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Augustin SM, Gracias AL, Luo G, Anumola RC, Lovinger DM. Striatonigral direct pathway 2-arachidonoylglycerol contributes to ethanol effects on synaptic transmission and behavior. Neuropsychopharmacology 2023; 48:1941-1951. [PMID: 37528221 PMCID: PMC10584873 DOI: 10.1038/s41386-023-01671-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 07/12/2023] [Indexed: 08/03/2023]
Abstract
Endocannabinoids (eCB) and cannabinoid receptor 1 (CB1) play important roles in mediating short- and long-term synaptic plasticity in many brain regions involved in learning and memory, as well as the reinforcing effects of misused substances. Ethanol-induced plasticity and neuroadaptations predominantly occur in striatal direct pathway projecting medium spiny neurons (dMSNs). It is hypothesized that alterations in eCB neuromodulation may be involved. Recent work has implicated a role of eCB 2-arachidonoylglycerol (2-AG) in the rewarding effects of ethanol. However, there is insufficient research to answer which cellular subtype is responsible for mediating the 2-AG eCB signal that might be involved in the rewarding properties of ethanol and the mechanisms by which that occurs. To examine the role of dMSN mediated 2-AG signaling in ethanol related synaptic transmission and behaviors, we used conditional knockout mice in which the 2-AG-synthesizing enzyme diacylglycerol lipase α (DGLα) was deleted in dMSNs, DGLαD1-Cre+. Using acute brain slice photometry and a genetically encoded fluorescent eCB sensor, GRABeCB2.0, to assess real-time eCB mediated activity of sensorimotor inputs from primary motor cortices (M1/M2) to the dorsolateral striatum, we showed that DGLαD1-Cre+ mice had blunted evoked eCB-mediated presynaptic eCB signaling compared to littermate controls. Furthermore, ethanol induced eCB inhibition was significantly reduced in DGLαD1-Cre+ deficient mice. Additionally, there was a reduction in the duration of loss of righting reflex (LORR) to a high dose of ethanol in the DGLαD1-Cre+ mice compared to controls. These mice also showed a male-specific decrease in ethanol preference accompanied by an increase in ethanol-induced water consumption in a voluntary drinking paradigm. There were no significant differences observed in sucrose and quinine consumption between the genotypes. These findings reveal a novel role for dMSN mediated 2-AG signaling in modulating ethanol effects on presynaptic function and behavior.
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Affiliation(s)
- Shana M Augustin
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892, USA.
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
| | - Alexa L Gracias
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Guoxiang Luo
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Rishitha C Anumola
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892, USA
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892, USA
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Bourdy R, Befort K. The Role of the Endocannabinoid System in Binge Eating Disorder. Int J Mol Sci 2023; 24:ijms24119574. [PMID: 37298525 DOI: 10.3390/ijms24119574] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
Eating disorders are multifactorial disorders that involve maladaptive feeding behaviors. Binge eating disorder (BED), the most prevalent of these in both men and women, is characterized by recurrent episodes of eating large amounts of food in a short period of time, with a subjective loss of control over eating behavior. BED modulates the brain reward circuit in humans and animal models, which involves the dynamic regulation of the dopamine circuitry. The endocannabinoid system plays a major role in the regulation of food intake, both centrally and in the periphery. Pharmacological approaches together with research using genetically modified animals have strongly highlighted a predominant role of the endocannabinoid system in feeding behaviors, with the specific modulation of addictive-like eating behaviors. The purpose of the present review is to summarize our current knowledge on the neurobiology of BED in humans and animal models and to highlight the specific role of the endocannabinoid system in the development and maintenance of BED. A proposed model for a better understanding of the underlying mechanisms involving the endocannabinoid system is discussed. Future research will be necessary to develop more specific treatment strategies to reduce BED symptoms.
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Affiliation(s)
- Romain Bourdy
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), Université de Strasbourg, UMR7364, CNRS, 12 Rue Goethe, 67000 Strasbourg, France
| | - Katia Befort
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), Université de Strasbourg, UMR7364, CNRS, 12 Rue Goethe, 67000 Strasbourg, France
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Soundararajan S, Kazmi N, Brooks AT, Krumlauf M, Schwandt ML, George DT, Hodgkinson CA, Wallen GR, Ramchandani VA. FAAH and CNR1 Polymorphisms in the Endocannabinoid System and Alcohol-Related Sleep Quality. Front Psychiatry 2021; 12:712178. [PMID: 34566715 PMCID: PMC8458733 DOI: 10.3389/fpsyt.2021.712178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/09/2021] [Indexed: 12/02/2022] Open
Abstract
Sleep disturbances are common among individuals with alcohol use disorder (AUD) and may not resolve completely with short-term abstinence from alcohol, potentially contributing to relapse to drinking. The endocannabinoid system (ECS) is associated with both sleep and alcohol consumption, and genetic variation in the ECS may underlie sleep-related phenotypes among individuals with AUD. In this study, we explored the influence of genetic variants in the ECS (Cannabinoid receptor 1/CNR1: rs806368, rs1049353, rs6454674, rs2180619, and Fatty Acid Amide Hydrolase/FAAH rs324420) on sleep quality in individuals with AUD (N = 497) and controls without AUD (N = 389). We assessed subjective sleep quality (from the Pittsburgh Sleep Quality Index/PSQI) for both groups at baseline and objective sleep efficiency and duration (using actigraphy) in a subset of individuals with AUD at baseline and after 4 weeks of inpatient treatment. We observed a dose-dependent relationship between alcohol consumption and sleep quality in both AUD and control groups. Sleep disturbance, a subscale measure in PSQI, differed significantly among CNR1 rs6454674 genotypes in both AUD (p = 0.015) and controls (p = 0.016). Only among controls, neuroticism personality scores mediated the relationship between genotype and sleep disturbance. Objective sleep measures (sleep efficiency, wake bouts and wake after sleep onset), differed significantly by CNR1 rs806368 genotype, both at baseline (p = 0.023, 0.029, 0.015, respectively) and at follow-up (p = 0.004, p = 0.006, p = 0.007, respectively), and by FAAH genotype for actigraphy recorded sleep duration at follow-up (p = 0.018). These relationships suggest a significant role of the ECS in alcohol-related sleep phenotypes.
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Affiliation(s)
- Soundarya Soundararajan
- Human Psychopharmacology Laboratory, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
| | - Narjis Kazmi
- National Institutes of Health Clinical Center, Bethesda, MD, United States
| | - Alyssa T Brooks
- National Institutes of Health Clinical Center, Bethesda, MD, United States
| | - Michael Krumlauf
- National Institutes of Health Clinical Center, Bethesda, MD, United States
| | - Melanie L Schwandt
- Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
| | - David T George
- Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
| | - Colin A Hodgkinson
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
| | - Gwenyth R Wallen
- National Institutes of Health Clinical Center, Bethesda, MD, United States
| | - Vijay A Ramchandani
- Human Psychopharmacology Laboratory, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
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Schuele LL, Glasmacher S, Gertsch J, Roggan MD, Transfeld JL, Bindila L, Lutz B, Kolbe CC, Bilkei-Gorzo A, Zimmer A, Leidmaa E. Diacylglycerol lipase alpha in astrocytes is involved in maternal care and affective behaviors. Glia 2020; 69:377-391. [PMID: 32876968 DOI: 10.1002/glia.23903] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 01/05/2023]
Abstract
Genetic deletion of cannabinoid CB1 receptors or diacylglycerol lipase alpha (DAGLa), the main enzyme involved in the synthesis of the endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG), produced profound phenotypes in animal models of depression-related behaviors. Furthermore, clinical studies have shown that antagonists of CB1 can increase the incidence and severity of major depressive episodes. However, the underlying pathomechanisms are largely unknown. In this study, we have focused on the possible involvement of astrocytes. Using the highly sensitive RNAscope technology, we show for the first time that a subpopulation of astrocytes in the adult mouse brain expresses Dagla, albeit at low levels. Targeted lipidomics revealed that astrocytic DAGLa only accounts for a minor percentage of the steady-state brain 2-AG levels and other arachidonic acid derived lipids like prostaglandins. Nevertheless, the deletion of Dagla in adult mouse astrocytes had profound behavioral consequences with significantly increased depressive-like behavioral responses and striking effects on maternal behavior, corresponding with increased levels of serum progesterone and estradiol. Our findings therefore indicate that lipids from the DAGLa metabolic axis in astrocytes play a key regulatory role in affective behaviors.
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Affiliation(s)
- Lena-Louise Schuele
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Sandra Glasmacher
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Jürg Gertsch
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Marie Denise Roggan
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Janis-Lisa Transfeld
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Laura Bindila
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | | | - Andras Bilkei-Gorzo
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Este Leidmaa
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
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Hauser SR, Katner SN, Waeiss RA, Truitt WA, Bell RL, McBride WJ, Rodd ZA. Selective breeding for high alcohol preference is associated with increased sensitivity to cannabinoid reward within the nucleus accumbens shell. Pharmacol Biochem Behav 2020; 197:173002. [PMID: 32710885 DOI: 10.1016/j.pbb.2020.173002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 11/30/2022]
Abstract
RATIONALE The rate of cannabinoid intake by those with alcohol use disorder (AUD) exceeds that of the general public. The high prevalence of co-abuse of alcohol and cannabis has been postulated to be predicated upon both a common predisposing genetic factor and the interaction of the drugs within the organism. The current experiments examined the effects of cannabinoids in an animal model of AUD. OBJECTIVES The present study assessed the reinforcing properties of a cannabinoid receptor 1 (CB1) agonist self-administered directly into the nucleus accumbens shell (AcbSh) in female Wistar and alcohol-preferring (P) rats. METHODS Following guide cannulae surgery aimed at AcbSh, subjects were placed in an operant box equipped with an 'active lever' (fixed ratio 1; FR1) that caused the delivery of the infusate and an 'inactive lever' that did not. Subjects were arbitrarily assigned to one of seven groups that self-administered either artificial cerebrospinal fluid (aCSF), or 3.125, 6.25, 12.5, or 25 pmol/100 nl of O-1057, a water-soluble CB1 agonist, dissolved in aCSF. The first four sessions of acquisition are followed by aCSF only infusates in sessions 5 and 6 during extinction, and finally the acquisition dose of infusate during session 7 as reinstatement. RESULTS The CB1 agonist was self-administered directly into the AcbSh. P rats self-administered the CB1 agonist at lower concentrations and at higher rates compared to Wistar rats. CONCLUSIONS Overall, the data indicate selective breeding for high alcohol preference has produced rats divergent in response to cannabinoids within the brain reward pathway. The data support the hypothesis that there can be common genetic factors influencing drug addiction.
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Affiliation(s)
- Sheketha R Hauser
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Simon N Katner
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Robert A Waeiss
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William A Truitt
- Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Richard L Bell
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William J McBride
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Zachary A Rodd
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
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Thoeni S, Loureiro M, O’Connor EC, Lüscher C. Depression of Accumbal to Lateral Hypothalamic Synapses Gates Overeating. Neuron 2020; 107:158-172.e4. [DOI: 10.1016/j.neuron.2020.03.029] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 02/21/2020] [Accepted: 03/25/2020] [Indexed: 02/06/2023]
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Kunos G. Interactions Between Alcohol and the Endocannabinoid System. Alcohol Clin Exp Res 2020; 44:790-805. [PMID: 32056226 DOI: 10.1111/acer.14306] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/05/2020] [Indexed: 12/12/2022]
Abstract
Endocannabinoids are lipid mediators that interact with the same cannabinoid receptors that recognize Δ9 -tetrahydrocannabinol (THC), the psychoactive constituent of marijuana, to induce similar effects in the brain and periphery. Alcohol and THC are both addictive substances whose acute use elicits rewarding effects that can lead to chronic and compulsive use via engaging similar signaling pathways in the brain. In the liver, both alcohol and endocannabinoids activate lipogenic gene expression leading to fatty liver disease. This review focuses on evidence accumulated over the last 2 decades to indicate that both the addictive neural effects of ethanol and its organ toxic effects in the liver and elsewhere are mediated, to a large extent, by endocannabinoids signaling via cannabinoid-1 receptors (CB1 R). The therapeutic potential of CB1 R blockade globally or in peripheral tissues only is also discussed.
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Affiliation(s)
- George Kunos
- From the, Division of Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
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Effect of cannabinoid-serotonin interactions in the regulation of neuropeptide Y1 receptors expression in rats: the role of CB1 and 5-HT2C receptor. ACTA ACUST UNITED AC 2020. [DOI: 10.1007/s00580-019-03081-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
AbstractNeuropeptide Y (NPY) is involved in a diversity of critical functions such as circadian rhythms, energy homeostasis, and appetite regulation in the hypothalamus. It has identified as a crucial participant in adjusting energy intake and energy storage as fat via central neuropeptide Y1 receptor (NPY1R), leading to obesity and metabolic disorders. The present study was expected to investigate the interaction between 2-AG (CB1R agonist), m-CPP (5HT2CR agonist), SB-242084 (5HT2CR antagonist), and SR-141716A (CB1R antagonist) by mediating through the NPY1R for treating or preventing obesity, metabolic disorders, and other abnormalities. The expression level of NPY1R mRNA has studied on the rat brain by real-time quantitative PCR assay. Based on our findings, intracerebroventricular (ICV) injection of combined 2-AG (1 μg) + m-CPP (2.5 μg) has antagonistic interaction in the expression of the NPY1R gene (P < 0.001). Moreover, the ICV co-injection of SB-242084 (3 μg) + SR-141716A (1 μg) has antagonistic interaction in the NPY1R gene expression (P < 0.001). Co-administration of 2-AG (1 μg) + SB-242084 (3 μg) amplified NPY1R gene expression (P < 0.001), while the ICV co-injection of m-CPP (2.5 μg) + SR-141716A (1 μg) decreased NPY1R gene expression in the hypothalamus (P < 0.001). These results revealed the interference in cannabinoid and serotonergic systems via CB1 and 5HT2C receptors in the expression of NPY1R mRNA in the hypothalamic area of rats.
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Neasta J, Darcq E, Jeanblanc J, Carnicella S, Ben Hamida S. GPCR and Alcohol-Related Behaviors in Genetically Modified Mice. Neurotherapeutics 2020; 17:17-42. [PMID: 31919661 PMCID: PMC7007453 DOI: 10.1007/s13311-019-00828-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest class of cell surface signaling receptors and regulate major neurobiological processes. Accordingly, GPCRs represent primary targets for the treatment of brain disorders. Several human genetic polymorphisms affecting GPCRs have been associated to different components of alcohol use disorder (AUD). Moreover, GPCRs have been reported to contribute to several features of alcohol-related behaviors in animal models. Besides traditional pharmacological tools, genetic-based approaches mostly aimed at deleting GPCR genes provided substantial information on how key GPCRs drive alcohol-related behaviors. In this review, we summarize the alcohol phenotypes that ensue from genetic manipulation, in particular gene deletion, of key GPCRs in rodents. We focused on GPCRs that belong to fundamental neuronal systems that have been shown as potential targets for the development of AUD treatment. Data are reviewed with particular emphasis on alcohol reward, seeking, and consumption which are behaviors that capture essential aspects of AUD. Literature survey indicates that in most cases, there is still a gap in defining the intracellular transducers and the functional crosstalk of GPCRs as well as the neuronal populations in which their signaling regulates alcohol actions. Further, the implication of only a few orphan GPCRs has been so far investigated in animal models. Combining advanced pharmacological technologies with more specific genetically modified animals and behavioral preclinical models is likely necessary to deepen our understanding in how GPCR signaling contributes to AUD and for drug discovery.
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Affiliation(s)
- Jérémie Neasta
- Laboratoire de Pharmacologie, Faculté de Pharmacie, University of Montpellier, 34093, Montpellier, France
| | - Emmanuel Darcq
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montreal, Quebec, H4H 1R3, Canada
| | - Jérôme Jeanblanc
- Research Group on Alcohol and Pharmacodependences-INSERM U1247, University of Picardie Jules Verne, 80025, Amiens, France
| | - Sebastien Carnicella
- INSERM U1216, Grenoble Institut des Neurosciences (GIN), University of Grenoble Alpes, 38000, Grenoble, France
| | - Sami Ben Hamida
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montreal, Quebec, H4H 1R3, Canada.
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Ogden SB, Malamas MS, Makriyannis A, Eckel LA. The novel cannabinoid CB 1 receptor agonist AM11101 increases food intake in female rats. Br J Pharmacol 2019; 176:3972-3982. [PMID: 31328790 DOI: 10.1111/bph.14797] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 06/02/2019] [Accepted: 07/08/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE Δ9 -tetrahydrocannabinol (THC) acts via cannabinoid CB1 receptors to increase feeding. Here, we assessed the orexigenic effect of AM11101, a novel CB1 receptor agonist designed to have a more favourable pharmacodynamic profile than THC. EXPERIMENTAL APPROACH The acute, orexigenic effects of AM11101 and THC were compared in female rats. Food intake and meal patterns were also examined following once daily treatment with AM11101 and THC for 7 days. KEY RESULTS AM11101 (0.01-0.1 mg·kg-1 ) increased food intake during the first hour following both acute and chronic treatments in pre-fed and freely feeding animals. This orexigenic effect persisted for up to 4 hr, with no compensatory decrease in feeding during the subsequent 4-22 hr. THC (1 mg·kg-1 ) increased 1-hr food intake in pre-fed animals, but was less reliable than AM11101 in increasing 1-hr food intake in freely feeding animals following both acute and chronic administration. The orexigenic effect of both compounds was due to an increase in meal size, not meal number. CONCLUSIONS AND IMPLICATIONS Our study provides the first demonstration that AM11101 increases short-term food intake via a selective increase in meal size. AM11101 promotes a more reliable orexigenic effect than THC in freely feeding animals, with no subsequent compensatory decrease in feeding. AM11101 may offer a greater efficacy than THC and its congeners in stimulating food intake in underweight clinical populations.
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Affiliation(s)
- Sean B Ogden
- Program in Neuroscience, Department of Psychology, Florida State University, Tallahassee, Florida
| | - Michael S Malamas
- Center for Drug Discovery, Departments of Chemistry, Chemical Biology, and Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts
| | - Alexandros Makriyannis
- Center for Drug Discovery, Departments of Chemistry, Chemical Biology, and Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts
| | - Lisa A Eckel
- Program in Neuroscience, Department of Psychology, Florida State University, Tallahassee, Florida
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Abstract
Cannabinoid receptors, endocannabinoids and the enzymes responsible for their biosynthesis and degradation constitute the endocannabinoid system. In recent decades, the endocannabinoid system has attracted considerable interest as a potential therapeutic target in numerous pathological conditions. Its involvement in several physiological processes is well known, such as in energy balance, appetite stimulation, blood pressure, pain modulation, embryogenesis, nausea and vomiting control, memory, learning and immune response, among others, as well as in pathological conditions where it exerts a protective role in the development of certain disorders. As a result, it has been reported that changes in endocannabinoid levels may be related to neurological diseases such as Parkinson's disease, Huntington's disease, Alzheimer's disease and multiple sclerosis, as well as anorexia and irritable bowel syndrome. Alterations in the endocannabinoid system have also been associated with cancer, affecting the growth, migration and invasion of some tumours. Cannabinoids have been tested in several cancer types, including brain, breast and prostate cancers. Cannabinoids have shown promise as analgesics for the treatment of both inflammatory and neuropathic pain. There is also evidence for a role of the endocannabinoid system in the control of emotional states, and cannabinoids could prove useful in decreasing and palliating post-traumatic stress disorder symptoms and anxiolytic disorders. The role of the endocannabinoid system in addictions has also been examined, and cannabinoids have been postulated as alternative and co-adjuvant treatments in some abuse syndromes, mainly in ethanol and opioid abuses. The expression of the endocannabinoid system in the eye suggests that it could be a potential therapeutic target for eye diseases. Considering the importance of the endocannabinoid system and the therapeutic potential of cannabinoids in this vast number of medical conditions, several clinical studies with cannabinoid-based medications are ongoing. In addition, some cannabinoid-based medications have already been approved in various countries, including nabilone and dronabinol capsules for the treatment of nausea and vomiting associated with chemotherapy, dronabinol capsules for anorexia, an oral solution of dronabinol for both vomiting associated with chemotherapy and anorexia, a Δ9-tetrahydrocannabinol/cannabidiol oromucosal spray for pain related to cancer and for spasticity and pain associated with multiple sclerosis, and an oral solution of cannabidiol for Dravet and Lennox-Gastaut syndromes. Here, we review the available efficacy, safety and tolerability data for cannabinoids in a range of medical conditions.
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Affiliation(s)
- Ana Isabel Fraguas-Sánchez
- Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Plaza Ramón y Cajal s/n, 28040 , Madrid, Spain
| | - Ana Isabel Torres-Suárez
- Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Plaza Ramón y Cajal s/n, 28040 , Madrid, Spain. .,Institute of Industrial Pharmacy, Complutense University of Madrid, 28040 , Madrid, Spain.
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Fatty acid-binding proteins 5 and 7 gene deletion increases sucrose consumption and diminishes forced swim immobility time. Behav Pharmacol 2018; 29:503-508. [PMID: 29570114 DOI: 10.1097/fbp.0000000000000402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Inhibition and genetic deletion of fatty acid-binding proteins (FABPs) 5 and 7 have been shown to increase the levels of the endocannabinoid anandamide as well as the related N-acylethanolamine's palmitoylethanolamide and oleoylethanolamide. This study examined the role of these FABPs on forced-swim (FS) behavior and on sucrose consumption in two experiments: (experiment 1) using wild-type (WT) mice treated with the FABP inhibitor SBFI26 or vehicle and (experiment 2) using WT and FABP5/7 deficient mice. Results from experiment 1 showed that acute treatment with SBFI26 did not have any effect on sucrose intake or FS behavior in mice. In experiment 2, male and female FABP5/7 deficient mice showed significant increases in sucrose consumption (25 and 21%, respectively) compared with their WT counterparts. In addition, immobility time during the FS was decreased by 27% in both male and female FABP5/7 knockout mice compared with their WT counterparts. The fact that such differences were seen between the acute pharmacological approach and the genetic approach (gene deletion) of FABP needs to be further investigated. The function of FABPs and their specific effects on endocannabinoid anandamide, oleoylethanolamide, and palmitoylethanolamide may play an important role in the development of reward and mood behaviors and could provide opportunities for potential therapeutic targets.
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Chronic stress leads to epigenetic dysregulation in the neuropeptide-Y and cannabinoid CB1 receptor genes in the mouse cingulate cortex. Neuropharmacology 2017; 113:301-313. [DOI: 10.1016/j.neuropharm.2016.10.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 10/06/2016] [Accepted: 10/08/2016] [Indexed: 12/16/2022]
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14
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Abburi C, Wolfman SL, Metz RAE, Kamber R, McGehee DS, McDaid J. Tolerance to Ethanol or Nicotine Results in Increased Ethanol Self-Administration and Long-Term Depression in the Dorsolateral Striatum. eNeuro 2016; 3:ENEURO.0112-15.2016. [PMID: 27517088 PMCID: PMC4972936 DOI: 10.1523/eneuro.0112-15.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 06/22/2016] [Accepted: 07/13/2016] [Indexed: 01/27/2023] Open
Abstract
Ethanol (EtOH) and nicotine are the most widely coabused drugs. Tolerance to EtOH intoxication, including motor impairment, results in greater EtOH consumption and may result in a greater likelihood of addiction. Previous studies suggest that cross-tolerance between EtOH and nicotine may contribute to the abuse potential of these drugs. Here we demonstrate that repeated intermittent administration of either EtOH or nicotine in adult male Sprague Dawley rats results in tolerance to EtOH-induced motor impairment and increased EtOH self-administration. These findings suggest that nicotine and EtOH cross-tolerance results in decreased aversive and enhanced rewarding effects of EtOH. Endocannabinoid signaling in the dorsolateral striatum (DLS) has been implicated in both EtOH tolerance and reward, so we investigated whether nicotine or EtOH pretreatment might modulate endocannabinoid signaling in this region. Using similar EtOH and nicotine pretreatment methods resulted in increased paired-pulse ratios of evoked EPSCs in enkephalin-positive medium spiny neurons in DLS slices. Thus, EtOH and nicotine pretreatment may modulate glutamatergic synapses in the DLS presynaptically. Bath application of the CB1 receptor agonist Win 55,2-212 increased the paired-pulse ratio of evoked EPSCs in control slices, while Win 55,2-212 had no effect on paired-pulse ratio in slices from either EtOH- or nicotine-pretreated rats. Consistent with these effects, nicotine pretreatment occluded LTD induction by high-frequency stimulation of the corticostriatal inputs to the dorsolateral striatum. These results suggest that nicotine and EtOH pretreatment modulates striatal synapses to induce tolerance to the motor-impairing effects of EtOH, which may contribute to nicotine and EtOH coabuse.
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Affiliation(s)
- Chandrika Abburi
- Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois 60637
| | - Shannon L. Wolfman
- Committee on Neurobiology, University of Chicago, Chicago, Illinois 60637
| | - Ryan A. E. Metz
- Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois 60637
| | - Rinya Kamber
- Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois 60637
| | - Daniel S. McGehee
- Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois 60637
- Committee on Neurobiology, University of Chicago, Chicago, Illinois 60637
| | - John McDaid
- Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois 60637
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15
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Edwards A, Abizaid A. Driving the need to feed: Insight into the collaborative interaction between ghrelin and endocannabinoid systems in modulating brain reward systems. Neurosci Biobehav Rev 2016; 66:33-53. [PMID: 27136126 DOI: 10.1016/j.neubiorev.2016.03.032] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 03/08/2016] [Accepted: 03/31/2016] [Indexed: 01/29/2023]
Abstract
Independent stimulation of either the ghrelin or endocannabinoid system promotes food intake and increases adiposity. Given the similar distribution of their receptors in feeding associated brain regions and organs involved in metabolism, it is not surprising that evidence of their interaction and its importance in modulating energy balance has emerged. This review documents the relationship between ghrelin and endocannabinoid systems within the periphery and hypothalamus (HYP) before presenting evidence suggesting that these two systems likewise work collaboratively within the ventral tegmental area (VTA) to modulate non-homeostatic feeding. Mechanisms, consistent with current evidence and local infrastructure within the VTA, will be proposed.
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Affiliation(s)
- Alexander Edwards
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
| | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
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16
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Wang S, Sun H, Liu S, Wang T, Guan J, Jia J. Role of hypothalamic cannabinoid receptors in post-stroke depression in rats. Brain Res Bull 2016; 121:91-7. [DOI: 10.1016/j.brainresbull.2016.01.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 01/02/2016] [Accepted: 01/11/2016] [Indexed: 11/27/2022]
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17
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Henderson-Redmond AN, Guindon J, Morgan DJ. Roles for the endocannabinoid system in ethanol-motivated behavior. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:330-9. [PMID: 26123153 PMCID: PMC4679600 DOI: 10.1016/j.pnpbp.2015.06.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 06/15/2015] [Accepted: 06/22/2015] [Indexed: 12/19/2022]
Abstract
Alcohol use disorder represents a significant human health problem that leads to substantial loss of human life and financial cost to society. Currently available treatment options do not adequately address this human health problem, and thus, additional therapies are desperately needed. The endocannabinoid system has been shown, using animal models, to modulate ethanol-motivated behavior, and it has also been demonstrated that chronic ethanol exposure can have potentially long-lasting effects on the endocannabinoid system. For example, chronic exposure to ethanol, in either cell culture or preclinical rodent models, causes an increase in endocannabinoid levels that results in down-regulation of the cannabinoid receptor 1 (CB1) and uncoupling of this receptor from downstream G protein signaling pathways. Using positron emission tomography (PET), similar down-regulation of CB1 has been noted in multiple regions of the brain in human alcoholic patients. In rodents, treatment with the CB1 inverse agonist SR141716A (Rimonabant), or genetic deletion of CB1 leads to a reduction in voluntary ethanol drinking, ethanol-stimulated dopamine release in the nucleus accumbens, operant self-administration of ethanol, sensitization to the locomotor effects of ethanol, and reinstatement/relapse of ethanol-motivated behavior. Although the clinical utility of Rimonabant or other antagonists/inverse agonists for CB1 is limited due to negative neuropsychiatric side effects, negative allosteric modulators of CB1 and inhibitors of endocannabinoid catabolism represent therapeutic targets worthy of additional examination.
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Affiliation(s)
| | - Josée Guindon
- Department of Pharmacology and Neuroscience, Texas Tech University Health Science Center, Lubbock, TX, 79430
| | - Daniel J Morgan
- Department of Anesthesiology, Penn State University College of Medicine, Hershey, PA 17033, United States; Department of Pharmacology, Penn State University College of Medicine, Hershey, PA 17033, United States.
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18
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Vähätalo LH, Ruohonen ST, Ailanen L, Savontaus E. Neuropeptide Y in noradrenergic neurons induces obesity in transgenic mouse models. Neuropeptides 2016; 55:31-7. [PMID: 26681068 DOI: 10.1016/j.npep.2015.11.088] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/20/2015] [Accepted: 11/22/2015] [Indexed: 11/22/2022]
Abstract
Neuropeptide Y (NPY) in noradrenergic neurons plays an important role in modulating the release and effects of catecholamines in a prolonged stress response. Among other functions, it controls energy metabolism. Transgenic expression of Npy in noradrenergic neurons in mice allowed showing that it is critical for diet- and stress-induced gain in fat mass. When overexpressed, NPY in noradrenergic neurons increases adiposity in gene-dose-dependent fashion, and leads to metabolic disorders such as impaired glucose tolerance. However, the mechanisms of obesity seem to be different in mice heterozygous and homozygous for the Npy transgene. While in heterozygous mice the adipogenic effect of NPY is important, in homozygous mice inhibition of sympathetic tone leading to decreased lipolytic activity and impaired brown fat function, as well as increased endocannabinoid levels contribute to obesity. The mouse model provides novel insight to the mechanisms of human diseases with increased NPY due to chronic stress or gain-of-function gene variants, and a tool for development of novel therapeutics.
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Affiliation(s)
- Laura H Vähätalo
- Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - Suvi T Ruohonen
- Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - Liisa Ailanen
- Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland; Drug Research Doctoral Program, University of Turku, Turku, Finland
| | - Eriika Savontaus
- Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland; Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland.
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19
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Mayfield J, Arends MA, Harris RA, Blednov YA. Genes and Alcohol Consumption: Studies with Mutant Mice. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 126:293-355. [PMID: 27055617 PMCID: PMC5302130 DOI: 10.1016/bs.irn.2016.02.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test.
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Affiliation(s)
- J Mayfield
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, United States
| | - M A Arends
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, United States
| | - R A Harris
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, United States.
| | - Y A Blednov
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, United States
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20
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Cannabinoid Ligands and Alcohol Addiction: A Promising Therapeutic Tool or a Humbug? Neurotox Res 2015; 29:173-96. [PMID: 26353844 PMCID: PMC4701763 DOI: 10.1007/s12640-015-9555-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 08/04/2015] [Accepted: 08/06/2015] [Indexed: 01/08/2023]
Abstract
The vast therapeutic potential of cannabinoids of both synthetic and plant-derived origins currently makes these compounds the focus of a growing interest. Although cannabinoids are still illicit drugs, their possible clinical usefulness, including treatment of acute or neuropathic pain, have been suggested by several studies. In addition, some observations indicate that cannabinoid receptor antagonists may be useful for the treatment of alcohol dependence and addiction, which is a major health concern worldwide. While the synergism between alcohol and cannabinoid agonists (in various forms) creates undesirable side effects when the two are consumed together, the administration of CB1 antagonists leads to a significant reduction in alcohol consumption. Furthermore, cannabinoid antagonists also mitigate alcohol withdrawal symptoms. Herein, we present an overview of studies focusing on the effects of cannabinoid ligands (agonists and antagonists) during acute or chronic consumption of ethanol.
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21
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Veeraraghavan P, Nistri A. Modulatory effects by CB1 receptors on rat spinal locomotor networks after sustained application of agonists or antagonists. Neuroscience 2015; 303:16-33. [DOI: 10.1016/j.neuroscience.2015.06.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/19/2015] [Accepted: 06/19/2015] [Indexed: 10/23/2022]
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22
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Vähätalo LH, Ruohonen ST, Mäkelä S, Ailanen L, Penttinen AM, Stormi T, Kauko T, Piscitelli F, Silvestri C, Savontaus E, Di Marzo V. Role of the endocannabinoid system in obesity induced by neuropeptide Y overexpression in noradrenergic neurons. Nutr Diabetes 2015; 5:e151. [PMID: 25915740 PMCID: PMC4423197 DOI: 10.1038/nutd.2015.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 12/12/2014] [Accepted: 12/23/2014] [Indexed: 01/06/2023] Open
Abstract
Objective: Endocannabinoids and neuropeptide Y (NPY) promote energy storage via central and peripheral mechanisms. In the hypothalamus, the two systems were suggested to interact. To investigate such interplay also in non-hypothalamic tissues, we evaluated endocannabinoid levels in obese OE-NPYDβH mice, which overexpress NPY in the noradrenergic neurons in the sympathetic nervous system and the brain. Methods: The levels of the endocannabinoids anandamide and 2-arachidonoylglycerol (2-AG) were measured in key regulatory tissues, that is, hypothalamus, pancreas, epididymal white adipose tissue (WAT), liver and soleus muscle, over the development of metabolic dysfunctions in OE-NPYDβH mice. The effects of a 5-week treatment with the CB1 receptor inverse agonist AM251 on adiposity and glucose metabolism were studied. Results: 2-AG levels were increased in the hypothalamus and epididymal WAT of pre-obese and obese OE-NPYDβH mice. Anandamide levels in adipose tissue and pancreas were increased at 4 months concomitantly with higher fat mass and impaired glucose tolerance. CB1 receptor blockage reduced body weight gain and glucose intolerance in OE-NPYDβH to the level of vehicle-treated wild-type mice. Conclusions: Altered endocannabinoid tone may underlie some of the metabolic dysfunctions in OE-NPYDβH mice, which can be attenuated with CB1 inverse agonism suggesting interactions between endocannabinoids and NPY also in the periphery. CB1 receptors may offer a target for the pharmacological treatment of the metabolic syndrome with altered NPY levels.
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Affiliation(s)
- L H Vähätalo
- 1] Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland [2] Drug Research Doctoral Program, University of Turku, Turku, Finland
| | - S T Ruohonen
- Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - S Mäkelä
- Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - L Ailanen
- 1] Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland [2] Drug Research Doctoral Program, University of Turku, Turku, Finland
| | - A-M Penttinen
- Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - T Stormi
- Department of Biostatistics, University of Turku, Turku, Finland
| | - T Kauko
- Department of Biostatistics, University of Turku, Turku, Finland
| | - F Piscitelli
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli (NA), Italy
| | - C Silvestri
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli (NA), Italy
| | - E Savontaus
- 1] Department of Pharmacology, Drug Development and Therapeutics and Turku Center for Disease Modeling, University of Turku, Turku, Finland [2] Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland
| | - V Di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli (NA), Italy
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23
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Growth Hormone Secretagogue Receptor Dimers: A New Pharmacological Target. eNeuro 2015; 2:eN-REV-0053-14. [PMID: 26464979 PMCID: PMC4596092 DOI: 10.1523/eneuro.0053-14.2015] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 03/25/2015] [Accepted: 04/07/2015] [Indexed: 01/04/2023] Open
Abstract
The growth hormone secretagogue receptor (GHSR1a), the target of the ghrelin peptide, is widely distributed throughout the brain, and, while studies have often reported very low or absent levels of central ghrelin, it is now known that GHSR1a, even in the absence of a natural ligand, has physiological roles. Not only do these roles originate from the receptor's constitutive activity, but recent data indicate that GHSR1a dimerizes with a wide array of other receptors. These include the dopamine 1 receptor (D1R), the dopamine 2 receptor (D2R), the melanocortin-3 receptor (MC3R), the serotonin 2C receptor (5-HT2C), and possibly the cannabinoid type 1 receptor (CB1). Within these dimers, signaling of the protomers involved are modified through facilitation, inhibition, and even modification of signaling pathways resulting in physiological consequences not seen in the absence of these dimers. While in some cases the ghrelin peptide is not required for these modifications to occur, in others, the presence is necessary for these changes to take effect. These heterodimers demonstrate the broad array of roles and complexity of the ghrelin system. By better understanding how these dimers work, it is hoped that improved treatments for a variety of disorders, including Parkinson's disease, schizophrenia, addiction, obesity, diabetes, and more, can be devised. In this review, we examine the current state of knowledge surrounding GHSR heterodimers, and how we can apply this knowledge to various pharmacological treatments.
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24
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Ortega-Álvaro A, Ternianov A, Aracil-Fernández A, Navarrete F, García-Gutiérrez MS, Manzanares J. Role of cannabinoid CB2 receptor in the reinforcing actions of ethanol. Addict Biol 2015; 20:43-55. [PMID: 23855434 DOI: 10.1111/adb.12076] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This study examines the role of the cannabinoid CB2 receptor (CB2 r) on the vulnerability to ethanol consumption. The time-related and dose-response effects of ethanol on rectal temperature, handling-induced convulsions (HIC) and blood ethanol concentrations were evaluated in CB2 KO and wild-type (WT) mice. The reinforcing properties of ethanol were evaluated in conditioned place preference (CPP), preference and voluntary ethanol consumption and oral ethanol self-administration. Water-maintained behavior schedule was performed to evaluate the degree of motivation induced by a natural stimulus. Preference for non-alcohol tastants assay was performed to evaluate the differences in taste sensitivity. Tyrosine hydroxylase (TH) and μ-opioid receptor gene expressions were also measured in the ventral tegmental area and nucleus accumbens (NAcc), respectively. CB2 KO mice presented increased HIC score, ethanol-CPP, voluntary ethanol consumption and preference, acquisition of ethanol self-administration, and increased motivation to drink ethanol compared with WT mice. No differences were found between genotypes in the water-maintained behavior schedule or preference for non-alcohol tastants. Naïve CB2 KO mice presented increased μ-opioid receptor gene expression in NAcc. Acute ethanol administration (1-2 g/kg) increased TH and μ-opioid receptor gene expressions in CB2 KO mice, whereas the lower dose of ethanol decreased TH gene expression in WT mice. These results suggest that deletion of the CB2 r gene increased preference for and vulnerability to ethanol consumption, at least in part, by increased ethanol-induced sensitivity of the TH and μ-opioid receptor gene expressions in mesolimbic neurons. Future studies will determine the role of CB2 r as a target for the treatment of problems related with alcohol consumption.
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Affiliation(s)
- Antonio Ortega-Álvaro
- Unidad de Neuropsicofarmacología Traslacional; Complejo Hospitalario Universitario de Albacete; Albacete Spain
| | - Alexander Ternianov
- Unidad de Neuropsicofarmacología Traslacional; Complejo Hospitalario Universitario de Albacete; Albacete Spain
| | - Auxiliadora Aracil-Fernández
- Instituto de Neurociencias; Universidad Miguel Hernández-CSIC; San Juan de Alicante Alicante Spain
- Red Temática de Investigación Cooperativa en Salud (RETICS-Trastornos Adictivos); Instituto de Salud Carlos III, MICINN and FEDER; Madrid Spain
| | - Francisco Navarrete
- Instituto de Neurociencias; Universidad Miguel Hernández-CSIC; San Juan de Alicante Alicante Spain
- Red Temática de Investigación Cooperativa en Salud (RETICS-Trastornos Adictivos); Instituto de Salud Carlos III, MICINN and FEDER; Madrid Spain
| | - Maria Salud García-Gutiérrez
- Instituto de Neurociencias; Universidad Miguel Hernández-CSIC; San Juan de Alicante Alicante Spain
- Red Temática de Investigación Cooperativa en Salud (RETICS-Trastornos Adictivos); Instituto de Salud Carlos III, MICINN and FEDER; Madrid Spain
| | - Jorge Manzanares
- Instituto de Neurociencias; Universidad Miguel Hernández-CSIC; San Juan de Alicante Alicante Spain
- Red Temática de Investigación Cooperativa en Salud (RETICS-Trastornos Adictivos); Instituto de Salud Carlos III, MICINN and FEDER; Madrid Spain
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25
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Abstract
The physiological and pathophysiological functions of the endocannabinoid system have been studied extensively using transgenic and targeted knockout mouse models. The first gene deletions of the cannabinoid CB(1) receptor were described in the late 1990s, soon followed by CB(2) and FAAH mutations in early 2000. These mouse models helped to elucidate the fundamental role of endocannabinoids as retrograde transmitters in the CNS and in the discovery of many unexpected endocannabinoid functions, for example, in the skin, bone and liver. We now have knockout mouse models for almost every receptor and enzyme of the endocannabinoid system. Conditional mutant mice were mostly developed for the CB(1) receptor, which is widely expressed on many different neurons, astrocytes and microglia, as well as on many cells outside the CNS. These mouse strains include "floxed" CB(1) alleles and mice with a conditional re-expression of CB(1). The availability of these mice made it possible to decipher the function of CB(1) in specific neuronal circuits and cell populations or to discriminate between central and peripheral effects. Many of the genetic mouse models were also used in combination with viral expression systems. The purpose of this review is to provide a comprehensive overview of the existing genetic models and to summarize some of the most important discoveries that were made with these animals.
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MESH Headings
- Amidohydrolases/genetics
- Amidohydrolases/metabolism
- Animals
- Endocannabinoids/genetics
- Endocannabinoids/metabolism
- Gene Deletion
- Gene Expression Regulation
- Genotype
- Humans
- Hydrolysis
- Mice, Knockout
- Mice, Mutant Strains
- Monoacylglycerol Lipases/genetics
- Monoacylglycerol Lipases/metabolism
- Mutation
- Phenotype
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Signal Transduction/genetics
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Affiliation(s)
- Andreas Zimmer
- Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany.
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26
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Friemel CM, Zimmer A, Schneider M. The CB1 receptor as an important mediator of hedonic reward processing. Neuropsychopharmacology 2014; 39:2387-96. [PMID: 24718372 PMCID: PMC4138748 DOI: 10.1038/npp.2014.86] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 04/04/2014] [Accepted: 04/06/2014] [Indexed: 11/09/2022]
Abstract
The endocannabinoid (ECB) system has emerged recently as a key mediator for reward processing. It is well known that cannabinoids affect appetitive learning processes and can induce reinforcing and rewarding effects. However, the involvement of the ECB system in hedonic aspects of reward-related behavior is not completely understood. With the present study, we investigated the modulatory role of the ECB system on hedonic perception, measured by the pleasure attenuated startle (PAS) paradigm for a palatable food reward. Here, a conditioned odor is thought to induce a pleasant affective state that attenuates an aversive reflex-the acoustic startle response. Modulatory effects of the CB1 receptor antagonist/inverse agonist SR1411716 and the cannabinoid agonist WIN 55 212-2 on PAS were examined in rats. PAS was also measured in CB1 receptor knockout (KO) and wild-type (WT) mice. Pharmacological inhibition as well as the absence of CB1 receptors was found to reduce PAS, whereas WIN 55 212-2 administration increased PAS. Finally, presentation of a conditioned reward cue was found to induce striatal FosB/ΔFosB expression in WT mice, but not in KO mice, indicating a reduced stimulation of reward-related brain regions in conditioned KO mice by odor presentation. We here show that in addition to our previous studies in rats, PAS may also serve as a valuable and suitable measure to assess hedonic processing in mice. Our data further indicate that the ECB system, and in particular CB1 receptor signaling, appears to be highly important for the mediation of hedonic aspects of reward processing.
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Affiliation(s)
- Chris M Friemel
- Reseach Group Developmental Neuropsychopharmacology, Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany
| | - Miriam Schneider
- Reseach Group Developmental Neuropsychopharmacology, Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany,Reseach Group Developmental Neuropsychopharmacology, Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany, Tel: +1 49 621 17036269, Fax: +1 49 621 17036255, E-mail:
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27
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Le Foll B, Pushparaj A, Pryslawsky Y, Forget B, Vemuri K, Makriyannis A, Trigo JM. Translational strategies for therapeutic development in nicotine addiction: rethinking the conventional bench to bedside approach. Prog Neuropsychopharmacol Biol Psychiatry 2014; 52:86-93. [PMID: 24140878 PMCID: PMC4002666 DOI: 10.1016/j.pnpbp.2013.10.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 10/08/2013] [Accepted: 10/09/2013] [Indexed: 12/16/2022]
Abstract
Tobacco produces an impressive burden of disease resulting in premature death in half of users. Despite effective smoking cessation medications (nicotine replacement therapies, bupropion and varenicline), there is a very high rate of relapse following quit attempts. The use of efficient strategies for the development of novel treatments is a necessity. A 'bench to bedside strategy' was initially used to develop cannabinoid CB1 receptor antagonists for the treatment of nicotine addiction. Unfortunately, after being tested on experimental animals, what seemed to be an interesting approach for the treatment of nicotine addiction resulted in serious unwanted side effects when tested in humans. Current research is focusing again on pre-clinical models in an effort to eliminate unwanted side effects while preserving the initially observed efficacy. A 'bed side to bench strategy' was used to study the role of the insula (part of the frontal cortex) in nicotine addiction. This line of research started based on clinical observations that patients suffering stroke-induced lesions to the insula showed a greater likelihood to report immediate smoking cessation without craving or relapse. Subsequently, animal models of addiction are used to explore the role of insula in addiction. Due to the inherent limitations existing in clinical versus preclinical studies, the possibility of close interaction between both models seems to be critical for the successful development of novel therapeutic strategies for nicotine dependence.
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Affiliation(s)
- Bernard Le Foll
- Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada; Alcohol Research and Treatment Clinic, Addiction Medicine Services, Ambulatory Care and Structured Treatments, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Family and Community Medicine, University of Toronto, Toronto, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada; Department of Psychiatry and Institute of Medical Sciences, University of Toronto, Toronto, Canada.
| | - Abhiram Pushparaj
- Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada
| | - Yaroslaw Pryslawsky
- Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada
| | - Benoit Forget
- Integrative Neurobiology of Cholinergic Systems, Department of Neuroscience, Pasteur Institute, 25 rue du Dr. Roux, Paris 75724, France
| | - Kiran Vemuri
- Center for Drug Discovery, Northeastern University, Boston, MA 02115-5005, United States; Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115-5005, United States; Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115-5005, United States
| | - Alexandros Makriyannis
- Center for Drug Discovery, Northeastern University, Boston, MA 02115-5005, United States; Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115-5005, United States; Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115-5005, United States
| | - Jose M Trigo
- Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada
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Dissociable effects of CB1 receptor blockade on anxiety-like and consummatory behaviors in the novelty-induced hypophagia test in mice. Psychopharmacology (Berl) 2013; 228:401-9. [PMID: 23483200 PMCID: PMC3707973 DOI: 10.1007/s00213-013-3042-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 02/20/2013] [Indexed: 01/02/2023]
Abstract
RATIONALE Central CB1 cannabinoid receptors regulate anxiety-like and appetitive consummatory behaviors. Pharmacological antagonism/inverse-agonism of CB1 receptors increases anxiety and decreases appetitive behaviors; however, neither well-defined dose nor context dependence of these effects has been simultaneously assessed in one behavioral assay. OBJECTIVES We sought to determine the context and dose dependence of the effects of CB1 receptor blockade on anxiety-like and consummatory behaviors in a model that allowed for simultaneous detection of anxiety-like and consummatory-related behaviors. METHODS We determined the effects of the CB1 receptor antagonist/inverse-agonist, rimonabant, in the novelty-induced hypophagia (NIH) assay in juvenile male ICR mice. RESULTS Rimonabant dose-dependently decreased consumption of a palatable reward solution completely independent of contextual novelty. Grooming and scratching behavior was also increased by rimonabant in a context-independent manner. In contrast, rimonabant increased feeding latency, a measure of anxiety-like behaviors, only in a novel, mildly anxiogenic context. The effects of rimonabant were specific since no effects of rimonabant on despair-like behavior were observed in the tail suspension assay. Blockade of CB2 receptors had no effect on novelty-induced increases in feeding latency or palatable food consumption. CONCLUSIONS Our findings indicate that CB1 receptor blockade decreases the hedonic value of palatable food irrespective of environmental novelty, whereas the anxiogenic-like effects are highly context-dependent. Blockade of CB2 receptors does not regulate either anxiety-like or consummatory behaviors in the NIH assay. These findings suggest that rimonabant modulates distinct and dissociable neural processes regulating anxiety and consummatory behavior to sculpt complex and context-dependent behavioral repertories.
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Neumeister A, Normandin MD, Murrough JW, Henry S, Bailey CR, Luckenbaugh DA, Tuit K, Zheng MQ, Galatzer-Levy IR, Sinha R, Carson RE, Potenza MN, Huang Y. Positron emission tomography shows elevated cannabinoid CB1 receptor binding in men with alcohol dependence. Alcohol Clin Exp Res 2012; 36:2104-9. [PMID: 22551199 PMCID: PMC3418442 DOI: 10.1111/j.1530-0277.2012.01815.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 03/05/2012] [Indexed: 01/18/2023]
Abstract
BACKGROUND Several lines of evidence link cannabinoid (CB) type 1 (CB (1) ) receptor-mediated endogenous CB (eCB) signaling to the etiology of alcohol dependence (AD). However, to date, only peripheral measures of eCB function have been collected in living humans with AD and no human in vivo data on the potentially critical role of the brain CB (1) receptor in AD have been published. This is an important gap in the literature, because recent therapeutic developments suggest that these receptors could be targeted for the treatment for AD. METHODS Medication-free participants were scanned during early abstinence 4 weeks after their last drink. Using positron emission tomography (PET) with a high-resolution research tomograph and the CB (1) receptor selective radiotracer [(11) C]OMAR, we determined [(11) C]OMAR volume of distribution ( V (T) ) values, a measure of CB (1) receptor density, in a priori selected brain regions in men with AD (n = 8, age 37.4 ± 7.9 years; 5 smokers) and healthy control (HC) men (n = 8, age 32.5 ± 6.9 years; all nonsmokers). PET images reconstructed using the MOLAR algorithm with hardware motion correction were rigidly aligned to the subject-specific magnetic resonance (MR) image, which in turn was warped to an MR template. Time-activity curves (TACs) were extracted from the dynamic PET data using a priori selected regions of interest delineated in the MR template space. RESULTS In AD relative to HC, [(11) C]OMAR V (T) values were elevated by approximately 20% (p = 0.023) in a circuit, including the amygdala, hippocampus, putamen, insula, anterior and posterior cingulate cortices, and orbitofrontal cortex. Age, body mass index, or smoking status did not influence the outcome. CONCLUSIONS These findings agree with preclinical evidence and provide the first, albeit still preliminary in vivo evidence suggesting a role for brain CB (1) receptors in AD. The current study design does not answer the important question of whether elevated CB (1) receptors are a preexisting vulnerability factor for AD or whether elevations develop as a consequence of AD.
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Affiliation(s)
- Alexander Neumeister
- Molecular Imaging Program, Department of Psychiatry and Radiology, New York University School of Medicine, New York, New York 10016, USA.
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Wiley JL, Marusich JA, Zhang Y, Fulp A, Maitra R, Thomas BF, Mahadevan A. Structural analogs of pyrazole and sulfonamide cannabinoids: effects on acute food intake in mice. Eur J Pharmacol 2012; 695:62-70. [PMID: 22975289 DOI: 10.1016/j.ejphar.2012.08.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 08/24/2012] [Accepted: 08/27/2012] [Indexed: 12/31/2022]
Abstract
Obesity contributes to a multitude of serious health problems. Given the demonstrated role of the endogenous cannabinoid system in appetite regulation, the purpose of the present study was to evaluate structural analogs of two cannabinoids, rimonabant (cannabinoid CB(1) receptor antagonist) and O-2050 (sulfonamide analog of Δ(8)-tetrahydrocannabinol), that showed appetite suppressant effects in previous studies. Structure-activity relationships of these two lead compounds were examined in several assays, including cannabinoid CB(1) and CB(2) receptor binding, food intake, and an in vivo test battery (locomotor activity, antinociception, ring immobility, and body temperature) in mice. Rimonabant and O-2050 reliably decreased feeding in mice; however, their analogs decreased feeding only at higher doses, even though some compounds had quite good cannabinoid CB(1) binding affinity. Results of the in vivo test battery were inconsistent, with some of the compounds producing effects characteristic of cannabinoid agonists while other compounds were inactive or were antagonists against an active dose of Δ(9)-tetrahydrocannabinol. These results demonstrate that reduction of food intake is not a characteristic effect of pyrazole and sulfonamide cannabinoid analogs with favorable cannabinoid CB(1) binding affinity, suggesting that development of these classes of cannabinoids for the treatment of obesity will require evaluation of their effects in a broad spectrum of pharmacological assays.
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Affiliation(s)
- Jenny L Wiley
- Research Triangle Institute, 3040 Cornwallis Drive, Research Triangle Park, NC 27709-2194, U.S.A.
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Endocannabinoid system: A newer molecular target for the treatment of alcohol-related behaviors. World J Pharmacol 2012; 1:44-49. [DOI: 10.5497/wjp.v1.i3.44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The cannabinoid (CB) receptors, endocannabinoids (eCB) and their synthesizing and catabolizing enzymes and the proteins involved in their transport, constitute what is now recognized as the eCB system. The eCBs are a class of lipids that have been identified as retrograde messengers and produce their effects via presynaptic CB receptors. The major function of the eCBs has been suggested to be that of modulating the release of several neurotransmitters implicated in a number of biological functions that include reward and reinforcement. There is now significant evidence to suggest that the eCB system plays an important role in the development of alcohol tolerance, dependence and relapse. Recent studies suggest that the pharmacological manipulation of the eCB system has the potential not only to block the direct reinforcing properties of alcohol but also alleviate behavioral abnormalities associated with relapse. There is also accumulating evidence that points to the possible utility of the eCB system targeted drugs in the treatment of alcoholism-related behavioral disorders. The agents that block CB1 receptor function or inhibit the synthesis of eCBs are attractive candidate drugs that need to be explored. Further understanding of the role of the eCB system in molecular mechanism/s that underlies alcoholism-related behaviors should lead to a better treatment of this devastating disorder.
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Vickers SP, Jackson HC, Cheetham SC. The utility of animal models to evaluate novel anti-obesity agents. Br J Pharmacol 2012; 164:1248-62. [PMID: 21265828 DOI: 10.1111/j.1476-5381.2011.01245.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The global incidence of obesity continues to rise and is a major driver of morbidity and mortality through cardiovascular and cerebrovascular diseases. Animal models used in the discovery of novel treatments for obesity range from straightforward measures of food intake in lean rodents to long-term studies in animals exhibiting obesity due to the continuous access to diets high in fat. The utility of these animal models can be extended to determine, for example, that weight loss is due to fat loss and/or assess whether beneficial changes in key plasma parameters (e.g. insulin) are evident. In addition, behavioural models such as the behavioural satiety sequence can be used to confirm that a drug treatment has a selective effect on food intake. Typically, animal models have excellent predictive validity whereby drug-induced weight loss in rodents subsequently translates to weight loss in man. However, despite this, at the time of writing orlistat (Europe; USA) remains the only drug currently marketed for the treatment of obesity, with sibutramine having recently been withdrawn from sale globally due to the increased incidence of serious, non-fatal cardiovascular events. While the utility of rodent models in predicting clinical weight loss is detailed, the review also discusses whether animals can be used to predict adverse events such as those seen with recent anti-obesity drugs in the clinic.
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Brand T, Spanagel R, Schneider M. Decreased reward sensitivity in rats from the Fischer344 strain compared to Wistar rats is paralleled by differences in endocannabinoid signaling. PLoS One 2012; 7:e31169. [PMID: 22347447 PMCID: PMC3275578 DOI: 10.1371/journal.pone.0031169] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 01/03/2012] [Indexed: 11/23/2022] Open
Abstract
Background The aim of the present study was to examine if differences in the endocannabinoid (ECB) system might be linked to strain specific variations in reward-related behavior in Fischer344 (Fischer) and Wistar rats. Methodology/Principal Findings Two rat strains, the Fischer and the Wistar strain, were tested for different aspects of reward sensitivity for a palatable food reward (sweetened condensed milk, SCM) in a limited-access intake test, a progressive ratio (PR) schedule and the pleasure-attenuated startle (PAS) paradigm. Additionally, basic differences in the ECB system and cannabinoid pharmacology were examined in both rat strains. Fischer rats were found to express lower reward sensitivity towards SCM compared to Wistar rats. These differences were observed for consummatory, motivational and hedonic aspects of the palatable food reward. Western blot analysis for the CB1 receptor and the ECB degrading enzyme fatty acid amide hydrolase (FAAH) revealed a lower expression of both proteins in the hippocampus (HPC) of Fischer rats compared to the Wistar strain. Furthermore, increased cannabinoid-stimulated extracellular-regulated kinase (ERK) phosphorylation was detected in Wistar rats compared to the Fischer strain, indicating alterations in ECB signaling. These findings were further supported by the pharmacological results, where Fischer rats were found to be less sensitive towards the effects of the CB1 receptor antagonist/inverse agonist SR141716 and the cannabinoid agonist WIN 55,212-2. Conclusions/Significance Our present findings indicate differences in the expression of the CB1 receptor and FAAH, as well as the activation of ECB signaling pathways between Fischer and Wistar rats. These basic differences in the ECB system might contribute to the pronounced differences observed in reward sensitivity between both rat strains.
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Affiliation(s)
- Theresa Brand
- Research Group Developmental Neuropsychopharmacology, Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Miriam Schneider
- Research Group Developmental Neuropsychopharmacology, Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
- * E-mail:
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Vinod KY, Maccioni P, Garcia-Gutierrez MS, Femenia T, Xie S, Carai MAM, Manzanares J, Cooper TB, Hungund BL, Colombo G. Innate difference in the endocannabinoid signaling and its modulation by alcohol consumption in alcohol-preferring sP rats. Addict Biol 2012; 17:62-75. [PMID: 21309960 DOI: 10.1111/j.1369-1600.2010.00299.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The present study was undertaken to examine whether genetically predetermined differences in components of the endocannabinoid system were present in the brain of Sardinian alcohol-preferring (sP) and Sardinian alcohol-non-preferring (sNP) rats, a pair of rat lines selectively bred for opposite alcohol preference. The effects of acquisition and maintenance of alcohol drinking, alcohol withdrawal, and alcohol re-exposure on the endocannabinoid system was also assessed in the striatum of sP rats. The findings revealed significantly higher density of the CB1 receptors and levels of CB1 receptor mRNA, CB1 receptor-mediated G-protein coupling, and endocannabinoids in the cerebral cortex, hippocampus and striatum of alcohol-naive sP rats than sNP rats. A significantly lower expression of mFAAH enzyme was evident in the hippocampus of alcohol-naive sP rats. Alcohol drinking (during both acquisition and maintenance phases) in sP rats resulted in a significant reduction in striatal CB1 receptor-mediated G-protein coupling whereas alcohol withdrawal attenuated this effect. Alcohol consumption was also associated with markedly increased levels of endocannabinoids in the striatum. Co-administration of the CB1 receptor antagonist, rimonabant (SR141716A) reduced alcohol intake, and reversed alcohol-induced changes in CB1 receptor-mediated G-protein activation. These findings provided a new insight into a potential genetic basis of excessive alcohol consumption, suggesting innate differences in the endocannabinoid system might be associated with higher alcohol preference in sP rats. The data also indicate a modulation of CB1 receptor-mediated signaling following alcohol consumption, and further strengthen the potential of the endocannabinoid system as a target for the treatment of alcohol related behaviors.
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Affiliation(s)
- K Yaragudri Vinod
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
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Barson JR, Morganstern I, Leibowitz SF. Neurobiology of consummatory behavior: mechanisms underlying overeating and drug use. ILAR J 2012; 53:35-58. [PMID: 23520598 PMCID: PMC3954603 DOI: 10.1093/ilar.53.1.35] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Consummatory behavior is driven by both caloric and emotional need, and a wide variety of animal models have been useful in research on the systems that drive consumption of food and drugs. Models have included selective breeding for a specific trait, manipulation of gene expression, forced or voluntary exposure to a substance, and identification of biomarkers that predict which animals are prone to overconsuming specific substances. This research has elucidated numerous brain areas and neurochemicals that drive consummatory behavior. Although energy homeostasis is primarily mediated by the hypothalamus, reinforcement is more strongly mediated by nuclei outside the hypothalamus, in mesocorticolimbic regions. Orexigenic neurochemicals that control food intake can provide a general signal for promoting caloric intake or a more specific signal for stimulating consumption of a particular macronutrient, fat, carbohydrate, or protein. The neurochemicals involved in controlling fat ingestion--galanin, enkephalin, orexin, melanin-concentrating hormone, and the endocannabinoids--show positive feedback with this macronutrient, as these peptides both increase fat intake and are further stimulated by its intake. This positive association offers some explanation for why foods high in fat are so often overconsumed. Consumption of ethanol, a drug of abuse that also contains calories, is similarly driven by the neurochemical systems involved in fat intake, according to evidence that closely relates fat and ethanol consumption. Further understanding of the systems involved in consummatory behavior will enable the development of effective therapies for the treatment of both overeating and drug abuse.
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Affiliation(s)
- Jessica R Barson
- Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, New York 10065, USA
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Erdozain AM, Callado LF. Involvement of the endocannabinoid system in alcohol dependence: the biochemical, behavioral and genetic evidence. Drug Alcohol Depend 2011; 117:102-10. [PMID: 21414731 DOI: 10.1016/j.drugalcdep.2011.02.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 02/07/2011] [Accepted: 02/14/2011] [Indexed: 11/18/2022]
Abstract
BACKGROUND Recent advances in the understanding of alcohol dependence suggest that the endocannabinoid system (ECS) plays a key role in the neurobiological mechanisms underlying this pathology. METHODS The aim of the present review is to show the currently available biochemical, behavioral and genetic evidence on the involvement of the ECS in alcohol dependence. DISCUSSION Firstly, biochemical studies have shown that both chronic and acute administration of ethanol produce alterations in different elements of this neurotransmission system. Secondly, the pharmacological and genetic manipulation of the ECS in rodents result in altered ethanol-related behavior. Furthermore, rodent strains with different preference for ethanol differ in their ECS state. Also, genetic studies have described that particular polymorphisms in the genes coding for some elements of this system are associated with some phenotypes of alcohol dependence. Finally, the possible efficacy of cannabinoid receptor blockers in the prevention of relapse to alcohol has been tested in clinical trials. CONCLUSION Altogether, these multiple lines of evidence suggest that the ECS is implicated in the development of alcohol abuse and dependence.
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Affiliation(s)
- Amaia M Erdozain
- Department of Pharmacology, University of the Basque Country, 48940 Leioa, Bizkaia, Spain
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37
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Bailey CR, Neumeister A. Cb1 receptor-mediated signaling emerges as a novel lead to evidence-based treatment development for stress-related psychopathology. Neurosci Lett 2011; 502:1-4. [DOI: 10.1016/j.neulet.2011.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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McLaughlin RJ, Gobbi G. Cannabinoids and emotionality: a neuroanatomical perspective. Neuroscience 2011; 204:134-44. [PMID: 21827834 DOI: 10.1016/j.neuroscience.2011.07.052] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 07/17/2011] [Accepted: 07/20/2011] [Indexed: 12/11/2022]
Abstract
The endocannabinoid system has recently emerged as a promising therapeutic target for the treatment of stress-related emotional disorders. A growing literature base has collectively demonstrated that facilitation of endocannabinoid signaling promotes antidepressant- and anxiolytic-like responses in preclinical animal models, while disruption of this system profoundly affects emotion, cognition, and neuroendocrine functioning. Although these findings are encouraging, the role of endocannabinoid signaling within discrete corticolimbic brain structures is considerably complex. Consequently, researchers have recently shifted focus to examining the effects of local cannabinoid manipulations on emotion from a neuroanatomical standpoint. This review provides an overview of the site-specific effects of cannabinergic compounds in preclinical tests of emotionality, as well as the alterations in endocannabinoid signaling observed in animal models of depression. Broadly speaking, these studies indicate that CB(1) receptors in the medial prefrontal cortex and ventral hippocampus appear to be responsible for the antidepressant- and anxiolytic-like phenotype elicited by systemic CB(1) receptor agonists, which parallels biochemical studies showing that endocannabinoids are downregulated in these two regions following exposure to chronic stress. Conversely, CB(1) receptor activation within distinct amygdalar nuclei yields opposing effects on emotional behavior, such that local stimulation of CB(1) receptors in the basolateral amygdala and central amygdala promoting anxiogenesis and anxiolysis, respectively. Moreover, a series of elegant studies has revealed that cannabinoid transmission in the basolateral amygdala strongly modulates the acquisition and processing of associative fear memory via interactions with the medial prefrontal cortex. Given the crucial role of this corticolimbic network in regulating emotional behavior, it is palpable that alterations in endocannabinoid signaling within any of these structures could have profound implications for the pathophysiological development of affective illnesses. Accordingly, local pharmacological augmentation of endocannabinoid signaling within discrete corticolimbic subregions may serve as a promising therapeutic strategy for the treatment of these debilitating disorders.
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Affiliation(s)
- R J McLaughlin
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4.
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Ward SJ, Raffa RB. Rimonabant redux and strategies to improve the future outlook of CB1 receptor neutral-antagonist/inverse-agonist therapies. Obesity (Silver Spring) 2011; 19:1325-34. [PMID: 21475141 DOI: 10.1038/oby.2011.69] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Sara Jane Ward
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, Pennsylvania, USA.
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Sex and cannabinoid CB1 genotype differentiate palatable food and cocaine self-administration behaviors in mice. Behav Pharmacol 2011; 20:605-13. [PMID: 19745722 DOI: 10.1097/fbp.0b013e328331ba30] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Both cannabinoid CB1 receptor knockout and antagonism produce well-established attenuation of palatable food and drug self-administration behavior. Although cannabinoid drugs have received attention as pharmacotherapeutics for various disorders, including obesity and addiction, it is unclear whether these agents produce equivalent behavioral effects in females and males. In this study, acquisition of 32% corn oil or 10% Ensure self-administration, and maintenance of corn oil, Ensure, or 0.56 mg/kg/infusion cocaine self-administration under both fixed ratio (FR)-1 and progressive ratio (PR) schedule of reinforcement, was compared in male and female wild type (WT) and CB1 knockout (KO) mice. Furthermore, the effect of pretreatment with the CB1 antagonist SR141716 (0.3-3.0) on Ensure self-administration in male and female WT and CB1 KO mice was assessed. CB1 genotype and sex significantly interacted to produce an attenuation of acquisition and maintenance of Ensure self-administration and PR self-administration for both Ensure and cocaine in male CB1 KO mice. In contrast, male CB1 KO mice showed no deficit in acquisition and maintenance of FR-1 responding or in PR responding maintained by corn oil. Sex differences also arose within genotypes for responding maintained under all three reinforcers. Lastly, pretreatment with SR141716 attenuated Ensure self-administration in WT and CB1 KO mice but was approximately five-fold more potent in WT mice than in CB1 KOs. The present data add to a small but growing literature suggesting that the cannabinoid system may be differentially sensitive in its modulation of appetitive behavior in males versus females.
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CB1 receptors regulate alcohol-seeking behavior and alcohol self-administration of alcohol-preferring (P) rats. Pharmacol Biochem Behav 2010; 97:669-75. [PMID: 21110997 DOI: 10.1016/j.pbb.2010.11.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 11/04/2010] [Accepted: 11/09/2010] [Indexed: 11/30/2022]
Abstract
RATIONALE The endogenous cannabinoid (CB) system mediates a number of behaviors associated with drug-seeking and drug self-administration. In this study the effects of CB1 receptor manipulations on operant ethanol (EtOH) responding during EtOH-seeking, EtOH-relapse as well as on-going EtOH self-administration were determined. METHODS Alcohol-preferring (P) rats were trained in 2-lever operant chambers to self-administer 15% EtOH (v/v) and water on a concurrent fixed-ratio 5-fixed-ratio 1 (FR5-FR1) schedule of reinforcement in daily 1-h sessions. After 10 weeks, rats underwent 7 extinction sessions, followed by 2 weeks in their home cages without access to EtOH or operant chambers. Rats were then returned to the operant chambers for testing of EtOH-seeking behavior (no EtOH present) for 4 sessions. After a week in their home cages following the EtOH-seeking test, rats were returned to the operant chambers with access to EtOH and water (relapse). Rats were then maintained in the operant chambers for daily 1-h sessions with access to 15% EtOH and water for several weeks. RESULTS The CB1 receptor antagonist (SR141716A), at doses of 1 and 2 mg/kg, i.p. reduced EtOH-seeking and transiently reduced EtOH self-administration during relapse and maintenance. Conversely, treatment with the CB1 receptor agonist CP 55, 940, at doses of 1 and 10 μg/kg i.p., increased EtOH-seeking and EtOH self-administration during relapse. CONCLUSIONS The results of this study demonstrate that activation of CB1 receptors are involved in regulating EtOH-seeking as well as the reinforcing effects of EtOH under relapse and on-going self-administration conditions.
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Zhang L, Lee NJ, Nguyen AD, Enriquez RF, Riepler SJ, Stehrer B, Yulyaningsih E, Lin S, Shi YC, Baldock PA, Herzog H, Sainsbury A. Additive actions of the cannabinoid and neuropeptide Y systems on adiposity and lipid oxidation. Diabetes Obes Metab 2010; 12:591-603. [PMID: 20590734 DOI: 10.1111/j.1463-1326.2009.01193.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS Energy homeostasis is regulated by a complex interaction of molecules and pathways, and new antiobesity treatments are likely to require multiple pharmacological targeting of anorexigenic or orexigenic pathways to achieve effective loss of excess body weight and adiposity. Cannabinoids, acting via the cannabinoid-1 (CB1) receptor, and neuropeptide Y (NPY) are important modulators of feeding behaviour, energy metabolism and body composition. We investigated the interaction of CB1 and NPY in the regulation of energy homeostasis, hypothesizing that dual blockade of CB1 and NPY signalling will induce greater weight and/or fat loss than that induced by single blockade of either system alone. METHODS We studied the effects of the CB1 antagonist Rimonabant on food intake, body weight, body composition, energy metabolism and bone physiology in wild-type (WT) and NPY knockout (NPY(-/-)) mice. Rimonabant was administered orally at 10 mg/kg body weight twice per day for 3 weeks. Oral Rimonabant was delivered voluntarily to mice via a novel method enabling studies to be carried out in the absence of gavage-induced stress. RESULTS Mice with dual blockade of CB1 and NPY signalling (Rimonabant-treated NPY(-/-) mice) exhibited greater reductions in body weight and adiposity than mice with single blockade of either system alone (Rimonabant-treated WT or vehicle-treated NPY(-/-) mice). These changes occurred without loss of lean tissue mass or bone mass. Furthermore, Rimonabant-treated NPY(-/-) mice showed a lower respiratory exchange ratio than that seen in Rimonabant-treated WT or vehicle-treated NPY(-/-) mice, suggesting that this additive effect of dual blockade of CB1 and NPY involves promotion of lipid oxidation. On the other hand, energy expenditure and physical activity were comparable amongst all treatment groups. Interestingly, Rimonabant similarly and transiently reduced spontaneous and fasting-induced food intake in WT and NPY(-/-) mice in the first hour after administration only, suggesting independent regulation of feeding by CB1 and NPY signalling. In contrast, Rimonabant increased serum corticosterone levels in WT mice, but this effect was not seen in NPY(-/-) mice, indicating that NPY signalling may be required for effects of CB1 on the hypothalamo-pituitary-adrenal axis. CONCLUSIONS Dual blockade of CB1 and NPY signalling leads to additive reductions in body weight and adiposity without concomitant loss of lean body mass or bone mass. An additive increase in lipid oxidation in dual CB1 and NPY blockade may contribute to the effect on adiposity. These findings open new avenues for more effective treatment of obesity via dual pharmacological manipulations of the CB1 and NPY systems.
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Affiliation(s)
- L Zhang
- Neuroscience Research Program, Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, Sydney, NSW 2010, Australia
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Menzies JRW, Ludwig M, Leng G. Direct and indirect effects of cannabinoids on in vitro GABA release in the rat arcuate nucleus. J Neuroendocrinol 2010; 22:585-92. [PMID: 20236227 DOI: 10.1111/j.1365-2826.2010.01990.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Within the hypothalamic arcuate nucleus, two neuronal subpopulations play particularly important roles in energy balance; neurones expressing neuropeptide Y (NPY), agouti-related peptide (AgRP) and GABA are orexigenic, whereas neurones expressing pro-opiomelanocortin and CART are anorexigenic. The pivotal role of these neuropeptides in energy homeostasis is well-known, although GABA may also be an important signal because targeted knockout of the GABA transporter in NPY/AgRP/GABA neurones results in a lean, obesity-resistant phenotype. In the present study, we describe an in vitro model of K(+)-evoked GABA release from the hypothalamus and determine the effects of cannabinoid receptor activation. K(+)-evoked GABA release was sensitive to leptin, insulin and PYY(3-36), indicating that GABA was released by arcuate NPY/AgRP/GABA neurones. In the presence of tetrodotoxin (TTX), the cannabinoid CB1 receptor agonist WIN 55,212-2 inhibited K(+)-evoked GABA release. This was prevented by the CB1 receptor inverse agonist rimonabant. Rimonabant had no effect when applied alone. In the absence of TTX, however, the opposite effects were observed: WIN 55,212-2 had no effect while rimonabant inhibited GABA release. This indicates that GABA release can involve an indirect, TTX-sensitive mechanism. The most parsimonious explanation for the inhibition of GABA release by a CB receptor inverse agonist is via the disinhibition of an cannabinoid-sensitive inhibitory input onto GABAergic neurones. One local source of an inhibitory neurotransmitter is the opioidergic arcuate neurones. In our in vitro model, K(+)-evoked GABA release was inhibited by the endogenous opioid peptide beta-endorphin in a naloxone-sensitive manner. The inhibitory effect of rimonabant was also prevented by naloxone and a kappa-opioid receptor selective antagonist, suggesting that GABA release from arcuate NPY/AgRP/GABA neurones can be inhibited by endogenous opioid peptides, and that the release of opioid peptides is sensitive to cannabinoids.
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Affiliation(s)
- J R W Menzies
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Edinburgh, UK.
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George DT, Herion DW, Jones CL, Phillips MJ, Hersh J, Hill D, Heilig M, Ramchandani VA, Geyer C, Spero DE, Singley ED, O’Malley SS, Bishai R, Rawlings RR, Kunos G. Rimonabant (SR141716) has no effect on alcohol self-administration or endocrine measures in nontreatment-seeking heavy alcohol drinkers. Psychopharmacology (Berl) 2010; 208:37-44. [PMID: 19902183 PMCID: PMC2963590 DOI: 10.1007/s00213-009-1704-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 10/06/2009] [Indexed: 11/29/2022]
Abstract
RATIONALE There is an extensive literature showing that the CB(1) cannabinoid receptor antagonist rimonabant (SR141716) decreases alcohol consumption in animals, but little is known about its effects in human alcohol drinkers. METHODS In this study, 49 nontreatment-seeking heavy alcohol drinkers participated in a 3-week study. After a 1-week baseline, participants received either 20 mg/day of rimonabant or placebo for 2 weeks under double-blind conditions. During these 3 weeks, participants reported their daily alcohol consumption by telephone. Subsequently, they participated in an alcohol self-administration paradigm in which they received a priming dose of alcohol followed by the option of consuming either eight alcohol drinks or receiving $3.00 for each nonconsumed drink. Endocrine measures and self-rating scales were also obtained. RESULTS Rimonabant did not change alcohol consumption during the 2 weeks of daily call-ins. Similarly, the drug did not change either alcohol self-administration or endocrine measures during the laboratory session. CONCLUSION We conclude that the daily administration of 20 mg of rimonabant for 2 weeks has no effect on alcohol consumption in nontreatment-seeking heavy alcohol drinkers.
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Affiliation(s)
- David Ted George
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA.
| | - David W. Herion
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | - Cheryl L. Jones
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | - Monte J. Phillips
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | - Jacqueline Hersh
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | - Debra Hill
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | - Markus Heilig
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | - Vijay A. Ramchandani
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | | | | | - Erick D. Singley
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | | | - Raafat Bishai
- International Clinical Development, Sanofi-Aventis, Malvern, PA, USA
| | - Robert R. Rawlings
- Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, 10 Center Drive, 10 CRC-Hatfield Center, Rm. 1-5330, MSC 1108, Bethesda, MD 20892-1108, USA
| | - George Kunos
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA,NIAAA, 5625 Fishers Ln, MSC 9413, Rm. 2S-24, Rockville, MD 20892-9413, USA
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Fong TM, Addy C, Erondu N, Heymsfield SB. CB1 receptor inverse agonist pharmacotherapy for metabolic disorders. Drug Dev Res 2009. [DOI: 10.1002/ddr.20335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Linsenbardt DN, Boehm SL. Agonism of the endocannabinoid system modulates binge-like alcohol intake in male C57BL/6J mice: involvement of the posterior ventral tegmental area. Neuroscience 2009; 164:424-34. [PMID: 19665522 DOI: 10.1016/j.neuroscience.2009.08.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 07/30/2009] [Accepted: 08/04/2009] [Indexed: 11/26/2022]
Abstract
Recent studies have indicated a role for the endocannabinoid system in the behavioral and physiological effects of alcohol (ethanol), particularly ethanol seeking behaviors. However, its role in modulating binge-like intake and/or the mechanism by which it may exert these effects remain poorly understood. The current study used a newly developed strain-specific animal model of binge drinking, dubbed 'Drinking In the Dark' (DID), to determine if facilitation of the endocannabinoid system with the synthetic cannabinoid agonist WIN 55-212,2 (WIN) modulates binge-like ethanol intake in male C57BL/6J (B6) mice. Based on the results of these systemic (i.p.) manipulations, and evidence in support of the involvement of subregions of the Ventral Tegmental Area (VTA) in governing self-administration of ethanol (Rodd-Henricks et al., (2000) Psychopharmacology (Berl) 149(3):217-224) as well as binge-like intake using the DID model (Moore & Boehm, (2009 Behav Neurosci 123(3):555-563), we extended these findings to evaluate the role of the endocannabinoid system within the anterior and posterior sub regions of the VTA using site-specific microinjections. Consistent with previous research, the lowest systemic dose of WIN (0.5 mg/kg) significantly increased ethanol intake in the first 30 minutes of access whereas the two highest doses (1 and 2 mg/kg) decreased ethanol intake within this time interval. Intra-posterior ventral tegmental area (pVTA) (but not aVTA (anterior ventral tegmental area) microinjections elicited time-dependent and dose-dependent increases (0.25 and 0.5 mug/side) and decreases (2.5 mug/side) in ethanol intake. Importantly, follow-up studies revealed that in some cases alterations in fluid consumption may have been influenced by competing locomotor activity (or inactivity). The present data are consistent with previous research in that agonism of the endocannabinoid system increases ethanol intake in rodents and implicate the pVTA in the modulation of drinking to intoxication. Moreover, the dose-dependent alterations in locomotor activity emphasize the importance of directly assessing multiple (possibly competing) behaviors when evaluating drug effects on voluntary consumption.
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Affiliation(s)
- D N Linsenbardt
- Center for Development and Behavioral Neuroscience, Department of Psychology, Binghamton University, Binghamton, NY 13902, USA.
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Lupica CR, Riegel AC. Endocannabinoid release from midbrain dopamine neurons: a potential substrate for cannabinoid receptor antagonist treatment of addiction. Neuropharmacology 2009; 48:1105-16. [PMID: 15878779 DOI: 10.1016/j.neuropharm.2005.03.016] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 02/18/2005] [Accepted: 03/09/2005] [Indexed: 11/30/2022]
Abstract
Substantial evidence suggests that all commonly abused drugs act upon the brain reward circuitry to ultimately increase extracellular concentrations of the neurotransmitter dopamine in the nucleus accumbens and other forebrain areas. Many drugs of abuse appear to increase dopamine levels by dramatically increase the firing and bursting rates of dopamine neurons located in the ventral mesencephalon. Recent clinical evidence in humans and behavioral evidence in animals indicate that cannabinoid receptor antagonists such as SR141716A (Rimonabant) can reduce the self-administration of, and craving for, several commonly addictive drugs. However, the mechanism of this potentially beneficial effect has not yet been identified. We propose, on the basis of recent studies in our laboratory and others, that these antagonists may act by blocking the effects of endogenously released cannabinoid molecules (endocannabinoids) that are released in an activity- and calcium-dependent manner from mesencephalic dopamine neurons. It is hypothesized that, through the antagonism of cannabinoid CB1 receptors located on inhibitory and excitatory axon terminals targeting the midbrain dopamine neurons, the effects of the endocannabinoids are occluded. The data from these studies therefore suggest that the endocannabinoid system and the CB1 receptors located in the ventral mesencephalon may play an important role in regulating drug reward processes, and that this substrate is recruited whenever dopamine neuron activity is increased.
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Affiliation(s)
- Carl R Lupica
- Cellular Neurobiology Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, U.S. Department of Health and Human Services, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
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Verty ANA, Boon WM, Mallet PE, McGregor IS, Oldfield BJ. Involvement of hypothalamic peptides in the anorectic action of the CB1receptor antagonist rimonabant (SR 141716). Eur J Neurosci 2009; 29:2207-16. [DOI: 10.1111/j.1460-9568.2009.06750.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The ability of Cannabis sativa to promote eating has been documented for many centuries, with the drug reported by its users to promote strong cravings for, and an intensification of the sensory and hedonic properties of food. These effects are now known to result from the actions of cannabinoid molecules at specific cannabinoid receptor sites within the brain, and to reflect the physiological role of their natural ligands, the endocannabinoids, in the control of appetite. Recent developments in the biochemistry and pharmacology of endocannabinoid systems have generated convincing evidence from animal models for a normal role of endocannabinoids in the control of eating motivation. The availability of specific cannabinoid receptor agonists and antagonists raises the possibility of improved therapies for disorders of eating and body weight: not only in the suppression of appetite to counter our susceptibility to the over-consumption of highly pleasurable and energy-dense foods; but also in the treatment of conditions that involve reduced appetite and weight loss. Here, we outline some of the findings of the past decade that link endocannabinoid function appetite control, and the possible clinical applications of that knowledge.
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Affiliation(s)
- Tim C Kirkham
- School of Psychology, University of Liverpool, Liverpool, UK.
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50
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Abstract
Cannabinoid receptors and their endogenous ligands are located throughout the limbic, or "emotional," brain, where they modulate synaptic neurotransmission. Converging preclinical and clinical data suggest a role for endogenous cannabinoid signaling in the modulation of anxiety and depression. Augmentation of endocannabinoid signaling (ECS) has anxiolytic effects, whereas blockade or genetic deletion of CB₁ receptors has anxiogenic properties. Augmentation of ECS also appears to have anti-depressant actions, and in some assays blockade and genetic deletion of CB₁ receptors produces depressive phenotypes. These data provide evidence that ECS serves in an anxiolytic, and possibly anti-depressant, role. These data suggest novel approaches to treatment of affective disorders which could include enhancement of endogenous cannabinoid signaling, and warrant cautious use of CB₁ receptor antagonists in patients with pre-existing affective disorders.
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