1
|
Marini P, Cowie P, Ayar A, Bewick GS, Barrow J, Pertwee RG, MacKenzie A, Tucci P. M3 Receptor Pathway Stimulates Rapid Transcription of the CB1 Receptor Activation through Calcium Signalling and the CNR1 Gene Promoter. Int J Mol Sci 2023; 24:ijms24021308. [PMID: 36674826 PMCID: PMC9867084 DOI: 10.3390/ijms24021308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/17/2022] [Accepted: 01/05/2023] [Indexed: 01/12/2023] Open
Abstract
In this study, we have investigated a possible mechanism that enables CB1/M3 receptor cross-talk, using SH-SY5Y cells as a model system. Our results show that M3 receptor activation initiates signaling that rapidly upregulates the CNR1 gene, resulting in a greatly potentiated CB1 receptor response to agonists. Calcium homeostasis plays an essential intermediary role in this functional CB1/M3 receptor cross-talk. We show that M3 receptor-triggered calcium release greatly increases CB1 receptor expression via both transcriptional and translational activity, by enhancing CNR1 promoter activity. The co-expression of M3 and CB1 receptors in brain areas such as the nucleus accumbens and amygdala support the hypothesis that the altered synaptic plasticity observed after exposure to cannabinoids involves cross-talk with the M3 receptor subtype. In this context, M3 receptors and their interaction with the cannabinoid system at the transcriptional level represent a potential pharmacogenomic target not only for the develop of new drugs for addressing addiction and tolerance. but also to understand the mechanisms underpinning response stratification to cannabinoids.
Collapse
Affiliation(s)
- Pietro Marini
- Institute of Education in Healthcare and Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Philip Cowie
- The Institute of Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Ahmet Ayar
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, 61080 Trabzon, Turkey
| | - Guy S. Bewick
- The Institute of Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - John Barrow
- Institute of Education in Healthcare and Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Roger G. Pertwee
- The Institute of Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Alasdair MacKenzie
- The Institute of Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Paolo Tucci
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy
- Correspondence:
| |
Collapse
|
2
|
Dvorakova M, Wilson S, Corey W, Billingsley J, Zimmowitch A, Tracey J, Straiker A, Mackie K. A Critical Evaluation of Terpenoid Signaling at Cannabinoid CB1 Receptors in a Neuronal Model. Molecules 2022; 27:molecules27175655. [PMID: 36080421 PMCID: PMC9457791 DOI: 10.3390/molecules27175655] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 08/30/2022] [Accepted: 08/31/2022] [Indexed: 11/29/2022] Open
Abstract
In addition to phytocannabinoids, cannabis contains terpenoids that are claimed to have a myriad of effects on the body. We tested a panel of five common cannabis terpenoids, myrcene, linalool, limonene, α-pinene and nerolidol, in two neuronal models, autaptic hippocampal neurons and dorsal root ganglion (DRG) neurons. Autaptic neurons express a form of cannabinoid CB1 receptor-dependent retrograde plasticity while DRGs express a variety of transient receptor potential (TRP) channels. Most terpenoids had little or no effect on neuronal cannabinoid signaling. The exception was nerolidol, which inhibited endocannabinoid signaling. Notably, this is not via inhibition of CB1 receptors but by inhibiting some aspect of 2-arachidonoylglycerol (2-AG) production/delivery; the mechanism does not involve reducing the activity of the 2-AG-synthesizing diacylglycerol lipases (DAGLs). Nerolidol was also the only terpenoid that activated a sustained calcium response in a small (7%) subpopulation of DRGs. In summary, we found that only one of five terpenoids tested had notable effects on cannabinoid signaling in two neuronal models. Our results suggest that a few terpenoids may indeed interact with some components of the cannabinoid signaling system and may therefore offer interesting insights upon further study.
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Rodríguez-Manzo G, González-Morales E, Garduño-Gutiérrez R. Endocannabinoids Released in the Ventral Tegmental Area During Copulation to Satiety Modulate Changes in Glutamate Receptors Associated With Synaptic Plasticity Processes. Front Synaptic Neurosci 2021; 13:701290. [PMID: 34483875 PMCID: PMC8416467 DOI: 10.3389/fnsyn.2021.701290] [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: 04/27/2021] [Accepted: 07/08/2021] [Indexed: 11/13/2022] Open
Abstract
Endocannabinoids modulate mesolimbic (MSL) dopamine (DA) neurons firing at the ventral tegmental area (VTA). These neurons are activated by copulation, increasing DA release in nucleus accumbens (NAcc). Copulation to satiety in male rats implies repeated ejaculation within a short period (around 2.5 h), during which NAcc dopamine concentrations remain elevated, suggesting continuous neuronal activation. During the 72 h that follow copulation to satiety, males exhibit long-lasting changes suggestive of brain plasticity processes. Enhanced DA neuron activity triggers the synthesis and release of endocannabinoids (eCBs) in the VTA, which participate in several long-term synaptic plasticity processes. Blockade of cannabinoid type 1 receptors (CB1Rs) during copulation to satiety interferes with the appearance of the plastic changes. Glutamatergic inputs to the VTA express CB1Rs and contribute to DA neuron burst firing and synaptic plasticity. We hypothesized that eCBs, released during copulation to satiety, would activate VTA CB1Rs and modulate synaptic plasticity processes involving glutamatergic transmission. To test this hypothesis, we determined changes in VTA CB1R density, phosphorylation, and internalization in rats that copulated to satiety 24 h earlier as compared both to animals that ejaculated only once and to sexually experienced unmated males. Changes in glutamate AMPAR and NMDAR densities and subunit composition and in ERK1/2 activation were determined in the VTA of males that copulated to satiety in the presence or absence of AM251, a CB1R antagonist. The CB1R density decreased and the proportion of phosphorylated CB1Rs increased in the animals that copulated compared to control rats. The CB1R internalization was detected only in sexually satiated males. A decrease in α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor (AMPAR) density, blocked by AM251 pretreatment, and an increase in the proportion of GluA2-AMPARs occurred in sexually satiated rats. GluN2A- N-methyl-D-aspartate receptor (NMDAR) expression decreased, and GluN2B-NMDARs increased in these animals, both of which were prevented by AM251 pre-treatment. An increase in phosphorylated ERK1/2 emerged in males copulating to satiety in the presence of AM251. Results demonstrate that during copulation to satiety, eCBs activate CB1Rs in the VTA, producing changes in glutamate receptors compatible with a reduced neuronal activation. These changes could play a role in the induction of the long-lasting physiological changes that characterize sexually satiated rats.
Collapse
Affiliation(s)
- Gabriela Rodríguez-Manzo
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav-Sede Sur), Ciudad de México, Mexico
| | - Estefanía González-Morales
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav-Sede Sur), Ciudad de México, Mexico
| | - René Garduño-Gutiérrez
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav-Sede Sur), Ciudad de México, Mexico
| |
Collapse
|
5
|
Straiker A, Wilson S, Corey W, Dvorakova M, Bosquez T, Tracey J, Wilkowski C, Ho K, Wager-Miller J, Mackie K. An Evaluation of Understudied Phytocannabinoids and Their Effects in Two Neuronal Models. Molecules 2021; 26:5352. [PMID: 34500785 PMCID: PMC8434068 DOI: 10.3390/molecules26175352] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 11/16/2022] Open
Abstract
Cannabis contains more than 100 phytocannabinoids. Most of these remain poorly characterized, particularly in neurons. We tested a panel of five phytocannabinoids-cannabichromene (CBC), cannabidiolic acid (CBDA), cannabidivarin (CBDV), cannabidivarinic acid (CBDVA), and Δ9-tetrahydrocannabivarin (THCV) in two neuronal models, autaptic hippocampal neurons and dorsal root ganglion (DRG) neurons. Autaptic neurons expressed a form of CB1-dependent retrograde plasticity while DRGs expressed a variety of transient receptor potential (TRP) channels. CBC, CBDA, and CBDVA had little or no effect on neuronal cannabinoid signaling. CBDV and THCV differentially inhibited cannabinoid signaling. THCV inhibited CB1 receptors presynaptically while CBDV acted post-synaptically, perhaps by inhibiting 2-AG production. None of the compounds elicited a consistent DRG response. In summary, we find that two of five 'minor' phytocannabinoids tested antagonized CB1-based signaling in a neuronal model, but with very different mechanisms. Our findings highlight the diversity of potential actions of phytocannabinoids and the importance of fully evaluating these compounds in neuronal models.
Collapse
Affiliation(s)
- Alex Straiker
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| | - Sierra Wilson
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| | - Wesley Corey
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| | - Michaela Dvorakova
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
- Department of Molecular Pharmacology, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic
| | - Taryn Bosquez
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| | - Joye Tracey
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| | - Caroline Wilkowski
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| | - Kathleen Ho
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| | - Jim Wager-Miller
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| | - Ken Mackie
- Gill Center for Molecular Bioscience, Program in Neuroscience, Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA; (S.W.); (W.C.); (M.D.); (T.B.); (J.T.); (C.W.); (K.H.); (J.W.-M.); (K.M.)
| |
Collapse
|
6
|
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).
Collapse
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
| |
Collapse
|
7
|
Morris G, Walder K, Kloiber S, Amminger P, Berk M, Bortolasci CC, Maes M, Puri BK, Carvalho AF. The endocannabinoidome in neuropsychiatry: Opportunities and potential risks. Pharmacol Res 2021; 170:105729. [PMID: 34119623 DOI: 10.1016/j.phrs.2021.105729] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/31/2021] [Accepted: 06/09/2021] [Indexed: 02/08/2023]
Abstract
The endocannabinoid system (ECS) comprises two cognate endocannabinoid receptors referred to as CB1R and CB2R. ECS dysregulation is apparent in neurodegenerative/neuro-psychiatric disorders including but not limited to schizophrenia, major depressive disorder and potentially bipolar disorder. The aim of this paper is to review mechanisms whereby both receptors may interact with neuro-immune and neuro-oxidative pathways, which play a pathophysiological role in these disorders. CB1R is located in the presynaptic terminals of GABAergic, glutamatergic, cholinergic, noradrenergic and serotonergic neurons where it regulates the retrograde suppression of neurotransmission. CB1R plays a key role in long-term depression, and, to a lesser extent, long-term potentiation, thereby modulating synaptic transmission and mediating learning and memory. Optimal CB1R activity plays an essential neuroprotective role by providing a defense against the development of glutamate-mediated excitotoxicity, which is achieved, at least in part, by impeding AMPA-mediated increase in intracellular calcium overload and oxidative stress. Moreover, CB1R activity enables optimal neuron-glial communication and the function of the neurovascular unit. CB2R receptors are detected in peripheral immune cells and also in central nervous system regions including the striatum, basal ganglia, frontal cortex, hippocampus, amygdala as well as the ventral tegmental area. CB2R upregulation inhibits the presynaptic release of glutamate in several brain regions. CB2R activation also decreases neuroinflammation partly by mediating the transition from a predominantly neurotoxic "M1" microglial phenotype to a more neuroprotective "M2" phenotype. CB1R and CB2R are thus novel drug targets for the treatment of neuro-immune and neuro-oxidative disorders including schizophrenia and affective disorders.
Collapse
Affiliation(s)
- Gerwyn Morris
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Ken Walder
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Deakin University, Centre for Molecular and Medical Research, School of Medicine, Geelong, Australia
| | - Stefan Kloiber
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 33 Ursula Franklin Street, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Paul Amminger
- Orygen, Parkville, Victoria, Australia; Centre for Youth Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Michael Berk
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Orygen, The National Centre of Excellence in Youth Mental Health, Centre for Youth Mental Health, Florey Institute for Neuroscience and Mental Health and the Department of Psychiatry, The University of Melbourne, Melbourne, Australia
| | - Chiara C Bortolasci
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Michael Maes
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Department of Psychiatry, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Bangkok, Thailand; Department of Psychiatry, Medical University of Plovdiv, Plovdiv, Bulgaria
| | | | - Andre F Carvalho
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia.
| |
Collapse
|
8
|
Restoring glutamate homeostasis in the nucleus accumbens via endocannabinoid-mimetic drug prevents relapse to cocaine seeking behavior in rats. Neuropsychopharmacology 2021; 46:970-981. [PMID: 33514875 PMCID: PMC8115336 DOI: 10.1038/s41386-021-00955-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 12/13/2020] [Accepted: 12/29/2020] [Indexed: 12/23/2022]
Abstract
Impaired glutamate homeostasis is a key characteristic of the neurobiology of drug addiction in rodent models and contributes to the vulnerability to relapse to drug seeking. Although disrupted astrocytic and presynaptic regulation of glutamate release has been considered to constitute with impaired glutamate homeostasis in rodent model of drug relapse, the involvement of endocannabinoids (eCBs) in this neurobiological process has remained largely unknown. Here, using cocaine self-administration in rats, we investigated the role of endocannabinoids in impaired glutamate homeostasis in the core of nucleus accumbens (NAcore), which was indicated by augmentation of spontaneous synaptic glutamate release, downregulation of metabotropic glutamate receptor 2/3 (mGluR2/3), and mGluR5-mediated astrocytic glutamate release. We found that the endocannabinoid, anandamide (AEA), rather than 2-arachidonoylglycerol elicited glutamate release through presynaptic transient receptor potential vanilloid 1 (TRPV1) and astrocytic cannabinoid type-1 receptors (CB1Rs) in the NAcore of saline-yoked rats. In rats with a history of cocaine self-administration and extinction training, AEA failed to alter synaptic glutamate release in the NAcore, whereas CB1R-mediated astrocytic glutamate release by AEA remained functional. In order to induce increased astrocytic glutamate release via exogenous AEA, (R)-methanandamide (methAEA, a metabolically stable form of AEA) was chronically infused in the NAcore via osmotic pumps during extinction training. Restoration of mGluR2/3 function and mGluR5-mediated astrocytic glutamate release was observed after chronic methAEA infusion. Additionally, priming or cue-induced reinstatement of cocaine seeking was inhibited in methAEA-infused rats. These results demonstrate that enhancing endocannabinoid signaling is a potential pathway to restore glutamate homeostasis and may represent a promising therapeutic strategy for preventing cocaine relapse.
Collapse
|
9
|
Orexin-A differentially modulates inhibitory and excitatory synaptic transmission in rat inner retina. Neuropharmacology 2021; 187:108492. [PMID: 33582153 DOI: 10.1016/j.neuropharm.2021.108492] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/08/2021] [Accepted: 02/06/2021] [Indexed: 11/21/2022]
Abstract
In this work, modulation by orexin-A of the release of glutamate and GABA from bipolar and amacrine cells respectively was studied by examining the effects of the neuropeptide on miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) of rat retinal ganglion cells (GCs). Using RNAscope in situ hybridization in combination with immunohistochemistry, we showed positive signals for orexin receptor-1 (OX1R) mRNA in the bipolar cell terminals and those for orexin receptor-2 (OX2R) mRNA in the amacrine cell terminals. With whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that application of orexin-A reduced the interevent interval of mEPSCs of GCs through OX1R. However, it increased the interevent interval of mIPSCs, mediated by GABAA receptors, through OX2R. Furthermore, orexin-A-induced reduction of mEPSC interevent interval was abolished by the application of PI-PLC inhibitors or PKC inhibitors. In contrast, orexin-A-induced increase of GABAergic mIPSC interevent interval was mimicked by 8-Br-cAMP or an adenylyl cyclase activator, but was eliminated by PKA antagonists. Finally, application of nimodipine, an L-type Ca2+ channel blocker, increased both mEPSC and mIPSC interevent interval, and co-application of orexin-A no longer changed the mEPSCs and mIPSCs. We conclude that orexin-A increases presynaptic glutamate release onto GCs by activating L-type Ca2+ channels in bipolar cells, a process that is mediated by an OX1R/PI-PLC/PKC signaling pathway. However, orexin-A decreases presynaptic GABA release onto GCs by inhibiting L-type Ca2+ channels in amacrine cells, a process that is mediated by an OX2R/cAMP-PKA signaling pathway.
Collapse
|
10
|
Silbern I, Pan KT, Fiosins M, Bonn S, Rizzoli SO, Fornasiero EF, Urlaub H, Jahn R. Protein Phosphorylation in Depolarized Synaptosomes: Dissecting Primary Effects of Calcium from Synaptic Vesicle Cycling. Mol Cell Proteomics 2021; 20:100061. [PMID: 33582301 PMCID: PMC7995663 DOI: 10.1016/j.mcpro.2021.100061] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/02/2021] [Indexed: 01/20/2023] Open
Abstract
Synaptic transmission is mediated by the regulated exocytosis of synaptic vesicles. When the presynaptic membrane is depolarized by an incoming action potential, voltage-gated calcium channels open, resulting in the influx of calcium ions that triggers the fusion of synaptic vesicles (SVs) with the plasma membrane. SVs are recycled by endocytosis. Phosphorylation of synaptic proteins plays a major role in these processes, and several studies have shown that the synaptic phosphoproteome changes rapidly in response to depolarization. However, it is unclear which of these changes are directly linked to SV cycling and which might regulate other presynaptic functions that are also controlled by calcium-dependent kinases and phosphatases. To address this question, we analyzed changes in the phosphoproteome using rat synaptosomes in which exocytosis was blocked with botulinum neurotoxins (BoNTs) while depolarization-induced calcium influx remained unchanged. BoNT-treatment significantly alters the response of the synaptic phoshoproteome to depolarization and results in reduced phosphorylation levels when compared with stimulation of synaptosomes by depolarization with KCl alone. We dissect the primary Ca2+-dependent phosphorylation from SV-cycling-dependent phosphorylation and confirm an effect of such SV-cycling-dependent phosphorylation events on syntaxin-1a-T21/T23, synaptobrevin-S75, and cannabinoid receptor-1-S314/T322 on exo- and endocytosis in cultured hippocampal neurons.
Collapse
Affiliation(s)
- Ivan Silbern
- Institute of Clinical Chemistry, University Medical Center Goettingen, Goettingen, Germany; Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Kuan-Ting Pan
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Maksims Fiosins
- German Center for Neurodegenerative Diseases, Tübingen, Germany; Institute for Medical Systems Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Bonn
- German Center for Neurodegenerative Diseases, Tübingen, Germany; Institute for Medical Systems Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Silvio O Rizzoli
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Göttingen, Germany
| | - Eugenio F Fornasiero
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany.
| | - Henning Urlaub
- Institute of Clinical Chemistry, University Medical Center Goettingen, Goettingen, Germany; Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany.
| | - Reinhard Jahn
- Laboratory of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
| |
Collapse
|
11
|
Reddy V, Grogan D, Ahluwalia M, Salles ÉL, Ahluwalia P, Khodadadi H, Alverson K, Nguyen A, Raju SP, Gaur P, Braun M, Vale FL, Costigliola V, Dhandapani K, Baban B, Vaibhav K. Targeting the endocannabinoid system: a predictive, preventive, and personalized medicine-directed approach to the management of brain pathologies. EPMA J 2020; 11:217-250. [PMID: 32549916 PMCID: PMC7272537 DOI: 10.1007/s13167-020-00203-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 03/10/2020] [Indexed: 02/07/2023]
Abstract
Cannabis-inspired medical products are garnering increasing attention from the scientific community, general public, and health policy makers. A plethora of scientific literature demonstrates intricate engagement of the endocannabinoid system with human immunology, psychology, developmental processes, neuronal plasticity, signal transduction, and metabolic regulation. Despite the therapeutic potential, the adverse psychoactive effects and historical stigma, cannabinoids have limited widespread clinical application. Therefore, it is plausible to weigh carefully the beneficial effects of cannabinoids against the potential adverse impacts for every individual. This is where the concept of "personalized medicine" as a promising approach for disease prediction and prevention may take into the account. The goal of this review is to provide an outline of the endocannabinoid system, including endocannabinoid metabolizing pathways, and will progress to a more in-depth discussion of the therapeutic interventions by endocannabinoids in various neurological disorders.
Collapse
Affiliation(s)
- Vamsi Reddy
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
| | - Dayton Grogan
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
| | - Meenakshi Ahluwalia
- Department of Pathology, Medical College of Georgia, Augusta University, Augusta, GA USA
| | - Évila Lopes Salles
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA USA
| | - Pankaj Ahluwalia
- Department of Pathology, Medical College of Georgia, Augusta University, Augusta, GA USA
| | - Hesam Khodadadi
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA USA
| | - Katelyn Alverson
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
| | - Andy Nguyen
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
| | - Srikrishnan P. Raju
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
- Brown University, Providence, RI USA
| | - Pankaj Gaur
- Georgia Cancer Center, Augusta University, Augusta, GA USA
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington DC, USA
| | - Molly Braun
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, USA
- VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), VA Puget Sound Health Care System, Seattle, USA
| | - Fernando L. Vale
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
| | | | - Krishnan Dhandapani
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
| | - Babak Baban
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA USA
| | - Kumar Vaibhav
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA USA
| |
Collapse
|
12
|
Thompson KJ, Tobin AB. Crosstalk between the M 1 muscarinic acetylcholine receptor and the endocannabinoid system: A relevance for Alzheimer's disease? Cell Signal 2020; 70:109545. [PMID: 31978506 PMCID: PMC7184673 DOI: 10.1016/j.cellsig.2020.109545] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/19/2020] [Accepted: 01/20/2020] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder which accounts for 60-70% of the 50 million worldwide cases of dementia and is characterised by cognitive impairments, many of which have long been associated with dysfunction of the cholinergic system. Although the M1 muscarinic acetylcholine receptor (mAChR) is considered a promising drug target for AD, ligands targeting this receptor have so far been unsuccessful in clinical trials. As modulatory receptors to cholinergic transmission, the endocannabinoid system may be a promising drug target to allow fine tuning of the cholinergic system. Furthermore, disease-related changes have been found in the endocannabinoid system during AD progression and indeed targeting the endocannabinoid system at specific disease stages alleviates cognitive symptoms in numerous mouse models of AD. Here we review the role of the endocannabinoid system in AD, and its crosstalk with mAChRs as a potential drug target for cholinergic dysfunction.
Collapse
Affiliation(s)
- Karen J Thompson
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, Davidson Building, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Andrew B Tobin
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, Davidson Building, University of Glasgow, Glasgow G12 8QQ, UK
| |
Collapse
|
13
|
Bekkers JM. Autaptic Cultures: Methods and Applications. Front Synaptic Neurosci 2020; 12:18. [PMID: 32425765 PMCID: PMC7203343 DOI: 10.3389/fnsyn.2020.00018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 04/01/2020] [Indexed: 11/13/2022] Open
Abstract
Neurons typically form daisy chains of synaptic connections with other neurons, but they can also form synapses with themselves. Although such self-synapses, or autapses, are comparatively rare in vivo, they are surprisingly common in dissociated neuronal cultures. At first glance, autapses in culture seem like a mere curiosity. However, by providing a simple model system in which a single recording electrode gives simultaneous access to the pre- and postsynaptic compartments, autaptic cultures have proven to be invaluable in facilitating important and elegant experiments in the area of synaptic neuroscience. Here, I provide detailed protocols for preparing and recording from autaptic cultures (also called micro-island or microdot cultures). Variations on the basic procedure are presented, as well as practical tips for optimizing the outcomes. I also illustrate the utility of autaptic cultures by reviewing the types of experiments that have used them over the past three decades. These examples serve to highlight the power and elegance of this simple model system, and will hopefully inspire new experiments for the interrogation of synaptic function.
Collapse
Affiliation(s)
- John M Bekkers
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| |
Collapse
|
14
|
Al-Zoubi R, Morales P, Reggio PH. Structural Insights into CB1 Receptor Biased Signaling. Int J Mol Sci 2019; 20:E1837. [PMID: 31013934 PMCID: PMC6515405 DOI: 10.3390/ijms20081837] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 12/21/2022] Open
Abstract
The endocannabinoid system has emerged as a promising target for the treatment of numerous diseases, including cancer, neurodegenerative disorders, and metabolic syndromes. Thus far, two cannabinoid receptors, CB1 and CB2, have been discovered, which are found predominantly in the central nervous system (CB1) or the immune system (CB2), among other organs and tissues. CB1 receptor ligands have been shown to induce a complex pattern of intracellular effects. The binding of a ligand induces distinct conformational changes in the receptor, which will eventually translate into distinct intracellular signaling pathways through coupling to specific intracellular effector proteins. These proteins can mediate receptor desensitization, trafficking, or signaling. Ligand specificity and selectivity, complex cellular components, and the concomitant expression of other proteins (which either regulate the CB1 receptor or are regulated by the CB1 receptor) will affect the therapeutic outcome of its targeting. With an increased interest in G protein-coupled receptors (GPCR) research, in-depth studies using mutations, biological assays, and spectroscopic techniques (such as NMR, EPR, MS, FRET, and X-ray crystallography), as well as computational modelling, have begun to reveal a set of concerted structural features in Class A GPCRs which relate to signaling pathways and the mechanisms of ligand-induced activation, deactivation, or activity modulation. This review will focus on the structural features of the CB1 receptor, mutations known to bias its signaling, and reported studies of CB1 receptor ligands to control its specific signaling.
Collapse
Affiliation(s)
- Rufaida Al-Zoubi
- Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science & Technology, P.O.BOX 3030, Irbid 22110, Jordan.
| | - Paula Morales
- Departamento de Química-Física Biológica, Instituto de Química Física Rocasolano (IQFR-CSIC), Serrano 119, 28006 Madrid, Spain.
| | - Patricia H Reggio
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, NC 27412, USA.
| |
Collapse
|
15
|
Pang C, Yang H, Hu B, Wang S, Chen M, Cohen DS, Chen HS, Jarrell JT, Carpenter KA, Rosin ER, Huang X. Identification and Analysis of Alzheimer's Candidate Genes by an Amplitude Deviation Algorithm. ACTA ACUST UNITED AC 2019; 9. [PMID: 31080696 PMCID: PMC6505709 DOI: 10.4172/2161-0460.1000460] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Background: Alzheimer’s disease (AD) is the most common form of senile dementia. However, its pathological mechanisms are not fully understood. In order to comprehend AD pathological mechanisms, researchers employed AD-related DNA microarray data and diverse computational algorithms. More efficient computational algorithms are needed to process DNA microarray data for identifying AD-related candidate genes. Methods: In this paper, we propose a specific algorithm that is based on the following observation: When an acrobat walks along a steel-wire, his/her body must have some swing; if the swing can be controlled, then the acrobat can maintain the body balance. Otherwise, the acrobat will fall. Based on this simple idea, we have designed a simple, yet practical, algorithm termed as the Amplitude Deviation Algorithm (ADA). Deviation, overall deviation, deviation amplitude, and 3δ are introduced to characterize ADA. Results: 52 candidate genes for AD have been identified via ADA. The implications for some of the AD candidate genes in AD pathogenesis have been discussed. Conclusions: Through the analysis of these AD candidate genes, we believe that AD pathogenesis may be related to the abnormality of signal transduction (AGTR1 and PTAFR), the decrease in protein transport capacity (COL5A2 (221729_at), COL5A2 (221730_at), COL4A1), the impairment of axon repair (CNR1), and the intracellular calcium dyshomeostasis (CACNB2, CACNA1E). However, their potential implication for AD pathology should be further validated by wet lab experiments as they were only identified by computation using ADA.
Collapse
Affiliation(s)
- Chaoyang Pang
- College of Computer Science, Sichuan Normal University, Chengdu, China
| | - Hualan Yang
- College of Mathematics and Software Science, Sichuan Normal University, Chengdu, China
| | - Benqiong Hu
- College of Management Science, Chengdu University of Technology, Chengdu, China
| | - Shipeng Wang
- College of Mathematics and Software Science, Sichuan Normal University, Chengdu, China
| | - Meixia Chen
- College of Mathematics and Software Science, Sichuan Normal University, Chengdu, China
| | - David S Cohen
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Hannah S Chen
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Juliet T Jarrell
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Kristy A Carpenter
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Eric R Rosin
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Xudong Huang
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| |
Collapse
|
16
|
Mardani P, Oryan S, Sarihi A, Komaki A, Shojaei A, Dehghan S, Mirnajafi-Zadeh J. ERK activation is required for the antiepileptogenic effect of low frequency electrical stimulation in kindled rats. Brain Res Bull 2018; 140:132-139. [PMID: 29705048 DOI: 10.1016/j.brainresbull.2018.04.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 04/22/2018] [Accepted: 04/24/2018] [Indexed: 01/01/2023]
Abstract
INTRODUCTION The signaling pathways involved in the antiepileptogenic effect of low frequency electrical stimulation (LFS) have not been fully understood. In the present study the role of extracellular signal-regulated kinase (ERK) signaling cascade was investigated in mediating the inhibitory effects of LFS on kindled seizures. METHODS Animals received kindling stimulations for seven days (the mean number of stimulation days for achieving stage 5 seizure) according to semi-rapid perforant path kindling protocol (12 stimulations per day at 10 min intervals). LFS (0.1 ms pulse duration at 1 Hz, 800 pulses) was applied at 5 min after the last kindling stimulation every day. During the kindling procedure, FR180204 (inhibitor of ERK) was daily microinjected (1 μg/μl; intracerebroventricular) immediately after the last kindling stimulation and before LFS application. The expression of activated ERK (p-ERK) in the dentate gyrus was also investigated using immunohistochemistry technique. RESULTS Application of LFS at 5 min after the last kindling stimulation had inhibitory effect on kindling rate. FR180204 had no significant effect on seizure parameters when administered at the dose of 1 μg/μl in kindled group of animals. However, microinjection of FR180204 before LFS application reduced the inhibitory effect of LFS on seizure severity and field potential parameters (i.e. the slope of population field excitatory postsynaptic potentials and population spike amplitude) during kindling. FR180204 also blocked the preventing effects of LFS on kindling-induced increase in early (at 10-40 ms intervals) and late (at 300-1000 ms intervals) paired pulse depression. In addition, application of LFS following kindling stimulations increased the expression of p-ERK in the dentate gyrus. CONCLUSION Obtained results showed ERK signaling pathway had important role in mediating the antiepileptogenic effect of LFS in perforant path kindling. These findings represent a promising opportunity to gain insight about LFS mechanism in epilepsy therapy.
Collapse
Affiliation(s)
- Parastoo Mardani
- Department of Biology, Faculty of Sciences, Kharazmi University, Tehran, Iran.
| | - Shahrbanoo Oryan
- Department of Biology, Faculty of Sciences, Kharazmi University, Tehran, Iran
| | - Abdolrahman Sarihi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Samaneh Dehghan
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| |
Collapse
|
17
|
Abstract
An agonist that acts through a single receptor can activate numerous signaling pathways. Recent studies have suggested that different ligands can differentially activate these pathways by stabilizing a limited range of receptor conformations, which in turn preferentially drive different downstream signaling cascades. This concept, termed "biased signaling" represents an exciting therapeutic opportunity to target specific pathways that elicit only desired effects, while avoiding undesired effects mediated by different signaling cascades. The cannabinoid receptors CB1 and CB2 each activate multiple pathways, and evidence is emerging for bias within these pathways. This review will summarize the current evidence for biased signaling through cannabinoid receptor subtypes CB1 and CB2.
Collapse
Affiliation(s)
- Mikkel Søes Ibsen
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Mark Connor
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, New South Wales, Australia
| | - Michelle Glass
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| |
Collapse
|
18
|
Nasehi M, Rostam-Nezhad E, Ebrahimi-Ghiri M, Zarrindast MR. Interaction between hippocampal serotonin and cannabinoid systems in reactivity to spatial and object novelty detection. Behav Brain Res 2017; 317:272-278. [DOI: 10.1016/j.bbr.2016.09.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 09/21/2016] [Accepted: 09/25/2016] [Indexed: 12/12/2022]
|
19
|
Johnson KA, Lovinger DM. Presynaptic Plasticity Found in Translation. Neuron 2016; 92:269-272. [PMID: 27764658 PMCID: PMC11257498 DOI: 10.1016/j.neuron.2016.09.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In this issue of Neuron, Younts et al. (2016) demonstrate that activation of presynaptic CB1 receptors by retrograde endocannabinoid signaling stimulates protein synthesis in axon terminals to induce long-term depression of hippocampal inhibitory transmission.
Collapse
Affiliation(s)
- Kari A Johnson
- Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - David M Lovinger
- Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
20
|
Schmitz SK, King C, Kortleven C, Huson V, Kroon T, Kevenaar JT, Schut D, Saarloos I, Hoetjes JP, de Wit H, Stiedl O, Spijker S, Li KW, Mansvelder HD, Smit AB, Cornelisse LN, Verhage M, Toonen RF. Presynaptic inhibition upon CB1 or mGlu2/3 receptor activation requires ERK/MAPK phosphorylation of Munc18-1. EMBO J 2016; 35:1236-50. [PMID: 27056679 DOI: 10.15252/embj.201592244] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 03/02/2016] [Indexed: 01/22/2023] Open
Abstract
Presynaptic cannabinoid (CB1R) and metabotropic glutamate receptors (mGluR2/3) regulate synaptic strength by inhibiting secretion. Here, we reveal a presynaptic inhibitory pathway activated by extracellular signal-regulated kinase (ERK) that mediates CB1R- and mGluR2/3-induced secretion inhibition. This pathway is triggered by a variety of events, from foot shock-induced stress to intense neuronal activity, and induces phosphorylation of the presynaptic protein Munc18-1. Mimicking constitutive phosphorylation of Munc18-1 results in a drastic decrease in synaptic transmission. ERK-mediated phosphorylation of Munc18-1 ultimately leads to degradation by the ubiquitin-proteasome system. Conversely, preventing ERK-dependent Munc18-1 phosphorylation increases synaptic strength. CB1R- and mGluR2/3-induced synaptic inhibition and depolarization-induced suppression of excitation (DSE) are reduced upon ERK/MEK pathway inhibition and further reduced when ERK-dependent Munc18-1 phosphorylation is blocked. Thus, ERK-dependent Munc18-1 phosphorylation provides a major negative feedback loop to control synaptic strength upon activation of presynaptic receptors and during intense neuronal activity.
Collapse
Affiliation(s)
- Sabine K Schmitz
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Cillian King
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Christian Kortleven
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Vincent Huson
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Tim Kroon
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Josta T Kevenaar
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Desiree Schut
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Ingrid Saarloos
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Joost P Hoetjes
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Heidi de Wit
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Oliver Stiedl
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Sabine Spijker
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Ka Wan Li
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - August B Smit
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Lennart Niels Cornelisse
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| | - Ruud F Toonen
- Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit (VU) and VU Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
21
|
An Introduction to the Endogenous Cannabinoid System. Biol Psychiatry 2016; 79:516-25. [PMID: 26698193 PMCID: PMC4789136 DOI: 10.1016/j.biopsych.2015.07.028] [Citation(s) in RCA: 695] [Impact Index Per Article: 86.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 07/14/2015] [Accepted: 07/20/2015] [Indexed: 11/20/2022]
Abstract
The endocannabinoid system (ECS) is a widespread neuromodulatory system that plays important roles in central nervous system development, synaptic plasticity, and the response to endogenous and environmental insults. The ECS comprises cannabinoid receptors, endogenous cannabinoids (endocannabinoids), and the enzymes responsible for the synthesis and degradation of the endocannabinoids. The most abundant cannabinoid receptors are the CB1 cannabinoid receptors; however, CB2 cannabinoid receptors, transient receptor potential channels, and peroxisome proliferator activated receptors are also engaged by some cannabinoids. Exogenous cannabinoids, such as tetrahydrocannabinol, produce their biological effects through their interactions with cannabinoid receptors. The best-studied endogenous cannabinoids are 2-arachidonoyl glycerol and arachidonoyl ethanolamide (anandamide). Despite similarities in chemical structure, 2-arachidonoyl glycerol and anandamide are synthesized and degraded by distinct enzymatic pathways, which impart fundamentally different physiologic and pathophysiologic roles to these two endocannabinoids. As a result of the pervasive social use of cannabis and the involvement of endocannabinoids in a multitude of biological processes, much has been learned about the physiologic and pathophysiologic roles of the ECS. This review provides an introduction to the ECS with an emphasis on its role in synaptic plasticity and how the ECS is perturbed in schizophrenia.
Collapse
|
22
|
Basavarajappa BS, Subbanna S. CB1 receptor-mediated signaling underlies the hippocampal synaptic, learning, and memory deficits following treatment with JWH-081, a new component of spice/K2 preparations. Hippocampus 2014; 24:178-88. [PMID: 24123667 DOI: 10.1002/hipo.22213] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 09/18/2013] [Accepted: 10/02/2013] [Indexed: 01/23/2023]
Abstract
Recently, synthetic cannabinoids have been sprayed onto plant material, which is subsequently packaged and sold as "Spice" or "K2" to mimic the effects of marijuana. A recent report identified several synthetic additives in samples of "Spice/K2", including JWH-081, a synthetic ligand for the cannabinoid receptor 1 (CB1). The deleterious effects of JWH-081 on brain function are not known, particularly on CB1 signaling, synaptic plasticity, learning and memory. Here, we evaluated the effects of JWH-081 on pCaMKIV, pCREB, and pERK1/2 signaling events followed by long-term potentiation (LTP), hippocampal-dependent learning and memory tasks using CB1 receptor wild-type (WT) and knockout (KO) mice. Acute administration of JWH-081 impaired CaMKIV phosphorylation in a dose-dependent manner, whereas inhibition of CREB phosphorylation in CB1 receptor WT mice was observed only at higher dose of JWH-081 (1.25 mg/kg). JWH-081 at higher dose impaired CaMKIV and CREB phosphorylation in a time-dependent manner in CB1 receptor WT mice but not in KO mice and failed to alter ERK1/2 phosphorylation. In addition, SR treated or CB1 receptor KO mice have a lower pCaMKIV/CaMKIV ratio and higher pCREB/CREB ratio compared with vehicle or WT littermates. In hippocampal slices, JWH-081 impaired LTP in CB1 receptor WT but not in KO littermates. Furthermore, JWH-081 at higher dose impaired object recognition, spontaneous alternation and spatial memory on the Y-maze in CB1 receptor WT mice but not in KO mice. Collectively our findings suggest that deleterious effects of JWH-081 on hippocampal function involves CB1 receptor mediated impairments in CaMKIV and CREB phosphorylation, LTP, learning and memory in mice.
Collapse
|
23
|
Simi A, Amin H, Maccione A, Nieus T, Berdondini L. Integration of microstructured scaffolds, neurons, and multielectrode arrays. PROGRESS IN BRAIN RESEARCH 2014; 214:415-42. [DOI: 10.1016/b978-0-444-63486-3.00017-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
24
|
Trimpin S, Wang B, Lietz CB, Marshall DD, Richards AL, Inutan ED. New ionization processes and applications for use in mass spectrometry. Crit Rev Biochem Mol Biol 2013; 48:409-29. [DOI: 10.3109/10409238.2013.806887] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
25
|
Endocannabinoid-mediated long-term depression of afferent excitatory synapses in hippocampal pyramidal cells and GABAergic interneurons. J Neurosci 2013; 32:14448-63. [PMID: 23055515 DOI: 10.1523/jneurosci.1676-12.2012] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Although endocannabinoids have emerged as essential retrograde messengers in several forms of synaptic plasticity, it remains controversial whether they mediate long-term depression (LTD) of glutamatergic synapses onto excitatory and inhibitory neurons in the hippocampus. Here, we show that parvalbumin- and somatostatin/metabotropic glutamate receptor 1(a) (mGlu(1a))-positive GABAergic interneurons express diacylglycerol lipase-α (DGL-α), a synthesizing enzyme of the endocannabinoid 2-arachidonoylglycerol (2-AG), albeit at lower levels than principal cells. Moreover, this lipase accumulates postsynaptically around afferent excitatory synapses in all three cell types. To address the role of retrograde 2-AG signaling in LTD, we investigated two forms: (1) produced by postsynaptic spiking paired with subsequent presynaptic stimulation or (2) induced by group I mGlu activation by (S)-3,5-dihydroxyphenylglycine (DHPG). Neither form of LTD was evoked in the presence of the mGlu(5) antagonist MPEP [2-methyl-6-(phenylethynyl)-pyridine], the DGL inhibitor THL [N-formyl-l-leucine (1S)-1-[[(2S,3S)-3-hexyl-4-oxo-2-oxetanyl]methyl]dodecyl ester], or the intracellularly applied Ca(2+) chelator BAPTA in CA1 pyramidal cells, fast-spiking interneurons (representing parvalbumin-containing cells) and interneurons projecting to stratum lacunosum-moleculare (representing somatostatin/mGlu(1a)-expressing interneurons). Both forms of LTD were completely absent in CB(1) cannabinoid receptor knock-out mice, whereas pharmacological blockade of CB(1) led to inconsistent results. Notably, in accordance with their lower DGL-α level, a higher stimulation frequency or higher DHPG concentration was required for LTD induction in interneurons compared with pyramidal cells. These findings demonstrate that hippocampal principal cells and interneurons produce endocannabinoids to mediate LTD in a qualitatively similar, but quantitatively different manner. The shifted induction threshold implies that endocannabinoid-LTD contributes to cortical information processing during distinct network activity patterns in a cell type-specific manner.
Collapse
|
26
|
The CB2-preferring agonist JWH015 also potently and efficaciously activates CB1 in autaptic hippocampal neurons. Pharmacol Res 2012; 66:437-42. [PMID: 22921769 DOI: 10.1016/j.phrs.2012.08.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 08/07/2012] [Accepted: 08/07/2012] [Indexed: 11/22/2022]
Abstract
The G protein coupled receptors CB(1) and CB(2) are targets for the psychoactive constituents of cannabis, chief among them Δ(9)-THC. They are also key components of the multifunctional endogenous cannabinoid signaling system. CB(1) and CB(2) receptors modulate a wide variety of physiological systems including analgesia, memory, mood, reward, appetite and immunity. Identification and characterization of selective CB(1) and CB(2) receptor agonists and antagonists will facilitate understanding the precise physiological and pathophysiological roles of cannabinoid receptors in these systems. This is particularly necessary in the case of CB(2) because these receptors are sparsely expressed and problematic to detect using traditional immunocytochemical approaches. 1-Propyl-2-methyl-3-(1-naphthoyl)indole (JWH015) is an aminoalkylindole that has been employed as a "CB(2)-selective" agonist in more than 40 published papers. However, we have found that JWH015 potently and efficaciously activates CB(1) receptors in neurons. Using murine autaptic hippocampal neurons, which express CB(1), but not CB(2) receptors, we find that JWH015 inhibits excitatory postsynaptic currents with an EC50 of 216nM. JWH015 inhibition is absent in neurons from CB(1)(-/-) cultures and is reversed by the CB(1) antagonist, SR141716 [200nM]. Furthermore, JWH015 partially occludes CB(1)-mediated DSE (∼35% remaining), an action reversed by the CB(2) antagonist, AM630 [1 and 3μM], suggesting that high concentrations of AM630 also antagonize CB(1) receptors. We conclude that while JWH015 is a CB(2)-preferring agonist, it also activates CB(1) receptors at experimentally encountered concentrations. Thus, CB(1) agonism of JWH015 needs to be considered in the design and interpretation of experiments that use JWH015 to probe CB(2)-signaling.
Collapse
|
27
|
Straiker A, Wager-Miller J, Hutchens J, Mackie K. Differential signalling in human cannabinoid CB1 receptors and their splice variants in autaptic hippocampal neurones. Br J Pharmacol 2012; 165:2660-71. [PMID: 22014238 DOI: 10.1111/j.1476-5381.2011.01744.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Cannabinoids such as Δ(9) - tetrahydrocannabinol, the major psychoactive component of marijuana and hashish, primarily act via cannabinoid CB(1) and CB(2) receptors to produce characteristic behavioural effects in humans. Due to the tractability of rodent models for electrophysiological and behavioural studies, most of the studies of cannabinoid receptor action have used rodent cannabinoid receptors. While CB(1) receptors are relatively well-conserved among mammals, human CB(1) (hCB(1) ) differs from rCB(1) and mCB(1) receptors at 13 residues, which may result in differential signalling. In addition, two hCB(1) splice variants (hCB(1a) and hCB(1b) ) have been reported, diverging in their amino-termini relative to hCB(1) receptors. In this study, we have examined hCB(1) signalling in neurones. EXPERIMENTAL APPROACH hCB(1) , hCB(1a) hCB(1b) or rCB(1) receptors were expressed in autaptic cultured hippocampal neurones from CB(1) (-/-) mice. Such cells express a complete endogenous cannabinoid signalling system. Electrophysiological techniques were used to assess CB(1) receptor-mediated signalling. KEY RESULTS Expressed in autaptic hippocampal neurones cultured from CB(1) (-/-) mice, hCB(1) , hCB(1a) and hCB(1b) signal differentially from one another and from rodent CB(1) receptors. Specifically, hCB(1) receptors inhibit synaptic transmission less effectively than rCB(1) receptors. CONCLUSIONS AND IMPLICATIONS Our results suggest that cannabinoid receptor signalling in humans is quantitatively very different from that in rodents. As the problems of marijuana and hashish abuse occur in humans, our results highlight the importance of studying hCB(1) receptors. They also suggest further study of the distribution and function of hCB(1) receptor splice variants, given their differential signalling and potential impact on human health. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.
Collapse
Affiliation(s)
- Alex Straiker
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, IN 47405, USA.
| | | | | | | |
Collapse
|
28
|
Straiker A, Wager-Miller J, Mackie K. The CB1 cannabinoid receptor C-terminus regulates receptor desensitization in autaptic hippocampal neurones. Br J Pharmacol 2012; 165:2652-9. [PMID: 22014214 DOI: 10.1111/j.1476-5381.2011.01743.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The cannabinoid CB(1) receptor is the chief mediator of the CNS effects of cannabinoids. In cell culture model systems, CB(1) receptors both desensitize and internalize on activation. Previous work suggests that the extreme carboxy-terminus of this receptor regulates internalization via phosphorylation of residues clustered within this region. Mutational analysis of the carboxy-terminus of CB(1) receptors has demonstrated that the last six serine/threonine residues are necessary for agonist-induced internalization. However, the structural determinants of CB(1) receptor internalization are also dependent on the local cellular environment. The importance of cell context on CB(1) receptor function calls for an investigation of the functional roles of these residues in neurones. EXPERIMENTAL APPROACH To determine the structural requirements of CB(1) internalization in neurones, we evaluated the signalling properties of carboxy-terminal mutated CB(1) receptors expressed in cultured autaptic hippocampal neurones, using electrophysiological methods. KEY RESULTS CB(1) receptors transfected into CB(1) knockout neurones signalled and desensitized as did wild-type neurones, allowing us to test specific CB(1) receptor mutations. Deletion of the last 13 residues yielded a CB(1) receptor that inhibited excitatory postsynaptic currents but did not desensitize. Furthermore, mutation of the final six serine and threonine residues to alanines resulted in a non-desensitizing receptor. In contrast, CB(1) receptors lacking residues 419-460, leaving the last 14 residues intact, did desensitize. CONCLUSIONS AND IMPLICATIONS The distal thirteen residues of CB(1) receptors are crucial for their desensitization in cultured neurones. Furthermore, this desensitization is likely to follow phosphorylation of serines and threonines within this region. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.
Collapse
Affiliation(s)
- Alex Straiker
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, IN 47405, USA.
| | | | | |
Collapse
|
29
|
Sarne Y, Asaf F, Fishbein M, Gafni M, Keren O. The dual neuroprotective-neurotoxic profile of cannabinoid drugs. Br J Pharmacol 2012; 163:1391-401. [PMID: 21323910 DOI: 10.1111/j.1476-5381.2011.01280.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Extensive in vitro and in vivo studies have shown that cannabinoid drugs have neuroprotective properties and suggested that the endocannabinoid system may be involved in endogenous neuroprotective mechanisms. On the other hand, neurotoxic effects of cannabinoids in vitro and in vivo were also described. Several possible explanations for these dual, opposite effects of cannabinoids on cellular fate were suggested, and it is conceivable that various factors may determine the final outcome of the cannabinoid effect in vivo. In the current review, we focus on one of the possible reasons for the dual neuroprotective/neurotoxic effects of cannabinoids in vivo, namely, the opposite effects of low versus high doses of cannabinoids. While many studies reported neuroprotective effects of the conventional doses of cannabinoids in various experimental models for acute brain injuries, we have shown that a single administration of an extremely low dose of Δ(9) -tetrahydrocannabinol (THC) (3-4 orders of magnitude lower than the conventional doses) to mice induced long-lasting mild cognitive deficits that affected various aspects of memory and learning. These findings led to the idea that this low dose of THC, which induces minor damage to the brain, may activate preconditioning and/or postconditioning mechanisms and thus will protect the brain from more severe insults. Indeed, our recent findings support this assumption and show that a pre- or a postconditioning treatment with extremely low doses of THC, several days before or after brain injury, provides effective long-term cognitive neuroprotection. The future therapeutical potential of these findings is discussed.
Collapse
Affiliation(s)
- Yosef Sarne
- The Adelson Center for the Biology of Addictive Diseases and The Mauerberger Chair in Neuropharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
| | | | | | | | | |
Collapse
|
30
|
Straiker A, Wager-Miller J, Hu SS, Blankman JL, Cravatt BF, Mackie K. COX-2 and fatty acid amide hydrolase can regulate the time course of depolarization-induced suppression of excitation. Br J Pharmacol 2011; 164:1672-83. [PMID: 21564090 PMCID: PMC3230814 DOI: 10.1111/j.1476-5381.2011.01486.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 04/11/2011] [Accepted: 04/20/2011] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Depolarization-induced suppression of inhibition (DSI) and excitation (DSE) are two forms of cannabinoid CB(1) receptor-mediated inhibition of synaptic transmission, whose durations are regulated by endocannabinoid (eCB) degradation. We have recently shown that in cultured hippocampal neurons monoacylglycerol lipase (MGL) controls the duration of DSE, while DSI duration is determined by both MGL and COX-2. This latter result suggests that DSE might be attenuated, and excitatory transmission enhanced, during inflammation and in other settings where COX-2 expression is up-regulated. EXPERIMENTAL APPROACH To investigate whether it is possible to control the duration of eCB-mediated synaptic plasticity by varied expression of eCB-degrading enzymes, we transfected excitatory autaptic hippocampal neurons with putative 2-AG metabolizing enzymes: COX-2, fatty acid amide hydrolase (FAAH), α/β hydrolase domain 6 (ABHD6), α/β hydrolase domain 12 (ABHD12) or MGL. KEY RESULTS We found that overexpression of either COX-2 or FAAH shortens the duration of DSE while ABHD6 or ABHD12 do not. In contrast, genetic deletion (MGL(-/-)) and overexpression of MGL both radically altered eCB-mediated synaptic plasticity. CONCLUSIONS AND IMPLICATIONS We conclude that both FAAH and COX-2 can be trafficked to neuronal sites where they are able to degrade eCBs to modulate DSE duration and, by extension, net endocannabinoid signalling at a given synapse. The results for COX-2, which is often up-regulated under pathological conditions, are of particular note in that they offer a mechanism by which up-regulated COX-2 may promote neuronal excitation by suppressing DSE while enhancing conversion of 2-AG to PGE(2) -glycerol ester under pathological conditions.
Collapse
Affiliation(s)
- A Straiker
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, IN 47405, USA.
| | | | | | | | | | | |
Collapse
|
31
|
Pan B, Zhong P, Sun D, Liu QS. Extracellular signal-regulated kinase signaling in the ventral tegmental area mediates cocaine-induced synaptic plasticity and rewarding effects. J Neurosci 2011; 31:11244-55. [PMID: 21813685 PMCID: PMC3153072 DOI: 10.1523/jneurosci.1040-11.2011] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 06/15/2011] [Accepted: 06/17/2011] [Indexed: 11/21/2022] Open
Abstract
Drugs of abuse such as cocaine induce long-term synaptic plasticity in the reward circuitry, which underlies the formation of drug-associated memories and addictive behavior. We reported previously that repeated cocaine exposure in vivo facilitates long-term potentiation (LTP) in dopamine neurons of the ventral tegmental area (VTA) by reducing the strength of GABAergic inhibition and that endocannabinoid-dependent long-term depression at inhibitory synapses (I-LTD) constitutes a mechanism for cocaine-induced reduction of GABAergic inhibition. The present study investigated the downstream signaling mechanisms and functional consequences of I-LTD in the VTA in the rat. Extracellular signal-regulated kinase (ERK) signaling has been implicated in long-term synaptic plasticity, associative learning, and drug addiction. We tested the hypothesis that VTA ERK activity is required for I-LTD and cocaine-induced long-term synaptic plasticity and behavioral effects. We show that the activation of receptors required for I-LTD increased ERK1/2 phosphorylation and inhibitors of ERK activation blocked I-LTD. We further demonstrate that ERK mediates cocaine-induced reduction of GABAergic inhibition and facilitation of LTP induction. Finally, we show that cocaine conditioned place preference (CPP) training (15 mg/kg; four pairings) increased ERK1/2 phosphorylation in the VTA, while bilateral intra-VTA injections of a CB(1) antagonist or an inhibitor of ERK activation attenuated ERK1/2 phosphorylation and the acquisition, but not the expression, of CPP to cocaine. Our study has identified the CB(1) and ERK signaling cascade as a key mediator of several forms of cocaine-induced synaptic plasticity and provided evidence linking long-term synaptic plasticity in the VTA to rewarding effects of cocaine.
Collapse
Affiliation(s)
- Bin Pan
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Peng Zhong
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Dalong Sun
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Qing-song Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| |
Collapse
|
32
|
Abstract
The endocannabinoid (ECB) system has been found throughout the central nervous system and modulates cell excitability in various forms of short-term plasticity. ECBs and their receptors have also been localized to all retinal cells, and cannabinoid receptor activation has been shown to alter voltage-dependent conductances in several different retinal cell types, suggesting a possible role for cannabinoids in retinal processing. Their effects on synaptic transmission in the mammalian retina, however, have not been previously investigated. Here, we show that exogenous cannabinoids alter spontaneous synaptic transmission onto retinal ganglion cells (RGCs). Using whole-cell voltage-clamp recordings in whole-mount retinas, we measured spontaneous postsynaptic currents (SPSCs) in RGCs in adult and young (P14-P21) mice. We found that the addition of an exogenous cannabinoid agonist, WIN55212-2 (5 μM), caused a significant reversible reduction in the frequency of SPSCs. This change, however, did not alter the kinetics of the SPSCs, indicating a presynaptic locus of action. Using blockers to isolate inhibitory or excitatory currents, we found that cannabinoids significantly reduced the release probability of both GABA and glutamate, respectively. While the addition of cannabinoids reduced the frequency of both GABAergic and glutamatergic SPSCs in both young and adult mice, we found that the largest effect was on GABA-mediated currents in young mice. These results suggest that the ECB system may potentially be involved in the modulation of signal transmission in the retina. Furthermore, they suggest that it might play a role in the developmental maturation of synaptic circuits, and that exogenous cannabinoids are likely able to disrupt retinal processing and consequently alter vision.
Collapse
|
33
|
Calcium-independent inhibitory G-protein signaling induces persistent presynaptic muting of hippocampal synapses. J Neurosci 2011; 31:979-91. [PMID: 21248122 DOI: 10.1523/jneurosci.4960-10.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Adaptive forms of synaptic plasticity that reduce excitatory synaptic transmission in response to prolonged increases in neuronal activity may prevent runaway positive feedback in neuronal circuits. In hippocampal neurons, for example, glutamatergic presynaptic terminals are selectively silenced, creating "mute" synapses, after periods of increased neuronal activity or sustained depolarization. Previous work suggests that cAMP-dependent and proteasome-dependent mechanisms participate in silencing induction by depolarization, but upstream activators are unknown. We, therefore, tested the role of calcium and G-protein signaling in silencing induction in cultured hippocampal neurons. We found that silencing induction by depolarization was not dependent on rises in intracellular calcium, from either extracellular or intracellular sources. Silencing was, however, pertussis toxin sensitive, which suggests that inhibitory G-proteins are recruited. Surprisingly, blocking four common inhibitory G-protein-coupled receptors (GPCRs) (adenosine A(1) receptors, GABA(B) receptors, metabotropic glutamate receptors, and CB(1) cannabinoid receptors) and one ionotropic receptor with metabotropic properties (kainate receptors) failed to prevent depolarization-induced silencing. Activating a subset of these GPCRs (A(1) and GABA(B)) with agonist application induced silencing, however, which supports the hypothesis that G-protein activation is a critical step in silencing. Overall, our results suggest that depolarization activates silencing through an atypical GPCR or through receptor-independent G-protein activation. GPCR agonist-induced silencing exhibited dependence on the ubiquitin-proteasome system, as was shown previously for depolarization-induced silencing, implicating the degradation of vital synaptic proteins in silencing by GPCR activation. These data suggest that presynaptic muting in hippocampal neurons uses a G-protein-dependent but calcium-independent mechanism to depress presynaptic vesicle release.
Collapse
|
34
|
Dual Neuroprotective and Neurotoxic Effects of Cannabinoid Drugs in Vitro. Cell Mol Neurobiol 2010; 31:195-202. [DOI: 10.1007/s10571-010-9604-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 09/20/2010] [Indexed: 10/18/2022]
|
35
|
Ludányi A, Hu SSJ, Yamazaki M, Tanimura A, Piomelli D, Watanabe M, Kano M, Sakimura K, Maglóczky Z, Mackie K, Freund TF, Katona I. Complementary synaptic distribution of enzymes responsible for synthesis and inactivation of the endocannabinoid 2-arachidonoylglycerol in the human hippocampus. Neuroscience 2010; 174:50-63. [PMID: 21035522 DOI: 10.1016/j.neuroscience.2010.10.062] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/08/2010] [Accepted: 10/21/2010] [Indexed: 01/07/2023]
Abstract
Clinical and experimental evidence demonstrates that endocannabinoids play either beneficial or adverse roles in many neurological and psychiatric disorders. Their medical significance may be best explained by the emerging concept that endocannabinoids are essential modulators of synaptic transmission throughout the central nervous system. However, the precise molecular architecture of the endocannabinoid signaling machinery in the human brain remains elusive. To address this issue, we investigated the synaptic distribution of metabolic enzymes for the most abundant endocannabinoid molecule, 2-arachidonoylglycerol (2-AG), in the postmortem human hippocampus. Immunostaining for diacylglycerol lipase-α (DGL-α), the main synthesizing enzyme of 2-AG, resulted in a laminar pattern corresponding to the termination zones of glutamatergic pathways. The highest density of DGL-α-immunostaining was observed in strata radiatum and oriens of the cornu ammonis and in the inner third of stratum moleculare of the dentate gyrus. At higher magnification, DGL-α-immunopositive puncta were distributed throughout the neuropil outlining the immunonegative main dendrites of pyramidal and granule cells. Electron microscopic analysis revealed that this pattern was due to the accumulation of DGL-α in dendritic spine heads. Similar DGL-α-immunostaining pattern was also found in hippocampi of wild-type, but not of DGL-α knockout mice. Using two independent antibodies developed against monoacylglycerol lipase (MGL), the predominant enzyme inactivating 2-AG, immunostaining also revealed a laminar and punctate staining pattern. However, as observed previously in rodent hippocampus, MGL was enriched in axon terminals instead of postsynaptic structures at the ultrastructural level. Taken together, these findings demonstrate the post- and presynaptic segregation of primary enzymes responsible for synthesis and elimination of 2-AG, respectively, in the human hippocampus. Thus, molecular architecture of the endocannabinoid signaling machinery supports retrograde regulation of synaptic activity, and its similar blueprint in rodents and humans further indicates that 2-AG's physiological role as a negative feed-back signal is an evolutionarily conserved feature of excitatory synapses.
Collapse
Affiliation(s)
- A Ludányi
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, H-1083, Szigony utca 43, Hungary
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Xu JY, Chen R, Zhang J, Chen C. Endocannabinoids differentially modulate synaptic plasticity in rat hippocampal CA1 pyramidal neurons. PLoS One 2010; 5:e10306. [PMID: 20421986 PMCID: PMC2858667 DOI: 10.1371/journal.pone.0010306] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 04/01/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Hippocampal CA1 pyramidal neurons receive two excitatory glutamatergic synaptic inputs: their most distal dendritic regions in the stratum lacunosum-moleculare (SLM) are innervated by the perforant path (PP), originating from layer III of the entorhinal cortex, while their more proximal regions of the apical dendrites in the stratum radiatum (SR) are innervated by the Schaffer-collaterals (SC), originating from hippocampal CA3 neurons. Endocannabinoids (eCBs) are naturally occurring mediators capable of modulating both GABAergic and glutamatergic synaptic transmission and plasticity via the CB1 receptor. Previous work on eCB modulation of excitatory synapses in the CA1 region largely focuses on the SC pathway. However, little information is available on whether and how eCBs modulate glutamatergic synaptic transmission and plasticity at PP synapses. METHODOLOGY/PRINCIPAL FINDINGS By employing somatic and dendritic patch-clamp recordings, Ca(2+) uncaging, and immunostaining, we demonstrate that there are significant differences in low-frequency stimulation (LFS)- or DHPG-, an agonist of group I metabotropic glutamate receptors (mGluRs), induced long-term depression (LTD) of excitatory synaptic transmission between SC and PP synapses in the same pyramidal neurons. These differences are eliminated by pharmacological inhibition with selective CB1 receptor antagonists or genetic deletion of the CB1 receptor, indicating that these differences likely result from differential modulation via a CB1 receptor-dependent mechanism. We also revealed that depolarization-induced suppression of excitation (DSE), a form of short-term synaptic plasticity, and photolysis of caged Ca(2+)-induced suppression of Excitatory postsynaptic currents (EPSCs) were less at the PP than that at the SC. In addition, application of WIN55212 (WIN) induced a more pronounced inhibition of EPSCs at the SC when compared to that at the PP. CONCLUSIONS/SIGNIFICANCE Our results suggest that CB1 dependent LTD and DSE are differentially expressed at the PP versus SC synapses in the same neurons, which may have an impact on synaptic scaling, integration and plasticity of hippocampal CA1 pyramidal neurons.
Collapse
Affiliation(s)
- Jian-Yi Xu
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Rongqing Chen
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Jian Zhang
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Chu Chen
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| |
Collapse
|
37
|
Self-modulation of neocortical pyramidal neurons by endocannabinoids. Nat Neurosci 2009; 12:1488-90. [PMID: 19915567 DOI: 10.1038/nn.2430] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 09/25/2009] [Indexed: 12/11/2022]
Abstract
Control of pyramidal neuron excitability is vital for the functioning of the neocortex. Somatodendritic slow self-inhibition (SSI) allows inhibitory neurons to regulate their own activity, but the existence of similar mechanisms in excitatory cells has not been shown. We found that in rodents endocannabinoids mediated SSI and long-term modulation of inhibitory connections in layer 2/3 pyramidal neurons with a distinct dendritic morphology, suggesting that a glutamatergic network in cortical circuits is self-regulated.
Collapse
|
38
|
Straiker A, Hu SSJ, Long JZ, Arnold A, Wager-Miller J, Cravatt BF, Mackie K. Monoacylglycerol lipase limits the duration of endocannabinoid-mediated depolarization-induced suppression of excitation in autaptic hippocampal neurons. Mol Pharmacol 2009; 76:1220-7. [PMID: 19767452 DOI: 10.1124/mol.109.059030] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Depolarization-induced suppression of excitation (DSE) is a major form of cannabinoid-mediated short-term retrograde neuronal plasticity and is found in numerous brain regions. Autaptically cultured murine hippocampal neurons are an architecturally simple model for the study of cannabinoid signaling, including DSE. The transient nature of DSE--tens of seconds--is probably determined by the regulated hydrolysis of the endocannabinoid 2-arachidonoyl glycerol (2-AG). No less than five candidate enzymes have been considered to serve this role: fatty acid amide hydrolase (FAAH), cyclooxygenase-2 (COX-2), monoacylglycerol lipase (MGL), and alpha/beta-hydrolase domain (ABHD) 6 and 12. We previously found that FAAH and COX-2 do not have a role in determining the duration of autaptic DSE. In the current study, we found that two structurally distinct inhibitors of MGL [N-arachidonoyl maleimide and 4-nitrophenyl 4-(dibenzo[d][1,3]dioxol-5-yl(hydroxy)methyl)piperidine-1-carboxylate (JZL184)] prolong DSE in autaptic hippocampal neurons, whereas inhibition of ABHD6 by N-methyl-N-[[3-(4-pyridinyl)phenyl]methyl]-4'-(aminocarbonyl)[1,1'-biphenyl]-4-yl ester, carbamic acid (WWL70) had no effect. In addition, we developed antibodies against MGL and ABHD6 and determined their expression in autaptic cultures. MGL is chiefly expressed at presynaptic terminals, optimally positioned to break down 2-AG that has engaged presynaptic CB(1) receptors. ABHD6 is expressed in two distinct locations on autaptic islands, including a prominent localization in some dendrites. In summary, we provide strong pharmacological and anatomical evidence that MGL regulates DSE in autaptic hippocampal neurons and, taken together with other studies, emphasizes that endocannabinoid signaling is terminated in temporally diverse ways.
Collapse
Affiliation(s)
- Alex Straiker
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, IN 47405, USA.
| | | | | | | | | | | | | |
Collapse
|