suggests that any negative changes in the structure or function of astrocytes will affect the activity of neurons, leading to neurodevelopmental disorders. The role of astrocytes in the pathophysiology of various neurological and psychiatric disorders caused by synaptic defects is increasingly appreciated. Understanding the roles of astrocytes in regulating synaptic development and the plasticity of neural circuits could help provide new treatments for these diseases.
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Affiliation(s)
- Xing Liu
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Jun Ying
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Xifeng Wang
- Department of Anesthesiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qingcui Zheng
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Tiancheng Zhao
- Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Sungtae Yoon
- Helping Minds International Charitable Foundation, New York, NY, United States
| | - Wen Yu
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Danying Yang
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Yang Fang
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Fuzhou Hua
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
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Copeland CS, Neale SA, Nisenbaum ES, Salt TE. Group II metabotropic glutamate receptor (mGlu 2 and mGlu 3 ) roles in thalamic processing. Br J Pharmacol 2021; 179:1607-1619. [PMID: 34355803 DOI: 10.1111/bph.15640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 06/02/2021] [Accepted: 07/12/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND AND PURPOSE As the thalamus underpins almost all aspects of behaviour, it is important to understand how the thalamus operates. Group II metabotropic glutamate (mGlu2 /mGlu3 ) receptor activation reduces inhibition in thalamic nuclei originating from the surrounding thalamic reticular nucleus (TRN). Whilst an mGlu2 component to this effect has been reported, in this study, we demonstrate that it is likely, largely mediated via mGlu3 . EXPERIMENTAL APPROACH The somatosensory ventrobasal thalamus (VB) is an established model for probing fundamental principles of thalamic function. In vitro slices conserving VB-TRN circuitry from wild-type and mGlu3 knockout mouse brains were used to record IPSPs and mIPSCs. In vivo extracellular recordings were made from VB neurons in anaesthetised rats. A range of selective pharmacological agents were used to probe Group II mGlu receptor function (agonist, LY354740; antagonist, LY341495; mGlu2 positive allosteric modulator, LY487379 and mixed mGlu2 agonist/mGlu3 antagonist LY395756). KEY RESULTS The in vitro and in vivo data are complementary and suggest that mGlu3 receptor activation is largely responsible for potentiating responses to somatosensory stimulation by reducing inhibition from the TRN. CONCLUSIONS AND IMPLICATIONS mGlu3 receptor activation in the VB likely enables important somatosensory information to be discerned from background activity. These mGlu3 receptors are likely to be endogenously activated via 'glutamate spillover'. In cognitive thalamic nuclei, this mechanism may be of importance in governing attentional processes. Positive allosteric modulation of endogenous mGlu3 receptor activation may therefore enhance cognitive function in pathophysiological disease states, such as schizophrenia, thus representing a highly specific therapeutic target.
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Affiliation(s)
- Caroline S Copeland
- Institute of Pharmaceutical Sciences, King's College London, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | | | - Eric S Nisenbaum
- Pain/Migraine Research Group, Eli Lilly and Company, Indianapolis, Indiana, USA
| | - Thomas E Salt
- Institute of Ophthalmology, University College London, London, UK.,Neurexpert Limited, The Core, Newcastle upon Tyne, UK
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14
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Defining the Homo- and Heterodimerization Propensities of Metabotropic Glutamate Receptors. Cell Rep 2021; 31:107605. [PMID: 32375054 PMCID: PMC7271767 DOI: 10.1016/j.celrep.2020.107605] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/10/2020] [Accepted: 04/10/2020] [Indexed: 01/02/2023] Open
Abstract
The eight metabotropic glutamate receptors (mGluRs) serve critical modulatory roles throughout the nervous system. The molecular diversity of mGluRs is thought to be further expanded by the formation of heterodimers, but the co-expression of mGluR subtypes at the cellular level and the relative propensities of heterodimer formation are not well known. Here, we analyze single-cell RNA sequencing data and find that cortical pyramidal cells express multiple mGluR subtypes with distinct profiles for different receptor combinations. We then develop quantitative, fluorescence-based assays to define the relative homo- and heterodimer propensities across group-I, -II, and -III mGluRs. We find a strong preference for heterodimerization in a number of cases, including mGluR2 with mGluR3, which we confirm in frontal cortex using in situ RNA hybridization and co-immunoprecipitation. Together, our findings support the biological relevance of mGluR heterodimerization and highlight the complex landscape of mGluR populations in the brain.
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15
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Boczek T, Mackiewicz J, Sobolczyk M, Wawrzyniak J, Lisek M, Ferenc B, Guo F, Zylinska L. The Role of G Protein-Coupled Receptors (GPCRs) and Calcium Signaling in Schizophrenia. Focus on GPCRs Activated by Neurotransmitters and Chemokines. Cells 2021; 10:cells10051228. [PMID: 34067760 PMCID: PMC8155952 DOI: 10.3390/cells10051228] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 01/13/2023] Open
Abstract
Schizophrenia is a common debilitating disease characterized by continuous or relapsing episodes of psychosis. Although the molecular mechanisms underlying this psychiatric illness remain incompletely understood, a growing body of clinical, pharmacological, and genetic evidence suggests that G protein-coupled receptors (GPCRs) play a critical role in disease development, progression, and treatment. This pivotal role is further highlighted by the fact that GPCRs are the most common targets for antipsychotic drugs. The GPCRs activation evokes slow synaptic transmission through several downstream pathways, many of them engaging intracellular Ca2+ mobilization. Dysfunctions of the neurotransmitter systems involving the action of GPCRs in the frontal and limbic-related regions are likely to underly the complex picture that includes the whole spectrum of positive and negative schizophrenia symptoms. Therefore, the progress in our understanding of GPCRs function in the control of brain cognitive functions is expected to open new avenues for selective drug development. In this paper, we review and synthesize the recent data regarding the contribution of neurotransmitter-GPCRs signaling to schizophrenia symptomology.
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Affiliation(s)
- Tomasz Boczek
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 92215 Lodz, Poland; (T.B.); (J.M.); (M.S.); (J.W.); (M.L.); (B.F.)
| | - Joanna Mackiewicz
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 92215 Lodz, Poland; (T.B.); (J.M.); (M.S.); (J.W.); (M.L.); (B.F.)
| | - Marta Sobolczyk
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 92215 Lodz, Poland; (T.B.); (J.M.); (M.S.); (J.W.); (M.L.); (B.F.)
| | - Julia Wawrzyniak
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 92215 Lodz, Poland; (T.B.); (J.M.); (M.S.); (J.W.); (M.L.); (B.F.)
| | - Malwina Lisek
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 92215 Lodz, Poland; (T.B.); (J.M.); (M.S.); (J.W.); (M.L.); (B.F.)
| | - Bozena Ferenc
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 92215 Lodz, Poland; (T.B.); (J.M.); (M.S.); (J.W.); (M.L.); (B.F.)
| | - Feng Guo
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang 110122, China;
| | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, 92215 Lodz, Poland; (T.B.); (J.M.); (M.S.); (J.W.); (M.L.); (B.F.)
- Correspondence:
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16
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Kryszkowski W, Boczek T. The G Protein-Coupled Glutamate Receptors as Novel Molecular Targets in Schizophrenia Treatment-A Narrative Review. J Clin Med 2021; 10:jcm10071475. [PMID: 33918323 PMCID: PMC8038150 DOI: 10.3390/jcm10071475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/24/2021] [Accepted: 03/28/2021] [Indexed: 12/02/2022] Open
Abstract
Schizophrenia is a severe neuropsychiatric disease with an unknown etiology. The research into the neurobiology of this disease led to several models aimed at explaining the link between perturbations in brain function and the manifestation of psychotic symptoms. The glutamatergic hypothesis postulates that disrupted glutamate neurotransmission may mediate cognitive and psychosocial impairments by affecting the connections between the cortex and the thalamus. In this regard, the greatest attention has been given to ionotropic NMDA receptor hypofunction. However, converging data indicates metabotropic glutamate receptors as crucial for cognitive and psychomotor function. The distribution of these receptors in the brain regions related to schizophrenia and their regulatory role in glutamate release make them promising molecular targets for novel antipsychotics. This article reviews the progress in the research on the role of metabotropic glutamate receptors in schizophrenia etiopathology.
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Affiliation(s)
- Waldemar Kryszkowski
- General Psychiatric Ward, Babinski Memorial Hospital in Lodz, 91229 Lodz, Poland;
| | - Tomasz Boczek
- Department of Molecular Neurochemistry, Medical University of Lodz, 92215 Lodz, Poland
- Correspondence:
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17
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Zinni M, Mairesse J, Pansiot J, Fazio F, Iacovelli L, Antenucci N, Orlando R, Nicoletti F, Vaiman D, Baud O. mGlu3 receptor regulates microglial cell reactivity in neonatal rats. J Neuroinflammation 2021; 18:13. [PMID: 33407565 PMCID: PMC7789385 DOI: 10.1186/s12974-020-02049-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 12/09/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Perinatal inflammation is a key factor of brain vulnerability in neonates born preterm or with intra-uterine growth restriction (IUGR), two leading conditions associated with brain injury and responsible for neurocognitive and behavioral disorders. Systemic inflammation is recognized to activate microglia, known to be the critical modulators of brain vulnerability. Although some evidence supports a role for metabotropic glutamate receptor 3 (mGlu3 receptor) in modulation of neuroinflammation, its functions are still unknown in the developing microglia. METHODS We used a double-hit rat model of perinatal brain injury induced by a gestational low-protein diet combined with interleukin-1β injections (LPD/IL-1β), mimicking both IUGR and prematurity-related inflammation. The effect of LPD/IL-1β on mGlu3 receptor expression and the effect of mGlu3 receptor modulation on microglial reactivity were investigated using a combination of pharmacological, histological, and molecular and genetic approaches. RESULTS Exposure to LPD/IL-1β significantly downregulated Grm3 gene expression in the developing microglia. Both transcriptomic analyses and pharmacological modulation of mGlu3 receptor demonstrated its central role in the control of inflammation in resting and activated microglia. Microglia reactivity to inflammatory challenge induced by LPD/IL-1β exposure was reduced by an mGlu3 receptor agonist. Conversely, both specific pharmacological blockade, siRNA knock-down, and genetic knock-out of mGlu3 receptors mimicked the pro-inflammatory phenotype observed in microglial cells exposed to LPD/IL-1β. CONCLUSIONS Overall, these data show that Grm3 plays a central role in the regulation of microglial reactivity in the immature brain. Selective pharmacological activation of mGlu3 receptors may prevent inflammatory-induced perinatal brain injury.
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Affiliation(s)
- Manuela Zinni
- Inserm UMR1141 NeuroDiderot, Univ. Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Jérôme Mairesse
- Inserm UMR1141 NeuroDiderot, Univ. Paris Diderot, Sorbonne Paris Cité, Paris, France.,Laboratory of Child Growth and Development, University of Geneva, Geneva, Switzerland
| | - Julien Pansiot
- Inserm UMR1141 NeuroDiderot, Univ. Paris Diderot, Sorbonne Paris Cité, Paris, France
| | | | - Luisa Iacovelli
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Nico Antenucci
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Rosamaria Orlando
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Ferdinando Nicoletti
- IRCCS Neuromed, Pozzilli, Italy.,Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Daniel Vaiman
- Institut Cochin, Inserm U1016, UMR8104 CNRS, Paris, France
| | - Olivier Baud
- Inserm UMR1141 NeuroDiderot, Univ. Paris Diderot, Sorbonne Paris Cité, Paris, France. .,Laboratory of Child Growth and Development, University of Geneva, Geneva, Switzerland. .,Division of Neonatology and Pediatric Intensive Care, Children's University Hospital of Geneva, Geneva, Switzerland.
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18
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Khodagholi F, Maleki A, Motamedi F, Mousavi MA, Rafiei S, Moslemi M. Oxytocin Prevents the Development of 3-NP-Induced Anxiety and Depression in Male and Female Rats: Possible Interaction of OXTR and mGluR2. Cell Mol Neurobiol 2020; 42:1105-1123. [PMID: 33201416 DOI: 10.1007/s10571-020-01003-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/07/2020] [Indexed: 01/01/2023]
Abstract
Huntington disease (HD) is a progressive neurological disorder with dominant motor symptoms. It also has psychiatric manifestations, like anxiety and depression, that can emerge themselves before motor symptoms and impose a major burden on patients. Oxytocin (OXT) is a newly emerged treatment for disorders like autism and schizophrenia and recently is using to alleviate depression and anxiety. In the current study, we investigated the behavioral and molecular effects of OXT on the development of anxiety and depression in 3-nitropropionic acid (3-NP)-induced model of HD. Anxiety- and depression-like behaviors as well as the levels of oxytocin receptor (OXTR), metabotropic glutamate receptor (mGluR) 2, mGluR5, and glutathione (GSH) were measured in striatum, hippocampus, prefrontal cortex, and amygdala. Also, we questioned if sex had any modulatory effect. We found that 3-NP increased anxiety and depression compared to controls. It also reduced the levels of OXTR and mGluR2, increased mGluR5, and reduced GSH in studied brain regions. Pretreatment with OXT before the injection of 3-NP ameliorated anxiety and depression. Additionally, it protected the brain from developing low levels of OXTR, mGluR2, and GSH and high levels of mGluR5 in studied regions. The protective effects of OXT were similar between male and female animals. These data suggest that OXTR, mGluR2, mGluR5, and GSH may contribute to psychiatric manifestations of HD. In addition, pretreatment with OXT could prevent the mood changes in male and female rats.
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Affiliation(s)
- Fariba Khodagholi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Maleki
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fereshteh Motamedi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Alsadat Mousavi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahrbanoo Rafiei
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehdi Moslemi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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19
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The mGluR2/3 agonist pomaglumetad methionil normalizes aberrant dopamine neuron activity via action in the ventral hippocampus. Neuropsychopharmacology 2020; 45:2106-2113. [PMID: 32663839 PMCID: PMC7547679 DOI: 10.1038/s41386-020-0764-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/27/2020] [Accepted: 07/08/2020] [Indexed: 11/09/2022]
Abstract
The group 2 metabotropic glutamate receptor (mGluR2/3) agonist, pomaglumetad methionil (POM), showed promise as a novel antipsychotic in preclinical research but failed to show efficacy in clinical trials, though it has been suggested that it may be effective in certain patient populations. Although previous studies have shown that mGluR2/3 agonists have no effect on dopamine (DA) in wild type rats, we used the methylzoxymethanol acetate (MAM) model to determine whether POM may indirectly normalize DA neuron activity in a model representative of the hyperdopaminergic state thought to underlie psychosis, compared to SAL rats, using in vivo, anesthetized, electrophysiological recordings. POM dose-dependently reduced the number of spontaneously active DA neurons in the VTA of MAM rats to control levels without affecting DA firing in SAL rats, which persisted following 14d repeated treatment with POM. In female MAM rats, POM significantly reduced DA neuron population activity only during proestrous and estrous stages. MAM rats also demonstrated dose-dependent improvement in novel object recognition following acute POM, which was not observed in SAL rats. Similar to the MAM rats, DA neuron population activity was increased in a hippocampal-dependent manner following acute restraint stress. Administration of POM prior to 2 h restraint stress prevented the restraint-induced increase in DA neuron population activity, and this effect was blocked by pretreatment with an mGluR2/3 antagonist. Thus, the ability of POM to reduce the hyperdopaminergic activity in both MAM rats and in wild type rats following restraint stress suggests that it can indirectly regulate DA neuron activity, which may underlie its potential therapeutic effects.
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20
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Moridi H, Sarihi A, Habibitabar E, Shateri H, Salehi I, Komaki A, Karimi J, Karimi SA. Effects of post-training administration of LY341495, as an mGluR2/3 antagonist on spatial memory deficit in rats fed with high-fat diet. IBRO Rep 2020; 9:241-246. [PMID: 33024878 PMCID: PMC7527618 DOI: 10.1016/j.ibror.2020.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
High-fat diets (HFDs) adversely influence glutamate metabolism and neurotransmission. The precise role of the group II metabotropic glutamate receptors (mGluR2/3) antagonist on spatial memory deficit following consumption of HFD has not yet been clarified. Therefore, in this study, we examined the effects of post-training administration of mGluR2/3 antagonism; LY341495 on spatial memory in rats fed with HFD (for 10 weeks) by using Morris Water Maze (MWM) task. The training session for testing memory acquisition in MWM consisted of 4 trials per day for 4 consecutive days. Twenty-four hours after the last training session the spatial probe test (retention) was given. Intraperitoneal injection (i.p) injection of LY341495 was done 30 min before probe test. Our results showed that 10 weeks consumption of HFD had no significant effect on escape latency and swimming distance in memory acquisition. Our finding showed that consumption of a HFD leads to reference memory impairment in the probe test. HFD animals spent less time in the target zone in compare with control animals. Also, LY341495 improved HFD-induced reference memory (retention) impairment. HFD animals treated with LY341495 spent more time in the target zone in compare with HFD animals. Escape latencies to find the visible platform during visual task were same in all experimental groups, indicating no visual impairment in the animals. We propose that a HFD may act through mGluR2/3 within the brain to reduce synaptic plasticity, which impairs memory retrieval, and post-training administration of LY341495 can reduce HFD-induced reference memory impairment.
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Affiliation(s)
- Heresh Moridi
- Student Research Committee, Hamadan University of Medical Sciences, Hamadan, Iran.,Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Abdolrahman Sarihi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Elahe Habibitabar
- Student Research Committee, Hamadan University of Medical Sciences, Hamadan, Iran.,Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hossein Shateri
- Student Research Committee, Hamadan University of Medical Sciences, Hamadan, Iran.,Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Iraj Salehi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Jamshid Karimi
- Department of Biochemistry, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Asaad Karimi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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21
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Logan CN, Bechard AR, Hamor PU, Wu L, Schwendt M, Knackstedt LA. Ceftriaxone and mGlu2/3 interactions in the nucleus accumbens core affect the reinstatement of cocaine-seeking in male and female rats. Psychopharmacology (Berl) 2020; 237:2007-2018. [PMID: 32382781 PMCID: PMC8587483 DOI: 10.1007/s00213-020-05514-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/26/2020] [Indexed: 11/25/2022]
Abstract
RATIONALE The beta-lactam antibiotic ceftriaxone reliably attenuates the reinstatement of cocaine seeking. While the restoration of nucleus accumbens core (NA core) GLT-1 expression is necessary for ceftriaxone to attenuate reinstatement, AAV-mediated GLT-1 overexpression is not sufficient to attenuate reinstatement and does not prevent glutamate efflux during reinstatement. AIMS Here, we test the hypothesis that ceftriaxone attenuates reinstatement through interactions with glutamate autoreceptors mGlu2 and mGlu3 in the NA core. METHODS Male and female rats self-administered cocaine for 12 days followed by 2-3 weeks of extinction training. During the last 6-10 days of extinction, rats received ceftriaxone (200 mg/kg IP) or vehicle. In experiment 1, rats were killed, and NA core tissue was biotinylated for assessment of total and surface expression of mGlu2 and mGlu3 via western blotting. In experiment 2, we tested the hypothesis that mGlu2/3 signaling is necessary for ceftriaxone to attenuate cue- and cocaine-primed reinstatement by administering bilateral intra-NA core infusion of mGlu2/3 antagonist LY341495 or vehicle immediately prior to reinstatement testing. RESULTS mGlu2 expression was reduced by cocaine and restored by ceftriaxone. There were no effects of cocaine or ceftriaxone on mGlu3 expression. We observed no effects of estrus on expression of either protein. The antagonism of mGlu2/3 in the NA core during both cue- and cocaine-primed reinstatement tests prevented ceftriaxone from attenuating reinstatement. CONCLUSIONS These results indicate that ceftriaxone's effects depend on mGlu2/3 function and possibly mGlu2 receptor expression. Future work will test this hypothesis by manipulating mGlu2 expression in pathways that project to the NA core.
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Affiliation(s)
- Carly N Logan
- Department of Psychology, University of Florida, 114 Psychology, 945 Center Dr, Gainesville, FL, 32611-2250, USA
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Allison R Bechard
- Department of Psychology, University of Florida, 114 Psychology, 945 Center Dr, Gainesville, FL, 32611-2250, USA
| | - Peter U Hamor
- Department of Psychology, University of Florida, 114 Psychology, 945 Center Dr, Gainesville, FL, 32611-2250, USA
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Lizhen Wu
- Department of Psychology, University of Florida, 114 Psychology, 945 Center Dr, Gainesville, FL, 32611-2250, USA
| | - Marek Schwendt
- Department of Psychology, University of Florida, 114 Psychology, 945 Center Dr, Gainesville, FL, 32611-2250, USA
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Lori A Knackstedt
- Department of Psychology, University of Florida, 114 Psychology, 945 Center Dr, Gainesville, FL, 32611-2250, USA.
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA.
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22
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Li Q, Jin R, Zhang S, Sun X, Wu J. Group II metabotropic glutamate receptor agonist promotes retinal ganglion cell survival by reducing neuronal excitotoxicity in a rat chronic ocular hypertension model. Neuropharmacology 2020; 170:108016. [PMID: 32101763 DOI: 10.1016/j.neuropharm.2020.108016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/24/2020] [Accepted: 02/21/2020] [Indexed: 02/06/2023]
Abstract
Glaucoma, the second leading cause of irreversible blindness worldwide, is characterized by the selective death of retinal ganglion cells (RGCs). The group II metabotropic glutamate receptor (mGluR II) activation has been linked to RGC survival, however, the mechanism by which it promotes neuronal survival remains poorly defined. In the present work, we show that extracellular application of LY341495, an mGluR II antagonist could increase the RGC firing frequency, suggesting that activation of mGluR II by endogenously released glutamate could modulate RGC excitability. LY354740, an mGluR II agonist, significantly decreased RGC excitability and the reduced presynaptic excitatory inputs and post-synaptic Ca2+-permeable currents mediated the LY354740-induced effects. By using a well-characterized in vivo male Sprague-Dawley rat glaucoma model, we further demonstrate that in the early stage of experimental glaucoma, the expression of mGluR II dimer-formed protein was significantly reduced, and pre-activation of mGluR II by intravitreal injection of LY354740 before establishment of the glaucoma model could effectively reduce excitatory inputs, thereby reversing hyperexcitability induced by elevated intraocular pressure. Furthermore, LY354740 could increase the expression level of brain-derived neurotrophic factor in the glaucomatous retinas, further protecting RGCs. Our study indicates that the abnormal expression of mGluR II may accelerate RGC apoptosis in glaucoma, and demonstrates that mGluR II agonist LY354740 can be used as a novel method to counter RGC apoptosis in glaucoma.
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Affiliation(s)
- Qian Li
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Ruiri Jin
- Department of Gastroenterology, Songjiang Central Hospital, Shanghai, 201600, China
| | - Shenghai Zhang
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
| | - Xinghuai Sun
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.
| | - Jihong Wu
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.
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23
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Chaki S. mGlu2/3 receptor as a novel target for rapid acting antidepressants. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2020; 89:289-309. [PMID: 32616210 DOI: 10.1016/bs.apha.2020.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Given that ketamine, a noncompetitive N-methyl-d-aspartate receptor antagonist that exerts rapid antidepressant effects in patients with treatment-resistant depression, also has undesirable adverse effects, agents that can be used as alternatives to ketamine have been actively pursued. Group II metabotropic glutamate (mGlu) receptors, consisting of mGlu2 and mGlu3 receptors, have emerged as one of the most promising targets in the development of ketamine-like antidepressants. Indeed, mGlu2/3 receptor antagonists have been demonstrated to exert rapid antidepressant effects in animal models and to be efficacious in animal models refractory to conventional antidepressants. Moreover, there are striking similarities between mGlu2/3 receptor antagonists and ketamine in terms of not only their antidepressant profiles, but also the underlying mechanisms of their antidepressant effects. Nonetheless, studies in rodents have shown that mGlu2/3 receptor antagonists do not cause ketamine-like adverse events, such as psychotomimetic-like behavior, abuse potential or neurotoxicity, supporting the usefulness of mGlu2/3 receptor antagonists as alternatives to ketamine. In this chapter, the past and recent research on the antidepressant effects of mGlu2/3 receptor antagonists will be reviewed. In particular, the potential of mGlu2/3 receptor antagonists as novel ketamine-like antidepressants will be emphasized.
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Affiliation(s)
- Shigeyuki Chaki
- Research Headquarters, Taisho Pharmaceutical Co., Ltd., Saitama, Japan.
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Griego E, Galván EJ. Metabotropic Glutamate Receptors at the Aged Mossy Fiber - CA3 Synapse of the Hippocampus. Neuroscience 2020; 456:95-105. [PMID: 31917351 DOI: 10.1016/j.neuroscience.2019.12.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 12/28/2022]
Abstract
Metabotropic glutamate receptors (mGluRs) are a group of G-protein-coupled receptors that exert a broad array of modulatory actions at excitatory synapses of the central nervous system. In the hippocampus, the selective activation of the different mGluRs modulates the intrinsic excitability, the strength of synaptic transmission, and induces multiple forms of long-term plasticity. Despite the relevance of mGluRs in the normal function of the hippocampus, we know very little about the changes that mGluRs functionality undergoes during the non-pathological aging. Here, we review data concerning the physiological actions of mGluRs, with particular emphasis on hippocampal area CA3. Later, we examine changes in the expression and functionality of mGluRs during the aging process. We complement this review with original data showing an array of electrophysiological modifications observed in the synaptic transmission and intrinsic excitability of aged CA3 pyramidal cells in response to the pharmacological stimulation of the different mGluRs.
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Affiliation(s)
- Ernesto Griego
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, Mexico
| | - Emilio J Galván
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, Mexico.
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25
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Srivastava A, Das B, Yao AY, Yan R. Metabotropic Glutamate Receptors in Alzheimer's Disease Synaptic Dysfunction: Therapeutic Opportunities and Hope for the Future. J Alzheimers Dis 2020; 78:1345-1361. [PMID: 33325389 PMCID: PMC8439550 DOI: 10.3233/jad-201146] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the presence of neuritic plaques and neurofibrillary tangles. The impaired synaptic plasticity and dendritic loss at the synaptic level is an early event associated with the AD pathogenesis. The abnormal accumulation of soluble oligomeric amyloid-β (Aβ), the major toxic component in amyloid plaques, is viewed to trigger synaptic dysfunctions through binding to several presynaptic and postsynaptic partners and thus to disrupt synaptic transmission. Over time, the abnormalities in neural transmission will result in cognitive deficits, which are commonly manifested as memory loss in AD patients. Synaptic plasticity is regulated through glutamate transmission, which is mediated by various glutamate receptors. Here we review recent progresses in the study of metabotropic glutamate receptors (mGluRs) in AD cognition. We will discuss the role of mGluRs in synaptic plasticity and their modulation as a possible strategy for AD cognitive improvement.
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Affiliation(s)
- Akriti Srivastava
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
| | - Brati Das
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
| | - Annie Y. Yao
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
| | - Riqiang Yan
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
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26
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Joffe ME, Santiago CI, Oliver KH, Maksymetz J, Harris NA, Engers JL, Lindsley CW, Winder DG, Conn PJ. mGlu 2 and mGlu 3 Negative Allosteric Modulators Divergently Enhance Thalamocortical Transmission and Exert Rapid Antidepressant-like Effects. Neuron 2019; 105:46-59.e3. [PMID: 31735403 DOI: 10.1016/j.neuron.2019.09.044] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/14/2019] [Accepted: 09/25/2019] [Indexed: 12/23/2022]
Abstract
Non-selective antagonists of metabotropic glutamate receptor subtypes 2 (mGlu2) and 3 (mGlu3) exert rapid antidepressant-like effects by enhancing prefrontal cortex (PFC) glutamate transmission; however, the receptor subtype contributions and underlying mechanisms remain unclear. Here, we leveraged newly developed negative allosteric modulators (NAMs), transgenic mice, and viral-assisted optogenetics to test the hypothesis that selective inhibition of mGlu2 or mGlu3 potentiates PFC excitatory transmission and confers antidepressant efficacy in preclinical models. We found that systemic treatment with an mGlu2 or mGlu3 NAM rapidly activated biophysically unique PFC pyramidal cell ensembles. Mechanistic studies revealed that mGlu2 and mGlu3 NAMs enhance thalamocortical transmission and inhibit long-term depression by mechanistically distinct presynaptic and postsynaptic actions. Consistent with these actions, systemic treatment with either NAM decreased passive coping and reversed anhedonia in two independent chronic stress models, suggesting that both mGlu2 and mGlu3 NAMs induce antidepressant-like effects through related but divergent mechanisms of action.
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Affiliation(s)
- Max E Joffe
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232, USA; Vanderbilt Center for Addiction Research, Nashville, TN 37232, USA.
| | - Chiaki I Santiago
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232, USA; Vanderbilt University, Nashville, TN 37232, USA
| | - Kendra H Oliver
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - James Maksymetz
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232, USA
| | - Nicholas A Harris
- Vanderbilt Center for Addiction Research, Nashville, TN 37232, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Julie L Engers
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232, USA; Vanderbilt Center for Addiction Research, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
| | - Danny G Winder
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Addiction Research, Nashville, TN 37232, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232, USA; Vanderbilt Center for Addiction Research, Nashville, TN 37232, USA.
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27
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Imbriglio T, Verhaeghe R, Martinello K, Pascarelli MT, Chece G, Bucci D, Notartomaso S, Quattromani M, Mascio G, Scalabrì F, Simeone A, Maccari S, Del Percio C, Wieloch T, Fucile S, Babiloni C, Battaglia G, Limatola C, Nicoletti F, Cannella M. Developmental abnormalities in cortical GABAergic system in mice lacking mGlu3 metabotropic glutamate receptors. FASEB J 2019; 33:14204-14220. [PMID: 31665922 DOI: 10.1096/fj.201901093rrr] [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: 12/19/2022]
Abstract
Polymorphic variants of the gene encoding for metabotropic glutamate receptor 3 (mGlu3) are linked to schizophrenia. Because abnormalities of cortical GABAergic interneurons lie at the core of the pathophysiology of schizophrenia, we examined whether mGlu3 receptors influence the developmental trajectory of cortical GABAergic transmission in the postnatal life. mGlu3-/- mice showed robust changes in the expression of interneuron-related genes in the prefrontal cortex (PFC), including large reductions in the expression of parvalbumin (PV) and the GluN1 subunit of NMDA receptors. The number of cortical cells enwrapped by perineuronal nets was increased in mGlu3-/- mice, suggesting that mGlu3 receptors shape the temporal window of plasticity of PV+ interneurons. Electrophysiological measurements of GABAA receptor-mediated responses revealed a more depolarized reversal potential of GABA currents in the somata of PFC pyramidal neurons in mGlu3-/- mice at postnatal d 9 associated with a reduced expression of the K+/Cl- symporter. Finally, adult mGlu3-/- mice showed lower power in electroencephalographic rhythms at 1-45 Hz in quiet wakefulness as compared with their wild-type counterparts. These findings suggest that mGlu3 receptors have a strong impact on the development of cortical GABAergic transmission and cortical neural synchronization mechanisms corroborating the concept that genetic variants of mGlu3 receptors may predispose to psychiatric disorders.-Imbriglio, T., Verhaeghe, R., Martinello, K., Pascarelli, M. T., Chece, G., Bucci, D., Notartomaso, S., Quattromani, M., Mascio, G., Scalabrì, F., Simeone, A., Maccari, S., Del Percio, C., Wieloch, T., Fucile, S., Babiloni, C., Battaglia, G., Limatola, C., Nicoletti, F., Cannella, M. Developmental abnormalities in cortical GABAergic system in mice lacking mGlu3 metabotropic glutamate receptors.
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Affiliation(s)
- Tiziana Imbriglio
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy
| | - Remy Verhaeghe
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy
| | - Katiuscia Martinello
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Maria Teresa Pascarelli
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Oasi Research Institute - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Troina, Italy
| | - Giuseppina Chece
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy
| | - Domenico Bucci
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Serena Notartomaso
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Miriana Quattromani
- Laboratory for Experimental Brain Research, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Giada Mascio
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Francesco Scalabrì
- Istituto di Ricerca Biologia Molecolare (IRBM) Science Park S.p.A., Pomezia, Rome, Italy
| | - Antonio Simeone
- Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", Centro Nazionale Ricerche (CNR), Naples, Italy
| | - Stefania Maccari
- Department of Science and Medical-Surgical Biotechnology, University Sapienza of Rome, Rome, Italy.,University of Lille, Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8576, UGSF, Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Claudio Del Percio
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy
| | - Tadeusz Wieloch
- Oasi Research Institute - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Troina, Italy
| | - Sergio Fucile
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Claudio Babiloni
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Hospital San Raffaele Cassino, Cassino, Italy
| | - Giuseppe Battaglia
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Cristina Limatola
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology "V. Erspamer" University Sapienza of Rome, Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - Milena Cannella
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
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28
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Kinoshita K, Ochi M, Iwata K, Fukasawa M, Yamaguchi J. Preclinical disposition of MGS0274 besylate, a prodrug of a potent group II metabotropic glutamate receptor agonist MGS0008 for the treatment of schizophrenia. Pharmacol Res Perspect 2019; 7:e00520. [PMID: 31523433 PMCID: PMC6743422 DOI: 10.1002/prp2.520] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 08/12/2019] [Accepted: 08/12/2019] [Indexed: 01/02/2023] Open
Abstract
MGS0274 besylate is an ester-based lipophilic prodrug of a metabotropic glutamate (mGlu) 2 and mGlu3 receptor agonist MGS0008 and being developed for the treatment of schizophrenia. We investigated the disposition of these compounds in rats and monkeys and in vitro metabolism in humans to evaluate whether MGS0274 besylate could be useful as a prodrug in humans. After the oral administration of MGS0274 besylate to monkeys (2.89 mg/kg), MGS0008 was immediately found in plasma, reached a maximum concentration at 4 hours postdose, and decreased with a terminal half-life of 16.7 hours; MGS0274 was barely detectable. The oral bioavailability as MGS0008 was 83.7%, which was approximately 20-fold greater than that after oral dosing of MGS0008 (3.8%). In rats, MGS0008 penetrated the cerebrospinal fluid and was eliminated slower than from plasma. The in vitro metabolism study indicated that MGS0274 was rapidly hydrolyzed to MGS0008, which was not further metabolized. After the intravenous administration of MGS0008 to rats and monkeys, almost all the dose was excreted unchanged in urine. These results suggested that MGS0274 was, as expected, presystemically hydrolyzed to MGS0008 after gastrointestinal absorption and that MGS0008 was distributed throughout the body without further metabolism and ultimately excreted in urine in the animals. Furthermore, the hydrolytic activity against MGS0274 in the human liver S9 fraction was comparable to that in monkeys, suggesting the possibility of the rapid presystemic hydrolysis of MGS0274 to MGS0008 in humans, as it is in monkeys. Consequently, MGS0274 besylate is expected to function as a preferable prodrug in humans.
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Affiliation(s)
- Kohnosuke Kinoshita
- Drug Metabolism and PharmacokineticsDrug Safety and Pharmacokinetics LaboratoriesResearch HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Motoki Ochi
- Drug Metabolism and PharmacokineticsDrug Safety and Pharmacokinetics LaboratoriesResearch HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Katsuya Iwata
- Drug Metabolism and PharmacokineticsDrug Safety and Pharmacokinetics LaboratoriesResearch HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Misako Fukasawa
- Drug Metabolism and PharmacokineticsDrug Safety and Pharmacokinetics LaboratoriesResearch HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Jun‐ichi Yamaguchi
- Drug Metabolism and PharmacokineticsDrug Safety and Pharmacokinetics LaboratoriesResearch HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
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29
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Highland JN, Zanos P, Georgiou P, Gould TD. Group II metabotropic glutamate receptor blockade promotes stress resilience in mice. Neuropsychopharmacology 2019; 44:1788-1796. [PMID: 30939596 PMCID: PMC6785136 DOI: 10.1038/s41386-019-0380-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/14/2019] [Accepted: 03/25/2019] [Indexed: 12/12/2022]
Abstract
Stress is a leading risk factor for the onset and recurrence of major depression. Enhancing stress resilience may be a therapeutic strategy to prevent the development of depression in at-risk populations or its recurrence in depressed patients. Group II metabotropic glutamate receptor (mGlu2/3) antagonists have been recognized for antidepressant-like actions in preclinical models, but have not been evaluated for prophylactic effects. We assessed the role of mGlu2/3 in modulating stress resilience using subtype-specific knockout mice lacking mGlu2 (Grm2-/-) or mGlu3 (Grm3-/-), and pharmacological manipulations of mGlu2/3 activity during or prior to the induction and reinstatement of stress-induced behavioral deficits. Grm2-/-, but not Grm3-/-, mice exhibited reduced forced-swimming test immobility time and were resilient to developing inescapable shock (IES)-induced escape deficits. Grm2-/- mice were also resilient to developing corticosterone (CORT)-induced escape deficits and chronic social defeat stress-induced anhedonia. Pharmacological blockade of mGlu2/3 with the antagonist LY341495 during stress prevented the development of IES- and CORT-induced escape deficits, while activation with the agonist LY379268 increased susceptibility to escape deficits. Prophylactic treatment with the LY341495, both systemically and via microinjection into the medial prefrontal cortex (mPFC), up to 7 days before IES, prevented both the induction of escape deficits and their reinstatement by brief re-exposure to IES up to 20 days after treatment. Overall, blockade of mGlu2/3 enhanced stress resilience and deletion of mGlu2, but not mGlu3, conferred a stress-resilient phenotype, indicating that prophylactic treatments reducing mGlu2 activity may protect against stress-induced changes underlying the development or recurrence of stress-induced disorders, including depression.
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Affiliation(s)
- Jaclyn N. Highland
- 0000 0001 2175 4264grid.411024.2Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD USA ,0000 0001 2175 4264grid.411024.2Program in Toxicology, University of Maryland School of Medicine, Baltimore, MD USA
| | - Panos Zanos
- 0000 0001 2175 4264grid.411024.2Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD USA
| | - Polymnia Georgiou
- 0000 0001 2175 4264grid.411024.2Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD USA
| | - Todd D. Gould
- 0000 0001 2175 4264grid.411024.2Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD USA ,0000 0001 2175 4264grid.411024.2Program in Toxicology, University of Maryland School of Medicine, Baltimore, MD USA ,0000 0001 2175 4264grid.411024.2Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD USA ,0000 0001 2175 4264grid.411024.2Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD USA ,0000 0000 9558 9225grid.417125.4Veterans Affairs Maryland Health Care System, Baltimore, MD USA
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30
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Okubo M, Yamanaka H, Kobayashi K, Noguchi K. Differential expression of mGluRs in rat spinal dorsal horns and their modulatory effects on nocifensive behaviors. Mol Pain 2019; 15:1744806919875026. [PMID: 31432760 PMCID: PMC6751533 DOI: 10.1177/1744806919875026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Glutamate is a neurotransmitter present in most excitatory synapses in the nervous system. It also plays a key role in the spinal cord’s physiological excitatory circuit and is involved in pathological neurotransmissions such as those observed in inflammatory and neuropathic pain conditions. The actions of glutamate are mediated by different types of ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs). Although expressions of iGluRs are well studied, those of mGluRs are not fully elucidated in the spinal cord. In this study, we examined the expressions of mGluRs (mGluR1-8) and investigated which mGluR subtypes can modulate pain transmission in the dorsal horn of the spinal cord using an inflammatory pain model. Reverse transcription-polymerase chain reaction revealed that mGluR mRNAs, except for mGluR2 and 6, were detected in the spinal cord. Double labeling analysis, in situ hybridization histochemistry with immunohistochemistry, was used to examine the distribution of each mGluR in neurons or glial cells in the lamina I–II of the spinal dorsal horn. mGluR1, 5, and 7 were generally, and 4 and 8 were frequently, expressed in neurons. mGluR3 was expressed not only in neurons but also in oligodendrocytes. We next examined the distribution of mGluR4 and 8 were expressed in excitatory or inhibitory neurons. Both mGluR4 and 8 were preferentially expressed in inhibitory neurons rather than in excitatory neurons. Furthermore, intrathecal delivery of CPPG((RS)-α-cyclopropyl-4-phosphonophenylglycine), an antagonist for mGluR 4 and 8, attenuated nocifensive behaviors and the increase in fos-positive-excitatory neurons of the dorsal horn induced by intraplantar injection of formalin. These findings suggest that mGluR4 and 8, which are preferentially expressed in inhibitory neurons, may play roles in the modulation of pain transmission in the spinal dorsal horn.
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Affiliation(s)
- Masamichi Okubo
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Hyogo, Japan
| | - Hiroki Yamanaka
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Hyogo, Japan
| | - Kimiko Kobayashi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Hyogo, Japan
| | - Koichi Noguchi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Hyogo, Japan
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Abstract
Abnormalities of glutamatergic transmission are implicated in neuropsychiatric disorders. Among the glutamate receptors, metabotropic (mGlu) 2/3 receptors have recently gained much attention as molecular targets for the treatment of several neuropsychiatric disorders including depression and anxiety. Both orthosteric and allosteric antagonists of mGlu2/3 receptors have been synthesized, and their therapeutic potential has been examined. These research activities have demonstrated the promise of mGlu2/3 receptor antagonists as potential treatment agents for the above-mentioned neuropsychiatric disorders. In particular, it has been considered that the antidepressant effects of mGlu2/3 receptor antagonists are worthy of pursuing, since the antidepressant profiles as well as synaptic/neural mechanisms involved in the actions of mGlu2/3 receptor antagonists are similar to those of ketamine, which has been demonstrated to show potent, rapid and sustained efficacy in patients with depression, even those resistant to the conventionally prescribed antidepressants. In this chapter, the general pharmacology of mGlu2/3 receptor antagonists and their therapeutic potential are reviewed. In particular, I focus on the usefulness of mGlu2/3 receptor antagonists as novel antidepressants, in comparison with ketamine.
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32
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( 2R,6R)-hydroxynorketamine exerts mGlu 2 receptor-dependent antidepressant actions. Proc Natl Acad Sci U S A 2019; 116:6441-6450. [PMID: 30867285 DOI: 10.1073/pnas.1819540116] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Currently approved antidepressant drugs often take months to take full effect, and ∼30% of depressed patients remain treatment resistant. In contrast, ketamine, when administered as a single subanesthetic dose, exerts rapid and sustained antidepressant actions. Preclinical studies indicate that the ketamine metabolite (2R,6R)-hydroxynorketamine [(2R,6R)-HNK] is a rapid-acting antidepressant drug candidate with limited dissociation properties and abuse potential. We assessed the role of group II metabotropic glutamate receptor subtypes 2 (mGlu2) and 3 (mGlu3) in the antidepressant-relevant actions of (2R,6R)-HNK using behavioral, genetic, and pharmacological approaches as well as cortical quantitative EEG (qEEG) measurements in mice. Both ketamine and (2R,6R)-HNK prevented mGlu2/3 receptor agonist (LY379268)-induced body temperature increases in mice lacking the Grm3, but not Grm2, gene. This action was not replicated by NMDA receptor antagonists or a chemical variant of ketamine that limits metabolism to (2R,6R)-HNK. The antidepressant-relevant behavioral effects and 30- to 80-Hz qEEG oscillation (gamma-range) increases resultant from (2R,6R)-HNK administration were prevented by pretreatment with an mGlu2/3 receptor agonist and absent in mice lacking the Grm2, but not Grm3 -/-, gene. Combined subeffective doses of the mGlu2/3 receptor antagonist LY341495 and (2R,6R)-HNK exerted synergistic increases on gamma oscillations and antidepressant-relevant behavioral actions. These findings highlight that (2R,6R)-HNK exerts antidepressant-relevant actions via a mechanism converging with mGlu2 receptor signaling and suggest enhanced cortical gamma oscillations as a marker of target engagement relevant to antidepressant efficacy. Moreover, these results support the use of (2R,6R)-HNK and inhibitors of mGlu2 receptor function in clinical trials for treatment-resistant depression either alone or in combination.
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Crupi R, Impellizzeri D, Cuzzocrea S. Role of Metabotropic Glutamate Receptors in Neurological Disorders. Front Mol Neurosci 2019; 12:20. [PMID: 30800054 PMCID: PMC6375857 DOI: 10.3389/fnmol.2019.00020] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 01/21/2019] [Indexed: 12/20/2022] Open
Abstract
Glutamate is a fundamental excitatory neurotransmitter in the mammalian central nervous system (CNS), playing key roles in memory, neuronal development, and synaptic plasticity. Moreover, excessive glutamate release has been implicated in neuronal cell death. There are both ionotropic and metabotropic glutamate receptors (mGluRs), the latter of which can be divided into eight subtypes and three subgroups based on homology sequence and their effects on cell signaling. Indeed, mGluRs exert fine control over glutamate activity by stimulating several cell-signaling pathways via the activation of G protein-coupled (GPC) or G protein-independent cell signaling. The involvement of specific mGluRs in different forms of synaptic plasticity suggests that modulation of mGluRs may aid in the treatment of cognitive impairments related to several neurodevelopmental/psychiatric disorders and neurodegenerative diseases, which are associated with a high economic and social burden. Preclinical and clinical data have shown that, in the CNS, mGluRs are able to modulate presynaptic neurotransmission by fine-tuning neuronal firing and neurotransmitter release in a dynamic, activity-dependent manner. Current studies on drugs that target mGluRs have identified promising, innovative pharmacological tools for the treatment of neurodegenerative and neuropsychiatric conditions, including chronic pain.
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Affiliation(s)
- Rosalia Crupi
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Daniela Impellizzeri
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Salvatore Cuzzocrea
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy.,Department of Pharmacology and Physiology, Saint Louis University, St. Louis, MO, United States
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34
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Smith JB, Alloway KD, Hof PR, Orman R, Reser DH, Watakabe A, Watson GDR. The relationship between the claustrum and endopiriform nucleus: A perspective towards consensus on cross-species homology. J Comp Neurol 2019; 527:476-499. [PMID: 30225888 PMCID: PMC6421118 DOI: 10.1002/cne.24537] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/28/2018] [Accepted: 08/30/2018] [Indexed: 01/08/2023]
Abstract
With the emergence of interest in studying the claustrum, a recent special issue of the Journal of Comparative Neurology dedicated to the claustrum (Volume 525, Issue 6, pp. 1313-1513) brought to light questions concerning the relationship between the claustrum (CLA) and a region immediately ventral known as the endopiriform nucleus (En). These structures have been identified as separate entities in rodents but appear as a single continuous structure in primates. During the recent Society for Claustrum Research meeting, a panel of experts presented data pertaining to the relationship of these regions and held a discussion on whether the CLA and En should be considered (a) separate unrelated structures, (b) separate nuclei within the same formation, or (c) subregions of a continuous structure. This review article summarizes that discussion, presenting comparisons of the cytoarchitecture, neurochemical profiles, genetic markers, and anatomical connectivity of the CLA and En across several mammalian species. In rodents, we conclude that the CLA and the dorsal endopiriform nucleus (DEn) are subregions of a larger complex, which likely performs analogous computations and exert similar effects on their respective cortical targets (e.g., sensorimotor versus limbic). Moving forward, we recommend that the field retain the nomenclature currently employed for this region but should continue to examine the delineation of these structures across different species. Using thorough descriptions of a variety of anatomical features, this review offers a clear definition of the CLA and En in rodents, which provides a framework for identifying homologous structures in primates.
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Affiliation(s)
- Jared B. Smith
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Kevin D. Alloway
- Neural and Behavioral Sciences, Center for Neural Engineering, Pennsylvania State University, University Park, PA 16802, USA
| | - Patrick R. Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rena Orman
- Department of Physiology and Pharmacology, State University of New York Downstate Medical Center, Brooklyn, NY, 11203 USA
| | - David H. Reser
- Graduate Entry Medicine Program, Monash Rural Health Churchill, Monash University, Churchill, Victoria 3842, Australia
- Department of Physiology, Monash University, Clayton 3800, Victoria, Australia
| | | | - Glenn D. R. Watson
- Department of Psychology and Neuroscience, Duke University, Durham, NC 27708, USA
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Tora AS, Rovira X, Cao AM, Cabayé A, Olofsson L, Malhaire F, Scholler P, Baik H, Van Eeckhaut A, Smolders I, Rondard P, Margeat E, Acher F, Pin JP, Goudet C. Chloride ions stabilize the glutamate-induced active state of the metabotropic glutamate receptor 3. Neuropharmacology 2018; 140:275-286. [PMID: 30102917 DOI: 10.1016/j.neuropharm.2018.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/25/2018] [Accepted: 08/09/2018] [Indexed: 02/06/2023]
Abstract
Due to the essential roles of glutamate, detection and response to a large range of extracellular concentrations of this excitatory amino acid are necessary for the fine-tuning of brain functions. Metabotropic glutamate receptors (mGluRs) are implicated in shaping the activity of many synapses in the central nervous system. Among the eight mGluR subtypes, there is increasing interest in studying the mGlu3 receptor which has recently been linked to various diseases, including psychiatric disorders. This receptor displays striking functional properties, with a high and, often, full basal activity, making its study elusive in heterologous systems. Here, we demonstrate that Cl- ions exert strong positive allosteric modulation of glutamate on the mGlu3 receptor. We have also identified the molecular and structural determinants lying behind this allostery: a unique interactive "chloride-lock" network. Indeed, Cl- ions dramatically stabilize the glutamate-induced active state of the extracellular domain of the mGlu3 receptor. Thus, the mGlu3 receptors' large basal activity does not correspond to a constitutive activity in absence of agonist. Instead, it results mostly from a Cl-mediated amplified response to low ambient glutamate concentrations, such as those measured in cell media. This strong interaction between glutamate and Cl- ions allows the mGlu3 receptor to sense and efficiently react to sub-micromolar concentrations of glutamate, making it the most sensitive member of mGluR family.
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Affiliation(s)
- Amélie S Tora
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Xavier Rovira
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France; Present Address: Molecular Photopharmacology Research Group, The Tissue Repair and Regeneration Laboratory, University of Vic - Central University of Catalonia, C. de La Laura,13, 08500, Vic, Spain
| | - Anne-Marinette Cao
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, F-34094, Montpellier, France
| | - Alexandre Cabayé
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, CNRS UMR8601, Université Paris Descartes, Sorbonne Paris Cité, F-75270, Paris Cedex 6, France
| | - Linnéa Olofsson
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, F-34094, Montpellier, France
| | - Fanny Malhaire
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Pauline Scholler
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Hayeon Baik
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Ann Van Eeckhaut
- Research Group Experimental Pharmacology (EFAR/FASC), Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), 1090, Brussel, Belgium
| | - Ilse Smolders
- Research Group Experimental Pharmacology (EFAR/FASC), Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), 1090, Brussel, Belgium
| | - Philippe Rondard
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Emmanuel Margeat
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, F-34094, Montpellier, France
| | - Francine Acher
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, CNRS UMR8601, Université Paris Descartes, Sorbonne Paris Cité, F-75270, Paris Cedex 6, France.
| | - Jean-Philippe Pin
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France.
| | - Cyril Goudet
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France.
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36
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Ngomba RT, van Luijtelaar G. Metabotropic glutamate receptors as drug targets for the treatment of absence epilepsy. Curr Opin Pharmacol 2018; 38:43-50. [PMID: 29547778 DOI: 10.1016/j.coph.2018.01.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/31/2018] [Indexed: 11/24/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are expressed in key regions of the cortex and the thalamus and are known to regulate spike and wave discharges (SWDs), the electroclinical hallmarks of absence seizures. Recent preclinical studies have highlighted the therapeutic potential of selective group I and III mGlu receptor subtype allosteric modulators, which can suppress pathological SWDs. Of particular interest are positive allosteric modulators (PAMs) for mGlu5 receptors, as they currently show the most promise as novel anti-absence epilepsy drugs. The rational design of novel selective positive and negative allosteric mGlu modulators, especially for the mGlu5 receptor, has been made possible following the recent crystallographic structure determination of group I mGlu receptors. Our current knowledge of the role of different mGlu receptor subtypes in absence epilepsy is outlined in this article.
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Affiliation(s)
- Richard Teke Ngomba
- School of Pharmacy in College of Science, University of Lincoln, Lincoln LN6 7TS, UK.
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Abstract
Traditional pharmacological treatments for depression have a delayed therapeutic onset, ranging from several weeks to months, and there is a high percentage of individuals who never respond to treatment. In contrast, ketamine produces rapid-onset antidepressant, anti-suicidal, and anti-anhedonic actions following a single administration to patients with depression. Proposed mechanisms of the antidepressant action of ketamine include N-methyl-D-aspartate receptor (NMDAR) modulation, gamma aminobutyric acid (GABA)-ergic interneuron disinhibition, and direct actions of its hydroxynorketamine (HNK) metabolites. Downstream actions include activation of the mechanistic target of rapamycin (mTOR), deactivation of glycogen synthase kinase-3 and eukaryotic elongation factor 2 (eEF2), enhanced brain-derived neurotrophic factor (BDNF) signaling, and activation of α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors (AMPARs). These putative mechanisms of ketamine action are not mutually exclusive and may complement each other to induce potentiation of excitatory synapses in affective-regulating brain circuits, which results in amelioration of depression symptoms. We review these proposed mechanisms of ketamine action in the context of how such mechanisms are informing the development of novel putative rapid-acting antidepressant drugs. Such drugs that have undergone pre-clinical, and in some cases clinical, testing include the muscarinic acetylcholine receptor antagonist scopolamine, GluN2B-NMDAR antagonists (i.e., CP-101,606, MK-0657), (2R,6R)-HNK, NMDAR glycine site modulators (i.e., 4-chlorokynurenine, pro-drug of the glycineB NMDAR antagonist 7-chlorokynurenic acid), NMDAR agonists [i.e., GLYX-13 (rapastinel)], metabotropic glutamate receptor 2/3 (mGluR2/3) antagonists, GABAA receptor modulators, and drugs acting on various serotonin receptor subtypes. These ongoing studies suggest that the future acute treatment of depression will typically occur within hours, rather than months, of treatment initiation.
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Affiliation(s)
- Panos Zanos
- Department of Psychiatry, University of Maryland School of Medicine, Rm. 934F MSTF, 685 W. Baltimore St., Baltimore, MD, 21201, USA.
| | - Scott M Thompson
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Physiology, University of Maryland School of Medicine, St. BRB 5-007, 655 W. Baltimore St., Baltimore, MD, 21201, USA, Baltimore, MD, 21201, USA
| | - Ronald S Duman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Carlos A Zarate
- Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Todd D Gould
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Psychiatry, University of Maryland School of Medicine, Rm. 936 MSTF, 685 W. Baltimore St., Baltimore, MD, 21201, USA
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38
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Tang ZQ, Lu Y. Anatomy and Physiology of Metabotropic Glutamate Receptors in Mammalian and Avian Auditory System. ACTA ACUST UNITED AC 2018; 1. [PMID: 30854519 DOI: 10.24966/tap-7752/100001] [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] [Indexed: 11/04/2022]
Abstract
Glutamate, as the major excitatory neurotransmitter used in the vertebrate brain, activates ionotropic and metabotropic glutamate receptors (iGluRs and mGluRs), which mediate fast and slow neuronal actions, respectively. mGluRs play important modulatory roles in many brain areas, forming potential targets for drugs developed to treat brain disorders. Here, we review studies on mGluRs in the mammalian and avian auditory system. Although anatomical expression of mGluRs in the cochlear nucleus has been well characterized, data for other auditory nuclei await more systematic investigations especially at the electron microscopy level. The physiology of mGluRs has been extensively studied using in vitro brain slice preparations, with a focus on the auditory circuitry in the brainstem. These in vitro physiological studies have demonstrated that mGluRs participate in synaptic transmission, regulate ionic homeostasis, induce synaptic plasticity, and maintain the balance between Excitation and Inhibition (E/I) in a variety of auditory structures. However, the modulatory roles of mGluRs in auditory processing remain largely unclear at the system and behavioral levels, and the functions of mGluRs in auditory disorders remain entirely unknown.
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Affiliation(s)
- Zheng-Quan Tang
- Oregon Hearing Research Center, Vollum Institute, Oregon Health and Science University, Oregon, USA
| | - Yong Lu
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Ohio, USA
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39
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Dong HW, Ennis M. Activation of Group II Metabotropic Glutamate Receptors Suppresses Excitability of Mouse Main Olfactory Bulb External Tufted and Mitral Cells. Front Cell Neurosci 2018; 11:436. [PMID: 29386998 PMCID: PMC5776129 DOI: 10.3389/fncel.2017.00436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/29/2017] [Indexed: 11/13/2022] Open
Abstract
Metabotropic glutamate receptors (mGluRs) are abundantly expressed in the rodent main olfactory bulb. The function of Group I mGluRs has been investigated in a number of studies, while the actions of Group II mGluRs, which include the mGluR2 and mGluR3 subtypes, have been less well explored. Here, we used electrophysiological approaches in mouse olfactory bulb slices to investigate how Group II mGluR activation and inactivation modifies the activity of external tufted (ET) and mitral cells. The Group II mGluR agonist DCG-IV was found to directly and uniformly reduce the spontaneous discharge of ET and mitral cells. The inhibitory effect of DCG-IV was absent in mitral cells with truncated apical dendrites, indicating a glomerular site of action. DCG-IV did not influence olfactory nerve-evoked monosynaptic responses in ET or mitral cells, indicating that Group II mGluRs do not presynaptically modulate glutamate release from olfactory nerve terminals. In contrast, DCG-IV suppressed polysynaptic responses in periglomerular cells evoked by olfactory nerve stimulation. DCG-IV also inhibited glutamate release from ET cells, and suppressed the spontaneous and olfactory nerve-evoked long-lasting depolarization in mitral cells. Applied alone, Group II receptor antagonists were without effect, suggesting that basal activation of these receptors is nil. These findings suggest that Group II mGluRs inhibit ET and mitral cell activity and further dampen intraglomerular excitatory circuits by suppressing glutamate release.
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Affiliation(s)
- Hong-Wei Dong
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States
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40
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Co-Activation of Metabotropic Glutamate Receptor 3 and Beta-Adrenergic Receptors Modulates Cyclic-AMP and Long-Term Potentiation, and Disrupts Memory Reconsolidation. Neuropsychopharmacology 2017; 42:2553-2566. [PMID: 28664928 PMCID: PMC5686489 DOI: 10.1038/npp.2017.136] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 05/20/2017] [Accepted: 06/14/2017] [Indexed: 12/13/2022]
Abstract
Activation of β-adrenergic receptors (βARs) enhances both the induction of long-term potentiation (LTP) in hippocampal CA1 pyramidal cells and hippocampal-dependent cognitive function. Interestingly, previous studies reveal that coincident activation of group II metabotropic glutamate (mGlu) receptors with βARs in the hippocampal astrocytes induces a large increase in cyclic-AMP (cAMP) accumulation and release of adenosine. Adenosine then acts on A1 adenosine receptors at neighboring excitatory Schaffer collateral terminals, which could counteract effects of activation of neuronal βARs on excitatory transmission. On the basis of this, we postulated that activation of the specific mGlu receptor subtype that mediates this response could inhibit βAR-mediated effects on hippocampal synaptic plasticity and cognitive function. Using novel mGlu receptor subtype-selective allosteric modulators along with knockout mice we now report that the effects of mGlu2/3 agonists on βAR-mediated increases in cAMP accumulation are exclusively mediated by mGlu3. Furthermore, mGlu3 activation inhibits the ability of the βAR agonist isoproterenol to enhance hippocampal LTP, and this effect is absent in slices treated with either a glial toxin or an adenosine A1 receptor antagonist. Finally, systemic administration of the mGlu2/3 agonist LY379268 disrupted contextual fear memory in a manner similar to the effect of the βAR antagonist propranolol, and this effect was reversed by the mGlu3-negative allosteric modulator VU0650786. Taken together, these data suggest that mGlu3 can influence astrocytic signaling and modulate βAR-mediated effects on hippocampal synaptic plasticity and cognitive function.
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41
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Olivero G, Bonfiglio T, Vergassola M, Usai C, Riozzi B, Battaglia G, Nicoletti F, Pittaluga A. Immuno-pharmacological characterization of group II metabotropic glutamate receptors controlling glutamate exocytosis in mouse cortex and spinal cord. Br J Pharmacol 2017; 174:4785-4796. [PMID: 28967122 PMCID: PMC5727332 DOI: 10.1111/bph.14061] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND AND PURPOSE We recently proposed the existence of mGlu3 -preferring autoreceptors in spinal cord terminals and of mGlu2 -preferring autoreceptors in cortical terminals. This study aims to verify our previous conclusions and to extend their pharmacological characterization. EXPERIMENTAL APPROACH We studied the effect of LY566332, an mGlu2 receptor positive allosteric modulator (PAM), and of LY2389575, a selective mGlu3 receptor negative allosteric (NAM) modulator, on the mGlu2/3 agonist LY379268-mediated inhibition of glutamate exocytosis [measured as KCl-evoked release of preloaded [3 H]-D-aspartate]. The mGlu2 PAM BINA and the mGlu3 NAM ML337, as well as selective antibodies recognizing the N-terminal of the receptor proteins, were used to confirm the pharmacological characterization of the native receptors. KEY RESULTS Cortical synaptosomes possess LY566332-sensitive autoreceptors that are slightly, although significantly, susceptible to LY2389575. In contrast, LY566332-insensitive and LY2389575-sensitive autoreceptors are present in spinal cord terminals. BINA and ML337 mimicked LY566332 and LY2389575, respectively, in controlling LY379268-mediated inhibition of glutamate exocytosis from both cortical and spinal cord synaptosomes. Incubation of cortical synaptosomes with anti-mGlu2 antibody prevented the LY379268-induced inhibition of glutamate exocytosis, and this response was partially reduced by the anti-mGlu3 antibody. Incubation of spinal cord synaptosomes with the anti-mGlu3 antibody abolished LY379268-mediated reduction of glutamate exocytosis from these terminals, while the anti-mGlu2 antibody was inactive. Western blot analysis and confocal microscopy data were largely consistent with these functional observations. CONCLUSIONS AND IMPLICATIONS We confirmed that mGlu3 -preferring autoreceptors exist in spinal cord terminals. Differently, cortical glutamatergic terminals possess mGlu2 /mGlu3 heterodimers, whose inhibitory effect is largely mediated by mGlu2 receptors.
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Affiliation(s)
| | | | | | - Cesare Usai
- National Research CouncilInstitute of BiophysicsGenoaItaly
| | | | | | - Ferdinando Nicoletti
- I.R.C.C.S. Neuromed, Località CamerellePozzilliItaly
- Department of Physiology and PharmacologySapienza UniversityRomeItaly
| | - Anna Pittaluga
- Department of Pharmacy, DiFARUniversity of GenoaGenoaItaly
- Centre of Excellence for Biomedical ResearchUniversity of GenoaGenoaItaly
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Blunted mGluR Activation Disinhibits Striatopallidal Transmission in Parkinsonian Mice. Cell Rep 2017; 17:2431-2444. [PMID: 27880915 PMCID: PMC5489133 DOI: 10.1016/j.celrep.2016.10.087] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 09/07/2016] [Accepted: 10/27/2016] [Indexed: 01/10/2023] Open
Abstract
The prevailing circuit model predicts that hyperactivity of the striatopallidal pathway and subsequently increased inhibition of external globus pallidus (GPe) neurons lead to the hypokinetic symptoms of Parkinson's disease (PD). It is believed that hyperactivity of the striatopallidal pathway is due to inactivity of dopamine receptors on the somatodendritic membrane of striatopallidal neurons, but the exact cellular underpinnings remain unclear. In this study, we show that mouse GPe astrocytes critically control ambient glutamate level, which in turn gates striatopallidal transmission via the activation of presynaptic metabotropic glutamate receptors. This presynaptic inhibition of striatopallidal transmission is diminished after the chronic loss of dopamine. Elevation of intracellular glutamate content in astrocytes restores the proper regulation of the striatopallidal input in PD models. These findings argue that astrocytes are key regulators of the striatopallidal synapse. Targeting this cell class may serve as an alternative therapeutic strategy for PD.
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43
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Li DP, Pan HL. Glutamatergic Regulation of Hypothalamic Presympathetic Neurons in Hypertension. Curr Hypertens Rep 2017; 19:78. [PMID: 28929331 DOI: 10.1007/s11906-017-0776-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Elevated sympathetic vasomotor tone emanating from the brain is a major mechanism involved in the development of hypertension. Increased glutamatergic excitatory input to presympathetic neurons in the paraventricular nucleus (PVN) of the hypothalamus leads to increased sympathetic outflow in various animal models of hypertension. Recent studies have revealed molecular and cellular mechanisms underlying enhanced glutamatergic synaptic input to PVN presympathetic neurons in hypertension. In this review article, we summarize recent findings on changes in inotropic and metabotropic glutamate receptors, at both presynaptic and postsynaptic sites, responsible for increased glutamatergic input to PVN presympathetic neurons in hypertension. Particular emphasis is placed on the role of protein kinases and phosphatases in the potentiated activity of synaptic NMDA receptors in the PVN in hypertension. New findings about glutamatergic synaptic plasticity in the PVN not only improve the understanding of molecular mechanisms involved in heightened activity of the sympathetic nervous system but also suggest new therapeutic targets for treating drug-resistant, neurogenic hypertension.
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Affiliation(s)
- De-Pei Li
- Center for Neuroscience and Pain Research, Division of Anesthesiology and Critical Care, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX, 77030, USA
| | - Hui-Lin Pan
- Center for Neuroscience and Pain Research, Division of Anesthesiology and Critical Care, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX, 77030, USA.
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44
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Johnson MP, Muhlhauser MA, Nisenbaum ES, Simmons RMA, Forster BM, Knopp KL, Yang L, Morrow D, Li DL, Kennedy JD, Swanson S, Monn JA. Broad spectrum efficacy with LY2969822, an oral prodrug of metabotropic glutamate 2/3 receptor agonist LY2934747, in rodent pain models. Br J Pharmacol 2017; 174:822-835. [PMID: 28177520 DOI: 10.1111/bph.13740] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 01/27/2017] [Accepted: 01/31/2017] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE A body of evidence suggests activation of metabotropic glutamate 2/3 (mGlu2/3 ) receptors would be an effective analgesic in chronic pain conditions. Thus, the analgesic properties of a novel mGlu2/3 receptor agonist prodrug were investigated. EXPERIMENTAL APPROACH After oral absorption, the prodrug LY2969822 rapidly converts to the brain penetrant, potent and subtype-selective mGlu2/3 receptor agonist LY2934747. Behavioural assessments of allodynia, hyperalgesia and nocifensive behaviours were determined in preclinical pain models after administration of LY2969822 0.3-10 mg·kg-1 . In addition, the ability of i.v. LY2934747 to modulate dorsal horn spinal cord wide dynamic range (WDR) neurons in spinal nerve ligated (SNL) rats was assessed. KEY RESULTS Following treatment with LY2934747, the spontaneous activity and electrically-evoked wind-up of WDR neurons in rats that had undergone spinal nerve ligation and developed mechanical allodynia were suppressed. In a model of sensitization, orally administered LY2969822 prevented the nociceptive behaviours induced by an intraplantar injection of formalin. The on-target nature of this effect was confirmed by blockade with an mGlu2/3 receptor antagonist. LY2969822 prevented capsaicin-induced tactile hypersensitivity, reversed the SNL-induced tactile hypersensitivity and reversed complete Freund's adjuvant - induced mechanical hyperalgesia. The mGlu2/3 receptor agonist prodrug demonstrated efficacy in visceral pain models, including a colorectal distension model and partially prevented the nocifensive behaviours in the mouse acetic acid writhing model. CONCLUSIONS AND IMPLICATIONS Following oral administration of the prodrug LY2969822, the mGlu2/3 receptor agonist LY2934747 was formed and this attenuated pain behaviours across a broad range of preclinical pain models.
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Affiliation(s)
- Michael P Johnson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Mark A Muhlhauser
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Eric S Nisenbaum
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Rosa M A Simmons
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Beth M Forster
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Kelly L Knopp
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Lijuan Yang
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Denise Morrow
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Dominic L Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Jeffrey D Kennedy
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Steven Swanson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - James A Monn
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
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45
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Ansari M, Sobhani S. Impaired glutamate release in GPe astrocytes, disinhibits striatopallidal transmission in Parkinsonian mice. Mov Disord 2017; 32:528. [PMID: 28186663 DOI: 10.1002/mds.26943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 01/12/2017] [Indexed: 11/10/2022] Open
Affiliation(s)
- Mina Ansari
- Neuroimaging Network, Universal Scientific Education and Research Network, Tehran, Iran.,Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Basir Eye Health Research Center, Tehran, Iran
| | - Soheila Sobhani
- Neuroimaging Network, Universal Scientific Education and Research Network, Tehran, Iran.,Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Basir Eye Health Research Center, Tehran, Iran
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46
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Senter RK, Ghoshal A, Walker AG, Xiang Z, Niswender CM, Conn PJ. The Role of mGlu Receptors in Hippocampal Plasticity Deficits in Neurological and Psychiatric Disorders: Implications for Allosteric Modulators as Novel Therapeutic Strategies. Curr Neuropharmacol 2017; 14:455-73. [PMID: 27296640 PMCID: PMC4983746 DOI: 10.2174/1570159x13666150421003225] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/18/2015] [Accepted: 04/09/2015] [Indexed: 11/22/2022] Open
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are two distinct forms of synaptic plasticity that have been extensively characterized at the Schaffer collateral-CA1 (SCCA1) synapse and the mossy fiber (MF)-CA3 synapse within the hippocampus, and are postulated to be the molecular underpinning for several cognitive functions. Deficits in LTP and LTD have been implicated in the pathophysiology of several neurological and psychiatric disorders. Therefore, there has been a large effort focused on developing an understanding of the mechanisms underlying these forms of plasticity and novel therapeutic strategies that improve or rescue these plasticity deficits. Among many other targets, the metabotropic glutamate (mGlu) receptors show promise as novel therapeutic candidates for the treatment of these disorders. Among the eight distinct mGlu receptor subtypes (mGlu1-8), the mGlu1,2,3,5,7 subtypes are expressed throughout the hippocampus and have been shown to play important roles in the regulation of synaptic plasticity in this brain area. However, development of therapeutic agents that target these mGlu receptors has been hampered by a lack of subtype-selective compounds. Recently, discovery of allosteric modulators of mGlu receptors has provided novel ligands that are highly selective for individual mGlu receptor subtypes. The mGlu receptors modulate the multiple forms of synaptic plasticity at both SC-CA1 and MF synapses and allosteric modulators of mGlu receptors have emerged as potential therapeutic agents that may rescue plasticity deficits and improve cognitive function in patients suffering from multiple neurological and psychiatric disorders.
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Affiliation(s)
| | | | | | | | | | - P Jeffrey Conn
- Department of Pharmacology, Faculty of Vanderbilt University Medical Center, 1205 Light Hall, Nashville, TN 37232, USA.
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Metabotropic glutamate receptors and neurodegenerative diseases. Pharmacol Res 2017; 115:179-191. [DOI: 10.1016/j.phrs.2016.11.013] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/11/2016] [Accepted: 11/15/2016] [Indexed: 12/21/2022]
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Nonaka T, Yamada T, Ishimura T, Zuo D, Moffett JR, Neale JH, Yamamoto T. A role for the locus coeruleus in the analgesic efficacy of N-acetylaspartylglutamate peptidase (GCPII) inhibitors ZJ43 and 2-PMPA. Mol Pain 2017; 13:1744806917697008. [PMID: 28326936 PMCID: PMC5407666 DOI: 10.1177/1744806917697008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 01/24/2017] [Accepted: 01/31/2017] [Indexed: 11/16/2022] Open
Abstract
N-acetylaspartylglutamate (NAAG) is the third most prevalent and widely distributed neurotransmitter in the mammalian nervous system. NAAG activates a group II metabotropic glutamate receptor (mGluR3) and is inactivated by an extracellular enzyme, glutamate carboxypeptidase II (GCPII) in vivo. Inhibitors of this enzyme are analgesic in animal models of inflammatory, neuropathic and bone cancer pain. NAAG and GCPII are present in the locus coeruleus, a center for the descending noradrenergic inhibitory pain system. In the formalin footpad model, systemic treatment with GCPII inhibitors reduces both phases of the inflammatory pain response and increases release of spinal noradrenaline. This analgesic efficacy is blocked by systemic injection of a group II mGluR antagonist, by intrathecal (spinal) injection of an alpha 2 adrenergic receptor antagonist and by microinjection of an α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor antagonist directly into the contralateral locus coeruleus. Footpad inflammation increases release of glutamate in the contralateral locus coeruleus and systemic treatment with a GCPII inhibitor blocks this increase. Direct injection of GCPII inhibitors into the contralateral or ipsilateral locus coeruleus reduces both phases of the inflammatory pain response in a dose-dependent manner and the contralateral effect also is blocked by intrathecal injection of an alpha 2 adrenergic receptor antagonist. These data support the hypothesis that the analgesic efficacy of systemically administered GCPII inhibitors is mediated, at least in part, by the contralateral locus coeruleus via group II mGluR, AMPA and alpha 2 adrenergic receptors.
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Affiliation(s)
- Takahiro Nonaka
- Department of Anesthesiology, School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Toshihiko Yamada
- Department of Anesthesiology, School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Tatsuhiro Ishimura
- Department of Anesthesiology, School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Daiying Zuo
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, China
| | - John R Moffett
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Joseph H Neale
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Tatsuo Yamamoto
- Department of Anesthesiology, School of Medical Science, Kumamoto University, Kumamoto, Japan
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McOmish CE, Demireva EY, Gingrich JA. Developmental expression of mGlu2 and mGlu3 in the mouse brain. Gene Expr Patterns 2016; 22:46-53. [PMID: 27818290 DOI: 10.1016/j.gep.2016.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 10/30/2016] [Accepted: 10/31/2016] [Indexed: 12/12/2022]
Abstract
The glutamatergic system directs central nervous system (CNS) neuronal activity and may underlie various neuropsychiatric disorders. Glutamate transmits its effects through multiple receptor classes. Class II metabotropic glutamate receptors, mGlu2 and mGlu3, play an important role in regulating synaptic release of different neurotransmitter systems and consequently modulate signaling across several neuronal subtypes. Drugs targeting mGlu2 and mGlu3 are seen as potential therapeutics for various psychiatric and neurological disorders, and defining their expression through development can aid in understanding their distinct function. Here, non-radioactive in situ hybridization was used to detect mGlu2 and mGlu3 mRNA in the CNS of 129SvEv mice at PN1, PN8, PN25, PN40, and PN100. At PN1, mGlu2 and mGlu3 are strongly expressed cortically, most notably in layer III and V. Subcortically, mGlu2 is detected in thalamic nuclei; mGlu3 is highly expressed in the striatum. By PN8, the most notable changes are in hippocampus and cortex, with mGlu2 densely expressed in the dentate gyrus, and showing increased cortical levels especially in medial cortex. At PN8, mGlu3 is observed in cortex and striatum, with highest levels detected in reticular thalamic nucleus. At PN25 patterns of expression approximated those observed across adulthood (PN40 & PN100): mGlu2 expression was high in cortex and dentate gyrus while mGlu3 showed expression in the reticular thalamic nucleus, cortex, and striatum. These studies provide a foundation for future research seeking to parse out the roles of mGlu2 from mGlu3, paving the way for better understanding of how these receptors regulate activity in the brain.
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Affiliation(s)
- Caitlin E McOmish
- Molecular Psychiatry, Florey Institute for Neuroscience and Mental Health, VIC, 3052, Australia; Department of Psychiatry, Columbia University, New York, NY 10032, USA.
| | - Elena Y Demireva
- Michigan State University, East Lansing, MI 48824, USA; Department of Psychiatry, Columbia University, New York, NY 10032, USA; New York State Psychiatric Institute, New York, NY 10032, USA
| | - Jay A Gingrich
- Department of Psychiatry, Columbia University, New York, NY 10032, USA; New York State Psychiatric Institute, New York, NY 10032, USA; Sackler Institute for Developmental Psychobiology, New York, NY 10032, USA
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