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Azarfarin M, Ghadiri T, Dadkhah M, Sahab-Negah S. The interaction between cannabinoids and long-term synaptic plasticity: A survey on memory formation and underlying mechanisms. Cell Biochem Funct 2024; 42:e4100. [PMID: 39090824 DOI: 10.1002/cbf.4100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 07/05/2024] [Accepted: 07/12/2024] [Indexed: 08/04/2024]
Abstract
Synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD), is an essential phenomenon in memory formation as well as maintenance along with many other cognitive functions, such as those needed for coping with external stimuli. Synaptic plasticity consists of gradual changes in the biochemistry and morphology of pre- and postsynaptic neurons, particularly in the hippocampus. Consuming marijuana as a primary source of exocannabinoids immediately impairs attention and working memory-related tasks. Evidence regarding the effects of cannabinoids on LTP and memory is contradictory. While cannabinoids can affect a variety of specific cannabinoid receptors (CBRs) and nonspecific receptors throughout the body and brain, they exert miscellaneous systemic and local cerebral effects. Given the increasing use of cannabis, mainly among the young population, plus its potential adverse long-term effects on learning and memory processes, it could be a future global health challenge. Indeed, the impact of cannabinoids on memory is multifactorial and depends on the dosage, timing, formula, and route of consumption, plus the background complex interaction of the endocannabinoids system with other cerebral networks. Herein, we review how exogenously administrated organic cannabinoids, CBRs agonists or antagonists, and endocannabinoids can affect LTP and synaptic plasticity through various receptors in interaction with other cerebral pathways and primary neurotransmitters.
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Affiliation(s)
- Maryam Azarfarin
- Department of Neuroscience,Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Tahereh Ghadiri
- Department of Neuroscience,Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Masoomeh Dadkhah
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sajad Sahab-Negah
- Pharmaceutical Sciences Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
- Department of Neuroscience, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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2
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Wen W, Turrigiano GG. Keeping Your Brain in Balance: Homeostatic Regulation of Network Function. Annu Rev Neurosci 2024; 47:41-61. [PMID: 38382543 DOI: 10.1146/annurev-neuro-092523-110001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
To perform computations with the efficiency necessary for animal survival, neocortical microcircuits must be capable of reconfiguring in response to experience, while carefully regulating excitatory and inhibitory connectivity to maintain stable function. This dynamic fine-tuning is accomplished through a rich array of cellular homeostatic plasticity mechanisms that stabilize important cellular and network features such as firing rates, information flow, and sensory tuning properties. Further, these functional network properties can be stabilized by different forms of homeostatic plasticity, including mechanisms that target excitatory or inhibitory synapses, or that regulate intrinsic neuronal excitability. Here we discuss which aspects of neocortical circuit function are under homeostatic control, how this homeostasis is realized on the cellular and molecular levels, and the pathological consequences when circuit homeostasis is impaired. A remaining challenge is to elucidate how these diverse homeostatic mechanisms cooperate within complex circuits to enable them to be both flexible and stable.
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Affiliation(s)
- Wei Wen
- Department of Biology, Brandeis University, Waltham, Massachusetts, USA;
| | - Gina G Turrigiano
- Department of Biology, Brandeis University, Waltham, Massachusetts, USA;
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3
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Barti B, Dudok B, Kenesei K, Zöldi M, Miczán V, Balla GY, Zala D, Tasso M, Sagheddu C, Kisfali M, Tóth B, Ledri M, Vizi ES, Melis M, Barna L, Lenkei Z, Soltész I, Katona I. Presynaptic nanoscale components of retrograde synaptic signaling. SCIENCE ADVANCES 2024; 10:eado0077. [PMID: 38809980 PMCID: PMC11135421 DOI: 10.1126/sciadv.ado0077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 04/23/2024] [Indexed: 05/31/2024]
Abstract
While our understanding of the nanoscale architecture of anterograde synaptic transmission is rapidly expanding, the qualitative and quantitative molecular principles underlying distinct mechanisms of retrograde synaptic communication remain elusive. We show that a particular form of tonic cannabinoid signaling is essential for setting target cell-dependent synaptic variability. It does not require the activity of the two major endocannabinoid-producing enzymes. Instead, by developing a workflow for physiological, anatomical, and molecular measurements at the same unitary synapse, we demonstrate that the nanoscale stoichiometric ratio of type 1 cannabinoid receptors (CB1Rs) to the release machinery is sufficient to predict synapse-specific release probability. Accordingly, selective decrease of extrasynaptic CB1Rs does not affect synaptic transmission, whereas in vivo exposure to the phytocannabinoid Δ9-tetrahydrocannabinol disrupts the intrasynaptic nanoscale stoichiometry and reduces synaptic variability. These findings imply that synapses leverage the nanoscale stoichiometry of presynaptic receptor coupling to the release machinery to establish synaptic strength in a target cell-dependent manner.
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Affiliation(s)
- Benjámin Barti
- Department of Psychological and Brain Sciences, Indiana University Bloomington, 702 N Walnut Grove Ave, Bloomington, IN 47405-2204, USA
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
- School of Ph.D. Studies, Semmelweis University, Üllői st 26, H-1085 Budapest, Hungary
| | - Barna Dudok
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
- Departments of Neurology and Neuroscience, Baylor College of Medicine, 1 Baylor Plz, Houston, TX 77030, USA
- Department of Neurosurgery, Stanford University, 450 Jane Stanford Way, Stanford, CA 94305, USA
| | - Kata Kenesei
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
| | - Miklós Zöldi
- Department of Psychological and Brain Sciences, Indiana University Bloomington, 702 N Walnut Grove Ave, Bloomington, IN 47405-2204, USA
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
- School of Ph.D. Studies, Semmelweis University, Üllői st 26, H-1085 Budapest, Hungary
| | - Vivien Miczán
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
- Synthetic and Systems Biology Unit, HUN-REN Biological Research Center, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Gyula Y. Balla
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
- School of Ph.D. Studies, Semmelweis University, Üllői st 26, H-1085 Budapest, Hungary
- Translational Behavioral Neuroscience Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
| | - Diana Zala
- Université Paris Cité, INSERM, Institute of Psychiatry and Neurosciences of Paris, F-75014 Paris, France
| | - Mariana Tasso
- Institute of Nanosystems, School of Bio and Nanotechnologies, National University of San Martín - CONICET, 25 de Mayo Ave., 1021 San Martín, Argentina
| | - Claudia Sagheddu
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, Monserrato, 09042 Cagliari, Italy
| | - Máté Kisfali
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
- BiTrial Ltd., Tállya st 23, H-1121 Budapest, Hungary
| | - Blanka Tóth
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellért square 4, H-1111 Budapest, Hungary
- Department of Molecular Biology, Semmelweis University, Üllői st 26, H-1085 Budapest, Hungary
| | - Marco Ledri
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
- Epilepsy Center, Department of Clinical Sciences, Faculty of Medicine, Lund University, Sölvegatan 17, BMC A11, 221 84 Lund, Sweden
| | - E. Sylvester Vizi
- Molecular Pharmacology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
| | - Miriam Melis
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, Monserrato, 09042 Cagliari, Italy
| | - László Barna
- Department of Psychological and Brain Sciences, Indiana University Bloomington, 702 N Walnut Grove Ave, Bloomington, IN 47405-2204, USA
| | - Zsolt Lenkei
- Université Paris Cité, INSERM, Institute of Psychiatry and Neurosciences of Paris, F-75014 Paris, France
| | - Iván Soltész
- Department of Neurosurgery, Stanford University, 450 Jane Stanford Way, Stanford, CA 94305, USA
| | - István Katona
- Department of Psychological and Brain Sciences, Indiana University Bloomington, 702 N Walnut Grove Ave, Bloomington, IN 47405-2204, USA
- Molecular Neurobiology Research Group, HUN-REN Institute of Experimental Medicine, Szigony st 43, H-1083 Budapest, Hungary
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4
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Forte N, Nicois A, Marfella B, Mavaro I, D'Angelo L, Piscitelli F, Scandurra A, De Girolamo P, Baldelli P, Benfenati F, Di Marzo V, Cristino L. Early endocannabinoid-mediated depolarization-induced suppression of excitation delays the appearance of the epileptic phenotype in synapsin II knockout mice. Cell Mol Life Sci 2024; 81:37. [PMID: 38214769 PMCID: PMC11072294 DOI: 10.1007/s00018-023-05029-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 10/16/2023] [Accepted: 10/31/2023] [Indexed: 01/13/2024]
Abstract
The mechanism underlying the transition from the pre-symptomatic to the symptomatic state is a crucial aspect of epileptogenesis. SYN2 is a member of a multigene family of synaptic vesicle phosphoproteins playing a fundamental role in controlling neurotransmitter release. Human SYN2 gene mutations are associated with epilepsy and autism spectrum disorder. Mice knocked out for synapsin II (SynII KO) are prone to epileptic seizures that appear after 2 months of age. However, the involvement of the endocannabinoid system, known to regulate seizure development and propagation, in the modulation of the excitatory/inhibitory balance in the epileptic hippocampal network of SynII KO mice has not been explored. In this study, we investigated the impact of endocannabinoids on glutamatergic and GABAergic synapses at hippocampal dentate gyrus granule cells in young pre-symptomatic (1-2 months old) and adult symptomatic (5-8 months old) SynII KO mice. We observed an increase in endocannabinoid-mediated depolarization-induced suppression of excitation in young SynII KO mice, compared to age-matched wild-type controls. In contrast, the endocannabinoid-mediated depolarization-induced suppression of inhibition remained unchanged in SynII KO mice at both ages. This selective alteration of excitatory synaptic transmission was accompanied by changes in hippocampal endocannabinoid levels and cannabinoid receptor type 1 distribution among glutamatergic and GABAergic synaptic terminals contacting the granule cells of the dentate gyrus. Finally, inhibition of type-1 cannabinoid receptors in young pre-symptomatic SynII KO mice induced seizures during a tail suspension test. Our results suggest that endocannabinoids contribute to maintaining network stability in a genetic mouse model of human epilepsy.
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Affiliation(s)
- Nicola Forte
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Alessandro Nicois
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Brenda Marfella
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Isabella Mavaro
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Livia D'Angelo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Fabiana Piscitelli
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Anna Scandurra
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Paolo De Girolamo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Vincenzo Di Marzo
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy.
- Faculty of Medicine and Faculty of Agricultural and Food Sciences, Canada Excellence Research Chair on the Microbiome-Endocannabinoidome Axis in Metabolic Health, Université Laval, Québec City, QC, Canada.
- Heart and Lung Research Institute of Université Laval, Québec City, QC, Canada.
- Institute for Nutrition and Functional Foods, Centre NUTRISS, Université Laval, Québec City, QC, Canada.
| | - Luigia Cristino
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy.
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5
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Steiger LJ, Tsintsadze T, Mattheisen GB, Smith SM. Somatic and terminal CB1 receptors are differentially coupled to voltage-gated sodium channels in neocortical neurons. Cell Rep 2023; 42:112247. [PMID: 36933217 PMCID: PMC10106091 DOI: 10.1016/j.celrep.2023.112247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/13/2023] [Accepted: 02/24/2023] [Indexed: 03/19/2023] Open
Abstract
Endogenous cannabinoid signaling is vital for important brain functions, and the same pathways can be modified pharmacologically to treat pain, epilepsy, and posttraumatic stress disorder. Endocannabinoid-mediated changes to excitability are predominantly attributed to 2-arachidonoylglycerol (2-AG) acting presynaptically via the canonical cannabinoid receptor, CB1. Here, we identify a mechanism in the neocortex by which anandamide (AEA), another major endocannabinoid, but not 2-AG, powerfully inhibits somatically recorded voltage-gated sodium channel (VGSC) currents in the majority of neurons. This pathway involves intracellular CB1 that, when activated by anandamide, decreases the likelihood of recurrent action potential generation. WIN 55,212-2 similarly activates CB1 and inhibits VGSC currents, indicating that this pathway is also positioned to mediate the actions of exogenous cannabinoids on neuronal excitability. The coupling between CB1 and VGSCs is absent at nerve terminals, and 2-AG does not block somatic VGSC currents, indicating functional compartmentalization of the actions of two endocannabinoids.
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Affiliation(s)
- Luke J Steiger
- Section of Pulmonary and Critical Care Medicine, VA Portland Health Care System, Portland, OR, USA; Department of Medicine, Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, OR 97239, USA
| | - Timur Tsintsadze
- Section of Pulmonary and Critical Care Medicine, VA Portland Health Care System, Portland, OR, USA; Department of Medicine, Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, OR 97239, USA
| | - Glynis B Mattheisen
- Section of Pulmonary and Critical Care Medicine, VA Portland Health Care System, Portland, OR, USA; Department of Medicine, Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, OR 97239, USA
| | - Stephen M Smith
- Section of Pulmonary and Critical Care Medicine, VA Portland Health Care System, Portland, OR, USA; Department of Medicine, Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, OR 97239, USA; Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA.
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6
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Valakh V, Wise D, Zhu XA, Sha M, Fok J, Van Hooser SD, Schectman R, Cepeda I, Kirk R, O'Toole SM, Nelson SB. A transcriptional constraint mechanism limits the homeostatic response to activity deprivation in mammalian neocortex. eLife 2023; 12:e74899. [PMID: 36749029 PMCID: PMC10010687 DOI: 10.7554/elife.74899] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 02/03/2023] [Indexed: 02/08/2023] Open
Abstract
Healthy neuronal networks rely on homeostatic plasticity to maintain stable firing rates despite changing synaptic drive. These mechanisms, however, can themselves be destabilizing if activated inappropriately or excessively. For example, prolonged activity deprivation can lead to rebound hyperactivity and seizures. While many forms of homeostasis have been described, whether and how the magnitude of homeostatic plasticity is constrained remains unknown. Here, we uncover negative regulation of cortical network homeostasis by the PARbZIP family of transcription factors. In cortical slice cultures made from knockout mice lacking all three of these factors, the network response to prolonged activity withdrawal measured with calcium imaging is much stronger, while baseline activity is unchanged. Whole-cell recordings reveal an exaggerated increase in the frequency of miniature excitatory synaptic currents reflecting enhanced upregulation of recurrent excitatory synaptic transmission. Genetic analyses reveal that two of the factors, Hlf and Tef, are critical for constraining plasticity and for preventing life-threatening seizures. These data indicate that transcriptional activation is not only required for many forms of homeostatic plasticity but is also involved in restraint of the response to activity deprivation.
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Affiliation(s)
- Vera Valakh
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Derek Wise
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Xiaoyue Aelita Zhu
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Mingqi Sha
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Jaidyn Fok
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Stephen D Van Hooser
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Robin Schectman
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Isabel Cepeda
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Ryan Kirk
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Sean M O'Toole
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
| | - Sacha B Nelson
- Department of Biology and Program in Neuroscience, Brandeis UniversityWalthamUnited States
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7
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Scheyer A, Yasmin F, Naskar S, Patel S. Endocannabinoids at the synapse and beyond: implications for neuropsychiatric disease pathophysiology and treatment. Neuropsychopharmacology 2023; 48:37-53. [PMID: 36100658 PMCID: PMC9700791 DOI: 10.1038/s41386-022-01438-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [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: 08/10/2022] [Accepted: 08/18/2022] [Indexed: 11/09/2022]
Abstract
Endocannabinoids (eCBs) are lipid neuromodulators that suppress neurotransmitter release, reduce postsynaptic excitability, activate astrocyte signaling, and control cellular respiration. Here, we describe canonical and emerging eCB signaling modes and aim to link adaptations in these signaling systems to pathological states. Adaptations in eCB signaling systems have been identified in a variety of biobehavioral and physiological process relevant to neuropsychiatric disease states including stress-related disorders, epilepsy, developmental disorders, obesity, and substance use disorders. These insights have enhanced our understanding of the pathophysiology of neurological and psychiatric disorders and are contributing to the ongoing development of eCB-targeting therapeutics. We suggest future studies aimed at illuminating how adaptations in canonical as well as emerging cellular and synaptic modes of eCB signaling contribute to disease pathophysiology or resilience could further advance these novel treatment approaches.
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Affiliation(s)
| | - Farhana Yasmin
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Saptarnab Naskar
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Sachin Patel
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA.
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
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Abstract
Electrophysiological technique is an efficient tool for investigating the synaptic regulatory effects mediated by the endocannabinoid system. Stimulation of presynaptic type 1 cannabinoid receptor (CB1) is the principal mode by which endocannabinoids suppress transmitter release in the central nervous system, but a non-retrograde manner of functioning and other receptors have also been described. Endocannabinoids are key modulators of both short- and long-term plasticity. Here, we discuss ex vivo electrophysiological approaches to examine synaptic signaling induced by cannabinoid and endocannabinoid molecules in the mammalian brain.
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Affiliation(s)
- Alessandra Musella
- Synaptic Immunopathology Lab, IRCCS San Raffaele Roma, Rome, Italy
- Department of Human Sciences and Quality of Life Promotion University of Rome San Raffaele, Rome, Italy
| | - Diego Centonze
- Department of Systems Medicine, Tor Vergata University, Rome, Italy.
- Unit of Neurology, IRCCS Neuromed, Pozzilli, IS, Italy.
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9
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Coordinated Regulation of CB1 Cannabinoid Receptors and Anandamide Metabolism Stabilizes Network Activity during Homeostatic Downscaling. eNeuro 2022; 9:ENEURO.0276-22.2022. [PMID: 36316118 PMCID: PMC9663203 DOI: 10.1523/eneuro.0276-22.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/20/2022] [Accepted: 09/28/2022] [Indexed: 12/24/2022] Open
Abstract
Neurons express overlapping homeostatic mechanisms to regulate synaptic function and network properties in response to perturbations of neuronal activity. Endocannabinoids (eCBs) are bioactive lipids synthesized in the postsynaptic compartments to regulate synaptic transmission, plasticity, and neuronal excitability primarily through retrograde activation of presynaptic cannabinoid receptor type 1 (CB1). The eCB system is well situated to regulate neuronal network properties and coordinate presynaptic and postsynaptic activity. However, the role of the eCB system in homeostatic adaptations to neuronal hyperactivity is unknown. To address this issue, we used Western blotting and targeted lipidomics to measure adaptations in eCB system to bicuculline (BCC)-induced chronic hyperexcitation in mature cultured rat cortical neurons, and used multielectrode array (MEA) recording and live-cell imaging of glutamate dynamics to test the effects of pharmacological manipulations of eCB on network activities. We show that BCC-induced chronic hyperexcitation triggers homeostatic downscaling and a coordinated adaptation to enhance tonic eCB signaling. Hyperexcitation triggers first the downregulation of fatty acid amide hydrolase (FAAH), the lipase that degrades the eCB anandamide, then an accumulation of anandamide and related metabolites, and finally a delayed upregulation of surface and total CB1. Additionally, we show that BCC-induced downregulation of surface AMPA-type glutamate receptors (AMPARs) and upregulation of CB1 occur through independent mechanisms. Finally, we show that endocannabinoids support baseline network activities before and after downscaling and is engaged to suppress network activity during adaptation to hyperexcitation. We discuss the implications of our findings in the context of downscaling and homeostatic regulation of in vitro oscillatory network activities.
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10
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Molecular study of endo and phytocannabinoids on lipid membranes of different composition. Colloids Surf B Biointerfaces 2022; 221:113020. [DOI: 10.1016/j.colsurfb.2022.113020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/08/2022] [Accepted: 11/11/2022] [Indexed: 11/14/2022]
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11
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Martin SC, Gay SM, Armstrong ML, Pazhayam NM, Reisdorph N, Diering GH. Tonic endocannabinoid signaling supports sleep through development in both sexes. Sleep 2022; 45:6565640. [PMID: 35395682 PMCID: PMC9366650 DOI: 10.1093/sleep/zsac083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 03/07/2022] [Indexed: 12/24/2022] Open
Abstract
Abstract
Sleep is an essential behavior that supports brain function and cognition throughout life, in part by acting on neuronal synapses. The synaptic signaling pathways that mediate the restorative benefits of sleep are not fully understood, particularly in the context of development. Endocannabinoids (eCBs) including 2-arachidonyl glycerol (2-AG) and anandamide (AEA), are bioactive lipids that activate cannabinoid receptor, CB1, to regulate synaptic transmission and mediate cognitive functions and many behaviors, including sleep. We used targeted mass spectrometry to measure changes in forebrain synaptic eCBs during the sleep/wake cycle in juvenile and adolescent mice of both sexes. We find that eCBs lack a daily rhythm in juvenile mice, while in adolescents AEA and related oleoyl ethanolamide are increased during the sleep phase in a circadian manner. Next, we manipulated the eCB system using selective pharmacology and measured the effects on sleep behavior in developing and adult mice of both sexes using a noninvasive piezoelectric home-cage recording apparatus. Enhancement of eCB signaling through inhibition of 2-AG or AEA degradation, increased dark-phase sleep amount and bout length in developing and adult males, but not in females. Inhibition of CB1 by injection of the antagonist AM251 reduced sleep time and caused sleep fragmentation in developing and adult males and females. Our data suggest that males are more sensitive to the sleep-promoting effects of enhanced eCBs but that tonic eCB signaling supports sleep behavior through multiple stages of development in both sexes. This work informs the further development of cannabinoid-based therapeutics for sleep disruption.
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Affiliation(s)
- Shenée C Martin
- Department of Cell Biology and Physiology and the UNC Neuroscience Center, University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
| | - Sean M Gay
- Department of Cell Biology and Physiology and the UNC Neuroscience Center, University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
| | - Michael L Armstrong
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus , Aurora, CO , USA
| | - Nila M Pazhayam
- Department of Cell Biology and Physiology and the UNC Neuroscience Center, University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
| | - Nichole Reisdorph
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus , Aurora, CO , USA
| | - Graham H Diering
- Department of Cell Biology and Physiology and the UNC Neuroscience Center, University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
- Carolina Institute for Developmental Disabilities , Carrboro, NC , USA
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12
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Jayanthi S, Peesapati R, McCoy MT, Ladenheim B, Cadet JL. Footshock-Induced Abstinence from Compulsive Methamphetamine Self-administration in Rat Model Is Accompanied by Increased Hippocampal Expression of Cannabinoid Receptors (CB1 and CB2). Mol Neurobiol 2022; 59:1238-1248. [PMID: 34978045 PMCID: PMC8857101 DOI: 10.1007/s12035-021-02656-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/17/2021] [Indexed: 01/06/2023]
Abstract
Methamphetamine (METH) use disorder (MUD) is characterized by compulsive and repeated drug taking despite negative life consequences. Large intake of METH in humans and animals is accompanied by dysfunctions in learning and memory processes. The endocannabinoid system (ECS) is known to modulate synaptic plasticity and cognitive functions. In addition, the ECS has been implicated in some of the manifestations of substance use disorders (SUDs). We therefore sought to identify potential changes in the expression of various enzymes and of the receptors (CB1 and CB2) that are members of that system. Herein, we used a model of METH self-administration (SA) that includes a punishment phase (footshocks) that helps to separate rats into a compulsive METH phenotype (compulsive) that continues to take METH and a non-compulsive METH (abstinent) group that suppressed or stopped taking METH. Animals were euthanized 2 h after the last METH SA session and their hippocampi were used to measure mRNA levels of cannabinoid receptors (CB/Cnr), as well as those of synthesizing (DAGL-A, DAGL-B, NAPEPLD) and metabolizing (MGLL, FAAH, PTGS2) enzymes of the endocannabinoid cascade. Non-compulsive rats exhibited significant increased hippocampal expression of CB1/Cnr1 and CB2/Cnr2 mRNAs. mRNA levels of the synthesizing enzyme, DAGL-A, and of the metabolic enzymes, MGLL and FAAH, were also increased. Non-compulsive rats also exhibited a significant decrease in hippocampal Ptgs2 mRNA levels. Taken together, these observations implicate the hippocampal endocannabinoid system in the suppression of METH intake in the presence of adverse consequences.
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Affiliation(s)
- Subramaniam Jayanthi
- Molecular Neuropsychiatry Research Branch, DHHS/NIH/NIDA Intramural Research Program, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Ritvik Peesapati
- Molecular Neuropsychiatry Research Branch, DHHS/NIH/NIDA Intramural Research Program, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Michael T McCoy
- Molecular Neuropsychiatry Research Branch, DHHS/NIH/NIDA Intramural Research Program, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Bruce Ladenheim
- Molecular Neuropsychiatry Research Branch, DHHS/NIH/NIDA Intramural Research Program, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, DHHS/NIH/NIDA Intramural Research Program, 251 Bayview Boulevard, Baltimore, MD, 21224, USA.
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13
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Gallego-Landin I, García-Baos A, Castro-Zavala A, Valverde O. Reviewing the Role of the Endocannabinoid System in the Pathophysiology of Depression. Front Pharmacol 2021; 12:762738. [PMID: 34938182 PMCID: PMC8685322 DOI: 10.3389/fphar.2021.762738] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 11/11/2021] [Indexed: 01/04/2023] Open
Abstract
Major depressive disorder is a high-impact, debilitating disease and it is currently considered the most prevalent mental illness. It is associated with disability, as well as increased morbidity and mortality. Despite its significant repercussions in our society, its exact pathophysiology remains unclear and therefore, available antidepressant treatment options are limited and, in some cases, ineffective. In the past years, research has focused on the development of a multifactorial theory of depression. Simultaneously, evidence supporting the role of the endocannabinoid system in the neurobiology of neuropsychiatric diseases has emerged. Studies have shown that the endocannabinoid system strongly impacts neurotransmission, and the neuroendocrine and neuroimmune systems, which are known to be dysfunctional in depressive patients. Accordingly, common antidepressants were shown to have a direct impact on the expression of cannabinoid receptors throughout the brain. Therefore, the relationship between the endocannabinoid system and major depressive disorder is worth consideration. Nevertheless, most studies focus on smaller pieces of what is undoubtedly a larger mosaic of interdependent processes. Therefore, the present review summarizes the existing literature regarding the role of the endocannabinoid system in depression aiming to integrate this information into a holistic picture for a better understanding of the relationship between the two.
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Affiliation(s)
- Ines Gallego-Landin
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Alba García-Baos
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Adriana Castro-Zavala
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Olga Valverde
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
- Neuroscience Research Programme, IMIM-Hospital del Mar Research Institute, Barcelona, Spain
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14
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Alexander C, Vasefi M. Cannabidiol and the corticoraphe circuit in post-traumatic stress disorder. IBRO Neurosci Rep 2021; 11:88-102. [PMID: 34485973 PMCID: PMC8408530 DOI: 10.1016/j.ibneur.2021.08.001] [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: 04/08/2021] [Revised: 08/04/2021] [Accepted: 08/18/2021] [Indexed: 01/06/2023] Open
Abstract
Post-Traumatic Stress Disorder (PTSD), characterized by re-experiencing, avoidance, negative affect, and impaired memory processing, may develop after traumatic events. PTSD is complicated by impaired plasticity and medial prefrontal cortex (mPFC) activity, hyperactivity of the amygdala, and impaired fear extinction. Cannabidiol (CBD) is a promising candidate for treatment due to its multimodal action that enhances plasticity and calms hyperexcitability. CBD’s mechanism in the mPFC of PTSD patients has been explored extensively, but literature on the mechanism in the dorsal raphe nucleus (DRN) is lacking. Following the PRISMA guidelines, we examined current literature regarding CBD in PTSD and overlapping symptomologies to propose a mechanism by which CBD treats PTSD via corticoraphe circuit. Acute CBD inhibits excess 5-HT release from DRN to amygdala and releases anandamide (AEA) onto amygdala inputs. By first reducing amygdala and DRN hyperactivity, CBD begins to ameliorate activity disparity between mPFC and amygdala. Chronic CBD recruits the mPFC, creating harmonious corticoraphe signaling. DRN releases enough 5-HT to ameliorate mPFC hypoactivity, while the mPFC continuously excites DRN 5-HT neurons via glutamate. Meanwhile, AEA regulates corticoraphe activity to stabilize signaling. AEA prevents DRN GABAergic interneurons from inhibiting 5-HT release so the DRN can assist the mPFC in overcoming its hypoactivity. DRN-mediated restoration of mPFC activity underlies CBD’s mechanism on fear extinction and learning of stress coping. CBD reduces PTSD symptoms via the DRN and corticoraphe circuit. Acute effects of CBD reduce DRN-amygdala excitatory signaling to lessen the activity disparity between amygdala and mPFC. Chronic CBD officially resolves mPFC hypoactivity by facilitating 5-HT release from DRN to mPFC. CBD-facilitated endocannabinoid signaling stabilizes DRN activity and restores mPFC inhibitory control. Chronically administered CBD acts via the corticoraphe circuit to favor fear extinction over fear memory reconsolidation.
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Key Words
- 2-AG, 2-arachidonoylglycerol
- 5-HT, Serotonin
- 5-HT1AR, 5-HT Receptor Type 1A
- 5-HT2AR, 5-HT Receptor Type 2 A
- AEA, Anandamide
- CB1R, Cannabinoid Receptor Type 1
- CB2R, Cannabinoid Receptor Type 2
- CBD, Cannabidiol
- COVID-19, SARS-CoV-2
- Cannabidiol
- DRN, Dorsal Raphe Nucleus
- ERK1/2, Extracellular Signal-Related Kinases Type 1 or Type 2
- FAAH, Fatty Acid Amide Hydrolase
- GABA, Gamma-Aminobutyric Acid
- GPCRs, G-Protein Coupled Receptors
- NMDAR, N-Methyl-D-aspartate Receptors
- PET, Positron Emission Tomography
- PFC, DRN and Raphe
- PFC, Prefrontal Cortex
- PTSD
- PTSD, Post-Traumatic Stress Disorder
- SSNRI, Selective Norepinephrine Reuptake Inhibitor
- SSRI, Selective Serotonin Reuptake Inhibitor
- Serotonin
- TRPV1, Transient Receptor Potential Vanilloid 1 Channels
- Traumatic Stress
- fMRI, Functional Magnetic Resonance Imaging
- mPFC, Medial Prefrontal Cortex
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Affiliation(s)
- Claire Alexander
- Department of Biology, Lamar University, Beaumont, TX 77710, USA
| | - Maryam Vasefi
- Department of Biology, Lamar University, Beaumont, TX 77710, USA
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15
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Balezina OP, Tarasova EO, Gaydukov AE. Noncanonical Activity of Endocannabinoids and Their Receptors in Central and Peripheral Synapses. BIOCHEMISTRY (MOSCOW) 2021; 86:818-832. [PMID: 34284706 DOI: 10.1134/s0006297921070038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review focuses on new aspects of endocannabinoid functions and mechanisms of activity in central and peripheral synapses, different from the general viewpoint that endocannabinoids are retrograde signaling molecules, which inhibit neurotransmitter release by activating specific presynaptic endocannabinoid receptors CB1 and CB2. Biased agonism of the endogenous and synthetic cannabinoids as well as ability of the CB-receptors to couple not only with classical Gi-proteins, but also with Gs- and Gq-proteins and, moreover, with β-arrestins (thereby triggering additional signaling pathways in synapses) are described here in detail. Examples of noncanonical tonic activity of endocannabinoids and their receptors and their role in synaptic function are also presented. The role of endocannabinoids in short-term and long-term potentiation of neurotransmitter release in central synapses and their facilitating effect on quantal size and other parameters of acetylcholine release in mammalian neuromuscular junctions are highlighted in this review. In conclusion, it is stated that the endocannabinoid system has a wider range of various multidirectional modulating effects (both potentiating and inhibiting) on neurotransmitter release than initially recognized. Re-evaluation of the functions of endocannabinoid system with consideration of its noncanonical features will lead to better understanding of its role in the normal and pathological functioning of the nervous system and other systems of the body, which has an enormous practical value.
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Affiliation(s)
- Olga P Balezina
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
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16
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Winters BL, Vaughan CW. Mechanisms of endocannabinoid control of synaptic plasticity. Neuropharmacology 2021; 197:108736. [PMID: 34343612 DOI: 10.1016/j.neuropharm.2021.108736] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/13/2023]
Abstract
The endogenous cannabinoid transmitter system regulates synaptic transmission throughout the nervous system. Unlike conventional transmitters, specific stimuli induce synthesis of endocannabinoids (eCBs) in the postsynaptic neuron, and these travel backwards to modulate presynaptic inputs. In doing so, eCBs can induce short-term changes in synaptic strength and longer-term plasticity. While this eCB regulation is near ubiquitous, it displays major regional and synapse specific variations with different synapse specific forms of short-versus long-term plasticity throughout the brain. These differences are due to the plethora of pre- and postsynaptic mechanisms which have been implicated in eCB signalling, the intricacies of which are only just being realised. In this review, we shall describe the current understanding and highlight new advances in this area, with a focus on the retrograde action of eCBs at CB1 receptors (CB1Rs).
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Affiliation(s)
- Bryony Laura Winters
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia.
| | - Christopher Walter Vaughan
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia
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17
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Oubraim S, Wang R, Hausknecht KA, Shen RY, Haj-Dahmane S. Tonic Endocannabinoid Signaling Gates Synaptic Plasticity in Dorsal Raphe Nucleus Serotonin Neurons Through Peroxisome Proliferator-Activated Receptors. Front Pharmacol 2021; 12:691219. [PMID: 34262460 PMCID: PMC8273699 DOI: 10.3389/fphar.2021.691219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/14/2021] [Indexed: 12/27/2022] Open
Abstract
Endocannabinoids (eCBs), which include 2-arachidonoylglycerol (2-AG) and anandamide (AEA) are lipid signaling molecules involved in the regulation of an array of behavioral and physiological functions. Released by postsynaptic neurons, eCBs mediate both phasic and tonic signaling at central synapses. While the roles of phasic eCB signaling in modulating synaptic functions and plasticity are well characterized, very little is known regarding the physiological roles and mechanisms regulating tonic eCB signaling at central synapses. In this study, we show that both 2-AG and AEA are constitutively released in the dorsal raphe nucleus (DRN), where they exert tonic control of glutamatergic synaptic transmission onto serotonin (5-HT) neurons. The magnitude of this tonic eCB signaling is tightly regulated by the overall activity of neuronal network. Thus, short term in vitro neuronal silencing or blockade of excitatory synaptic transmission abolishes tonic eCB signaling in the DRn. Importantly, in addition to controlling basal synaptic transmission, this study reveals that tonic 2-AG, but not AEA signaling, modulates synaptic plasticity. Indeed, short-term increase in tonic 2-AG signaling impairs spike-timing dependent potentiation (tLTP) of glutamate synapses. This tonic 2-AG-mediated homeostatic control of DRN glutamate synapses is not signaled by canonical cannabinoid receptors, but by intracellular peroxisome proliferator-activated receptor gamma (PPARγ). Further examination reveals that 2-AG mediated activation of PPARγ blocks tLTP by inhibiting nitric oxide (NO), soluble guanylate cyclase, and protein kinase G (NO/sGC/PKG) signaling pathway. Collectively, these results unravel novel mechanisms by which tonic 2-AG signaling integrates network activities and controls the synaptic plasticity in the brain.
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Affiliation(s)
- Saida Oubraim
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Ruixiang Wang
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Kathryn A Hausknecht
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Roh-Yu Shen
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States.,Neuroscience Program, University at Buffalo, Buffalo, NY, United States
| | - Samir Haj-Dahmane
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States.,Neuroscience Program, University at Buffalo, Buffalo, NY, United States
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18
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Perin P, Mabou Tagne A, Enrico P, Marino F, Cosentino M, Pizzala R, Boselli C. Cannabinoids, Inner Ear, Hearing, and Tinnitus: A Neuroimmunological Perspective. Front Neurol 2020; 11:505995. [PMID: 33329293 PMCID: PMC7719758 DOI: 10.3389/fneur.2020.505995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
Cannabis has been used for centuries for recreational and therapeutic purposes. Whereas, the recreative uses are based on the psychotropic effect of some of its compounds, its therapeutic effects range over a wide spectrum of actions, most of which target the brain or the immune system. Several studies have found cannabinoid receptors in the auditory system, both at peripheral and central levels, thus raising the interest in cannabinoid signaling in hearing, and especially in tinnitus, which is affected also by anxiety, memory, and attention circuits where cannabinoid effects are well described. Available studies on animal models of tinnitus suggest that cannabinoids are not likely to be helpful in tinnitus treatment and could even be harmful. However, the pharmacology of cannabinoids is very complex, and most studies focused on neural CB1R-based responses. Cannabinoid effects on the immune system (where CB2Rs predominate) are increasingly recognized as essential in understanding nervous system pathological responses, and data on immune cannabinoid targets have emerged in the auditory system as well. In addition, nonclassical cannabinoid targets (such as TRP channels) appear to play an important role in the auditory system as well. This review will focus on neuroimmunological mechanisms for cannabinoid effects and their possible use as protective and therapeutic agents in the ear and auditory system, especially in tinnitus.
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Affiliation(s)
- Paola Perin
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
| | | | | | | | | | - Roberto Pizzala
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Cinzia Boselli
- Department of Drug Sciences, University of Pavia, Pavia, Italy
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19
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Marcus DJ, Bedse G, Gaulden AD, Ryan JD, Kondev V, Winters ND, Rosas-Vidal LE, Altemus M, Mackie K, Lee FS, Delpire E, Patel S. Endocannabinoid Signaling Collapse Mediates Stress-Induced Amygdalo-Cortical Strengthening. Neuron 2020; 105:1062-1076.e6. [PMID: 31948734 DOI: 10.1016/j.neuron.2019.12.024] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 11/25/2019] [Accepted: 12/18/2019] [Indexed: 11/27/2022]
Abstract
Functional coupling between the amygdala and the dorsomedial prefrontal cortex (dmPFC) has been implicated in the generation of negative affective states; however, the mechanisms by which stress increases amygdala-dmPFC synaptic strength and generates anxiety-like behaviors are not well understood. Here, we show that the mouse basolateral amygdala (BLA)-prelimbic prefrontal cortex (plPFC) circuit is engaged by stress and activation of this pathway in anxiogenic. Furthermore, we demonstrate that acute stress exposure leads to a lasting increase in synaptic strength within a reciprocal BLA-plPFC-BLA subcircuit. Importantly, we identify 2-arachidonoylglycerol (2-AG)-mediated endocannabinoid signaling as a key mechanism limiting glutamate release at BLA-plPFC synapses and the functional collapse of multimodal 2-AG signaling as a molecular mechanism leading to persistent circuit-specific synaptic strengthening and anxiety-like behaviors after stress exposure. These data suggest that circuit-specific impairment in 2-AG signaling could facilitate functional coupling between the BLA and plPFC and the translation of environmental stress to affective pathology.
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Affiliation(s)
- David J Marcus
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA; The Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Gaurav Bedse
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Andrew D Gaulden
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - James D Ryan
- Department of Psychiatry, Weill Cornell Medicine, New York, NY 10065, USA; Sackler Institute for Developmental Psychobiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Veronika Kondev
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA; The Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Nathan D Winters
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA; The Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Luis E Rosas-Vidal
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Megan Altemus
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Ken Mackie
- Gill Center for Biomolecular Science, Indiana University, Bloomington, IN 47405, USA; Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - Francis S Lee
- Department of Psychiatry, Weill Cornell Medicine, New York, NY 10065, USA; Sackler Institute for Developmental Psychobiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sachin Patel
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA; The Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA; Departments of Pharmacology and Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Vanderbilt Center for Addiction Research, Nashville, TN 37232, USA.
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20
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Manza P, Yuan K, Shokri-Kojori E, Tomasi D, Volkow ND. Brain structural changes in cannabis dependence: association with MAGL. Mol Psychiatry 2020; 25:3256-3266. [PMID: 31695165 PMCID: PMC7200265 DOI: 10.1038/s41380-019-0577-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/20/2019] [Accepted: 10/23/2019] [Indexed: 12/16/2022]
Abstract
Cannabis use is rising, yet there is poor understanding of biological processes that might link chronic cannabis use to brain structural abnormalities. To lend insight into this topic, we examined white matter microstructural integrity and gray matter cortical thickness/density differences between 89 individuals with cannabis dependence (CD) and 89 matched controls (64 males, 25 females in each group) from the Human Connectome Project. We tested whether cortical patterns for expression of genes relevant for cannabinoid signaling (from Allen Human Brain Atlas postmortem tissue) were associated with spatial patterns of cortical thickness/density differences in CD. CD had lower fractional anisotropy than controls in white matter bundles innervating posterior cingulate and parietal cortex, basal ganglia, and temporal cortex. The CD group also had significantly less gray matter thickness and density in precuneus, relative to controls. Sibling-pair analysis found support for causal and graded liability effects of cannabis on precuneus structure. Spatial patterns of gray matter differences in CD were significantly associated with regional differences in monoacylglycerol lipase (MAGL) expression in postmortem brain tissue, such that regions with higher MAGL expression (but not fatty-acid amide hydrolase or FAAH) were more vulnerable to cortical thinning. In sum, chronic cannabis use is associated with structural differences in white and gray matter, which was most prominent in precuneus and associated white matter tracts. Regions with high MAGL expression, and therefore with potentially physiologically restricted endogenous cannabinoid signaling, may be more vulnerable to the effects of chronic cannabis use on cortical thickness.
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Affiliation(s)
- Peter Manza
- National Institute on Alcoholism and Alcohol Abuse, National Institutes of Health, Bethesda, MD, USA.
| | - Kai Yuan
- grid.94365.3d0000 0001 2297 5165National Institute on Alcoholism and Alcohol Abuse, National Institutes of Health, Bethesda, MD USA ,grid.440736.20000 0001 0707 115XSchool of Life Science and Technology, Xidian University, 710071 Xi’an, Shaanxi PR China
| | - Ehsan Shokri-Kojori
- grid.94365.3d0000 0001 2297 5165National Institute on Alcoholism and Alcohol Abuse, National Institutes of Health, Bethesda, MD USA
| | - Dardo Tomasi
- grid.94365.3d0000 0001 2297 5165National Institute on Alcoholism and Alcohol Abuse, National Institutes of Health, Bethesda, MD USA
| | - Nora D. Volkow
- grid.94365.3d0000 0001 2297 5165National Institute on Alcoholism and Alcohol Abuse, National Institutes of Health, Bethesda, MD USA ,grid.94365.3d0000 0001 2297 5165National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD USA
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21
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Suppression of Presynaptic Glutamate Release by Postsynaptic Metabotropic NMDA Receptor Signalling to Pannexin-1. J Neurosci 2019; 40:729-742. [PMID: 31818976 DOI: 10.1523/jneurosci.0257-19.2019] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 01/22/2023] Open
Abstract
The impact of pannexin-1 (Panx1) channels on synaptic transmission is poorly understood. Here, we show that selective block of Panx1 in single postsynaptic hippocampal CA1 neurons from male rat or mouse brain slices causes intermittent, seconds long increases in the frequency of sEPSC following Schaffer collateral stimulation. The increase in sEPSC frequency occurred without an effect on evoked neurotransmission. Consistent with a presynaptic origin of the augmented glutamate release, the increased sEPSC frequency was prevented by bath-applied EGTA-AM or TTX. Manipulation of a previously described metabotropic NMDAR pathway (i.e., by preventing ligand binding to NMDARs with competitive antagonists or blocking downstream Src kinase) also increased sEPSC frequency similar to that seen when Panx1 was blocked. This facilitated glutamate release was absent in transient receptor potential vanilloid 1 (TRPV1) KO mice and prevented by the TRPV1 antagonist, capsazepine, suggesting it required presynaptic TRPV1. We show presynaptic expression of TRPV1 by immunoelectron microscopy and link TRPV1 to Panx1 because Panx1 block increases tissue levels of the endovanilloid, anandamide. Together, these findings demonstrate an unexpected role for metabotropic NMDARs and postsynaptic Panx1 in suppression of facilitated glutamate neurotransmission.SIGNIFICANCE STATEMENT The postsynaptic ion and metabolite channel, pannexin-1, is regulated by metabotropic NMDAR signaling through Src kinase. This pathway suppresses facilitated release of presynaptic glutamate during synaptic activity by regulating tissue levels of the transient receptor potential vanilloid 1 agonist anandamide.
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22
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Xue SS, Xue F, Ma QR, Wang SQ, Wang Y, Tan QR, Wang HN, Zhou CH, Peng ZW. Repetitive high-frequency transcranial magnetic stimulation reverses depressive-like behaviors and protein expression at hippocampal synapses in chronic unpredictable stress-treated rats by enhancing endocannabinoid signaling. Pharmacol Biochem Behav 2019; 184:172738. [PMID: 31229467 DOI: 10.1016/j.pbb.2019.172738] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/19/2019] [Accepted: 06/19/2019] [Indexed: 12/15/2022]
Abstract
The anti-depressant effect of repetitive transcranial magnetic stimulation (rTMS), a clinically-useful treatment for depression, is associated with changes to the endocannabinoid system (ECS). However, it is currently unknown whether different frequencies of rTMS alter the ECS differently. To test this, rats exposed to chronic unpredictable stress (CUS) were treated with rTMS at two different frequencies (5 (high) or 1 Hz (low), 1.26 Tesla) for 7 consecutive days. Twenty-four hours after the final rTMS treatment, we evaluated depressive-like behaviors and the expression of several synaptic proteins and ECS-related proteins in the hippocampus. In addition, we knocked-down diacylglycerol lipase alpha (DAGLα) and cannabinoid type 1 receptor (CB1R), two important components of the ECS, and measured depressive-like behaviors and synaptic protein expression following rTMS. Furthermore, we measured the expression levels of several components of the ECS system in hippocampal-derived astrocytes and neurons exposed to repetitive magnetic stimulation (rMS) with different parameters (5 or 1 Hz, 0.84 or 1.26 Tesla). Interestingly, we found that only high-frequency rTMS ameliorated depressive-like behaviors and normalized the expression of hippocampal synaptic proteins in CUS-treated rats; this effect was eliminated by knockdown of DAGLα or CB1R. Moreover, we found that rMS at 5 Hz increased the expression of DAGLα and CB1R in hippocampal astrocytes and neurons. Collectively, our results suggest that high-frequency rTMS exerts its anti-depressant effect by up-regulating DAGLα and CB1R.
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Affiliation(s)
- Shan-Shan Xue
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Fen Xue
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Quan-Rui Ma
- Department of Human Anatomy and Histology and Embryology, Basic Medical College, Ningxia Medical University, 750004, China
| | - Shi-Quan Wang
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Ying Wang
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Qing-Rong Tan
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Hua-Ning Wang
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Cui-Hong Zhou
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
| | - Zheng-Wu Peng
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
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23
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Morris JL, Letson HL, Gillman R, Hazratwala K, Wilkinson M, McEwen P, Dobson GP. The CNS theory of osteoarthritis: Opportunities beyond the joint. Semin Arthritis Rheum 2019; 49:331-336. [PMID: 30982553 DOI: 10.1016/j.semarthrit.2019.03.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/02/2019] [Accepted: 03/14/2019] [Indexed: 01/06/2023]
Abstract
Osteoarthritis (OA) is a leading cause of global disability that affects more than half of the population over 65. It is not a single disease but a progressive, inflammatory- and immune-altering multi-disease that affects the whole joint. OA has many risk factors including age, obesity, gender, lifestyle, joint morphology, metabolic dysfunction and genetic disposition. A major stumbling block in treating clinical OA has been the inability to detect its early onset and disease progression. This gap in understanding may arise from our failure to recognize that the OA patient exhibits a vulnerability to dysregulation of central feedback circuits that control sympathetic tone, inflammation, circadian rhythms (central and peripheral clocks), gut microbiome, metabolic redox and whole joint pathology. Early detection of OA and slowing its progression may come from discoveries outside the joint targeting these potentially modifiable upstream targets. We argue that future treatments may benefit from moving from a knee-centric viewpoint to a more systems-based, whole-body approach. The challenge, however, will be to better characterize these key circuits and apply this knowledge to develop new therapies and interventions.
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Affiliation(s)
- Jodie L Morris
- The Orthopaedic Research Institute of Queensland (ORIQL), Townsville 4812, Queensland, Australia; Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, James Cook University, 1 James Cook Drive, 4811, Queensland, Australia.
| | - Hayley L Letson
- Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, James Cook University, 1 James Cook Drive, 4811, Queensland, Australia.
| | - Rhys Gillman
- The Orthopaedic Research Institute of Queensland (ORIQL), Townsville 4812, Queensland, Australia.
| | - Kaushik Hazratwala
- The Orthopaedic Research Institute of Queensland (ORIQL), Townsville 4812, Queensland, Australia.
| | - Matthew Wilkinson
- The Orthopaedic Research Institute of Queensland (ORIQL), Townsville 4812, Queensland, Australia.
| | - Peter McEwen
- The Orthopaedic Research Institute of Queensland (ORIQL), Townsville 4812, Queensland, Australia
| | - Geoffrey P Dobson
- The Orthopaedic Research Institute of Queensland (ORIQL), Townsville 4812, Queensland, Australia; Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, James Cook University, 1 James Cook Drive, 4811, Queensland, Australia.
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24
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Navarro-Romero A, Vázquez-Oliver A, Gomis-González M, Garzón-Montesinos C, Falcón-Moya R, Pastor A, Martín-García E, Pizarro N, Busquets-Garcia A, Revest JM, Piazza PV, Bosch F, Dierssen M, de la Torre R, Rodríguez-Moreno A, Maldonado R, Ozaita A. Cannabinoid type-1 receptor blockade restores neurological phenotypes in two models for Down syndrome. Neurobiol Dis 2019; 125:92-106. [PMID: 30685352 DOI: 10.1016/j.nbd.2019.01.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 12/24/2018] [Accepted: 01/23/2019] [Indexed: 12/31/2022] Open
Abstract
Intellectual disability is the most limiting hallmark of Down syndrome, for which there is no gold-standard clinical treatment yet. The endocannabinoid system is a widespread neuromodulatory system involved in multiple functions including learning and memory processes. Alterations of this system contribute to the pathogenesis of several neurological and neurodevelopmental disorders. However, the involvement of the endocannabinoid system in the pathogenesis of Down syndrome has not been explored before. We used the best-characterized preclinical model of Down syndrome, the segmentally trisomic Ts65Dn model. In male Ts65Dn mice, cannabinoid type-1 receptor (CB1R) expression was enhanced and its function increased in hippocampal excitatory terminals. Knockdown of CB1R in the hippocampus of male Ts65Dn mice restored hippocampal-dependent memory. Concomitant with this result, pharmacological inhibition of CB1R restored memory deficits, hippocampal synaptic plasticity and adult neurogenesis in the subgranular zone of the dentate gyrus. Notably, the blockade of CB1R also normalized hippocampal-dependent memory in female Ts65Dn mice. To further investigate the mechanisms involved, we used a second transgenic mouse model overexpressing a single gene candidate for Down syndrome cognitive phenotypes, the dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A). CB1R pharmacological blockade similarly improved cognitive performance, synaptic plasticity and neurogenesis in transgenic male Dyrk1A mice. Our results identify CB1R as a novel druggable target potentially relevant for the improvement of cognitive deficits associated with Down syndrome.
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Affiliation(s)
- Alba Navarro-Romero
- Laboratory of Neuropharmacology-NeuroPhar, Department of Experimental and Health Sciences, University Pompeu Fabra, 08003 Barcelona, Spain
| | - Anna Vázquez-Oliver
- Laboratory of Neuropharmacology-NeuroPhar, Department of Experimental and Health Sciences, University Pompeu Fabra, 08003 Barcelona, Spain
| | - Maria Gomis-González
- Laboratory of Neuropharmacology-NeuroPhar, Department of Experimental and Health Sciences, University Pompeu Fabra, 08003 Barcelona, Spain
| | - Carlos Garzón-Montesinos
- Laboratory of Cellular Neuroscience and Plasticity, Department of Physiology, Anatomy and Cell Biology, University Pablo de Olavide, Ctra Utrera km. 1, 41013 Seville, Spain
| | - Rafael Falcón-Moya
- Laboratory of Cellular Neuroscience and Plasticity, Department of Physiology, Anatomy and Cell Biology, University Pablo de Olavide, Ctra Utrera km. 1, 41013 Seville, Spain
| | - Antoni Pastor
- Integrative Pharmacology and Systems Neuroscience Research Group, Hospital del Mar Medical Research Institute, 08003 Barcelona, Spain; CIBER Pathophysiology of Obesity and Nutrition, Institute of Health Carlos III, 28029 Madrid, Spain
| | - Elena Martín-García
- Laboratory of Neuropharmacology-NeuroPhar, Department of Experimental and Health Sciences, University Pompeu Fabra, 08003 Barcelona, Spain; Department of Psychobiology and Methodology of Health Sciences, Universitat Autònoma de Barcelona, Spain
| | - Nieves Pizarro
- Integrative Pharmacology and Systems Neuroscience Research Group, Hospital del Mar Medical Research Institute, 08003 Barcelona, Spain
| | - Arnau Busquets-Garcia
- Laboratory of Neuropharmacology-NeuroPhar, Department of Experimental and Health Sciences, University Pompeu Fabra, 08003 Barcelona, Spain
| | - Jean-Michel Revest
- INSERM U1215, Neurocentre Magendie, Physiopathology and Therapeutic Approaches of Stress-Related Diseases, 33077 Bordeaux, France
| | - Pier-Vincenzo Piazza
- INSERM U1215, Neurocentre Magendie, Physiopathology and Therapeutic Approaches of Stress-Related Diseases, 33077 Bordeaux, France
| | - Fátima Bosch
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain; Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; CIBER Diabetes and Associated Metabolic Disorders (CIBERDEM), 08017 Madrid, Spain
| | - Mara Dierssen
- Cellular & Systems Neurobiology, Systems Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, 08003 Barcelona, Spain; CIBER Rare Disorders (CIBERER), Spain; Hospital del Mar Medical Research Institute, 08003 Barcelona, Spain
| | - Rafael de la Torre
- Integrative Pharmacology and Systems Neuroscience Research Group, Hospital del Mar Medical Research Institute, 08003 Barcelona, Spain; CIBER Pathophysiology of Obesity and Nutrition, Institute of Health Carlos III, 28029 Madrid, Spain
| | - Antonio Rodríguez-Moreno
- Laboratory of Cellular Neuroscience and Plasticity, Department of Physiology, Anatomy and Cell Biology, University Pablo de Olavide, Ctra Utrera km. 1, 41013 Seville, Spain
| | - Rafael Maldonado
- Laboratory of Neuropharmacology-NeuroPhar, Department of Experimental and Health Sciences, University Pompeu Fabra, 08003 Barcelona, Spain
| | - Andrés Ozaita
- Laboratory of Neuropharmacology-NeuroPhar, Department of Experimental and Health Sciences, University Pompeu Fabra, 08003 Barcelona, Spain.
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25
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Lisboa SF, Vila-Verde C, Rosa J, Uliana DL, Stern CAJ, Bertoglio LJ, Resstel LB, Guimaraes FS. Tempering aversive/traumatic memories with cannabinoids: a review of evidence from animal and human studies. Psychopharmacology (Berl) 2019; 236:201-226. [PMID: 30604182 DOI: 10.1007/s00213-018-5127-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 11/14/2018] [Indexed: 01/08/2023]
Abstract
RATIONALE Aversive learning and memory are essential to cope with dangerous and stressful stimuli present in an ever-changing environment. When this process is dysfunctional, however, it is associated with posttraumatic stress disorder (PTSD). The endocannabinoid (eCB) system has been implicated in synaptic plasticity associated with physiological and pathological aversive learning and memory. OBJECTIVE AND METHODS The objective of this study was to review and discuss evidence on how and where in the brain genetic or pharmacological interventions targeting the eCB system would attenuate aversive/traumatic memories through extinction facilitation in laboratory animals and humans. The effect size of the experimental intervention under investigation was also calculated. RESULTS Currently available data indicate that direct or indirect activation of cannabinoid type-1 (CB1) receptor facilitates the extinction of aversive/traumatic memories. Activating CB1 receptors around the formation of aversive/traumatic memories or their reminders can potentiate their subsequent extinction. In most cases, the effect size has been large (Cohen's d ≥ 1.0). The brain areas responsible for the abovementioned effects include the medial prefrontal cortex, amygdala, and/or hippocampus. The potential role of cannabinoid type-2 (CB2) receptors in extinction learning is now under investigation. CONCLUSION Drugs augmenting the brain eCB activity can temper the impact of aversive/traumatic experiences by diverse mechanisms depending on the moment of their administration. Considering the pivotal role the extinction process plays in PTSD, the therapeutic potential of these drugs is evident. The sparse number of clinical trials testing these compounds in stress-related disorders is a gap in the literature that needs to be addressed.
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Affiliation(s)
- Sabrina F Lisboa
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil. .,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
| | - C Vila-Verde
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - J Rosa
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - D L Uliana
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - C A J Stern
- Department of Pharmacology, Federal University of Parana, Curitiba, PR, Brazil
| | - L J Bertoglio
- Department of Pharmacology, Federal University of Santa Catarina, Florianopolis, SC, Brazil
| | - L B Resstel
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - F S Guimaraes
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
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26
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Prenatal immune activation potentiates endocannabinoid-related plasticity of inhibitory synapses in the hippocampus of adolescent rat offspring. Eur Neuropsychopharmacol 2018; 28:1405-1417. [PMID: 30257799 DOI: 10.1016/j.euroneuro.2018.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 08/17/2018] [Accepted: 09/05/2018] [Indexed: 12/29/2022]
Abstract
There is strong evidence that immune activation from prenatal infection increases the risk for offspring to develop schizophrenia. The endocannabinoid (eCB) system has been implicated in the pathophysiology of schizophrenia while models of cortical dysfunction postulate an imbalance between neuronal excitation and inhibition in the disorder. The current study examined the impact of prenatal immune activation on eCB-mediated inhibitory mechanisms. We compared two forms of eCB-related plasticity of evoked inhibitory postsynaptic currents, namely depolarization-induced suppression of inhibition (DSI) and metabotropic glutamate receptor-induced long term depression (mGluR-iLTD), in both the dorsal and ventral hippocampus between adolescent offspring from rat dams that received either saline or bacterial lipopolysaccharide (LPS) during pregnancy. Compared to prenatal saline offspring, prenatal LPS offspring displayed prolonged DSI and stronger mGluR-iLTD in the dorsal and ventral hippocampus, respectively. The sensitivity of mGluR-iLTD to the CB1 receptor antagonist AM251 was also lower in the dorsal hippocampus of prenatal LPS compared to prenatal saline offspring. Testing whether changes in eCB receptor signaling or levels could contribute to these changes in inhibitory transmission, we found region specific increases in 2-arachidonoylglycerol-stimulated signaling and in basal and mGluR-induced levels of anandamide in prenatal LPS offspring when compared to prenatal saline offspring. Our findings indicate that prenatal immune activation can lead to long-term changes in eCB-related plasticity of hippocampal inhibitory synaptic transmission in adolescent rat offspring. Perturbation of the eCB system resulting from prenatal immune activation could represent a mechanism linking early life immune events to the development of psychopathology in adolescence.
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27
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Augustin SM, Lovinger DM. Functional Relevance of Endocannabinoid-Dependent Synaptic Plasticity in the Central Nervous System. ACS Chem Neurosci 2018; 9:2146-2161. [PMID: 29400439 DOI: 10.1021/acschemneuro.7b00508] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The endocannabinoid (eCB) signaling system plays a key role in short-term and long-term synaptic plasticity in brain regions involved in various neural functions ranging from action selection to appetite control. This review will explore the role of eCBs in shaping neural circuit function to regulate behaviors. In particular, we will discuss the behavioral consequences of eCB mediated long-term synaptic plasticity in different brain regions. This review brings together evidence from in vitro and ex vivo studies and points out the need for more in vivo studies.
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Affiliation(s)
- Shana M. Augustin
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland 20852, United States
| | - David M. Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland 20852, United States
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28
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Salgado-Mendialdúa V, Aguirre-Plans J, Guney E, Reig-Viader R, Maldonado R, Bayés À, Oliva B, Ozaita A. Δ9-tetrahydrocannabinol modulates the proteasome system in the brain. Biochem Pharmacol 2018; 157:159-168. [PMID: 30134192 DOI: 10.1016/j.bcp.2018.08.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/17/2018] [Indexed: 12/22/2022]
Abstract
Cannabis is the most consumed illicit drug worldwide. Its principal psychoactive component, Δ9-tetrahydrocannabinol (THC), affects multiple brain functions, including cognitive performance, by modulating cannabinoid type-1 (CB1) receptors. These receptors are strongly enriched in presynaptic terminals, where they modulate neurotransmitter release. We analyzed, through a proteomic screening of hippocampal synaptosomal fractions, those proteins and pathways modulated 3 h after a single administration of an amnesic dose of THC (10 mg/kg, i.p.). Using an isobaric labeling approach, we identified 2040 proteins, 1911 of them previously reported in synaptic proteomes, confirming the synaptic content enrichment of the samples. Initial analysis revealed a significant alteration of 122 proteins, where 42 increased and 80 decreased their expression. Gene set enrichment analysis indicated an over-representation of mitochondrial associated functions and cellular metabolic processes. A second analysis focusing on extreme changes revealed 28 proteins with altered expression after THC treatment, 15 of them up-regulated and 13 down-regulated. Using a network topology-based scoring algorithm we identified those proteins in the mouse proteome with the greatest association to the 28 modulated proteins. This analysis pinpointed a significant alteration of the proteasome function, since top scoring proteins were related to the proteasome system (PS), a protein complex involved in ATP-dependent protein degradation. In this regard, we observed that THC decreases 20S proteasome chymotrypsin-like protease activity in the hippocampus. Our data describe for the first time the modulation of the PS in the hippocampus following THC administration under amnesic conditions that may contribute to an aberrant plasticity at synapses.
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Affiliation(s)
- V Salgado-Mendialdúa
- Laboratory of Neuropharmacology, Dept. Experimental and Health Sciences, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain
| | - J Aguirre-Plans
- Structural Bioinformatics Laboratory, Biomedical Informatics Research Unit, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain
| | - E Guney
- Structural Bioinformatics Laboratory, Biomedical Informatics Research Unit, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain
| | - R Reig-Viader
- Molecular Physiology of the Synapse Laboratory, Biomedical Research Institute Sant Pau (IIB Sant Pau), Sant Antoni Maria Claret 167, 08025 Barcelona, Spain; Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Bellaterra, Spain
| | - R Maldonado
- Laboratory of Neuropharmacology, Dept. Experimental and Health Sciences, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain
| | - À Bayés
- Molecular Physiology of the Synapse Laboratory, Biomedical Research Institute Sant Pau (IIB Sant Pau), Sant Antoni Maria Claret 167, 08025 Barcelona, Spain; Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Bellaterra, Spain
| | - B Oliva
- Structural Bioinformatics Laboratory, Biomedical Informatics Research Unit, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain
| | - A Ozaita
- Laboratory of Neuropharmacology, Dept. Experimental and Health Sciences, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain.
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29
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Dobson GP, Letson HL, Grant A, McEwen P, Hazratwala K, Wilkinson M, Morris JL. Defining the osteoarthritis patient: back to the future. Osteoarthritis Cartilage 2018; 26:1003-1007. [PMID: 29775734 DOI: 10.1016/j.joca.2018.04.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/30/2018] [Accepted: 04/09/2018] [Indexed: 02/08/2023]
Abstract
The history of osteoarthritis (OA) is important because it can help broaden our perspective on past and present controversies. The naming of OA, beginning with Heberden's nodes, is itself a fascinating story. According to Albert Hoffa, R. Llewellyn Jones and Archibald Edward Garrod, the name OA was introduced in the mid-nineteenth century by surgeon Richard von Volkmann who distinguished it from rheumatoid arthritis and gout. Others preferred the terms 'chronical rheumatism', 'senile arthritis', 'hypertrophic arthritis' or 'arthritis deformans'. A similar narrative applies to the concept of OA affecting the whole joint vs the 'wear-and-tear' hypothesis, inflammation and the role of the central nervous system (CNS). In the late nineteenth and early twentieth centuries, the Garrods (father and son) and Hermann Senator argued that OA was a whole joint disease, and that inflammation played a major role in its progression. Garrod Jnr and John Spender also linked OA to a neurogenic lesion 'outside the joint'. The remaining twentieth century was no less dynamic, with major advances in basic science, diagnostics, treatments, surgical interventions and technologies. Today, OA is characterized as a multi-disease with inflammation, immune and CNS dysfunction playing central roles in whole joint damage, injury progression, pain and disability. In the current 'omics' era (genomics, proteomics and metabolomics), we owe a great debt to past physicians and surgeons who dared to think 'outside-the-box' to explain and treat OA. Over 130 years later, despite these developments, we still don't fully understand the underlying complexities of OA, and we still don't have a cure.
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Affiliation(s)
- G P Dobson
- Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, 1 James Cook Drive, James Cook University, Queensland, 4811, Australia.
| | - H L Letson
- Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, 1 James Cook Drive, James Cook University, Queensland, 4811, Australia.
| | - A Grant
- The Orthopaedic Research Institute of Queensland (ORIQL), Mater Hospital, Pimlico, Townsville, Queensland, 4812, Australia; Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, 1 James Cook Drive, James Cook University, Queensland, 4811, Australia.
| | - P McEwen
- The Orthopaedic Research Institute of Queensland (ORIQL), Mater Hospital, Pimlico, Townsville, Queensland, 4812, Australia.
| | - K Hazratwala
- The Orthopaedic Research Institute of Queensland (ORIQL), Mater Hospital, Pimlico, Townsville, Queensland, 4812, Australia.
| | - M Wilkinson
- The Orthopaedic Research Institute of Queensland (ORIQL), Mater Hospital, Pimlico, Townsville, Queensland, 4812, Australia.
| | - J L Morris
- The Orthopaedic Research Institute of Queensland (ORIQL), Mater Hospital, Pimlico, Townsville, Queensland, 4812, Australia; Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, 1 James Cook Drive, James Cook University, Queensland, 4811, Australia.
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30
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Worley NB, Hill MN, Christianson JP. Prefrontal endocannabinoids, stress controllability and resilience: A hypothesis. Prog Neuropsychopharmacol Biol Psychiatry 2018; 85:180-188. [PMID: 28392485 PMCID: PMC6746235 DOI: 10.1016/j.pnpbp.2017.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 03/09/2017] [Accepted: 04/05/2017] [Indexed: 01/29/2023]
Abstract
Stressor exposure is a predisposing risk factor for many psychiatric conditions such as PTSD and depression. However, stressors do not influence all individuals equally and in response to an identical stressor some individuals may be vulnerable while others are resilient. While various biological and behavioral factors contribute to vulnerability versus resilience, an individual's degree of control over the stressor is among the most potent. Even with only one experience with control over stress, behavioral control has been shown to have acute and long-lasting stress-mitigating effects. This suggests that control both blunts the response to acute stress and prepares the subject to be resilient to future stressors. In this review, we first summarize the evidence which suggests the ventromedial prefrontal cortex (vmPFC) is a critical component of stressor controllability circuits and a locus of neuroplasticity supporting the acute and long-lasting consequences of control. We next review the central endocannabinoid (eCB) system as a possible mediator of short and long-term synaptic transmission in the vmPFC, and offer a hypothesis whereby eCBs regulate vmPFC circuits engaged when a subject has control over stress and may contribute to the encoding of acute stress coping into long lasting stressor resilience.
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Affiliation(s)
- Nicholas B. Worley
- Department of Psychology, Boston College, Chestnut Hill, MA USA,Corresponding Author: Nicholas Worley, Boston College, Department of Psychology, McGuinn Hall Rm. 300, Chestnut Hill, MA 02467 USA,
| | - Matthew N. Hill
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, CAN
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31
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Gao M, Whitt JL, Huang S, Lee A, Mihalas S, Kirkwood A, Lee HK. Experience-dependent homeostasis of 'noise' at inhibitory synapses preserves information coding in adult visual cortex. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0156. [PMID: 28093550 DOI: 10.1098/rstb.2016.0156] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2016] [Indexed: 02/05/2023] Open
Abstract
Synapses are intrinsically 'noisy' in that neurotransmitter is occasionally released in the absence of an action potential. At inhibitory synapses, the frequency of action potential-independent release is orders of magnitude higher than that at excitatory synapses raising speculations that it may serve a function. Here we report that the frequency of action potential-independent inhibitory synaptic 'noise' (i.e. miniature inhibitory postsynaptic currents, mIPSCs) is highly regulated by sensory experience in visual cortex. Importantly, regulation of mIPSC frequency is so far the predominant form of functional plasticity at inhibitory synapses in adults during the refractory period for plasticity and is a locus of rapid non-genomic actions of oestrogen. Models predict that regulating the frequency of mIPSCs, together with the previously characterized synaptic scaling of miniature excitatory PSCs, allows homeostatic maintenance of both the mean and variance of inputs to a neuron, a necessary feature of probabilistic population codes. Furthermore, mIPSC frequency regulation allows preservation of the temporal profile of neural responses while homeostatically regulating the overall firing rate. Our results suggest that the control of inhibitory 'noise' allows adaptive maintenance of adult cortical function in tune with the sensory environment.This article is part of the themed issue 'Integrating Hebbian and homeostatic plasticity'.
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Affiliation(s)
- Ming Gao
- Solomon H. Snyder Department of Neuroscience, Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jessica L Whitt
- Solomon H. Snyder Department of Neuroscience, Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Shiyong Huang
- Solomon H. Snyder Department of Neuroscience, Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Angela Lee
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Stefan Mihalas
- Allen Institute for Brain Science, Seattle, WA 98103, USA
| | - Alfredo Kirkwood
- Solomon H. Snyder Department of Neuroscience, Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Hey-Kyoung Lee
- Solomon H. Snyder Department of Neuroscience, Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA .,Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, USA
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32
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Lötsch J, Weyer-Menkhoff I, Tegeder I. Current evidence of cannabinoid-based analgesia obtained in preclinical and human experimental settings. Eur J Pain 2017; 22:471-484. [PMID: 29160600 DOI: 10.1002/ejp.1148] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2017] [Indexed: 12/11/2022]
Abstract
Cannabinoids have a long record of recreational and medical use and become increasingly approved for pain therapy. This development is based on preclinical and human experimental research summarized in this review. Cannabinoid CB1 receptors are widely expressed throughout the nociceptive system. Their activation by endogenous or exogenous cannabinoids modulates the release of neurotransmitters. This is reflected in antinociceptive effects of cannabinoids in preclinical models of inflammatory, cancer and neuropathic pain, and by nociceptive hypersensitivity of cannabinoid receptor-deficient mice. Cannabis-based medications available for humans mainly comprise Δ9 -tetrahydrocannabinol (THC), cannabidiol (CBD) and nabilone. During the last 10 years, six controlled studies assessing analgesic effects of cannabinoid-based drugs in human experimental settings were reported. An effect on nociceptive processing could be translated to the human setting in functional magnetic resonance imaging studies that pointed at a reduced connectivity within the pain matrix of the brain. However, cannabinoid-based drugs heterogeneously influenced the perception of experimentally induced pain including a reduction in only the affective but not the sensory perception of pain, only moderate analgesic effects, or occasional hyperalgesic effects. This extends to the clinical setting. While controlled studies showed a lack of robust analgesic effects, cannabis was nearly always associated with analgesia in open-label or retrospective reports, possibly indicating an effect on well-being or mood, rather than on sensory pain. Thus, while preclinical evidence supports cannabinoid-based analgesics, human evidence presently provides only reluctant support for a broad clinical use of cannabinoid-based medications in pain therapy. SIGNIFICANCE Cannabinoids consistently produced antinociceptive effects in preclinical models, whereas they heterogeneously influenced the perception of experimentally induced pain in humans and did not provide robust clinical analgesia, which jeopardizes the translation of preclinical research on cannabinoid-mediated antinociception into the human setting.
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Affiliation(s)
- J Lötsch
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany.,Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Project Group Translational Medicine and Pharmacology TMP, Frankfurt am Main, Germany
| | - I Weyer-Menkhoff
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
| | - I Tegeder
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
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33
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Colangeli R, Pierucci M, Benigno A, Campiani G, Butini S, Di Giovanni G. The FAAH inhibitor URB597 suppresses hippocampal maximal dentate afterdischarges and restores seizure-induced impairment of short and long-term synaptic plasticity. Sci Rep 2017; 7:11152. [PMID: 28894217 PMCID: PMC5593993 DOI: 10.1038/s41598-017-11606-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/25/2017] [Indexed: 11/09/2022] Open
Abstract
Synthetic cannabinoids and phytocannabinoids have been shown to suppress seizures both in humans and experimental models of epilepsy. However, they generally have a detrimental effect on memory and memory-related processes. Here we compared the effect of the inhibition of the endocannabinoid (eCB) degradation versus synthetic CB agonist on limbic seizures induced by maximal dentate activation (MDA) acute kindling. Moreover, we investigated the dentate gyrus (DG) granule cell reactivity and synaptic plasticity in naïve and in MDA-kindled anaesthetised rats. We found that both the fatty acid amide hydrolase (FAAH) inhibitor URB597 and the synthetic cannabinoid agonist WIN55,212-2 displayed AM251-sensitive anti-seizure effects. WIN55,212-2, dose-dependently (0.5-2 mg/kg, i.p.) impaired short-term plasticity (STP) and long-term potentiation (LTP) at perforant path-DG synapses in naïve rats. Strikingly, URB597 (1 mg/kg, i.p.) was devoid of any deleterious effects in normal conditions, while it prevented seizure-induced alterations of both STP and LTP. Our evidence indicates that boosting the eCB tone rather than general CB1 activation might represent a potential strategy for the development of a new class of drugs for treatment of both seizures and comorbid memory impairments associated with epilepsy.
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Affiliation(s)
- Roberto Colangeli
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.
| | - Massimo Pierucci
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Arcangelo Benigno
- Department of Experimental Biomedicine and Clinical Neurosciences (BIONEC), Human Physiology Section, University of Palermo, Palermo, Italy
| | - Giuseppe Campiani
- European Research Centre for Drug Discovery and Development (NatSynDrugs) and Department of Biotechnology, Chemistry, and Pharmacy, Università degli Studi di Siena, Siena, Italy
| | - Stefania Butini
- European Research Centre for Drug Discovery and Development (NatSynDrugs) and Department of Biotechnology, Chemistry, and Pharmacy, Università degli Studi di Siena, Siena, Italy
| | - Giuseppe Di Giovanni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta. .,School of Biosciences, Cardiff University, Cardiff, UK.
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Drug-Induced Alterations of Endocannabinoid-Mediated Plasticity in Brain Reward Regions. J Neurosci 2017; 36:10230-10238. [PMID: 27707960 DOI: 10.1523/jneurosci.1712-16.2016] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/25/2016] [Indexed: 12/21/2022] Open
Abstract
The endocannabinoid (eCB) system has emerged as one of the most important mediators of physiological and pathological reward-related synaptic plasticity. eCBs are retrograde messengers that provide feedback inhibition, resulting in the suppression of neurotransmitter release at both excitatory and inhibitory synapses, and they serve a critical role in the spatiotemporal regulation of both short- and long-term synaptic plasticity that supports adaptive learning of reward-motivated behaviors. However, mechanisms of eCB-mediated synaptic plasticity in reward areas of the brain are impaired following exposure to drugs of abuse. Because of this, it is theorized that maladaptive eCB signaling may contribute to the development and maintenance of addiction-related behavior. Here we review various forms of eCB-mediated synaptic plasticity present in regions of the brain involved in reward and reinforcement and explore the potential physiological relevance of maladaptive eCB signaling to addiction vulnerability.
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35
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Soni N, Prabhala BK, Mehta V, Mirza O, Kohlmeier KA. Anandamide and 2-AG are endogenously present within the laterodorsal tegmental nucleus: Functional implications for a role of eCBs in arousal. Brain Res 2017; 1665:74-79. [PMID: 28404451 DOI: 10.1016/j.brainres.2017.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 03/27/2017] [Accepted: 04/06/2017] [Indexed: 12/29/2022]
Abstract
Previously, we presented electrophysiological evidence for presence in mice brain slices of functional cannabinoid type I receptors (CB1Rs) within the laterodorsal tegmentum (LDT), a brain stem nucleus critical in control of arousal and rapid eye movement (REM) sleep. Further, using pharmacological agents, we provided data suggestive of the endogenous presence of cannabinoids (CBs) acting at LDT CB1Rs. However, in those studies, identification of the type(s) of CB ligands endogenously present in the LDT remained outstanding, and this information has not been provided elsewhere. Accordingly, we used the highly-sensitive liquid chromatography/mass spectrometry (LC-MS) method to determine whether N-arachidonoylethanolamide (Anandamide or AEA) and 2-arachidonyl glycerol (2-AG), which are both endogenous CB ligands acting at CB1Rs, are present in the LDT. Mice brain tissue samples of the LDT were assayed using ion trap LC-MS in selected ion monitoring mode. Chromatographic analysis and product-ion MS scans identified presence of the CBs, AEA and 2-AG, from LDT mouse tissue. Data using the LC-MS method show that AEA and 2-AG are endogenously present within the LDT and when coupled with our electrophysiological findings, lead to the suggestion that AEA and 2-AG act at electropharmacologically-demonstrated CB1Rs in this nucleus. Accordingly, AEA and 2-AG likely play a role in processes governed by the LDT, including control of states of cortical gamma band activity seen in alert, aroused states, as well as cortical and motor activity characteristic of REM sleep.
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Affiliation(s)
- Neeraj Soni
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Bala Krishna Prabhala
- Biostructural Research, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Ved Mehta
- Biostructural Research, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Osman Mirza
- Biostructural Research, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Kristi Anne Kohlmeier
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark.
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Park A, Li Y, Masri R, Keller A. Presynaptic and extrasynaptic regulation of posterior nucleus of thalamus. J Neurophysiol 2017; 118:507-519. [PMID: 28331010 DOI: 10.1152/jn.00862.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/21/2017] [Accepted: 03/16/2017] [Indexed: 11/22/2022] Open
Abstract
The posterior nucleus of thalamus (PO) is a higher-order nucleus involved in sensorimotor processing, including nociception. An important characteristic of PO is its wide range of activity profiles that vary across states of arousal, thought to underlie differences in somatosensory perception subject to attention and degree of consciousness. Furthermore, PO loses the ability to downregulate its activity level in some forms of chronic pain, suggesting that regulatory mechanisms underlying the normal modulation of PO activity may be pathologically altered. However, the mechanisms responsible for regulating such a wide dynamic range of activity are unknown. Here, we test a series of hypotheses regarding the function of several presynaptic receptors on both GABAergic and glutamatergic afferents targeting PO in mouse, using acute slice electrophysiology. We found that presynaptic GABAB receptors are present on both GABAergic and glutamatergic terminals in PO, but only those on GABAergic terminals are tonically active. We also found that release from GABAergic terminals, but not glutamatergic terminals, is suppressed by cholinergic activation and that a subpopulation of GABAergic terminals is regulated by cannabinoids. Finally, we discovered the presence of tonic currents mediated by extrasynaptic GABAA receptors in PO that are heterogeneously distributed across the nucleus. Thus we demonstrate that multiple regulatory mechanisms concurrently exist in PO, and we propose that regulation of inhibition, rather than excitation, is the more consequential mechanism by which PO activity can be regulated.NEW & NOTEWORTHY The posterior nucleus of thalamus (PO) is a key sensorimotor structure, whose activity is tightly regulated by inhibition from several nuclei. Maladaptive plasticity in this inhibition leads to severe pathologies, including chronic pain. We reveal here, for the first time in PO, multiple regulatory mechanisms that modulate synaptic transmission within PO. These findings may lead to targeted therapies for chronic pain and other disorders.
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Affiliation(s)
- Anthony Park
- Program in Neuroscience and Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland; and
| | - Ying Li
- Program in Neuroscience and Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland; and
| | - Radi Masri
- Program in Neuroscience and Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland; and.,Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Baltimore, School of Dentistry, Baltimore, Maryland
| | - Asaf Keller
- Program in Neuroscience and Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland; and
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Persistent inhibitory circuit defects and disrupted social behaviour following in utero exogenous cannabinoid exposure. Mol Psychiatry 2017; 22:56-67. [PMID: 26976041 PMCID: PMC5025333 DOI: 10.1038/mp.2016.17] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 01/15/2016] [Accepted: 01/20/2016] [Indexed: 01/10/2023]
Abstract
Placental transfer of Δ9-tetrahydrocannabinol (THC) during pregnancy has the potential to interfere with endogenous cannabinoid (CB) regulation of fetal nervous system development in utero. Here we examined the effect of maternal CB intake on mouse hippocampal interneurons largely focusing on cholecystokinin-expressing interneurons (CCK-INTs), a prominent CB subtype-1 receptor (CB1R) expressing neuronal population throughout development. Maternal treatment with THC or the synthetic CB1R agonist WIN55,212-2 (WIN) produced a significant loss of CCK-INTs in the offspring. Further, residual CCK-INTs in animals prenatally treated with WIN displayed decreased dendritic complexity. Consistent with these anatomical deficits, pups born to CB-treated dams exhibited compromised CCK-INT-mediated feedforward and feedback inhibition. Moreover, pups exposed to WIN in utero lacked constitutive CB1R-mediated suppression of inhibition from residual CCK-INTs and displayed altered social behavior. Our findings add to a growing list of potential cell/circuit underpinnings that may underlie cognitive impairments in offspring of mothers that abuse marijuana during pregnancy.
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38
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Lee SH, Dudok B, Parihar VK, Jung KM, Zöldi M, Kang YJ, Maroso M, Alexander AL, Nelson GA, Piomelli D, Katona I, Limoli CL, Soltesz I. Neurophysiology of space travel: energetic solar particles cause cell type-specific plasticity of neurotransmission. Brain Struct Funct 2016; 222:2345-2357. [PMID: 27905022 PMCID: PMC5504243 DOI: 10.1007/s00429-016-1345-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/25/2016] [Indexed: 12/03/2022]
Abstract
In the not too distant future, humankind will embark on one of its greatest adventures, the travel to distant planets. However, deep space travel is associated with an inevitable exposure to radiation fields. Space-relevant doses of protons elicit persistent disruptions in cognition and neuronal structure. However, whether space-relevant irradiation alters neurotransmission is unknown. Within the hippocampus, a brain region crucial for cognition, perisomatic inhibitory control of pyramidal cells (PCs) is supplied by two distinct cell types, the cannabinoid type 1 receptor (CB1)-expressing basket cells (CB1BCs) and parvalbumin (PV)-expressing interneurons (PVINs). Mice subjected to low-dose proton irradiation were analyzed using electrophysiological, biochemical and imaging techniques months after exposure. In irradiated mice, GABA release from CB1BCs onto PCs was dramatically increased. This effect was abolished by CB1 blockade, indicating that irradiation decreased CB1-dependent tonic inhibition of GABA release. These alterations in GABA release were accompanied by decreased levels of the major CB1 ligand 2-arachidonoylglycerol. In contrast, GABA release from PVINs was unchanged, and the excitatory connectivity from PCs to the interneurons also underwent cell type-specific alterations. These results demonstrate that energetic charged particles at space-relevant low doses elicit surprisingly selective long-term plasticity of synaptic microcircuits in the hippocampus. The magnitude and persistent nature of these alterations in synaptic function are consistent with the observed perturbations in cognitive performance after irradiation, while the high specificity of these changes indicates that it may be possible to develop targeted therapeutic interventions to decrease the risk of adverse events during interplanetary travel.
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Affiliation(s)
- Sang-Hun Lee
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, 92697, USA. .,Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| | - Barna Dudok
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary.,School of Ph.D. Studies, Semmelweis University, Budapest, Hungary
| | - Vipan K Parihar
- Department of Radiation Oncology, University of California, Irvine, CA, 92697, USA
| | - Kwang-Mook Jung
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, 92697, USA
| | - Miklós Zöldi
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary.,School of Ph.D. Studies, Semmelweis University, Budapest, Hungary
| | - Young-Jin Kang
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Mattia Maroso
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, 92697, USA.,Department of Neurosurgery, and Neurology and Neurological Sciences, Stanford University, Palo Alto, CA, 94305, USA
| | - Allyson L Alexander
- Department of Neurosurgery, and Neurology and Neurological Sciences, Stanford University, Palo Alto, CA, 94305, USA
| | - Gregory A Nelson
- Division of Radiation Research, Department of Basic Sciences, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Daniele Piomelli
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, 92697, USA
| | - István Katona
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, CA, 92697, USA
| | - Ivan Soltesz
- Department of Neurosurgery, and Neurology and Neurological Sciences, Stanford University, Palo Alto, CA, 94305, USA
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Yang L, Xu T, Zhang K, Wei Z, Li X, Huang M, Rose GM, Cai X. The essential role of hippocampal alpha6 subunit-containing GABAA receptors in maternal separation stress-induced adolescent depressive behaviors. Behav Brain Res 2016; 313:135-143. [DOI: 10.1016/j.bbr.2016.07.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/29/2016] [Accepted: 07/02/2016] [Indexed: 12/14/2022]
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40
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Ligresti A, De Petrocellis L, Di Marzo V. From Phytocannabinoids to Cannabinoid Receptors and Endocannabinoids: Pleiotropic Physiological and Pathological Roles Through Complex Pharmacology. Physiol Rev 2016; 96:1593-659. [DOI: 10.1152/physrev.00002.2016] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Apart from having been used and misused for at least four millennia for, among others, recreational and medicinal purposes, the cannabis plant and its most peculiar chemical components, the plant cannabinoids (phytocannabinoids), have the merit to have led humanity to discover one of the most intriguing and pleiotropic endogenous signaling systems, the endocannabinoid system (ECS). This review article aims to describe and critically discuss, in the most comprehensive possible manner, the multifaceted aspects of 1) the pharmacology and potential impact on mammalian physiology of all major phytocannabinoids, and not only of the most famous one Δ9-tetrahydrocannabinol, and 2) the adaptive pro-homeostatic physiological, or maladaptive pathological, roles of the ECS in mammalian cells, tissues, and organs. In doing so, we have respected the chronological order of the milestones of the millennial route from medicinal/recreational cannabis to the ECS and beyond, as it is now clear that some of the early steps in this long path, which were originally neglected, are becoming important again. The emerging picture is rather complex, but still supports the belief that more important discoveries on human physiology, and new therapies, might come in the future from new knowledge in this field.
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Affiliation(s)
- Alessia Ligresti
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Comprensorio Olivetti, Pozzuoli, Italy
| | - Luciano De Petrocellis
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Comprensorio Olivetti, Pozzuoli, Italy
| | - Vincenzo Di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Comprensorio Olivetti, Pozzuoli, Italy
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41
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Aaltonen N, Kedzierska E, Orzelska-Górka J, Lehtonen M, Navia-Paldanius D, Jakupovic H, Savinainen JR, Nevalainen T, Laitinen JT, Parkkari T, Gynther M. In Vivo Characterization of the Ultrapotent Monoacylglycerol Lipase Inhibitor {4-[bis-(benzo[d][1,3]dioxol-5-yl)methyl]-piperidin-1-yl}(1H-1,2,4-triazol-1-yl)methanone (JJKK-048). J Pharmacol Exp Ther 2016; 359:62-72. [PMID: 27451409 DOI: 10.1124/jpet.116.233114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 07/08/2016] [Indexed: 02/04/2023] Open
Abstract
Monoacylglycerol lipase (MAGL) is a serine hydrolase that acts as a principal degradative enzyme for the endocannabinoid 2-arachidonoylglycerol (2-AG). In addition to terminating the signaling function of 2-AG, MAGL liberates arachidonic acid to be used as a primary source for neuroinflammatory prostaglandin synthesis in the brain. MAGL activity also contributes to cancer pathogenicity by producing precursors for tumor-promoting bioactive lipids. Pharmacological inhibitors of MAGL provide valuable tools for characterization of MAGL and 2-AG signaling pathways. They also hold great therapeutic potential to treat several pathophysiological conditions, such as pain, neurodegenerative disorders, and cancer. We have previously reported piperidine triazole urea, {4-[bis-(benzo[d][1,3]dioxol-5-yl)methyl]-piperidin-1-yl}(1H-1,2,4-triazol-1-yl)methanone (JJKK-048), to be an ultrapotent and highly selective inhibitor of MAGL in vitro. Here, we characterize in vivo effects of JJKK-048. Acute in vivo administration of JJKK-048 induced a massive increase in mouse brain 2-AG levels without affecting brain anandamide levels. JJKK-048 appeared to be extremely potent in vivo. Activity-based protein profiling revealed that JJKK-048 maintains good selectivity toward MAGL over other serine hydrolases. Our results are also the first to show that JJKK-048 promoted significant analgesia in a writhing test with a low dose that did not cause cannabimimetic side effects. At a high dose, JJKK-048 induced analgesia both in the writhing test and in the tail-immersion test, as well as hypomotility and hyperthermia, but not catalepsy.
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Affiliation(s)
- Niina Aaltonen
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Ewa Kedzierska
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Jolanta Orzelska-Górka
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Marko Lehtonen
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Dina Navia-Paldanius
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Hermina Jakupovic
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Juha R Savinainen
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Tapio Nevalainen
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Jarmo T Laitinen
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Teija Parkkari
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
| | - Mikko Gynther
- School of Medicine, Institute of Biomedicine/Physiology (N.A., D.N.-P., H.J., J.R.S., J.T.L.), and School of Pharmacy, (M.L., T.N., T.P., M.G.), University of Eastern Finland, Kuopio, Finland; and Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, Lublin, Poland (E.K., J.O.-G.)
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Xia S, Zhou Z, Leung C, Zhu Y, Pan X, Qi J, Morena M, Hill MN, Xie W, Jia Z. p21-activated kinase 1 restricts tonic endocannabinoid signaling in the hippocampus. eLife 2016; 5. [PMID: 27296803 PMCID: PMC4907698 DOI: 10.7554/elife.14653] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 05/13/2016] [Indexed: 12/16/2022] Open
Abstract
PAK1 inhibitors are known to markedly improve social and cognitive function in several animal models of brain disorders, including autism, but the underlying mechanisms remain elusive. We show here that disruption of PAK1 in mice suppresses inhibitory neurotransmission through an increase in tonic, but not phasic, secretion of endocannabinoids (eCB). Consistently, we found elevated levels of anandamide (AEA), but not 2-arachidonoylglycerol (2-AG) following PAK1 disruption. This increased tonic AEA signaling is mediated by reduced cyclooxygenase-2 (COX-2), and COX-2 inhibitors recapitulate the effect of PAK1 deletion on GABAergic transmission in a CB1 receptor-dependent manner. These results establish a novel signaling process whereby PAK1 upregulates COX-2, reduces AEA and restricts tonic eCB-mediated processes. Because PAK1 and eCB are both critically involved in many other organ systems in addition to the brain, our findings may provide a unified mechanism by which PAK1 regulates these systems and their dysfunctions including cancers, inflammations and allergies. DOI:http://dx.doi.org/10.7554/eLife.14653.001 Brain cells communicate by sending chemical signals that activate or excite neighbouring cells. However, too much signalling can be harmful. As such the brain has systems in place to inhibit brain signals, and healthy brain activity relies striking a proper balance between excitation and inhibition. In some brain mental health conditions, like autism or schizophrenia, the balance is skewed which has an impact on the brain’s activity. A chemical produced by brain cells called endocannabinoid helps maintain the appropriate balance in brain excitation and inhibition. Endocannabinoid is similar to a chemical found in cannabis, but little is known about how it works and which proteins interact with endocannabinoid. A family of proteins called p21-activated kinases (PAKs) has been implicated in autism and other disorders like Huntingtin disease and Alzheimer disease, but it is not fully understood how these proteins interact with endocannabinoid. Now, Xia, Zhou et al. show that one member of this protein family called PAK1 plays a key role in controlling endocannabinoid activity. The experiments showed that mice genetically engineered to lack the PAK1 protein have higher levels of endocannabinoids and, as a consequence, the chemical signals that inhibit brain cells are affected more. The experiments also revealed that PAK1 does not interact directly with endocannabinoids. Instead PAK1 boosts levels of another protein called COX-2 and reduces levels of a molecule called anandamide, which together restrict endocannabinoid’s inhibitory effects. Scientists are currently interested in developing drugs that target the endocannabinoids and their regulators in the brain as a way to treat anxiety, pain and sleep problems. Drugs that block PAK1 are already being studied. Future studies are needed to determine if such PAK1-targeting drugs could be useful for restoring excitatory and inhibitory balance in brain diseases or for treating other diseases involving the PAK proteins. DOI:http://dx.doi.org/10.7554/eLife.14653.002
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Affiliation(s)
- Shuting Xia
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, China
| | - Zikai Zhou
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, China.,Institute of Life Sciences, Collaborative Innovation Center for Brain Science, Southeast University, Nanjing, China
| | - Celeste Leung
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Yuehua Zhu
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, China
| | - Xingxiu Pan
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, China
| | - Junxia Qi
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, China
| | - Maria Morena
- Hotchkiss Brain Institute, Cumming School of Medicine, Calgary, Canada.,Department of Cell Biology and Anatomy and Psychiatry, University of Calgary, Calgary, Canada
| | - Matthew N Hill
- Hotchkiss Brain Institute, Cumming School of Medicine, Calgary, Canada.,Department of Cell Biology and Anatomy and Psychiatry, University of Calgary, Calgary, Canada
| | - Wei Xie
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, China.,Institute of Life Sciences, Collaborative Innovation Center for Brain Science, Southeast University, Nanjing, China
| | - Zhengping Jia
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
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Dean C, Hillard CJ, Seagard JL, Hopp FA, Hogan QH. Components of the cannabinoid system in the dorsal periaqueductal gray are related to resting heart rate. Am J Physiol Regul Integr Comp Physiol 2016; 311:R254-62. [PMID: 27280429 DOI: 10.1152/ajpregu.00154.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 06/05/2016] [Indexed: 11/22/2022]
Abstract
The present study was undertaken to examine whether variations in endocannabinoid signaling in the dorsal periaqueductal gray (dPAG) are associated with baseline autonomic nerve activity, heart rate, and blood pressure. Blood pressure was recorded telemetrically in rats, and heart rate and power spectral analysis of heart rate variability were determined. Natural variations from animal to animal provided a range of baseline values for analysis. Transcript levels of endocannabinoid signaling components in the dPAG were analyzed, and endocannabinoid content and catabolic enzyme activity were measured. Higher baseline heart rate was associated with increased anandamide content and with decreased activity of the anandamide-hydrolyzing enzyme, fatty acid amide hydrolase (FAAH), and it was negatively correlated with transcript levels of both FAAH and monoacylglycerol lipase (MAGL), a catabolic enzyme for 2-arachidonoylglycerol (2-AG). Autonomic tone and heart rate, but not blood pressure, were correlated to levels of FAAH mRNA. In accordance with these data, exogenous anandamide in the dPAG of anesthetized rats increased heart rate. These data indicate that in the dPAG, anandamide, a FAAH-regulated lipid, contributes to regulation of baseline heart rate through influences on autonomic outflow.
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Affiliation(s)
- Caron Dean
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Cecilia J Hillard
- Department of Pharmacology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Jeanne L Seagard
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Francis A Hopp
- Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Quinn H Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
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Cannabinoid Type 2 Receptors Mediate a Cell Type-Specific Plasticity in the Hippocampus. Neuron 2016; 90:795-809. [PMID: 27133464 DOI: 10.1016/j.neuron.2016.03.034] [Citation(s) in RCA: 203] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 01/20/2016] [Accepted: 03/18/2016] [Indexed: 02/07/2023]
Abstract
Endocannabinoids (eCBs) exert major control over neuronal activity by activating cannabinoid receptors (CBRs). The functionality of the eCB system is primarily ascribed to the well-documented retrograde activation of presynaptic CB1Rs. We find that action potential-driven eCB release leads to a long-lasting membrane potential hyperpolarization in hippocampal principal cells that is independent of CB1Rs. The hyperpolarization, which is specific to CA3 and CA2 pyramidal cells (PCs), depends on the activation of neuronal CB2Rs, as shown by a combined pharmacogenetic and immunohistochemical approach. Upon activation, they modulate the activity of the sodium-bicarbonate co-transporter, leading to a hyperpolarization of the neuron. CB2R activation occurred in a purely self-regulatory manner, robustly altered the input/output function of CA3 PCs, and modulated gamma oscillations in vivo. To conclude, we describe a cell type-specific plasticity mechanism in the hippocampus that provides evidence for the neuronal expression of CB2Rs and emphasizes their importance in basic neuronal transmission.
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Báldi R, Ghose D, Grueter BA, Patel S. Electrophysiological Measurement of Cannabinoid-Mediated Synaptic Modulation in Acute Mouse Brain Slices. CURRENT PROTOCOLS IN NEUROSCIENCE 2016; 75:6.29.1-6.29.19. [PMID: 27063786 PMCID: PMC4866814 DOI: 10.1002/cpns.8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Endocannabinoids (eCBs) are a class of bioactive lipids that mediate retrograde synaptic modulation at central and peripheral synapses. The highly lipophilic nature of eCBs and the pharmacological tools available to interrogate this system require unique methodological consideration, especially when applied to ex vivo systems such as electrophysiological analysis in acute brain slices. This unit provides protocols for measuring cannabinoid and eCB-mediated synaptic signaling in mouse brain slices, including analysis of short-term, long-term, and tonic eCB signaling modes, and the unique considerations for working with eCBs and TRPV1/cannabinoid ligands in acute brain slices.
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Affiliation(s)
- Rita Báldi
- Department of Psychiatry, 2213 Garland Avenue, 8415 MRBIV, Vanderbilt University Medical Center, Nashville, TN 37232-0413, Tel. 615-936-7768, Fax. 615-936-4075
| | - Dipanwita Ghose
- Department of Anesthesiology, 2213 Garland Avenue, P445 MRBIV, Vanderbilt University Medical Center, Nashville, TN 37232-0413, Tel. 615-936-1684, Fax. 615-936-0456
| | - Brad A. Grueter
- Department of Anesthesiology, 2213 Garland Avenue, P435H MRBIV, Vanderbilt University Medical Center, Nashville, TN 37232-0413, Tel. 615-936-2586, Fax. 615-936-0456
| | - Sachin Patel
- Departments of Psychiatry and Molecular Physiology & Biophysics, 2213 Garland Avenue, 8425B MRBIV, Vanderbilt University Medical Center, Nashville, TN 37232-0413, Tel. 615-936-7768, Fax. 615-936-4075
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Lee TTY, Hill MN, Lee FS. Developmental regulation of fear learning and anxiety behavior by endocannabinoids. GENES, BRAIN, AND BEHAVIOR 2016; 15:108-24. [PMID: 26419643 PMCID: PMC4713313 DOI: 10.1111/gbb.12253] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/03/2015] [Accepted: 09/14/2015] [Indexed: 12/31/2022]
Abstract
The developing brain undergoes substantial maturation into adulthood and the development of specific neural structures occurs on differing timelines. Transient imbalances between developmental trajectories of corticolimbic structures, which are known to contribute to regulation over fear learning and anxiety, can leave an individual susceptible to mental illness, particularly anxiety disorders. There is a substantial body of literature indicating that the endocannabinoid (eCB) system critically regulates stress responsivity and emotional behavior throughout the life span, making this system a novel therapeutic target for stress- and anxiety-related disorders. During early life and adolescence, corticolimbic eCB signaling changes dynamically and coincides with different sensitive periods of fear learning, suggesting that eCB signaling underlies age-specific fear learning responses. Moreover, perturbations to these normative fluctuations in corticolimbic eCB signaling, such as stress or cannabinoid exposure, could serve as a neural substrate contributing to alterations to the normative developmental trajectory of neural structures governing emotional behavior and fear learning. In this review, we first introduce the components of the eCB system and discuss clinical and rodent models showing eCB regulation of fear learning and anxiety in adulthood. Next, we highlight distinct fear learning and regulation profiles throughout development and discuss the ontogeny of the eCB system in the central nervous system, and models of pharmacological augmentation of eCB signaling during development in the context of fear learning and anxiety.
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Affiliation(s)
- Tiffany T.-Y. Lee
- Dept. of Psychology, University of British Columbia, Vancouver, Canada, V6T 1Z4
| | - Matthew N. Hill
- Hotchkiss Brain Institute and Mathison Center for Mental Health Research and Education, Departments of Cell Biology and Anatomy & Psychiatry, University of Calgary, Calgary AB, Canada T2N4N1
| | - Francis S. Lee
- Department of Psychiatry, Weill Cornell Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, USA
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, USA
- Sackler Institute for Developmental Psychobiology, Weill Cornell Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, USA
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47
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Appiah-Kusi E, Leyden E, Parmar S, Mondelli V, McGuire P, Bhattacharyya S. Abnormalities in neuroendocrine stress response in psychosis: the role of endocannabinoids. Psychol Med 2016; 46:27-45. [PMID: 26370602 DOI: 10.1017/s0033291715001786] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The aim of this article is to summarize current evidence regarding alterations in the neuroendocrine stress response system and endocannabinoid system and their relationship in psychotic disorders such as schizophrenia. Exposure to stress is linked to the development of a number of psychiatric disorders including psychosis. However, the precise role of stress in the development of psychosis and the possible mechanisms that might underlie this are not well understood. Recently the cannabinoid hypothesis of schizophrenia has emerged as a potential line of enquiry. Endocannabinoid levels are increased in patients with psychosis compared with healthy volunteers; furthermore, they increase in response to stress, which suggests another potential mechanism for how stress might be a causal factor in the development of psychosis. However, research regarding the links between stress and the endocannabinoid system is in its infancy. Evidence summarized here points to an alteration in the baseline tone and reactivity of the hypothalamic-pituitary-adrenal (HPA) axis as well as in various components of the endocannabinoid system in patients with psychosis. Moreover, the precise nature of the inter-relationship between these two systems is unclear in man, especially their biological relevance in the context of psychosis. Future studies need to simultaneously investigate HPA axis and endocannabinoid alterations both at baseline and following experimental perturbation in healthy individuals and those with psychosis to understand how they interact with each other in health and disease and obtain mechanistic insight as to their relevance to the pathophysiology of schizophrenia.
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Affiliation(s)
- E Appiah-Kusi
- Department of Psychosis Studies,King's College London,Institute of Psychiatry,Psychology & Neuroscience (IoPPN),PO Box 63,De Crespigny Park,Denmark Hill,London SE5 8AF,UK
| | - E Leyden
- Department of Psychosis Studies,King's College London,Institute of Psychiatry,Psychology & Neuroscience (IoPPN),PO Box 63,De Crespigny Park,Denmark Hill,London SE5 8AF,UK
| | - S Parmar
- Department of Psychosis Studies,King's College London,Institute of Psychiatry,Psychology & Neuroscience (IoPPN),PO Box 63,De Crespigny Park,Denmark Hill,London SE5 8AF,UK
| | - V Mondelli
- Department of Psychological Medicine,King's College London,Institute of Psychiatry,Psychology & Neuroscience (IoPPN),PO Box 92,De Crespigny Park,Denmark Hill,London SE5 8AF,UK
| | - P McGuire
- Department of Psychosis Studies,King's College London,Institute of Psychiatry,Psychology & Neuroscience (IoPPN),PO Box 63,De Crespigny Park,Denmark Hill,London SE5 8AF,UK
| | - S Bhattacharyya
- Department of Psychosis Studies,King's College London,Institute of Psychiatry,Psychology & Neuroscience (IoPPN),PO Box 63,De Crespigny Park,Denmark Hill,London SE5 8AF,UK
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48
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Tasker JG, Chen C, Fisher MO, Fu X, Rainville JR, Weiss GL. Endocannabinoid Regulation of Neuroendocrine Systems. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 125:163-201. [PMID: 26638767 DOI: 10.1016/bs.irn.2015.09.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The hypothalamus is a part of the brain that is critical for sustaining life through its homeostatic control and integrative regulation of the autonomic nervous system and neuroendocrine systems. Neuroendocrine function in mammals is mediated mainly through the control of pituitary hormone secretion by diverse neuroendocrine cell groups in the hypothalamus. Cannabinoid receptors are expressed throughout the hypothalamus, and endocannabinoids have been found to exert pronounced regulatory effects on neuroendocrine function via modulation of the outputs of several neuroendocrine systems. Here, we review the physiological regulation of neuroendocrine function by endocannabinoids, focusing on the role of endocannabinoids in the neuroendocrine regulation of the stress response, food intake, fluid homeostasis, and reproductive function. Cannabis sativa (marijuana) has a long history of recreational and/or medicinal use dating back to ancient times. It was used as an analgesic, anesthetic, and antianxiety herb as early as 2600 B.C. The hedonic, anxiolytic, and mood-elevating properties of cannabis have also been cited in ancient records from different cultures. However, it was not until 1964 that the psychoactive constituent of cannabis, Δ(9)-tetrahydrocannabinol, was isolated and its chemical structure determined (Gaoni & Mechoulam, 1964).
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Affiliation(s)
- Jeffrey G Tasker
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA; Neuroscience Program, Tulane University, New Orleans, Louisiana, USA.
| | - Chun Chen
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA
| | - Marc O Fisher
- Neuroscience Program, Tulane University, New Orleans, Louisiana, USA
| | - Xin Fu
- Neuroscience Program, Tulane University, New Orleans, Louisiana, USA
| | - Jennifer R Rainville
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA
| | - Grant L Weiss
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA
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Song Y, Zhang J, Chen C. Fine-tuning of synaptic upscaling at excitatory synapses by endocannabinoid signaling is mediated via the CB1 receptor. Sci Rep 2015; 5:16257. [PMID: 26541090 PMCID: PMC4635378 DOI: 10.1038/srep16257] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/12/2015] [Indexed: 12/11/2022] Open
Abstract
The endocannabinoid 2-arachidonoylglycerol (2-AG) functions as a retrograde signaling molecule mediating synaptic transmission and plasticity at both inhibitory and excitatory synapses. However, little is known about whether 2-AG signaling is involved in homeostatic regulation of miniature synaptic events at excitatory synapses in response to activity deprivation. Here, we report that chronic blockade of firing by tetrodotoxin (TTX) for two days resulted in increases both in the frequency and amplitude of spontaneous miniature excitatory postsynaptic currents (mEPSCs) in cultured mouse hippocampal neurons. However, treatment with 2-AG alone or JZL184, a potent and selective inhibitor for monoacylglycerol lipase (MAGL) that hydrolyzes 2-AG, induced a CB1 receptor-dependent reduction of the frequency of mEPSCs, but not the amplitude. The TTX-increased frequency was blunted by 2-AG or JZL184 and this effect was eliminated by pharmacological or genetic inhibition of CB1 receptors. In addition, TTX still increased frequency and amplitude of mEPSCs in the presence of CB1 receptor inhibition. Our results suggest that while endocannabinoids are not required for induction of synaptic scaling at excitatory glutamate synapses after chronic activity deprivation, 2-AG signaling may play a role in fine-tuning of synaptic strengths via presynaptically-expressed CB1 receptors.
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Affiliation(s)
- Yunping Song
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Jian Zhang
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Chu Chen
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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Multiple Forms of Endocannabinoid and Endovanilloid Signaling Regulate the Tonic Control of GABA Release. J Neurosci 2015; 35:10039-57. [PMID: 26157003 DOI: 10.1523/jneurosci.4112-14.2015] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
UNLABELLED Persistent CB1 cannabinoid receptor activity limits neurotransmitter release at various synapses throughout the brain. However, it is not fully understood how constitutively active CB1 receptors, tonic endocannabinoid signaling, and its regulation by multiple serine hydrolases contribute to the synapse-specific calibration of neurotransmitter release probability. To address this question at perisomatic and dendritic GABAergic synapses in the mouse hippocampus, we used a combination of paired whole-cell patch-clamp recording, liquid chromatography/tandem mass spectrometry, stochastic optical reconstruction microscopy super-resolution imaging, and immunogold electron microscopy. Unexpectedly, application of the CB1 antagonist and inverse agonist AM251 [N-1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-1-piperidinyl-1H-pyrazole-3-carboxamide], but not the neutral antagonist NESS0327 [8-chloro-1-(2,4-dichlorophenyl)-N-piperidin-1-yl-5,6-dihydro-4H-benzo[2,3]cyclohepta[2,4-b]pyrazole-3-carboxamine], significantly increased synaptic transmission between CB1-positive perisomatic interneurons and CA1 pyramidal neurons. JZL184 (4-nitrophenyl 4-[bis(1,3-benzodioxol-5-yl)(hydroxy)methyl]piperidine-1-carboxylate), a selective inhibitor of monoacylglycerol lipase (MGL), the presynaptic degrading enzyme of the endocannabinoid 2-arachidonoylglycerol (2-AG), elicited a robust increase in 2-AG levels and concomitantly decreased GABAergic transmission. In contrast, inhibition of fatty acid amide hydrolase (FAAH) by PF3845 (N-pyridin-3-yl-4-[[3-[5-(trifluoromethyl)pyridin-2-yl]oxyphenyl]methyl]piperidine-1-carboxamide) elevated endocannabinoid/endovanilloid anandamide levels but did not change GABAergic synaptic activity. However, FAAH inhibitors attenuated tonic 2-AG increase and also decreased its synaptic effects. This antagonistic interaction required the activation of the transient receptor potential vanilloid receptor TRPV1, which was concentrated on postsynaptic intracellular membrane cisternae at perisomatic GABAergic symmetrical synapses. Interestingly, neither AM251, JZL184, nor PF3845 affected CB1-positive dendritic interneuron synapses. Together, these findings are consistent with the possibility that constitutively active CB1 receptors substantially influence perisomatic GABA release probability and indicate that the synaptic effects of tonic 2-AG release are tightly controlled by presynaptic MGL activity and also by postsynaptic endovanilloid signaling and FAAH activity. SIGNIFICANCE STATEMENT Tonic cannabinoid signaling plays a critical role in the regulation of synaptic transmission. However, the mechanistic details of how persistent CB1 cannabinoid receptor activity inhibits neurotransmitter release have remained elusive. Therefore, electrophysiological recordings, lipid measurements, and super-resolution imaging were combined to elucidate those signaling molecules and mechanisms that underlie tonic cannabinoid signaling. The findings indicate that constitutive CB1 activity has pivotal function in the tonic control of hippocampal GABA release. Moreover, the endocannabinoid 2-arachidonoylglycerol (2-AG) is continuously generated postsynaptically, but its synaptic effect is regulated strictly by presynaptic monoacylglycerol lipase activity. Finally, anandamide signaling antagonizes tonic 2-AG signaling via activation of postsynaptic transient receptor potential vanilloid TRPV1 receptors. This unexpected mechanistic diversity may be necessary to fine-tune GABA release probability under various physiological and pathophysiological conditions.
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