1
|
Scheyer A, Yasmin F, Naskar S, Patel S. Endocannabinoids at the synapse and beyond: implications for neuropsychiatric disease pathophysiology and treatment. Neuropsychopharmacology 2023; 48:37-53. [PMID: 36100658 PMCID: PMC9700791 DOI: 10.1038/s41386-022-01438-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/10/2022] [Accepted: 08/18/2022] [Indexed: 11/09/2022]
Abstract
Endocannabinoids (eCBs) are lipid neuromodulators that suppress neurotransmitter release, reduce postsynaptic excitability, activate astrocyte signaling, and control cellular respiration. Here, we describe canonical and emerging eCB signaling modes and aim to link adaptations in these signaling systems to pathological states. Adaptations in eCB signaling systems have been identified in a variety of biobehavioral and physiological process relevant to neuropsychiatric disease states including stress-related disorders, epilepsy, developmental disorders, obesity, and substance use disorders. These insights have enhanced our understanding of the pathophysiology of neurological and psychiatric disorders and are contributing to the ongoing development of eCB-targeting therapeutics. We suggest future studies aimed at illuminating how adaptations in canonical as well as emerging cellular and synaptic modes of eCB signaling contribute to disease pathophysiology or resilience could further advance these novel treatment approaches.
Collapse
Affiliation(s)
| | - Farhana Yasmin
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Saptarnab Naskar
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Sachin Patel
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA.
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
| |
Collapse
|
2
|
Imbriani P, Sciamanna G, El Atiallah I, Cerri S, Hess EJ, Pisani A. Synaptic effects of ethanol on striatal circuitry: therapeutic implications for dystonia. FEBS J 2022; 289:5834-5849. [PMID: 34217152 PMCID: PMC9786552 DOI: 10.1111/febs.16106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/21/2021] [Accepted: 07/02/2021] [Indexed: 12/30/2022]
Abstract
Alcohol consumption affects motor behavior and motor control. Both acute and chronic alcohol abuse have been extensively investigated; however, the therapeutic efficacy of alcohol on some movement disorders, such as myoclonus-dystonia or essential tremor, still does not have a plausible mechanistic explanation. Yet, there are surprisingly few systematic trials with known GABAergic drugs mimicking the effect of alcohol on neurotransmission. In this brief survey, we aim to summarize the effects of EtOH on striatal function, providing an overview of its cellular and synaptic actions in a 'circuit-centered' view. In addition, we will review both experimental and clinical evidence, in the attempt to provide a plausible mechanistic explanation for alcohol-responsive movement disorders, with particular emphasis on dystonia. Different hypotheses emerge, which may provide a rationale for the utilization of drugs that mimic alcohol effects, predicting potential drug repositioning.
Collapse
Affiliation(s)
- Paola Imbriani
- Department of Systems MedicineUniversity of Rome ‘Tor Vergata’Italy,IRCCS Fondazione Santa LuciaRomeItaly
| | - Giuseppe Sciamanna
- Department of Systems MedicineUniversity of Rome ‘Tor Vergata’Italy,IRCCS Fondazione Santa LuciaRomeItaly
| | - Ilham El Atiallah
- Department of Systems MedicineUniversity of Rome ‘Tor Vergata’Italy,IRCCS Fondazione Santa LuciaRomeItaly
| | | | - Ellen J. Hess
- Departments of Pharmacology and Chemical Biology and NeurologyEmory UniversityAtlantaGAUSA
| | - Antonio Pisani
- IRCCS Mondino FoundationPaviaItaly,Department of Brain and Behavioral SciencesUniversity of PaviaItaly
| |
Collapse
|
3
|
Fernández-Espejo E, Núñez-Domínguez L. Endocannabinoid-mediated synaptic plasticity and substance use disorders. Neurologia 2022; 37:459-465. [PMID: 30857785 DOI: 10.1016/j.nrl.2018.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/27/2018] [Accepted: 12/03/2018] [Indexed: 01/15/2023] Open
Abstract
Drugs impact brain reward circuits, causing dependence and addiction, in a condition currently described as substance use disorders. Mechanisms of synaptic plasticity in these circuits are crucial in the development of addictive behaviour, and endocannabinoids, particularly anandamide and 2-arachidonyl-glycerol, participate in normal neuroplasticity. Substance use disorders are known to be associated with disruption of endocannabinoid-mediated synaptic plasticity, among other phenomena. Endocannabinoids mediate neuroplasticity in the short and the long term. In the short term, we may stress «inhibitory» phenomena, such as depolarisation-induced suppression of inhibition and depolarisation-induced suppression of excitation, and such «disinhibitory» phenomena as long-lasting disinhibition of neuronal activity, particularly in the striatum, and suppression of hippocampal GABA release. Drugs of abuse can also disrupt normal endocannabinoid-mediated long-term potentiation and long-term depression. Endocannabinoids are also involved in the development of drug-induced hypofrontality and sensitisation. In summary, substance abuse causes a disruption in the synaptic plasticity of the brain circuits involved in addiction, with the alteration of normal endocannabinoid activity playing a prominent role. This facilitates abnormal changes in the brain and the development of the addictive behaviours that characterise substance use disorders.
Collapse
Affiliation(s)
- E Fernández-Espejo
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Sevilla, España.
| | | |
Collapse
|
4
|
Endocannabinoid-mediated synaptic plasticity and substance use disorders. NEUROLOGÍA (ENGLISH EDITION) 2022; 37:459-465. [PMID: 34538595 DOI: 10.1016/j.nrleng.2018.12.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/03/2018] [Indexed: 11/21/2022] Open
Abstract
Drugs impact brain reward circuits, causing dependence and addiction, in a condition currently described as substance use disorders. Mechanisms of synaptic plasticity in these circuits are crucial in the development of addictive behaviour, and endocannabinoids, particularly anandamide and 2-arachidonyl-glycerol, participate in normal neuroplasticity. Substance use disorders are known to be associated with disruption of endocannabinoid-mediated synaptic plasticity, among other phenomena. Endocannabinoids mediate neuroplasticity in the short and the long term. In the short term, we may stress "inhibitory" phenomena, such as depolarisation-induced suppression of inhibition and depolarisation-induced suppression of excitation, and such "disinhibitory" phenomena as long-lasting disinhibition of neuronal activity, particularly in the striatum, and suppression of hippocampal GABA release. Drugs of abuse can also disrupt normal endocannabinoid-mediated long-term potentiation and long-term depression. Endocannabinoids are also involved in the development of drug-induced hypofrontality and sensitisation. In summary, substance abuse causes a disruption in the synaptic plasticity of the brain circuits involved in addiction, with the alteration of normal endocannabinoid activity playing a prominent role. This facilitates abnormal changes in the brain and the development of the addictive behaviours that characterise substance use disorders.
Collapse
|
5
|
Abstract
PURPOSE A growing body of evidence has implicated the endocannabinoid (eCB) system in the acute, chronic, and withdrawal effects of alcohol/ethanol on synaptic function. These eCB-mediated synaptic effects may contribute to the development of alcohol use disorder (AUD). Alcohol exposure causes neurobiological alterations similar to those elicited by chronic cannabinoid (CB) exposure. Like alcohol, cannabinoids alter many central processes, such as cognition, locomotion, synaptic transmission, and neurotransmitter release. There is a strong need to elucidate the effects of ethanol on the eCB system in different brain regions to understand the role of eCB signaling in AUD. SEARCH METHODS For the scope of this review, preclinical studies were identified through queries of the PubMed database. SEARCH RESULTS This search yielded 459 articles. Clinical studies and papers irrelevant to the topic of this review were excluded. DISCUSSION AND CONCLUSIONS The endocannabinoid system includes, but is not limited to, cannabinoid receptors 1 (CB1), among the most abundantly expressed neuronal receptors in the brain; cannabinoid receptors 2 (CB2); and endogenously formed CB1 ligands, including arachidonoylethanolamide (AEA; anandamide), and 2-arachidonoylglycerol (2-AG). The development of specific CB1 agonists, such as WIN 55,212-2 (WIN), and antagonists, such as SR 141716A (rimonabant), provide powerful pharmacological tools for eCB research. Alcohol exposure has brain region-specific effects on the eCB system, including altering the synthesis of endocannabinoids (e.g., AEA, 2-AG), the synthesis of their precursors, and the density and coupling efficacy of CB1. These alcohol-induced alterations of the eCB system have subsequent effects on synaptic function including neuronal excitability and postsynaptic conductance. This review will provide a comprehensive evaluation of the current literature on the synaptic interactions of alcohol exposure and eCB signaling systems, with an emphasis on molecular and physiological synaptic effects of alcohol on the eCB system. A limited volume of studies has focused on the underlying interactions of alcohol and the eCB system at the synaptic level in the brain. Thus, the data on synaptic interactions are sparse, and future research addressing these interactions is much needed.
Collapse
Affiliation(s)
- Sarah A Wolfe
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, California
| | - Valentina Vozella
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, California
| | - Marisa Roberto
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, California
| |
Collapse
|
6
|
Parks C, Rogers CM, Prins P, Williams RW, Chen H, Jones BC, Moore BM, Mulligan MK. Genetic Modulation of Initial Sensitivity to Δ9-Tetrahydrocannabinol (THC) Among the BXD Family of Mice. Front Genet 2021; 12:659012. [PMID: 34367237 PMCID: PMC8343140 DOI: 10.3389/fgene.2021.659012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/08/2021] [Indexed: 11/16/2022] Open
Abstract
Cannabinoid receptor 1 activation by the major psychoactive component in cannabis, Δ9-tetrahydrocannabinol (THC), produces motor impairments, hypothermia, and analgesia upon acute exposure. In previous work, we demonstrated significant sex and strain differences in acute responses to THC following administration of a single dose (10 mg/kg, i.p.) in C57BL/6J (B6) and DBA/2J (D2) inbred mice. To determine the extent to which these differences are heritable, we quantified acute responses to a single dose of THC (10 mg/kg, i.p.) in males and females from 20 members of the BXD family of inbred strains derived by crossing and inbreeding B6 and D2 mice. Acute THC responses (initial sensitivity) were quantified as changes from baseline for: 1. spontaneous activity in the open field (mobility), 2. body temperature (hypothermia), and 3. tail withdrawal latency to a thermal stimulus (antinociception). Initial sensitivity to the immobilizing, hypothermic, and antinociceptive effects of THC varied substantially across the BXD family. Heritability was highest for mobility and hypothermia traits, indicating that segregating genetic variants modulate initial sensitivity to THC. We identified genomic loci and candidate genes, including Ndufs2, Scp2, Rps6kb1 or P70S6K, Pde4d, and Pten, that may control variation in THC initial sensitivity. We also detected strong correlations between initial responses to THC and legacy phenotypes related to intake or response to other drugs of abuse (cocaine, ethanol, and morphine). Our study demonstrates the feasibility of mapping genes and variants modulating THC responses in the BXDs to systematically define biological processes and liabilities associated with drug use and abuse.
Collapse
Affiliation(s)
- Cory Parks
- Department of Genetics, Genomics and Informatics, The University of Tennessee Health Science Center, Memphis, TN, United States
- Department of Agriculture, Biology and Health Sciences, Cameron University, Lawton, OK, United States
| | - Chris M. Rogers
- Department of Genetics, Genomics and Informatics, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Pjotr Prins
- Department of Genetics, Genomics and Informatics, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Robert W. Williams
- Department of Genetics, Genomics and Informatics, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Hao Chen
- Department of Pharmacology, Addiction Science and Toxicology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Byron C. Jones
- Department of Genetics, Genomics and Informatics, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Bob M. Moore
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Megan K. Mulligan
- Department of Genetics, Genomics and Informatics, The University of Tennessee Health Science Center, Memphis, TN, United States
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Karoly HC, Mueller RL, Bidwell LC, Hutchison KE. Cannabinoids and the Microbiota-Gut-Brain Axis: Emerging Effects of Cannabidiol and Potential Applications to Alcohol Use Disorders. Alcohol Clin Exp Res 2019; 44:340-353. [PMID: 31803950 DOI: 10.1111/acer.14256] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/25/2019] [Indexed: 02/06/2023]
Abstract
The endocannabinoid system (ECS) has emerged in recent years as a potential treatment target for alcohol use disorders (AUD). In particular, the nonpsychoactive cannabinoid cannabidiol (CBD) has shown preclinical promise in ameliorating numerous clinical symptoms of AUD. There are several proposed mechanism(s) through which cannabinoids (and CBD in particular) may confer beneficial effects in the context of AUD. First, CBD may directly impact specific brain mechanisms underlying AUD to influence alcohol consumption and the clinical features of AUD. Second, CBD may influence AUD symptoms through its actions across the digestive, immune, and central nervous systems, collectively known as the microbiota-gut-brain axis (MGBA). Notably, emerging work suggests that alcohol and cannabinoids exert opposing effects on the MGBA. Alcohol is linked to immune dysfunction (e.g., chronic systemic inflammation in the brain and periphery) as well as disturbances in gut microbial species (microbiota) and increased intestinal permeability. These MGBA disruptions have been associated with AUD symptoms such as craving and impaired cognitive control. Conversely, existing preclinical data suggest that cannabinoids may confer beneficial effects on the gastrointestinal and immune system, such as reducing intestinal permeability, regulating gut bacteria, and reducing inflammation. Thus, cannabinoids may exert AUD harm-reduction effects, at least in part, through their beneficial actions across the MGBA. This review will provide a brief introduction to the ECS and the MGBA, discuss the effects of cannabinoids (particularly CBD) and alcohol in the brain, gut, and immune system (i.e., across the MGBA), and put forth a theoretical framework to inform future research questions.
Collapse
Affiliation(s)
- Hollis C Karoly
- Institute of Cognitive Science, University of Colorado Boulder, Boulder, Colorado
| | - Raeghan L Mueller
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado
| | - L Cinnamon Bidwell
- Institute of Cognitive Science, University of Colorado Boulder, Boulder, Colorado.,Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado
| | - Kent E Hutchison
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado
| |
Collapse
|
9
|
Basavarajappa BS, Joshi V, Shivakumar M, Subbanna S. Distinct functions of endogenous cannabinoid system in alcohol abuse disorders. Br J Pharmacol 2019; 176:3085-3109. [PMID: 31265740 DOI: 10.1111/bph.14780] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 06/11/2019] [Accepted: 06/18/2019] [Indexed: 12/20/2022] Open
Abstract
Δ9 -tetrahydrocannabinol, the principal active component in Cannabis sativa extracts such as marijuana, participates in cell signalling by binding to cannabinoid CB1 and CB2 receptors on the cell surface. The CB1 receptors are present in both inhibitory and excitatory presynaptic terminals and the CB2 receptors are found in neuronal subpopulations in addition to microglial cells and astrocytes and are present in both presynaptic and postsynaptic terminals. Subsequent to the discovery of the endocannabinoid (eCB) system, studies have suggested that alcohol alters the eCB system and that this system plays a major role in the motivation to abuse alcohol. Preclinical studies have provided evidence that chronic alcohol consumption modulates eCBs and expression of CB1 receptors in brain addiction circuits. In addition, studies have further established the distinct function of the eCB system in the development of fetal alcohol spectrum disorders. This review provides a recent and comprehensive assessment of the literature related to the function of the eCB system in alcohol abuse disorders.
Collapse
Affiliation(s)
- Balapal S Basavarajappa
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA.,New York State Psychiatric Institute, New York, NY, USA.,Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Department of Psychiatry, New York University Langone Medical Center, New York, NY, USA
| | - Vikram Joshi
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Madhu Shivakumar
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Shivakumar Subbanna
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| |
Collapse
|
10
|
Adermark L, Morud J, Lotfi A, Ericson M, Söderpalm B. Acute and chronic modulation of striatal endocannabinoid-mediated plasticity by nicotine. Addict Biol 2019; 24:355-363. [PMID: 29292565 PMCID: PMC6585825 DOI: 10.1111/adb.12598] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/09/2017] [Accepted: 12/05/2017] [Indexed: 11/27/2022]
Abstract
The endocannabinoid (eCB) system modulates several phenomena related to addictive behaviors, and drug‐induced changes in eCB signaling have been postulated to be important mediators of physiological and pathological reward‐related synaptic plasticity. Here, we studied eCB‐mediated long‐term depression (eCB‐LTD) in the dorsolateral striatum, a brain region critical for acquisition of habitual and automatic behavior. We report that nicotine differentially affects ex vivo eCB signaling depending on previous exposure in vivo. In the nicotine‐naïve brain, nicotine facilitates eCB‐signaling and LTD, whereas tolerance develops to this facilitating effect after subchronic exposure in vivo. In the end, a progressive impairment of eCB‐induced LTD is established after protracted withdrawal from nicotine. Endocannabinoid‐LTD is reinstated 6 months after the last drug injection, but a brief period of nicotine re‐exposure is sufficient to yet again impair eCB‐signaling. LTD induced by the cannabinoid 1 receptor agonist WIN55,212‐2 is not affected, suggesting that nicotine modulates eCB production or release. Nicotine‐induced facilitation of eCB‐LTD is occluded by the dopamine D2 receptor agonist quinpirole, and by the muscarinic acetylcholine receptor antagonist scopolamine. In addition, the same compounds restore eCB‐LTD during protracted withdrawal. Nicotine may thus modulate eCB‐signaling by affecting dopaminergic and cholinergic neurotransmission in a long‐lasting manner. Overall, the data presented here suggest that nicotine facilitates eCB‐LTD in the initial phase, which putatively could promote neurophysiological and behavioral adaptations to the drug. Protracted withdrawal, however, impairs eCB‐LTD, which may influence or affect the ability to maintain cessation.
Collapse
Affiliation(s)
- Louise Adermark
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska AcademyUniversity of Gothenburg Sweden
| | - Julia Morud
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska AcademyUniversity of Gothenburg Sweden
| | - Amir Lotfi
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska AcademyUniversity of Gothenburg Sweden
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska AcademyUniversity of Gothenburg Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska AcademyUniversity of Gothenburg Sweden
- Beroendekliniken, Sahlgrenska University Hospital Sweden
| |
Collapse
|
11
|
Lagström O, Danielsson K, Söderpalm B, Ericson M, Adermark L. Voluntary Ethanol Intake Produces Subregion-Specific Neuroadaptations in Striatal and Cortical Areas of Wistar Rats. Alcohol Clin Exp Res 2019; 43:803-811. [PMID: 30860600 DOI: 10.1111/acer.14014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 02/27/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND Addiction has been conceptualized as a shift from controlled recreational use toward compulsive and habitual drug-taking behavior. Although the brain reward system is vital for alcohol reward and reinforcement, other neuronal circuits may be involved in controlling long-term alcohol-seeking and drug-taking behaviors. The aim of this study was to outline alcohol-induced neuroplasticity in defined cortical and striatal subregions, previously implicated in alcohol use disorder. METHODS Male Wistar rats were allowed to voluntarily consume ethanol (EtOH) in an intermittent manner for 2 months, after which ex vivo electrophysiological recordings were performed and data compared with isolated water controls housed in parallel. RESULTS Field potential recordings revealed an increase in field excitatory postsynaptic potentials (fEPSPs) in the dorsomedial striatum (DMS) of rats consuming EtOH, while a depression of evoked potentials was detected in the dorsolateral striatum (DLS). Mean activity in cortical (medial prefrontal cortex, lateral orbitofrontal cortex [OFC]), and accumbal regions (nucleus accumbens [nAc] core/shell) was not significantly altered as compared to water-drinking controls, but a correlation between the amount of alcohol consumed and evoked potentials could be found in both dorsal striatal subregions, OFC, and nAc core. Removal of EtOH for 1 to 2 days was sufficient to restore neurotransmission in the DLS, while the increase in fEPSP amplitude sustained in the DMS. CONCLUSIONS These preclinical findings are in line with clinical observations indicating that alcohol produces neurophysiological transformations in dorsal striatal circuits, which in turn may lead to disruptions in decision-making processes that could further promote alcohol misuse.
Collapse
Affiliation(s)
- Oona Lagström
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Klara Danielsson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Louise Adermark
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
12
|
Endocannabinoid System and Alcohol Abuse Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1162:89-127. [PMID: 31332736 DOI: 10.1007/978-3-030-21737-2_6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Δ9-tetrahydrocannabinol (Δ9-THC), the primary active component in Cannabis sativa preparations such as hashish and marijuana, signals by binding to cell surface receptors. Two types of receptors have been cloned and characterized as cannabinoid (CB) receptors. CB1 receptors (CB1R) are ubiquitously present in the central nervous system (CNS) and are present in both inhibitory interneurons and excitatory neurons at the presynaptic terminal. CB2 receptors (CB2R) are demonstrated in microglial cells, astrocytes, and several neuron subpopulations and are present in both pre- and postsynaptic terminals. The majority of studies on these receptors have been conducted in the past two and half decades after the identification of the molecular constituents of the endocannabinoid (eCB) system that started with the characterization of CB1R. Subsequently, the seminal discovery was made, which suggested that alcohol (ethanol) alters the eCB system, thus establishing the contribution of the eCB system in the motivation to consume ethanol. Several preclinical studies have provided evidence that CB1R significantly contributes to the motivational and reinforcing properties of ethanol and that the chronic consumption of ethanol alters eCB transmitters and CB1R expression in the brain nuclei associated with addiction pathways. Additionally, recent seminal studies have further established the role of the eCB system in the development of ethanol-induced developmental disorders, such as fetal alcohol spectrum disorders (FASD). These results are augmented by in vitro and ex vivo studies, showing that acute and chronic treatment with ethanol produces physiologically relevant alterations in the function of the eCB system during development and in the adult stage. This chapter provides a current and comprehensive review of the literature concerning the role of the eCB system in alcohol abuse disorders (AUD).
Collapse
|
13
|
Budzynska B, Wnorowski A, Kaszubska K, Biala G, Kruk-Słomka M, Kurzepa J, Boguszewska-Czubara A. Acute MDMA and Nicotine Co-administration: Behavioral Effects and Oxidative Stress Processes in Mice. Front Behav Neurosci 2018; 12:149. [PMID: 30116179 PMCID: PMC6082960 DOI: 10.3389/fnbeh.2018.00149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 06/28/2018] [Indexed: 11/13/2022] Open
Abstract
3,4-Methylenedioxy-methylamphetamine (MDMA), a synthetic substance commonly known as ecstasy, is a worldwide recreational drug of abuse. As MDMA and nicotine activate the same neuronal pathways, we examined the influence of co-administration of nicotine (0.05 mg/kg) and MDMA (1 mg/kg) on cognitive processes, nicotine-induced behavioral sensitization and on processes linked with oxidative stress and α7 nicotinic acetylcholine receptors (nAChRs) expression in the brain of male Swiss mice. For behavioral study the passive avoidance (PA) test and locomotor sensitization paradigm were used. Also, the oxidative stress parameters as well as expression levels of α7 nAChRs in prefrontal cortex and hippocampus of mice treated with MDMA alone or in combination with nicotine were assessed. The results revealed that MDMA injections as well as co-administrations of MDMA and nicotine improved memory consolidation in male Swiss mice tested in PA task. Furthermore, one of the main findings of the present study is that MDMA increased locomotor activity in nicotine-sensitized mice. Our study showed for the first time strong behavioral and biochemical interactions between nicotine and MDMA. Both drugs are very often used in combination, especially by young people, thus these results may help explaining why psychoactive substances are being co-abused and why this polydrug administration is still a social problem.
Collapse
Affiliation(s)
- Barbara Budzynska
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Lublin, Poland
| | - Artur Wnorowski
- Department of Biopharmacy, Medical University of Lublin, Lublin, Poland
| | - Katarzyna Kaszubska
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Lublin, Poland
| | - Grazyna Biala
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Lublin, Poland
| | - Marta Kruk-Słomka
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Lublin, Poland
| | - Jacek Kurzepa
- Department of Medical Chemistry, Medical University of Lublin, Lublin, Poland
| | | |
Collapse
|
14
|
Complex Control of Striatal Neurotransmission by Nicotinic Acetylcholine Receptors via Excitatory Inputs onto Medium Spiny Neurons. J Neurosci 2018; 38:6597-6607. [PMID: 29941445 DOI: 10.1523/jneurosci.0071-18.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/06/2018] [Accepted: 05/10/2018] [Indexed: 01/12/2023] Open
Abstract
The prevalence of nicotine dependence is higher than that for any other substance abuse disorder; still, the underlying mechanisms are not fully established. To this end, we studied acute effects by nicotine on neurotransmission in the dorsolateral striatum, a key brain region with respect to the formation of habits. Electrophysiological recordings in acutely isolated brain slices from rodent showed that nicotine (10 nm to 10 μm) produced an LTD of evoked field potentials. Current-clamp recordings revealed no significant effect by nicotine on membrane voltage or action potential frequency, indicating that the effect by nicotine is primarily synaptic. Nicotine did not modulate sIPSCs, or the connectivity between fast-spiking interneurons and medium spiny neurons, as assessed by whole-cell recordings combined with optogenetics. However, the frequency of sEPSCs was significantly depressed by nicotine. The effect by nicotine was mimicked by agonists targeting α7- or α4-containing nAChRs and blocked in slices pretreated with a mixture of antagonists targeting these receptor subtypes. Nicotine-induced LTD was furthermore inhibited by dopamine D2 receptor antagonist and occluded by D2 receptor agonist. In addition, modulation of cholinergic neurotransmission suppressed the responding to nicotine, which might reflect upon the postulated role for nAChRs as a presynaptic filter to differentially govern dopamine release depending on neuronal activity. Nicotine-induced suppression of excitatory inputs onto medium spiny neurons may promote nicotine-induced locomotor stimulation and putatively initiate neuroadaptations that could contribute to the transition toward compulsive drug taking.SIGNIFICANCE STATEMENT To decrease smoking, prevalence factors that may contribute to the development of nicotine addiction need to be identified. The data presented here show that nicotine suppresses striatal neurotransmission by selectively reducing the frequency of excitatory inputs to medium spiny neurons (MSNs) while rendering excitability, inhibitory neurotransmission, and fast-spiking interneuron-MSN connectivity unaltered. In addition, we show that the effect displayed by nicotine outlasts the presence of the drug, which could be fundamental for the addictive properties of nicotine. Considering the inhibitory tone displayed by MSNs on dopaminergic cell bodies and local terminals, nicotine-induced long-lasting depression of striatal output could play a role in behavioral transformations associated with nicotine use, and putatively elicit neuroadaptations underlying compulsive drug-seeking habits.
Collapse
|
15
|
Augier E, Barbier E, Dulman RS, Licheri V, Augier G, Domi E, Barchiesi R, Farris S, Nätt D, Mayfield RD, Adermark L, Heilig M. A molecular mechanism for choosing alcohol over an alternative reward. Science 2018; 360:1321-1326. [DOI: 10.1126/science.aao1157] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 02/28/2018] [Accepted: 05/01/2018] [Indexed: 12/22/2022]
Abstract
Alcohol addiction leads to increased choice of alcohol over healthy rewards. We established an exclusive choice procedure in which ~15% of outbred rats chose alcohol over a high-value reward. These animals displayed addiction-like traits, including high motivation to obtain alcohol and pursuit of this drug despite adverse consequences. Expression of the γ-aminobutyric acid (GABA) transporter GAT-3 was selectively decreased within the amygdala of alcohol-choosing rats, whereas a knockdown of this transcript reversed choice preference of rats that originally chose a sweet solution over alcohol. GAT-3 expression was selectively decreased in the central amygdala of alcohol-dependent people compared to those who died of unrelated causes. Impaired GABA clearance within the amygdala contributes to alcohol addiction, appears to translate between species, and may offer targets for new pharmacotherapies for treating this disorder.
Collapse
|
16
|
Klenowski PM, Tapper AR. Molecular, Neuronal, and Behavioral Effects of Ethanol and Nicotine Interactions. Handb Exp Pharmacol 2018; 248:187-212. [PMID: 29423839 DOI: 10.1007/164_2017_89] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
17
|
Abrahao KP, Salinas AG, Lovinger DM. Alcohol and the Brain: Neuronal Molecular Targets, Synapses, and Circuits. Neuron 2017; 96:1223-1238. [PMID: 29268093 PMCID: PMC6566861 DOI: 10.1016/j.neuron.2017.10.032] [Citation(s) in RCA: 247] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/30/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
Abstract
Ethanol is one of the most commonly abused drugs. Although environmental and genetic factors contribute to the etiology of alcohol use disorders, it is ethanol's actions in the brain that explain (1) acute ethanol-related behavioral changes, such as stimulant followed by depressant effects, and (2) chronic changes in behavior, including escalated use, tolerance, compulsive seeking, and dependence. Our knowledge of ethanol use and abuse thus relies on understanding its effects on the brain. Scientists have employed both bottom-up and top-down approaches, building from molecular targets to behavioral analyses and vice versa, respectively. This review highlights current progress in the field, focusing on recent and emerging molecular, cellular, and circuit effects of the drug that impact ethanol-related behaviors. The focus of the field is now on pinpointing which molecular effects in specific neurons within a brain region contribute to behavioral changes across the course of acute and chronic ethanol exposure.
Collapse
Affiliation(s)
- Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - Armando G Salinas
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|
18
|
Zhang GJ, Wu MC, Shi JD, Xu YH, Chu CP, Cui SB, Qiu DL. Ethanol Modulates the Spontaneous Complex Spike Waveform of Cerebellar Purkinje Cells Recorded in vivo in Mice. Front Cell Neurosci 2017; 11:43. [PMID: 28293172 PMCID: PMC5328976 DOI: 10.3389/fncel.2017.00043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 02/09/2017] [Indexed: 11/18/2022] Open
Abstract
Cerebellar Purkinje cells (PCs) are sensitive to ethanol, but the effect of ethanol on spontaneous complex spike (CS) activity in these cells in vivo is currently unknown. Here, we investigated the effect of ethanol on spontaneous CS activity in PCs in urethane-anesthetized mice using in vivo patch-clamp recordings and pharmacological manipulation. Ethanol (300 mM) induced a decrease in the CS-evoked pause in simple spike (SS) firing and in the amplitude of the afterhyperpolarization (AHP) under current clamp conditions. Under voltage-clamp conditions, ethanol significantly decreased the area under the curve (AUC) and the number of CS spikelets, without changing the spontaneous frequency of the CSs or the instantaneous frequency of the CS spikelets. Ethanol-induced a decrease in the AUC of spontaneous CSs was concentration dependent. The EC50 of ethanol for decreasing the AUC of spontaneous CSs was 168.5 mM. Blocking N-methyl-D-aspartate receptors (NMDARs) failed to prevent the ethanol-induced decreases in the CS waveform parameters. However, blockade of cannabinoid receptor 1 (CB1) significantly suppressed the ethanol-induced effects on the CS-evoked pause in SS firing, amplitude of the AHP, spikelet number and the AUC of CSs. Moreover, a CB1 receptor agonist not only reduced the number of spikelets and the AUC of CSs, but also prevented the ethanol-induced inhibition of CS activity. Our results indicate that ethanol inhibits CS activity via activation of the CB1 receptor in vivo in mice, suggesting that excessive ethanol intake inhibits climbing fiber (CF)–PC synaptic transmission by modulating CB1 receptors in the cerebellar cortex.
Collapse
Affiliation(s)
- Guang-Jian Zhang
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, YanBian UniversityYanji City, China; Department of Pain, Affiliated Hospital of Yanbian UniversityYanji City, China
| | - Mao-Cheng Wu
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, YanBian UniversityYanji City, China; Department of Osteology, Affiliated Hospital of Yanbian UniversityYanji City, China
| | - Jin-Di Shi
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, YanBian UniversityYanji City, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian UniversityYanji City, China
| | - Yin-Hua Xu
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, YanBian UniversityYanji City, China; Department of Neurology, Affiliated Hospital of Yanbian UniversityYanji City, China
| | - Chun-Ping Chu
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, YanBian University Yanji City, China
| | - Song-Biao Cui
- Department of Neurology, Affiliated Hospital of Yanbian University Yanji City, China
| | - De-Lai Qiu
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, YanBian UniversityYanji City, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian UniversityYanji City, China
| |
Collapse
|
19
|
Adermark L, Morud J, Lotfi A, Danielsson K, Ulenius L, Söderpalm B, Ericson M. Temporal Rewiring of Striatal Circuits Initiated by Nicotine. Neuropsychopharmacology 2016; 41:3051-3059. [PMID: 27388328 PMCID: PMC5101553 DOI: 10.1038/npp.2016.118] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 05/18/2016] [Accepted: 06/30/2016] [Indexed: 01/24/2023]
Abstract
Drug addiction has been conceptualized as maladaptive recruitment of integrative circuits coursing through the striatum, facilitating drug-seeking and drug-taking behavior. The aim of this study was to define temporal neuroadaptations in striatal subregions initiated by 3 weeks of intermittent nicotine exposure followed by protracted abstinence. Enhanced rearing activity was assessed in motor activity boxes as a measurement of behavioral change induced by nicotine (0.36 mg/kg), whereas electrophysiological field potential recordings were performed to evaluate treatment effects on neuronal activity. Dopamine receptor mRNA expression was quantified by qPCR, and nicotine-induced dopamine release was measured in striatal subregions using in vivo microdialysis. Golgi staining was performed to assess nicotine-induced changes in spine density of medium spiny neurons. The data presented here show that a brief period of nicotine exposure followed by abstinence leads to temporal changes in synaptic efficacy, dopamine receptor expression, and spine density in a subregion-specific manner. Nicotine may thus initiate a reorganization of striatal circuits that continues to develop despite protracted abstinence. We also show that the response to nicotine is modulated in previously exposed rats even after 6 months of abstinence. The data presented here suggests that, even though not self-administered, nicotine may produce progressive neuronal alterations in brain regions associated with goal-directed and habitual performance, which might contribute to the development of compulsive drug seeking and the increased vulnerability to relapse, which are hallmarks of drug addiction.
Collapse
Affiliation(s)
- Louise Adermark
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at The University of Gothenburg, Gothenburg, Sweden
| | - Julia Morud
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at The University of Gothenburg, Gothenburg, Sweden
| | - Amir Lotfi
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at The University of Gothenburg, Gothenburg, Sweden
| | - Klara Danielsson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at The University of Gothenburg, Gothenburg, Sweden
| | - Lisa Ulenius
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at The University of Gothenburg, Gothenburg, Sweden
- Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at The University of Gothenburg, Gothenburg, Sweden
- Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at The University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
20
|
Zhang X, Yao N, Chergui K. The GABAA receptor agonist muscimol induces an age- and region-dependent form of long-term depression in the mouse striatum. ACTA ACUST UNITED AC 2016; 23:479-85. [PMID: 27531838 PMCID: PMC4986858 DOI: 10.1101/lm.043190.116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 07/11/2016] [Indexed: 01/21/2023]
Abstract
Several forms of long-term depression (LTD) of glutamatergic synaptic transmission have been identified in the dorsal striatum and in the nucleus accumbens (NAc). Such experience-dependent synaptic plasticity might play important roles in reward-related learning. The GABAA receptor agonist muscimol was recently found to trigger a long-lasting depression of glutamatergic synaptic transmission in the NAc of adolescent mice, but the mechanisms that underlie this novel form of LTD were not studied. Here we examined the effect of muscimol applied in the perfusion solution on the amplitude of field excitatory postsynaptic potentials/population spikes (fEPSP/PSs) in mouse brain slices. We found that muscimol depressed the fEPSP/PS in the NAc of adolescent mice but not adult mice, through both postsynaptic and presynaptic mechanisms. Indeed, muscimol altered the fEPSP/PS paired-pulse ratio, depolarized the membrane of projection neurons, and decreased the frequency, but not amplitude, of spontaneous excitatory postsynaptic currents in the NAc of adolescent mice. The LTD induced by muscimol likely involved endocannabinoids, metabotropic glutamate receptors (mGluRs), but not TRPV1 receptors. Muscimol-LTD was occluded by prior induction of LTD through low-frequency stimulation (LFS) of the slice, demonstrating a common pathway in the induction of LFS-LTD and muscimol-LTD. We also found that muscimol induced a form of LTD in the dorsolateral striatum of adult but not adolescent mice. This LTD was mediated by endocannabinoids but did not involve mGluRs or TRPV1 receptors. These results identify a novel form of synaptic plasticity, and its mechanisms of induction, which is age and region dependent. These findings may contribute to a better understanding of the increased susceptibility of the adolescent brain to long-term synaptic changes in regions associated with reward mechanisms.
Collapse
Affiliation(s)
- Xiaoqun Zhang
- The Karolinska Institute, Department of Physiology and Pharmacology, Section of Molecular Neurophysiology, 171 77 Stockholm, Sweden
| | - Ning Yao
- The Karolinska Institute, Department of Physiology and Pharmacology, Section of Molecular Neurophysiology, 171 77 Stockholm, Sweden
| | - Karima Chergui
- The Karolinska Institute, Department of Physiology and Pharmacology, Section of Molecular Neurophysiology, 171 77 Stockholm, Sweden
| |
Collapse
|
21
|
Ethanol modulates facial stimulation-evoked outward currents in cerebellar Purkinje cells in vivo in mice. Sci Rep 2016; 6:30857. [PMID: 27489024 PMCID: PMC4973232 DOI: 10.1038/srep30857] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 07/08/2016] [Indexed: 11/16/2022] Open
Abstract
Acute ethanol overdose can induce dysfunction of cerebellar motor regulation and cerebellar ataxia. In this study, we investigated the effect of ethanol on facial stimulation-evoked inhibitory synaptic responses in cerebellar Purkinje cells (PCs) in urethane-anesthetized mice, using in vivo patch-clamp recordings. Under voltage-clamp conditions, ethanol (300 mM) decreased the amplitude, half-width, rise time and decay time of facial stimulation-evoked outward currents in PCs. The ethanol-induced inhibition of facial stimulation-evoked outward currents was dose-dependent, with an IC50 of 148.5 mM. Notably, the ethanol-induced inhibition of facial stimulation-evoked outward currents were significantly abrogated by cannabinoid receptor 1 (CB1) antagonists, AM251 and O-2050, as well as by the CB1 agonist WIN55212-2. Moreover, the ethanol-induced inhibition of facial stimulation-evoked outward currents was prevented by cerebellar surface perfusion of the PKA inhibitors H-89 and Rp-cAMP, but not by intracellular administration of the PKA inhibitor PKI. Our present results indicate that ethanol inhibits the facial stimulation-evoked outward currents by activating presynaptic CB1 receptors via the PKA signaling pathway. These findings suggest that ethanol overdose impairs sensory information processing, at least in part, by inhibiting GABA release from molecular layer interneurons onto PCs.
Collapse
|
22
|
Patton MH, Roberts BM, Lovinger DM, Mathur BN. Ethanol Disinhibits Dorsolateral Striatal Medium Spiny Neurons Through Activation of A Presynaptic Delta Opioid Receptor. Neuropsychopharmacology 2016; 41:1831-40. [PMID: 26758662 PMCID: PMC4869052 DOI: 10.1038/npp.2015.353] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/14/2015] [Accepted: 12/01/2015] [Indexed: 11/09/2022]
Abstract
The dorsolateral striatum mediates habit formation, which is expedited by exposure to alcohol. Across species, alcohol exposure disinhibits the DLS by dampening GABAergic transmission onto this structure's principal medium spiny projection neurons (MSNs), providing a potential mechanistic basis for habitual alcohol drinking. However, the molecular and circuit components underlying this disinhibition remain unknown. To examine this, we used a combination of whole-cell patch-clamp recordings and optogenetics to demonstrate that ethanol potently depresses both MSN- and fast-spiking interneuron (FSI)-MSN GABAergic synaptic transmission in the DLS. Concentrating on the powerfully inhibitory FSI-MSN synapse, we further show that acute exposure of ethanol (50 mM) to striatal slices activates delta opioid receptors that reside on FSI axon terminals and negatively couple to adenylyl cyclase to induce a long-term depression of GABA release onto both direct and indirect pathway MSNs. These findings elucidate a mechanism through which ethanol may globally disinhibit the DLS.
Collapse
Affiliation(s)
- Mary H Patton
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bradley M Roberts
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - David M Lovinger
- Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, US National Institutes of Health, Bethesda, MD, USA
| | - Brian N Mathur
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Pharmacology, University of Maryland School of Medicine, BRB RM 4011, 655 West Baltimore Street, Baltimore, MD 21201, USA, Tel: +410 706 8239, Fax: +410 706 8341, E-mail:
| |
Collapse
|
23
|
Korpi ER, den Hollander B, Farooq U, Vashchinkina E, Rajkumar R, Nutt DJ, Hyytiä P, Dawe GS. Mechanisms of Action and Persistent Neuroplasticity by Drugs of Abuse. Pharmacol Rev 2015; 67:872-1004. [DOI: 10.1124/pr.115.010967] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
24
|
Abstract
Brain endocannabinoid (eCB) signalling influences the motivation for natural rewards (such as palatable food, sexual activity and social interaction) and modulates the rewarding effects of addictive drugs. Pathological forms of natural and drug-induced reward are associated with dysregulated eCB signalling that may derive from pre-existing genetic factors or from prolonged drug exposure. Impaired eCB signalling contributes to dysregulated synaptic plasticity, increased stress responsivity, negative emotional states and cravings that propel addiction. Understanding the contributions of eCB disruptions to behavioural and physiological traits provides insight into the eCB influence on addiction vulnerability.
Collapse
Affiliation(s)
- Loren H Parsons
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Yasmin L Hurd
- Friedman Brain Institute, Departments of Psychiatry and Neuroscience, Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York City, New York 10029, USA
| |
Collapse
|
25
|
Ji X, Saha S, Martin GE. The origin of glutamatergic synaptic inputs controls synaptic plasticity and its modulation by alcohol in mice nucleus accumbens. Front Synaptic Neurosci 2015; 7:12. [PMID: 26257641 PMCID: PMC4507144 DOI: 10.3389/fnsyn.2015.00012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/06/2015] [Indexed: 01/08/2023] Open
Abstract
It is widely accepted that long-lasting changes of synaptic strength in the nucleus accumbens (NAc), a brain region involved in drug reward, mediate acute and chronic effects of alcohol. However, our understanding of the mechanisms underlying the effects of alcohol on synaptic plasticity is limited by the fact that the NAc receives glutamatergic inputs from distinct brain regions (e.g., the prefrontal cortex (PFCx), the amygdala and the hippocampus), each region providing different information (e.g., spatial, emotional and cognitive). Combining whole-cell patch-clamp recordings and the optogenetic technique, we examined synaptic plasticity, and its regulation by alcohol, at cortical, hippocampal and amygdala inputs in fresh slices of mouse tissue. We showed that the origin of synaptic inputs determines the basic properties of glutamatergic synaptic transmission, the expression of spike-timing dependent long-term depression (tLTD) and long-term potentiation (LTP) and long-term potentiation (tLTP) and their regulation by alcohol. While we observed both tLTP and tLTD at amygadala and hippocampal synapses, we showed that cortical inputs only undergo tLTD. Functionally, we provide evidence that acute Ethyl Alcohol (EtOH) has little effects on higher order information coming from the PFCx, while severely impacting the ability of emotional and contextual information to induce long-lasting changes of synaptic strength.
Collapse
Affiliation(s)
- Xincai Ji
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School Worcester, MA, USA
| | - Sucharita Saha
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School Worcester, MA, USA
| | - Gilles E Martin
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School Worcester, MA, USA
| |
Collapse
|
26
|
Adermark L, Morud J, Lotfi A, Jonsson S, Söderpalm B, Ericson M. Age-contingent influence over accumbal neurotransmission and the locomotor stimulatory response to acute and repeated administration of nicotine in Wistar rats. Neuropharmacology 2015; 97:104-12. [PMID: 26079444 DOI: 10.1016/j.neuropharm.2015.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/28/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022]
Abstract
Nicotine addiction is one of the leading contributors to the global burden of disease, and early onset smokers report a more severe addiction with lower chance of cessation than those with a late onset. Preclinical research supports an age-dependent component to the rewarding and reinforcing properties of nicotine, and the aim of this study was to define behavioral adaptations and changes in accumbal neurotransmission that arise over 15 days of intermittent nicotine treatment (0.36 mg/kg/day) in rats of three different ages (5 weeks, 10 weeks, 36 weeks old). Repeated treatment increased the locomotor stimulatory response to nicotine in all age groups, but significantly faster in the two younger groups. In addition, nicotine decreased rearing activity in a way that sustained even after repeated administration in aged rats but not in the younger age groups. Electrophysiological field potential recordings revealed a decline in input/output function in the nucleus accumbens (NAc) of animals intermittently treated with nicotine starting at 5 weeks of age, but not in older animals. In drug naïve rats, acute administration of nicotine modulated both accumbal dopamine output and excitatory transmission in a partially age-dependent manner. Fifteen days of intermittent nicotine treatment did not alter the acute effect displayed by nicotine on dopamine levels or evoked field potentials. The data presented here show that both acute and repeated nicotine administration modulates accumbal neurotransmission and behavior in an age-contingent manner and that these age-dependent differences could reflect important neurobiological underpinnings associated with the increased vulnerability for nicotine-addiction in adolescents.
Collapse
Affiliation(s)
- L Adermark
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
| | - J Morud
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - A Lotfi
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - S Jonsson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - B Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - M Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
27
|
Zhang X, Feng ZJ, Chergui K. Induction of cannabinoid- and N-methyl-D-aspartate receptor-mediated long-term depression in the nucleus accumbens and dorsolateral striatum is region and age dependent. Int J Neuropsychopharmacol 2015; 18:pyu052. [PMID: 25618403 PMCID: PMC4360221 DOI: 10.1093/ijnp/pyu052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The adolescent brain is sensitive to experience-dependent plasticity and might be more vulnerable than the adult brain to the effects of some drugs of abuse. The factors that contribute to these differences are not fully identified. We have examined the ability of cannabinoids to induce a form of synaptic plasticity, long-term depression, in the nucleus accumbens and dorsolateral striatum of adolescent and adult mice. METHODS We measured field excitatory postsynaptic potentials/population spikes in brain slices. RESULTS We found that the cannabinoid receptor agonist WIN 55,212-2 (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone mesylate) induced long-term depression in the nucleus accumbens of adolescent but not adult mice and failed to induce long-term depression in the dorsolateral striatum of adolescent or adult mice. Similar results were obtained with the group I metabotropic glutamate receptor agonist (S)-3,5- dihydroxyphenylglycine, which has previously been shown to promote the release of endocannabinoids. These age-related differences were associated with reduced protein levels of the cannabinoid type 1 receptor and metabotropic glutamate receptor 1 in adult nucleus accumbens and dorsolateral striatum and with an increased tone of endocannabinoids in the dorsolateral striatum of adult mice. We also found that N-methyl-D-aspartate receptor-dependent long-term depression, which was induced in the nucleus accumbens of adolescent mice, was blunted in adult mice, possibly because of decreased levels of GluN1, the obligatory subunit of N-methyl-D-aspartate receptors. CONCLUSIONS This study identifies region- and age-specific differences in the ability of endogenous and exogenous cannabinoids, and of N-methyl-D-aspartate receptors, to induce long-term depression in the striatal complex. These observations might contribute to a better understanding of the increased sensitivity of the adolescent brain to drug induced-plasticity.
Collapse
Affiliation(s)
| | | | - Karima Chergui
- The Karolinska Institute, Department of Physiology and Pharmacology, Section of Molecular Neurophysiology, Von Eulers väg 8, 171 77 Stockholm, Sweden (Drs Zhang, Feng, and Chergui).
| |
Collapse
|
28
|
The involvement of accumbal glycine receptors in the dopamine-elevating effects of addictive drugs. Neuropharmacology 2014; 82:69-75. [PMID: 24686030 DOI: 10.1016/j.neuropharm.2014.03.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 03/14/2014] [Accepted: 03/18/2014] [Indexed: 10/25/2022]
Abstract
The ability of drugs of abuse to increase mesolimbic levels of dopamine is a characteristic associated with their rewarding effects. Exactly how these effects are produced by different substances is not as well characterised. Our previous work in rats has demonstrated that accumbal glycine receptors (GlyRs) are involved in mediating the dopamine-activating effects of ethanol, and in modulating ethanol intake. In this study the investigation of GlyR involvement was extended to include several different drugs of abuse. By using microdialysis and electrophysiology we compared effects of addictive drugs, with and without the GlyR antagonist strychnine, on dopamine levels and neurotransmission in nucleus accumbens. The dopamine-increasing effect of systemic ethanol and the drug-induced change in neurotransmission in vitro, as measured by microdialysis and field potential recordings, were dependent on GlyRs in nAc. Accumbal GlyRs were also involved in the actions of tetrahydrocannabinol and nicotine, but not in those of cocaine or morphine. These data indicate that accumbal GlyRs play a key role in ethanol-induced dopamine activation and contribute also to that of cannabinoids and nicotine.
Collapse
|
29
|
McPartland JM, Guy GW, Di Marzo V. Care and feeding of the endocannabinoid system: a systematic review of potential clinical interventions that upregulate the endocannabinoid system. PLoS One 2014; 9:e89566. [PMID: 24622769 PMCID: PMC3951193 DOI: 10.1371/journal.pone.0089566] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 01/21/2014] [Indexed: 12/31/2022] Open
Abstract
Background The “classic” endocannabinoid (eCB) system includes the cannabinoid receptors CB1 and CB2, the eCB ligands anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and their metabolic enzymes. An emerging literature documents the “eCB deficiency syndrome” as an etiology in migraine, fibromyalgia, irritable bowel syndrome, psychological disorders, and other conditions. We performed a systematic review of clinical interventions that enhance the eCB system—ways to upregulate cannabinoid receptors, increase ligand synthesis, or inhibit ligand degradation. Methodology/Principal Findings We searched PubMed for clinical trials, observational studies, and preclinical research. Data synthesis was qualitative. Exclusion criteria limited the results to 184 in vitro studies, 102 in vivo animal studies, and 36 human studies. Evidence indicates that several classes of pharmaceuticals upregulate the eCB system, including analgesics (acetaminophen, non-steroidal anti-inflammatory drugs, opioids, glucocorticoids), antidepressants, antipsychotics, anxiolytics, and anticonvulsants. Clinical interventions characterized as “complementary and alternative medicine” also upregulate the eCB system: massage and manipulation, acupuncture, dietary supplements, and herbal medicines. Lifestyle modification (diet, weight control, exercise, and the use of psychoactive substances—alcohol, tobacco, coffee, cannabis) also modulate the eCB system. Conclusions/Significance Few clinical trials have assessed interventions that upregulate the eCB system. Many preclinical studies point to other potential approaches; human trials are needed to explore these promising interventions.
Collapse
Affiliation(s)
- John M. McPartland
- GW Pharmaceuticals, Porton Down Science Park, Salisbury, Wiltshire, United Kingdom
- Department of Family Medicine, University of Vermont, Burlington, Vermont, United States of America
- * E-mail:
| | - Geoffrey W. Guy
- GW Pharmaceuticals, Porton Down Science Park, Salisbury, Wiltshire, United Kingdom
| | - Vincenzo Di Marzo
- Endocannabinoid Research Group, Istituto di Chimica Biomoleculare, CNR, Via Campi Flegrei, Pozzuoli, Napoli, Italy
| |
Collapse
|
30
|
Acute and chronic effects of ethanol on learning-related synaptic plasticity. Alcohol 2014; 48:1-17. [PMID: 24447472 DOI: 10.1016/j.alcohol.2013.09.045] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 09/16/2013] [Accepted: 09/18/2013] [Indexed: 11/23/2022]
Abstract
Alcoholism is associated with acute and long-term cognitive dysfunction including memory impairment, resulting in substantial disability and cost to society. Thus, understanding how ethanol impairs cognition is essential for developing treatment strategies to dampen its adverse impact. Memory processing is thought to involve persistent, use-dependent changes in synaptic transmission, and ethanol alters the activity of multiple signaling molecules involved in synaptic processing, including modulation of the glutamate and gamma-aminobutyric acid (GABA) transmitter systems that mediate most fast excitatory and inhibitory transmission in the brain. Effects on glutamate and GABA receptors contribute to ethanol-induced changes in long-term potentiation (LTP) and long-term depression (LTD), forms of synaptic plasticity thought to underlie memory acquisition. In this paper, we review the effects of ethanol on learning-related forms of synaptic plasticity with emphasis on changes observed in the hippocampus, a brain region that is critical for encoding contextual and episodic memories. We also include studies in other brain regions as they pertain to altered cognitive and mental function. Comparison of effects in the hippocampus to other brain regions is instructive for understanding the complexities of ethanol's acute and long-term pharmacological consequences.
Collapse
|
31
|
Alijanpour S, Rezayof A. Involvement of dorsal hippocampal and medial septal nicotinic receptors in cross state-dependent memory between WIN55, 212-2 and nicotine or ethanol in mice. Neuroscience 2013; 245:61-73. [DOI: 10.1016/j.neuroscience.2013.04.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 04/11/2013] [Accepted: 04/15/2013] [Indexed: 12/28/2022]
|
32
|
Region-specific depression of striatal activity in Wistar rat by modest ethanol consumption over a ten-month period. Alcohol 2013; 47:289-98. [PMID: 23601928 DOI: 10.1016/j.alcohol.2013.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/11/2013] [Accepted: 03/25/2013] [Indexed: 11/22/2022]
Abstract
The nucleus accumbens (nAc) is the primary target for the mesolimbic dopamine system and a key brain region for the reinforcing effects displayed by drugs of abuse, including ethanol. During the transition from recreational to compulsive consumption of reinforcing drugs, however, the dorsal striatum seems to be recruited. Understanding how synaptic activity is altered in a sub-region specific manner in the striatum during the course of long-term drug consumption thus could be essential for understanding the long-lasting changes produced by addictive substances, including ethanol. Here we evaluated synaptic activity in the dorsolateral striatum (DLS) and ventral striatum (nucleus accumbens, nAc) of single-housed Wistar rats consuming water, or water and ethanol, for up to 10 months. Even though ethanol intake was moderate, it was sufficient to decrease input/output function in response to stimulation intensity in the DLS, while recorded population spike (PS) amplitudes in the nAc were unaffected. Striatal disinhibition induced by the GABAA receptor antagonist bicuculline had a slower onset in rats that had consumed ethanol for 2 months, and was significantly depressed in slices from rats that had consumed ethanol for 4 months. Bicuculline-induced disinhibition in the nAc, on the other hand, was not significantly altered by long-term ethanol intake. Changes in PS amplitude induced by taurine or the glycine receptor antagonist strychnine were not significantly altered by ethanol in any brain region. Even though input/output function was not significantly affected by age, there was a significant decline in antagonist-induced disinhibition in brain slices from aged rats. The data presented here suggest that even modest consumption of ethanol is sufficient to alter neurotransmission in the striatum, while synaptic activity appears to be relatively well-preserved in the nAc during the course of long-term ethanol consumption.
Collapse
|
33
|
Pava MJ, Woodward JJ. A review of the interactions between alcohol and the endocannabinoid system: implications for alcohol dependence and future directions for research. Alcohol 2012; 46:185-204. [PMID: 22459871 PMCID: PMC3327810 DOI: 10.1016/j.alcohol.2012.01.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/10/2012] [Accepted: 01/26/2012] [Indexed: 12/17/2022]
Abstract
Over the past fifty years a significant body of evidence has been compiled suggesting an interaction between the endocannabinoid (EC) system and alcohol dependence. However, much of this work has been conducted only in the past two decades following the elucidation of the molecular constituents of the EC system that began with the serendipitous discovery of the cannabinoid 1 receptor (CB1). Since then, novel pharmacological and genetic tools have enabled researchers to manipulate select components of the EC system, to determine their contribution to the motivation to consume ethanol. From these preclinical studies, it is evident that CB1 contributes the motivational and reinforcing properties of ethanol, and chronic consumption of ethanol alters EC transmitter levels and CB1 expression in brain nuclei associated with addiction pathways. These results are augmented by in vitro and ex vivo studies showing that acute and chronic treatment with ethanol produces physiologically relevant alterations in the function of the EC system. This report provides a current and comprehensive review of the literature regarding the interactions between ethanol and the EC system. We begin be reviewing the studies published prior to the discovery of the EC system that compared the behavioral and physiological effects of cannabinoids with ethanol in addition to cross-tolerance between these drugs. Next, a brief overview of the molecular constituents of the EC system is provided as context for the subsequent review of more recent studies examining the interaction of ethanol with the EC system. These results are compiled into a summary providing a scheme for the known changes to the components of the EC system in different stages of alcohol dependence. Finally, future directions for research are discussed.
Collapse
Affiliation(s)
- Matthew J. Pava
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29403, USA
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC 29403, USA
| | - John J. Woodward
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29403, USA
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC 29403, USA
| |
Collapse
|
34
|
Adermark L, Clarke RBC, Ericson M, Söderpalm B. Subregion-Specific Modulation of Excitatory Input and Dopaminergic Output in the Striatum by Tonically Activated Glycine and GABA(A) Receptors. Front Syst Neurosci 2011; 5:85. [PMID: 22028683 PMCID: PMC3199543 DOI: 10.3389/fnsys.2011.00085] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 09/28/2011] [Indexed: 12/29/2022] Open
Abstract
The flow of cortical information through the basal ganglia is a complex spatiotemporal pattern of increased and decreased firing. The striatum is the biggest input nucleus to the basal ganglia and the aim of this study was to assess the role of inhibitory GABAA and glycine receptors in regulating synaptic activity in the dorsolateral striatum (DLS) and ventral striatum (nucleus accumbens, nAc). Local field potential recordings from coronal brain slices of juvenile and adult Wistar rats showed that GABAA receptors and strychnine-sensitive glycine receptors are tonically activated and inhibit excitatory input to the DLS and to the nAc. Strychnine-induced disinhibition of glutamatergic transmission was insensitive to the muscarinic receptor inhibitor scopolamine (10 μM), inhibited by the nicotinic acetylcholine receptor antagonist mecamylamine (10 μM) and blocked by GABAA receptor inhibitors, suggesting that tonically activated glycine receptors depress excitatory input to the striatum through modulation of cholinergic and GABAergic neurotransmission. As an end-product example of striatal GABAergic output in vivo we measured dopamine release in the DLS and nAc by microdialysis in the awake and freely moving rat. Reversed dialysis of bicuculline (50 μM in perfusate) only increased extrasynaptic dopamine levels in the nAc, while strychnine administered locally (200 μM in perfusate) decreased dopamine output by 60% in both the DLS and nAc. Our data suggest that GABAA and glycine receptors are tonically activated and modulate striatal transmission in a partially subregion-specific manner.
Collapse
Affiliation(s)
- Louise Adermark
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg Gothenburg, Sweden
| | | | | | | |
Collapse
|
35
|
Adermark L. Modulation of endocannabinoid-mediated long-lasting disinhibition of striatal output by cholinergic interneurons. Neuropharmacology 2011; 61:1314-20. [PMID: 21839753 DOI: 10.1016/j.neuropharm.2011.07.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 07/22/2011] [Accepted: 07/25/2011] [Indexed: 12/22/2022]
Abstract
The frequency and duration of glutamatergic inputs to the striatum are strong determinants of the net effect of retrograde endocannabinoid (eCB) signaling, and key factors in determining if long-term depression (LTD) has a net disinhibitory or inhibitory action in striatum. Low to moderate frequency stimulation in the dorsolateral striatum elevates eCB levels to an extent that primarily depresses transmitter release at inhibitory synapses, leading to a long-lasting disinhibition (DLL) of synaptic output. The aim of this study was to further characterize the basic features of endocannabinoid-mediated DLL of striatal output induced by moderate frequency stimulation (5 Hz, 60 s). DLL was inhibited in slices treated with the group 1 metabotropic glutamate receptor (mGluR) antagonists MPEP (40 μM) and CPCCOEt (40 μM), the dopamine D2 receptor antagonist sulpiride (5 μM), the L-type calcium channel blocker nifedipine (20 μM), the nicotinic receptor antagonist mecamylamine (10 μM), the muscarinic agonist oxotremorine sesquifumarate (10 μM), and strychnine (0.1 μM). Strychnine did not block DLL induced by WIN55,212-2 (250 nM), showing that glycine receptor-mediated modulation of eCB signaling occurs upstream from CB(1)R activation. Scopolamine (10 μM) restored DLL in strychnine-treated slices, suggesting that inhibition of glycine receptors on cholinergic interneurons could modulate eCB signaling by enhancing muscarinic receptor activation and reducing the opening of L-type calcium channels in response to depolarization. These data suggests that similar activation points are required for stimulation-induced DLL as for LTD at excitatory striatal synapses, and that cholinergic interneurons are key modulators of stimulation-induced eCB signaling in the striatum.
Collapse
Affiliation(s)
- Louise Adermark
- Addiction Biology Unit, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Box 410, 405 30 Gothenburg, Sweden.
| |
Collapse
|
36
|
Serrano A, Parsons LH. Endocannabinoid influence in drug reinforcement, dependence and addiction-related behaviors. Pharmacol Ther 2011; 132:215-41. [PMID: 21798285 DOI: 10.1016/j.pharmthera.2011.06.005] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 06/17/2011] [Indexed: 12/12/2022]
Abstract
The endogenous cannabinoid system is an important regulatory system involved in physiological homeostasis. Endocannabinoid signaling is known to modulate neural development, immune function, metabolism, synaptic plasticity and emotional state. Accumulating evidence also implicates brain endocannabinoid signaling in the etiology of drug addiction which is characterized by compulsive drug seeking, loss of control in limiting drug intake, emergence of a negative emotional state in the absence of drug use and a persistent vulnerability toward relapse to drug use during protracted abstinence. In this review we discuss the effects of drug intake on brain endocannabinoid signaling, evidence implicating the endocannabinoid system in the motivation for drug consumption, and drug-induced alterations in endocannabinoid function that may contribute to various aspects of addiction including dysregulated synaptic plasticity, increased stress responsivity, negative affective states, drug craving and relapse to drug taking. Current knowledge of genetic variants in endocannabinoid signaling associated with addiction is also discussed.
Collapse
Affiliation(s)
- Antonia Serrano
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | |
Collapse
|
37
|
Sidhpura N, Parsons LH. Endocannabinoid-mediated synaptic plasticity and addiction-related behavior. Neuropharmacology 2011; 61:1070-87. [PMID: 21669214 DOI: 10.1016/j.neuropharm.2011.05.034] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 05/26/2011] [Accepted: 05/29/2011] [Indexed: 01/20/2023]
Abstract
Endogenous cannabinoids (eCBs) are retrograde messengers that provide feedback inhibition of both excitatory and inhibitory transmission in brain through the activation of presynaptic CB₁ receptors. Substantial evidence indicates that eCBs mediate various forms of short- and long-term plasticity in brain regions involved in the etiology of addiction. The present review provides an overview of the mechanisms through which eCBs mediate various forms of synaptic plasticity and discusses evidence that eCB-mediated plasticity is disrupted following exposure to a variety of abused substances that differ substantially in pharmacodynamic mechanism including alcohol, psychostimulants and cannabinoids. The possible involvement of dysregulated eCB signaling in maladaptive behaviors that evolve over long-term drug exposure is also discussed, with a particular focus on altered behavioral responses to drug exposure, deficient extinction of drug-related memories, increased drug craving and relapse, heightened stress sensitivity and persistent affective disruption (anxiety and depression).
Collapse
Affiliation(s)
- Nimish Sidhpura
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | | |
Collapse
|
38
|
Ethanol affects striatal interneurons directly and projection neurons through a reduction in cholinergic tone. Neuropsychopharmacology 2011; 36:1033-46. [PMID: 21289603 PMCID: PMC3077272 DOI: 10.1038/npp.2010.241] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The acute effects of ethanol on the neurons of the striatum, a basal ganglia nucleus crucially involved in motor control and action selection, were investigated using whole-cell recordings. An intoxicating concentration of ethanol (50 mM) produced inhibitory effects on striatal large aspiny cholinergic interneurons (LAIs) and low-threshold spike interneurons (LTSIs). These effects persisted in the presence of tetrodotoxin and were because of an increase in potassium currents, including those responsible for medium and slow afterhyperpolarizations. In contrast, fast-spiking interneurons (FSIs) were directly excited by ethanol, which depolarized these neurons through the suppression of potassium currents. Medium spiny neurons (MSNs) became hyperpolarized in the presence of ethanol, but this effect did not persist in the presence of tetrodotoxin and was mimicked and occluded by application of the M1 muscarinic receptor antagonist telenzepine. Ethanol effects on MSNs were also abolished by 100 μM barium. This showed that the hyperpolarizations observed in MSNs were because of decreased tonic activation of M1 muscarinic receptors, resulting in an increase in Kir2 conductances. Evoked GABAergic responses of MSNs were reversibly decreased by ethanol with no change in paired-pulse ratio. Furthermore, ethanol impaired the ability of thalamostriatal inputs to inhibit a subsequent corticostriatal glutamatergic response in MSNs. These results offer the first comprehensive description of the highly cell type-specific effects of ethanol on striatal neurons and provide a cellular basis for the interpretation of ethanol influence on a brain area crucially involved in the motor and decisional impairment caused by this drug.
Collapse
|
39
|
Adermark L, Jonsson S, Ericson M, Söderpalm B. Intermittent ethanol consumption depresses endocannabinoid-signaling in the dorsolateral striatum of rat. Neuropharmacology 2011; 61:1160-5. [PMID: 21251919 DOI: 10.1016/j.neuropharm.2011.01.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 12/23/2010] [Accepted: 01/10/2011] [Indexed: 11/19/2022]
Abstract
Recent research suggests that adaptations elicited by drugs of abuse share common features with traditional learning models, and that drugs of abuse cause long-term changes in behavior by altering synaptic function and plasticity. In this study, endocannabinoid (eCB) signaling in the dorsolateral striatum, a brain region vital for habit formation, was evaluated in acutely isolated brain slices from ethanol (EtOH)-consuming rats and control rats. EtOH-consuming rats had free access to a 20% EtOH solution for three 24 hour sessions a week during seven weeks and consumed an average of 3.4 g/kg per session. eCB-mediated long-lasting disinhibition (DLL) of population spike (PS) amplitude induced by moderate frequency stimulation was impaired in EtOH-consuming rats, and was not restored by the muscarinic receptor antagonist scopolamine (10 μM). The lack of DLL could be linked to a reduced GABA(A) receptor tone, since bicuculline-mediated disinhibition of striatal output was significantly reduced in slices from EtOH-consuming rats. However, eCB signaling induced by high frequency stimulation (HFS) was also impaired in slices from EtOH-consuming rats and isolated control rats. Activation of presynaptic cannabinoid 1 receptors (CB1R) with WIN55,212-2 (250 nM, 1 μM) significantly modulated PS amplitude in slices from age-matched control rats while slices from EtOH-consuming rats remained unaffected, indicating that eCB signaling is inhibited at a level that is downstream from CB1R activation. Intermittent alcohol intake for seven weeks might thus be sufficient to modulate a presynaptic mechanism that needs to be synergized with CB1R activation for induction of long-term depression (LTD). In conclusion, alcohol consumption inhibits striatal eCB signaling in a way that could be of importance for understanding the neurological underpinnings of addictive behavior.
Collapse
Affiliation(s)
- Louise Adermark
- Addiction Biology Unit, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Box 410, 405 30 Gothenburg, Sweden.
| | | | | | | |
Collapse
|
40
|
Ethanol modulation of synaptic plasticity. Neuropharmacology 2010; 61:1097-108. [PMID: 21195719 DOI: 10.1016/j.neuropharm.2010.12.028] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 12/10/2010] [Accepted: 12/22/2010] [Indexed: 12/19/2022]
Abstract
Synaptic plasticity in the most general terms represents the flexibility of neurotransmission in response to neuronal activity. Synaptic plasticity is essential both for the moment-by-moment modulation of neural activity in response to dynamic environmental cues and for long-term learning and memory formation. These temporal characteristics are served by an array of pre- and post-synaptic mechanisms that are frequently modulated by ethanol exposure. This modulation likely makes significant contributions to both alcohol abuse and dependence. In this review, I discuss the modulation of both short-term and long-term synaptic plasticity in the context of specific ethanol-sensitive cellular substrates. A general discussion of the available preclinical, animal-model based neurophysiology literature provides a comparison between results from in vitro and in vivo studies. Finally, in the context of alcohol abuse and dependence, the review proposes potential behavioral contributions by ethanol modulation of plasticity.
Collapse
|