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Hilal FF, Jeanblanc J, Deschamps C, Naassila M, Pierrefiche O, Ben Hamida S. Epigenetic drugs and psychedelics as emerging therapies for alcohol use disorder: insights from preclinical studies. J Neural Transm (Vienna) 2024; 131:525-561. [PMID: 38554193 DOI: 10.1007/s00702-024-02757-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 02/22/2024] [Indexed: 04/01/2024]
Abstract
Alcohol use disorder (AUD) is a public health issue that affects millions of people worldwide leading to physical, mental and socio-economic consequences. While current treatments for AUD have provided relief to individuals, their effectiveness on the long term is often limited, leaving a number of affected individuals without sustainable solutions. In this review, we aim to explore two emerging approaches for AUD: psychedelics and epigenetic drugs (i.e., epidrugs). By examining preclinical studies, different animal species and procedures, we delve into the potential benefits of each of these treatments in terms of addictive behaviors (alcohol drinking and seeking, motivation to drink alcohol and prevention of relapse). Because psychedelics and epidrugs may share common and complementary mechanisms of action, there is an exciting opportunity for exploring synergies between these approaches and their parallel effectiveness in treating AUD and the diverse associated psychiatric conditions.
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Affiliation(s)
- Fahd François Hilal
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Jerome Jeanblanc
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Chloé Deschamps
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Mickael Naassila
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France.
| | - Olivier Pierrefiche
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Sami Ben Hamida
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France.
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2
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Fort TD, Cain ME. Inefficacy of N-acetylcysteine in mitigating cue-induced amphetamine-seeking. ADDICTION NEUROSCIENCE 2023; 8:100119. [PMID: 38213396 PMCID: PMC10783794 DOI: 10.1016/j.addicn.2023.100119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Glutamatergic imbalances are characteristic of SUDs. Astrocytic and neuronal transporters help regulate glutamate homeostasis and disruptions in this homeostasis engender SUD. The cysteine-glutamate exchanger (xCT) is primarily localized on astrocytes and maintains glutamate concentrations. This process is disrupted by cocaine use, and the therapeutic N-acetylcysteine (NAC) lowers cue-induced relapse to cocaine by restoring xCT function. However, little research has shown how these effects extend to other psychostimulants, such as amphetamine (AMP). Here, we assessed xCT expression following relapse to AMP cues, and if NAC can attenuate relapse via changes to astrocyte and xCT expression. We administered NAC (100 mg/kg ip) daily during a 14-day abstinence period following AMP (0.1 mg/kg/infusion; 2 h sessions) self-administration. Relapse was tested following one (WD 1) or 14 days (WD 14) of withdrawal. The overall number of astrocytes was also quantified within the medial prefrontal cortex (mPFC) and nucleus accumbens (ACb). NAC failed to lower cue-induced AMP craving via cue-induced relapse and reinstatement testing. Cue-induced craving did not increase from WD 1 to WD 14. AMP-exposed rats had greater astrocyte counts in the mPFC and ACb when compared AMP-naïve rats. Repeated injection with NAC decreased xCT expression within the mPFC and ACb. Overall, these results suggest that NAC may be an ineffective treatment option for lowering cue-induced relapse to AMP. Further, the results suggest that stimulating xCT via NAC may not be an effective therapeutic approach for decreasing cue-seeking for AMP.
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3
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Grimm JW, Sauter F, MacDougall D, Spaulding E, Stensgaard K, Hardy M, Griffin K, Marx R. The mGlu2/3 agonist LY379268 reduces sucrose taking, seeking, and motivation in male and female rats. Behav Pharmacol 2023; 34:340-349. [PMID: 37462142 PMCID: PMC10527415 DOI: 10.1097/fbp.0000000000000740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
OBJECTIVES The mGlu2/3 receptor agonist LY379268 reduces sucrose-seeking, but not sucrose-taking, in male rats. This study explored the generality of this effect across the sexes. In addition, the effect of the drug on motivation to receive sucrose was assessed. METHODS Adult male and female Long-Evans rats ( N = 91) were challenged with LY379268 in three experiments: (1) a fixed ratio (FR) schedule of reinforcement (taking), (2) extinction of responding previously reinforced on the FR (seeking) or (3) responding reinforced on a progressive ratio (PR) schedule of reinforcement (motivation). For each experiment, rats first responded to 10% liquid sucrose on an FR in 10 daily 2-h sessions. For the PR study, this was followed by training on a PR for 7 daily 3-h sessions. Rats were then challenged in a counterbalanced order with LY379268 (0, 1.5, 3 and 6 mg/kg; IP; 30-min pretreatment) on test days, followed by either three reacquisition days of FR (experiments 1 and 2) or PR (experiment 3) responding. RESULTS Female rats responded more to sucrose on the FR and PR. LY379268 reduced responding in all three experiments. LY379268 challenge to sucrose taking on the FR produced an inverted U-shaped function while extinction responding and responding for sucrose on the PR were decreased dose-dependently, with PR responding insensitive to the 1.5 mg/kg dose. There were no sex-dependent effects of the drug on sucrose-directed responding. CONCLUSIONS The sucrose anti-taking, -seeking, and -motivation effects of LY379268 across male and female rats support further evaluation of glutamate modulation as an antiaddiction pharmacotherapy.
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Affiliation(s)
- Jeffrey William Grimm
- Department of Psychology and Program in Behavioral Neuroscience, Western Washington University, Bellingham, Washington, USA
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4
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Tyler RE, Besheer J, Joffe ME. Advances in translating mGlu 2 and mGlu 3 receptor selective allosteric modulators as breakthrough treatments for affective disorders and alcohol use disorder. Pharmacol Biochem Behav 2022; 219:173450. [PMID: 35988792 PMCID: PMC10405528 DOI: 10.1016/j.pbb.2022.173450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/26/2022] [Accepted: 08/13/2022] [Indexed: 11/16/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are promising targets for the treatment of affective disorders and alcohol use disorder (AUD). Nonspecific ligands for Group II (mGlu2 and mGlu3) mGlu receptors have demonstrated consistent therapeutic potential for affective disorders in preclinical models. Disentangling the specific roles of mGlu2 versus mGlu3 receptors in these effects has persisted as a major challenge, in part due to pharmacological limitations. However, the recent development of highly specific allosteric modulators for both mGlu2 and mGlu3 receptors have enabled straightforward and rigorous investigations into the specific function of each receptor. Here, we review recent experiments using these compounds that have demonstrated both similar and distinct receptor functions in behavioral, molecular, and electrophysiological measures associated with basal function and preclinical models of affective disorders. Studies using these selective drugs have demonstrated that mGlu2 is the predominant receptor subclass involved in presynaptic neurotransmitter release in prefrontal cortex. By contrast, the activation of postsynaptic mGlu3 receptors induces a cascade of cellular changes that results in AMPA receptor internalization, producing long-term depression and diminishing excitatory drive. Acute stress decreases the mGlu3 receptor function and dynamically alters transcript expression for both mGlu2 (Grm2) and mGlu3 (Grm3) receptors in brain areas involved in reward and stress. Accordingly, both mGlu2 and mGlu3 negative allosteric modulators show acute antidepressant-like effects and potential prophylactic effects against acute and traumatic stressors. The wide array of effects displayed by these new allosteric modulators of mGlu2 and mGlu3 receptors suggest that these drugs may act through improving endophenotypes of symptoms observed across several neuropsychiatric disorders. Therefore, recently developed allosteric modulators selective for mGlu2 or mGlu3 receptors show promise as potential therapeutics for affective disorders and AUD.
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Affiliation(s)
- Ryan E Tyler
- Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Neuroscience Curriculum, University of North Carolina at Chapel Hill, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, USA
| | - Joyce Besheer
- Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Neuroscience Curriculum, University of North Carolina at Chapel Hill, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, USA
| | - Max E Joffe
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15219, USA; Translational Neuroscience Program, University of Pittsburgh, USA.
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Abulseoud OA, Alasmari F, Hussein AM, Sari Y. Ceftriaxone as a Novel Therapeutic Agent for Hyperglutamatergic States: Bridging the Gap Between Preclinical Results and Clinical Translation. Front Neurosci 2022; 16:841036. [PMID: 35864981 PMCID: PMC9294323 DOI: 10.3389/fnins.2022.841036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 06/07/2022] [Indexed: 12/02/2022] Open
Abstract
Dysregulation of glutamate homeostasis is a well-established core feature of neuropsychiatric disorders. Extracellular glutamate concentration is regulated by glutamate transporter 1 (GLT-1). The discovery of a beta-lactam antibiotic, ceftriaxone (CEF), as a safe compound with unique ability to upregulate GLT-1 sparked the interest in testing its efficacy as a novel therapeutic agent in animal models of neuropsychiatric disorders with hyperglutamatergic states. Indeed, more than 100 preclinical studies have shown the efficacy of CEF in attenuating the behavioral manifestations of various hyperglutamatergic brain disorders such as ischemic stroke, amyotrophic lateral sclerosis (ALS), seizure, Huntington’s disease, and various aspects of drug use disorders. However, despite rich and promising preclinical data, only one large-scale clinical trial testing the efficacy of CEF in patients with ALS is reported. Unfortunately, in that study, there was no significant difference in survival between placebo- and CEF-treated patients. In this review, we discussed the translational potential of preclinical efficacy of CEF based on four different parameters: (1) initiation of CEF treatment in relation to induction of the hyperglutamatergic state, (2) onset of response in preclinical models in relation to onset of GLT-1 upregulation, (3) mechanisms of action of CEF on GLT-1 expression and function, and (4) non-GLT-1-mediated mechanisms for CEF. Our detailed review of the literature brings new insights into underlying molecular mechanisms correlating the preclinical efficacy of CEF. We concluded here that CEF may be clinically effective in selected cases in acute and transient hyperglutamatergic states such as early drug withdrawal conditions.
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Affiliation(s)
- Osama A. Abulseoud
- Department of Psychiatry and Psychology, Alex School of Medicine at Mayo Clinic, Phoenix, AZ, United States
- *Correspondence: Osama A. Abulseoud,
| | - Fawaz Alasmari
- Department of Pharmacology and Experimental Therapeutics, University of Toledo, Toledo, OH, United States
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdelaziz M. Hussein
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Youssef Sari
- Department of Pharmacology and Experimental Therapeutics, University of Toledo, Toledo, OH, United States
- Youssef Sari,
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6
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Fan S, Li L, Liu L, Li H, Xian X, Li W. Ceftriaxone Suppresses Group II Metabotropic Glutamate Receptor Expression Contributing to Reversal of Recognition Memory Deficits of Amyloid Precursor Protein/Presenilin 1 AD Mice. Front Neurosci 2022; 16:905403. [PMID: 35860293 PMCID: PMC9289516 DOI: 10.3389/fnins.2022.905403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
Group II metabotropic glutamate receptors (Group II mGluRs) are the peri-synaptic receptor of glutamatergic neurons and negatively regulate glutamate release from presynaptic neurons. Glutamate in the synaptic cleft is mainly taken into astrocytes by glutamate transporter-1 (GLT-1), which is primarily expressed in astrocytes. Increasing evidence showed that inhibiting or suppressing the activation of Group II mGluRs would contribute to the improvement of learning and memory deficits in Alzheimer’s disease (AD) animal models. Ceftriaxone (Cef) has been reported to alleviate the spatial memory deficits in AD model mice by improving GLT-1-related clearance and metabolism of glutamate. Therefore, the present study further investigates the improving effect of Cef on recognition memory deficits and the involvement of Group II mGluRs in the process using the APP/PS1 AD mouse model. Novel object recognition tests showed that the Cef treatment significantly improved the recognition memory deficits of the AD mice. The Western blot and immunohistochemistry analysis showed that the Cef treatment significantly suppressed the upregulation of Group II mGluRs expression in APP/PS1 AD mice. The above suppression effect of Cef was blocked by dihydrokainic acid, an inhibitor of GLT-1 uptake activity. Furthermore, the Cef treatment significantly restored the downregulation in the downstream molecules of Group II mGluRs activation, including the expression of PKA and phosphorylated SNAP-25 in the APP/PS1 AD mice. The Cef treatment had no effect on the content of Aβ40 and Aβ42 in the hippocampus of APP/PS1 AD mice. The above results suggested that the suppression of Group II mGluRs contributed to the Cef-induced reversal of the recognition memory deficits in APP/PS1 AD mice.
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Affiliation(s)
- ShuJuan Fan
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China
| | - Li Li
- Department of Central Laboratory, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - LiRong Liu
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China
| | - He Li
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China
| | - XiaoHui Xian
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China
- *Correspondence: XiaoHui Xian,
| | - WenBin Li
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China
- WenBin Li,
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7
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Elsilä LV, Harkki J, Enberg E, Martti A, Linden AM, Korpi ER. Effects of acute lysergic acid diethylamide on intermittent ethanol and sucrose drinking and intracranial self-stimulation in C57BL/6 mice. J Psychopharmacol 2022; 36:860-874. [PMID: 35695174 PMCID: PMC9247434 DOI: 10.1177/02698811221104641] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Psychedelics, like lysergic acid diethylamide (LSD), are again being studied as potential therapies for many neuropsychiatric disorders, including addictions. At the same time, the acute effects of psychedelics on rewarding behaviours have been scarcely studied. AIMS The current study aimed to clarify if LSD decreases binge-like ethanol drinking in mice, and whether the observed acute effects on ethanol consumption are generalizable to a natural reinforcer, sucrose, and if the effects resulted from aversive or reward-attenuating effects caused by LSD. METHODS The effects of acute LSD were examined using 2-bottle choice intermittent ethanol (20%) and sucrose drinking (10%), discrete-trial current-intensity threshold method of intracranial self-stimulation and short-term feeding behaviour assay in C57BL/6 male mice. RESULTS The results showed that acute 0.1 mg/kg, but not 0.05 mg/kg, dose (i.p.) of LSD reduced 2-h intermittent ethanol drinking transiently without any prolonged effects. No effects were seen in intermittent 2-h sucrose drinking. The tested LSD doses had neither effect on the intracranial self-stimulation current-intensity thresholds, nor did LSD affect the threshold-lowering, or rewarding, effects of simultaneous amphetamine treatment. Furthermore, LSD had small, acute diminishing effects on 2-h food and water intake. CONCLUSIONS Based on these results, LSD decreases binge-like ethanol drinking in mice, but only acutely. This effect is not likely to stem from reward-attenuating effects but could be in part due to reduced consummatory behaviour.
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Affiliation(s)
- Lauri V Elsilä
- Lauri V Elsilä, Department of
Pharmacology, Faculty of Medicine, University of Helsinki, P.O. Box 63
(Haartmaninkatu 8), Biomedicum Helsinki, Helsinki FI-00014, Finland.
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8
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Shipman ML, Corbit LH. Diet-induced deficits in goal-directed control are rescued by agonism of group II metabotropic glutamate receptors in the dorsomedial striatum. Transl Psychiatry 2022; 12:42. [PMID: 35091538 PMCID: PMC8799694 DOI: 10.1038/s41398-022-01807-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 01/06/2022] [Accepted: 01/12/2022] [Indexed: 11/09/2022] Open
Abstract
Many overweight or obese people struggle to sustain the behavioural changes necessary to achieve and maintain weight loss. In rodents, obesogenic diet can disrupt goal-directed control of responding for food reinforcers, which may indicate that diet can disrupt brain regions associated with behavioural control. We investigated a potential glutamatergic mechanism to return goal-directed control to rats who had been given an obesogenic diet prior to operant training. We found that an obesogenic diet reduced goal-directed control and that systemic injection of LY379268, a Group II metabotropic glutamate receptor (mGluR2/3) agonist, returned goal-directed responding in these rats. Further, we found that direct infusion of LY379268 into the dorsomedial striatum, a region associated with goal-directed control, also restored goal-directed responding in the obesogenic-diet group. This indicates that one mechanism through which obesogenic diet disrupts goal-directed control is glutamatergic, and infusion of a mGluR2/3 agonist into the DMS is sufficient to ameliorate deficits in goal-directed control.
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Affiliation(s)
- Megan L Shipman
- University of Toronto Department of Psychology, 100 St. George Street, Toronto, ON, M5S 3G3, Canada
| | - Laura H Corbit
- University of Toronto Department of Psychology, 100 St. George Street, Toronto, ON, M5S 3G3, Canada.
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Kreek MJ, Zhang Y, Windisch KA, Dunn A. The Laboratory of the Biology of Addictive Diseases: Four Women in Neuroscience. J Neurosci Res 2020; 99:29-36. [PMID: 32640494 DOI: 10.1002/jnr.24612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/18/2020] [Accepted: 02/24/2020] [Indexed: 11/07/2022]
Affiliation(s)
- Mary Jeanne Kreek
- The Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA
| | - Yong Zhang
- The Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA
| | - Kyle A Windisch
- The Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA
| | - Amelia Dunn
- The Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA
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10
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Johnson KA, Lovinger DM. Allosteric modulation of metabotropic glutamate receptors in alcohol use disorder: Insights from preclinical investigations. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2020; 88:193-232. [PMID: 32416868 DOI: 10.1016/bs.apha.2020.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are family C G protein-coupled receptors (GPCRs) that modulate neuronal excitability and synaptic transmission throughout the nervous system. Owing to recent advances in development of subtype-selective allosteric modulators of mGlu receptors, individual members of the mGlu receptor family have been proposed as targets for treating a variety of neurological and psychiatric disorders, including substance use disorders. In this chapter, we highlight preclinical evidence that allosteric modulators of mGlu receptors could be useful for reducing alcohol consumption and preventing relapse in alcohol use disorder (AUD). We begin with an overview of the preclinical models that are used to study mGlu receptor involvement in alcohol-related behaviors. Alcohol exposure causes adaptations in both expression and function of various mGlu receptor subtypes, and pharmacotherapies aimed at reversing these adaptations have the potential to reduce alcohol consumption and seeking. Positive allosteric modulators (PAMs) of mGlu2 and negative allosteric modulators of mGlu5 show particular promise for reducing alcohol intake and/or preventing relapse. Finally, this chapter discusses important considerations for translating preclinical findings toward the development of clinically useful drugs, including the potential for PAMs to avoid tolerance issues that are frequently observed with repeated administration of GPCR agonists.
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Affiliation(s)
- Kari A Johnson
- Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, US National Institutes of Health, Rockville, MD, United States
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11
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Age-dependent impairment of metabotropic glutamate receptor 2-dependent long-term depression in the mouse striatum by chronic ethanol exposure. Alcohol 2020; 82:11-21. [PMID: 31233806 PMCID: PMC6925350 DOI: 10.1016/j.alcohol.2019.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/10/2019] [Accepted: 06/14/2019] [Indexed: 12/22/2022]
Abstract
Chronic alcohol exposure is associated with increased reliance on behavioral strategies involving the dorsolateral striatum (DLS), including habitual or stimulus-response behaviors. Presynaptic G protein-coupled receptors (GPCRs) on cortical and thalamic inputs to the DLS inhibit glutamate release, and alcohol-induced disruption of presynaptic GPCR function represents a mechanism by which alcohol could disinhibit DLS neurons and thus bias toward use of DLS-dependent behaviors. Metabotropic glutamate receptor 2 (mGlu2) is a Gi/o-coupled GPCR that robustly modulates glutamate transmission in the DLS, inducing long-term depression (LTD) at both cortical and thalamic synapses. Loss of mGlu2 function has recently been associated with increased ethanol seeking and consumption, but the ability of alcohol to produce adaptations in mGlu2 function in the DLS has not been investigated. We exposed male C57Bl/6J mice to a 2-week chronic intermittent ethanol (CIE) paradigm followed by a brief withdrawal period, then used whole-cell patch clamp recordings of glutamatergic transmission in the striatum to assess CIE effects on mGlu2-mediated synaptic plasticity. We report that CIE differentially disrupts mGlu2-mediated long-term depression in the DLS vs. dorsomedial striatum (DMS). Interestingly, CIE-induced impairment of mGlu2-LTD in the dorsolateral striatum is only observed when alcohol exposure occurs during adolescence. Incubation of striatal slices from CIE-exposed adolescent mice with a positive allosteric modulator of mGlu2 fully rescues mGlu2-LTD. In contrast to the 2-week CIE paradigm, acute exposure of striatal slices to ethanol concentrations that mimic ethanol levels during CIE exposure fails to disrupt mGlu2-LTD. We did not observe a reduction of mGlu2 mRNA or protein levels following CIE exposure, suggesting that alcohol effects on mGlu2 occur at the functional level. Our findings contribute to growing evidence that adolescents are uniquely vulnerable to certain alcohol-induced neuroadaptations, and identify enhancement of mGlu2 activity as a strategy to reverse the effects of adolescent alcohol exposure on DLS physiology.
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12
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Randall PA, Vetreno RP, Makhijani VH, Crews FT, Besheer J. The Toll-Like Receptor 3 Agonist Poly(I:C) Induces Rapid and Lasting Changes in Gene Expression Related to Glutamatergic Function and Increases Ethanol Self-Administration in Rats. Alcohol Clin Exp Res 2018; 43:48-60. [PMID: 30403408 DOI: 10.1111/acer.13919] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 10/29/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND Growing evidence suggests that neuroimmune signaling via Toll-like receptors (TLRs) alters brain circuitry related to alcohol use disorders. Both ethanol (EtOH) exposure and the TLR3 agonist, poly(I:C), increase brain TLR3 expression in neurons and glia. Furthermore, previous studies have shown that cortical TLR3 expression is correlated with lifetime EtOH intake in humans. METHODS The current experiments investigated the consequences of poly(I:C) treatment on gene expression in 2 brain regions contributing to alcohol reinforcement, the insular cortex (IC) and nucleus accumbens (Acb) and on operant EtOH self-administration, in Long Evans rats. RESULTS TLR3 activation increased mRNA levels of neuroimmune genes (TLR3, COX2), glutamatergic genes (mGluR2, mGluR3, GLT1), and the trophic factor BDNF in Acb and IC. Furthermore, increases in each of these genes were correlated with increases in TLR3 mRNA, suggesting that TLR3 induction of these genes may impact excitatory transmission in IC and Acb. TLR3 activation also increased EtOH self-administration 18 days postinjection and enhanced the effects of the mGluR2/3 agonist LY379268 to reduce EtOH self-administration following poly(I:C). CONCLUSIONS Together, these findings suggest lasting consequences of TLR3 activation on gene expression including increases in Group II mGluRs in the Acb. Furthermore, we show an important role for TLR3 signaling in EtOH intake, and a functional involvement of Group II mGluRs.
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Affiliation(s)
- Patrick A Randall
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Ryan P Vetreno
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Viren H Makhijani
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Neuroscience Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Fulton T Crews
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Neuroscience Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Joyce Besheer
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Neuroscience Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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13
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Joffe ME, Centanni SW, Jaramillo AA, Winder DG, Conn PJ. Metabotropic Glutamate Receptors in Alcohol Use Disorder: Physiology, Plasticity, and Promising Pharmacotherapies. ACS Chem Neurosci 2018; 9:2188-2204. [PMID: 29792024 PMCID: PMC6192262 DOI: 10.1021/acschemneuro.8b00200] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Developing efficacious treatments for alcohol use disorder (AUD) has proven difficult. The insidious nature of the disease necessitates a deep understanding of its underlying biology as well as innovative approaches to ameliorate ethanol-related pathophysiology. Excessive ethanol seeking and relapse are generated by long-term changes to membrane properties, synaptic physiology, and plasticity throughout the limbic system and associated brain structures. Each of these factors can be modulated by metabotropic glutamate (mGlu) receptors, a diverse set of G protein-coupled receptors highly expressed throughout the central nervous system. Here, we discuss how different components of the mGlu receptor family modulate neurotransmission in the limbic system and other brain regions involved in AUD etiology. We then describe how these processes are dysregulated following ethanol exposure and speculate about how mGlu receptor modulation might restore such pathophysiological changes. To that end, we detail the current understanding of the behavioral pharmacology of mGlu receptor-directed drug-like molecules in animal models of AUD. Together, this review highlights the prominent position of the mGlu receptor system in the pathophysiology of AUD and provides encouragement that several classes of mGlu receptor modulators may be translated as viable treatment options.
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Affiliation(s)
- Max E. Joffe
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
| | - Samuel W. Centanni
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - Anel A. Jaramillo
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - Danny G. Winder
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
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Alper K, Dong B, Shah R, Sershen H, Vinod KY. LSD Administered as a Single Dose Reduces Alcohol Consumption in C57BL/6J Mice. Front Pharmacol 2018; 9:994. [PMID: 30233372 PMCID: PMC6127266 DOI: 10.3389/fphar.2018.00994] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 08/13/2018] [Indexed: 12/31/2022] Open
Abstract
There is a substantive clinical literature on classical hallucinogens, most commonly lysergic acid diethylamide (LSD) for the treatment of alcohol use disorder. However, there has been no published research on the effect of LSD on alcohol consumption in animals. This study evaluated the effect of LSD in mice using a two-bottle choice alcohol drinking paradigm. Adult male C57BL/6J mice were exposed to ethanol to develop preference and divided into three groups of equal ethanol consumption, and then treated with single intraperitoneal injection of saline or 25 or 50 μg/kg LSD and offered water and 20% ethanol. The respective LSD-treated groups were compared to the control group utilizing a multilevel model for repeated measures. In mice treated with 50 μg/kg LSD ethanol consumption was reduced relative to controls (p = 0.0035), as was ethanol preference (p = 0.0024), with a group mean reduction of ethanol consumption of 17.9% sustained over an interval of 46 days following LSD administration. No significant effects on ethanol consumption or preference were observed in mice treated with 25 μg/kg LSD. Neither total fluid intake nor locomotor activity in the LSD-treated groups differed significantly from controls. These results suggest that classical hallucinogens in the animal model merit further study as a potential approach to the identification of targets for drug discovery and investigation of the neurobiology of addiction.
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Affiliation(s)
- Kenneth Alper
- Department of Psychiatry, New York University School of Medicine, New York, NY, United States.,Department of Neurology, New York University School of Medicine, New York, NY, United States
| | - Bin Dong
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
| | - Relish Shah
- Emotional Brain Institute, Orangeburg, NY, United States
| | - Henry Sershen
- Department of Psychiatry, New York University School of Medicine, New York, NY, United States.,Department of Neurochemistry, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
| | - K Yaragudri Vinod
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States.,Emotional Brain Institute, Orangeburg, NY, United States.,Department of Child and Adolescent Psychiatry, New York University School of Medicine, New York, NY, United States
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