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Carlson ER, Guerin SP, Nixon K, Fonken LK. The neuroimmune system - Where aging and excess alcohol intersect. Alcohol 2023; 107:153-167. [PMID: 36150610 PMCID: PMC10023388 DOI: 10.1016/j.alcohol.2022.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/21/2022] [Accepted: 08/31/2022] [Indexed: 01/05/2023]
Abstract
As the percentage of the global population over age 65 grows, and with it a subpopulation of individuals with alcohol use disorder (AUD), understanding the effect of alcohol on the aged brain is of utmost importance. Neuroinflammation is implicated in both natural aging as well as alcohol use, and its role in alterations to brain morphology and function may be exacerbated in aging individuals who drink alcohol to excess. The neuroimmune response to alcohol in aging is complex. The few studies investigating this issue have reported heightened basal activity and either hypo- or hyper-reactivity to an alcohol challenge. This review of preclinical research will first introduce key players of the immune system, then explore changes in neuroimmune function with aging or alcohol alone, with discussion of vulnerable brain regions, changes in cytokines, and varied reactions of microglia and astrocytes. We will then consider different levels of alcohol exposure, relevant animal models of AUD, and neuroimmune activation by alcohol across the lifespan. By identifying key findings, challenges, and targets for future research, we hope to bring more attention and resources to this underexplored area of inquiry.
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Affiliation(s)
- Erika R Carlson
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, United States
| | - Steven P Guerin
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, United States
| | - Kimberly Nixon
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, United States
| | - Laura K Fonken
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, United States.
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2
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Flores-Bonilla A, De Oliveira B, Silva-Gotay A, Lucier KW, Richardson HN. Shortening time for access to alcohol drives up front-loading behavior, bringing consumption in male rats to the level of females. Biol Sex Differ 2021; 12:51. [PMID: 34526108 PMCID: PMC8444481 DOI: 10.1186/s13293-021-00395-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/31/2021] [Indexed: 11/25/2022] Open
Abstract
Background Incentives to promote drinking (“happy hour”) can encourage faster rates of alcohol consumption, especially in women. Sex differences in drinking dynamics may underlie differential health vulnerabilities relating to alcohol in women versus men. Herein, we used operant procedures to model the happy hour effect and gain insight into the alcohol drinking dynamics of male and female rats. Methods Adult male and female Wistar rats underwent operant training to promote voluntary drinking of 10% (w/v) alcohol (8 rats/sex). We tested how drinking patterns changed after manipulating the effort required for alcohol (fixed ratio, FR), as well as the length of time in which rats had access to alcohol (self-administration session length). Rats were tested twice within the 12 h of the dark cycle, first at 2 h (early phase of the dark cycle, “early sessions”) and then again at 10 h into the dark cycle (late phase of the dark cycle, “late sessions”) with an 8-h break between the two sessions in the home cage. Results Adult females consumed significantly more alcohol (g/kg) than males in the 30-min sessions with the FR1 schedule of reinforcement when tested late in the dark cycle. Front-loading of alcohol was the primary factor driving higher consumption in females. Changing the schedule of reinforcement from FR1 to FR3 reduced total consumption. Notably, this manipulation had minimal effect on front-loading behavior in females, whereas front-loading behavior was significantly reduced in males when more effort was required to access alcohol. Compressing drinking access to 15 min to model a happy hour drove up front-loading behavior, generating alcohol drinking patterns in males that were similar to patterns in females (faster drinking and higher intake). Conclusions This strategy could be useful for exploring sex differences in the neural mechanisms underlying alcohol drinking and related health vulnerabilities. Our findings also highlight the importance of the time of testing for detecting sex differences in drinking behavior. Voluntary alcohol drinking is higher in adult female rats compared to adult male rats. This sex difference is most pronounced in the later phase of the dark cycle, and when the operant effort is minimal (when 1 lever press gives 1 reward: fixed ratio 1, FR1). Higher alcohol intake in females is primarily due to “front-loading”, or the rapid consumption of alcohol within the first 5 min of access. Increasing the effort required to obtain alcohol from FR1 to FR3 dampens front-loading drinking behavior, resulting in similar levels of total intake in males and females. Compressing the time of access to 15 min drives up front-loading to such a degree that rats end up consuming more alcohol in total than they do in 30-min sessions. In males, this increase in drinking is large enough that it eliminates the sex difference in total alcohol intake.
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Affiliation(s)
- Annabelle Flores-Bonilla
- Neuroscience and Behavior Program, The University of Massachusetts Amherst, Amherst, MA, 01003, USA.,Department of Psychological and Brain Sciences, The University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Barbara De Oliveira
- Department of Psychological and Brain Sciences, The University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Andrea Silva-Gotay
- Neuroscience and Behavior Program, The University of Massachusetts Amherst, Amherst, MA, 01003, USA.,Department of Psychological and Brain Sciences, The University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Kyle W Lucier
- Department of Psychological and Brain Sciences, The University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Heather N Richardson
- Neuroscience and Behavior Program, The University of Massachusetts Amherst, Amherst, MA, 01003, USA. .,Department of Psychological and Brain Sciences, The University of Massachusetts Amherst, Amherst, MA, 01003, USA.
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3
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N-acylethanolamine acid amidase (NAAA) inhibition decreases the motivation for alcohol in Marchigian Sardinian alcohol-preferring rats. Psychopharmacology (Berl) 2021; 238:249-258. [PMID: 33037452 PMCID: PMC7796956 DOI: 10.1007/s00213-020-05678-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/05/2020] [Indexed: 10/23/2022]
Abstract
RATIONALE N-acylethanolamine acid amidase (NAAA) is an intracellular cysteine hydrolase that terminates the biological actions of oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), two endogenous lipid-derived agonists of the nuclear receptor, and peroxisome proliferator-activated receptor-α. OEA and PEA are important regulators of energy balance, pain, and inflammation, but recent evidence suggests that they might also contribute to the control of reward-related behaviors. OBJECTIVES AND METHODS In the present study, we investigated the effects of systemic and intracerebral NAAA inhibition in the two-bottle choice model of voluntary alcohol drinking and on operant alcohol self-administration. RESULTS Intraperitoneal injections of the systemically active NAAA inhibitor ARN19702 (3 and 10 mg/kg) lowered voluntary alcohol intake in a dose-dependent manner, achieving ≈ 47% reduction at the 10 mg/kg dose (p < 0.001). Water, food, or saccharin consumption was not affected by the inhibitor. Similarly, ARN19702 dose-dependently attenuated alcohol self-administration under both fixed ratio 1 (FR-1) and progressive ratio schedules of reinforcement. Furthermore, microinjection of ARN19702 (1, 3 and 10 μg/μl) or of two chemically different NAAA inhibitors, ARN077 and ARN726 (both at 3 and 10 μg/μl), into the midbrain ventral tegmental area produced dose-dependent decreases in alcohol self-administration under FR-1 schedule. Microinjection of ARN19702 into the nucleus accumbens had no such effect. CONCLUSION Collectively, the results point to NAAA as a possible molecular target for the treatment of alcohol use disorder.
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4
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Abstract
Sex differences may play a critical role in modulating how chronic or heavy alcohol use impacts the brain to cause the development of alcohol use disorder (AUD). AUD is a multifaceted and complex disorder driven by changes in key neurobiological structures that regulate executive function, memory, and stress. A three-stage framework of addiction (binge/intoxication; withdrawal/negative affect; preoccupation/anticipation) has been useful for conceptualizing the complexities of AUD and other addictions. Initially, alcohol drinking causes short-term effects that involve signaling mediated by several neurotransmitter systems such as dopamine, corticotropin releasing factor, and glutamate. With continued intoxication, alcohol leads to dysfunctional behaviors that are thought to be due in part to alterations of these and other neurotransmitter systems, along with alterations in neural pathways connecting prefrontal and limbic structures. Using the three-stage framework, this review highlights examples of research examining sex differences in drinking and differential modulation of neural systems contributing to the development of AUD. New insights addressing the role of sex differences in AUD are advancing the field forward by uncovering the complex interactions that mediate vulnerability.
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Affiliation(s)
| | - Heather N Richardson
- Department of Psychological and Brain Sciences at the University of Massachusetts, Amherst, Massachusetts
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5
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Vena AA, Zandy SL, Cofresí RU, Gonzales RA. Behavioral, neurobiological, and neurochemical mechanisms of ethanol self-administration: A translational review. Pharmacol Ther 2020; 212:107573. [PMID: 32437827 PMCID: PMC7580704 DOI: 10.1016/j.pharmthera.2020.107573] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2020] [Indexed: 12/16/2022]
Abstract
Alcohol use disorder has multiple characteristics including excessive ethanol consumption, impaired control over drinking behaviors, craving and withdrawal symptoms, compulsive seeking behaviors, and is considered a chronic condition. Relapse is common. Determining the neurobiological targets of ethanol and the adaptations induced by chronic ethanol exposure is critical to understanding the clinical manifestation of alcohol use disorders, the mechanisms underlying the various features of the disorder, and for informing medication development. In the present review, we discuss ethanol's interactions with a variety of neurotransmitter systems, summarizing findings from preclinical and translational studies to highlight recent progress in the field. We then describe animal models of ethanol self-administration, emphasizing the value, limitations, and validity of commonly used models. Lastly, we summarize the behavioral changes induced by chronic ethanol self-administration, with an emphasis on cue-elicited behavior, the role of ethanol-related memories, and the emergence of habitual ethanol seeking behavior.
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Affiliation(s)
- Ashley A Vena
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, United States of America
| | | | - Roberto U Cofresí
- Psychological Sciences, University of Missouri, United States of America
| | - Rueben A Gonzales
- Division of Pharmacology and Toxicology, College of Pharmacy and Institute for Neuroscience, The University of Texas at Austin, United States of America.
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6
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Popoola DO, Cameron NM. Maternal care-related differences in males and females rats' sensitivity to ethanol and the associations between the GABAergic system and steroids in males. Dev Psychobiol 2018; 60:380-394. [PMID: 29442358 DOI: 10.1002/dev.21607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 11/20/2017] [Indexed: 02/06/2023]
Abstract
This study investigated the effect of maternal care on adolescent ethanol consumption, sensitivity to ethanol-induced hypnosis, as well as gonadal hormones and γ-aminobutyric acid type-A (GABAA ) systems. Long Evans rat dams were categorized by maternal licking/grooming (LG) frequency into High- and Low-LG mothers. Both female and male offspring from Low-LG rats demonstrated a greater sensitivity to ethanol-induced hypnosis in the loss-of-righting-reflex test at ethanol doses of 3.0 and 3.5 g/kg during late-adolescence (postnatal Day 50) but not at mid-adolescence (postnatal Day 42). However, we found no effect of maternal care on consumption of a 5% ethanol solution in a two-bottle choice test. We further investigated the association between the observed variations in sensitivity to ethanol-induced hypnosis and baseline hormonal levels in males. In male offspring from Low-LG mothers compared to High-LG mothers, baseline plasma corticosterone and progesterone levels were higher. GABAA α1 and δ subunit expressions were also higher in the cerebral cortex of Low-LG males but lower in the cerebellar synaptosomal fraction. Early environmental influences on adolescent sensitivity to ethanol-induced hypnosis, consumption, and preference may be mediated by gonadal hormones and possibly through GABAergic functions.
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Affiliation(s)
- Daniel O Popoola
- Department of Psychology, Center for Developmental and Behavioral Neuroscience, Binghamton University, Binghamton, New York.,Developmental Exposure Alcohol Research Center, Binghamton University, Binghamton, New York.,Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, University of Buffalo, Buffalo, New York
| | - Nicole M Cameron
- Department of Psychology, Center for Developmental and Behavioral Neuroscience, Binghamton University, Binghamton, New York.,Developmental Exposure Alcohol Research Center, Binghamton University, Binghamton, New York
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7
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Ma T, Cheng Y, Roltsch Hellard E, Wang X, Lu J, Gao X, Huang CCY, Wei XY, Ji JY, Wang J. Bidirectional and long-lasting control of alcohol-seeking behavior by corticostriatal LTP and LTD. Nat Neurosci 2018; 21:373-383. [PMID: 29434375 PMCID: PMC5857235 DOI: 10.1038/s41593-018-0081-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/08/2018] [Indexed: 12/21/2022]
Abstract
Addiction is proposed to arise from alterations in synaptic strength via mechanisms of long-term potentiation (LTP) and depression (LTD). However, the causality between these synaptic processes and addictive behaviors is difficult to demonstrate. Here we report that LTP and LTD induction altered operant alcohol self-administration, a motivated drug-seeking behavior. We first induced LTP by pairing presynaptic glutamatergic stimulation with optogenetic postsynaptic depolarization in the dorsomedial striatum, a brain region known to control goal-directed behavior. Blockade of this LTP by NMDA-receptor inhibition unmasked an endocannabinoid-dependent LTD. In vivo application of the LTP-inducing protocol caused a long-lasting increase in alcohol-seeking behavior, while the LTD protocol decreased this behavior. We further identified that optogenetic LTP and LTD induction at cortical inputs onto striatal dopamine D1 receptor-expressing neurons controlled these behavioral changes. Our results demonstrate a causal link between synaptic plasticity and alcohol-seeking behavior and suggest that modulation of this plasticity may inspire a therapeutic strategy for addiction.
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Affiliation(s)
- Tengfei Ma
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Yifeng Cheng
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Emily Roltsch Hellard
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Xuehua Wang
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Jiayi Lu
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Xinsheng Gao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Cathy C Y Huang
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Xiao-Yan Wei
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Jun Wang
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA.
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8
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Bell RL, Hauser SR, Liang T, Sari Y, Maldonado-Devincci A, Rodd ZA. Rat animal models for screening medications to treat alcohol use disorders. Neuropharmacology 2017; 122:201-243. [PMID: 28215999 PMCID: PMC5659204 DOI: 10.1016/j.neuropharm.2017.02.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 02/02/2017] [Accepted: 02/05/2017] [Indexed: 01/21/2023]
Abstract
The purpose of this review is to present animal research models that can be used to screen and/or repurpose medications for the treatment of alcohol abuse and dependence. The focus will be on rats and in particular selectively bred rats. Brief introductions discuss various aspects of the clinical picture, which provide characteristics of individuals with alcohol use disorders (AUDs) to model in animals. Following this, multiple selectively bred rat lines will be described and evaluated in the context of animal models used to screen medications to treat AUDs. Next, common behavioral tests for drug efficacy will be discussed particularly as they relate to stages in the addiction cycle. Tables highlighting studies that have tested the effects of compounds using the respective techniques are included. Wherever possible the Tables are organized chronologically in ascending order to describe changes in the focus of research on AUDs over time. In general, high ethanol-consuming selectively bred rats have been used to test a wide range of compounds. Older studies usually followed neurobiological findings in the selected lines that supported an association with a propensity for high ethanol intake. Most of these tests evaluated the compound's effects on the maintenance of ethanol drinking. Very few compounds have been tested during ethanol-seeking and/or relapse and fewer still have assessed their effects during the acquisition of AUDs. Overall, while a substantial number of neurotransmitter and neuromodulatory system targets have been assessed; the roles of sex- and age-of-animal, as well as the acquisition of AUDs, ethanol-seeking and relapse continue to be factors and behaviors needing further study. This article is part of the Special Issue entitled "Alcoholism".
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Affiliation(s)
- Richard L Bell
- Indiana University School of Medicine, Department of Psychiatry, Indianapolis, IN 46202, USA.
| | - Sheketha R Hauser
- Indiana University School of Medicine, Department of Psychiatry, Indianapolis, IN 46202, USA
| | - Tiebing Liang
- Indiana University School of Medicine, Department of Gastroenterology, Indianapolis, IN 46202, USA
| | - Youssef Sari
- University of Toledo, Department of Pharmacology, Toledo, OH 43614, USA
| | | | - Zachary A Rodd
- Indiana University School of Medicine, Department of Psychiatry, Indianapolis, IN 46202, USA
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9
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Fu R, Zuo W, Gregor D, Li J, Grech D, Ye JH. Pharmacological Manipulation of the Rostromedial Tegmental Nucleus Changes Voluntary and Operant Ethanol Self-Administration in Rats. Alcohol Clin Exp Res 2016; 40:572-82. [PMID: 26876382 PMCID: PMC4775316 DOI: 10.1111/acer.12974] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/23/2015] [Indexed: 01/07/2023]
Abstract
BACKGROUND The aversive properties of ethanol (EtOH) that limit its intake are poorly understood. There is an increasing interest in the role of the rostromedial tegmental nucleus (RMTg), because it encodes aversion signals and inhibits motivated behaviors. It is also a major source of inhibitory GABAergic inputs to the midbrain dopamine neurons. Up to this time, the role of the RMTg in EtOH-drinking behaviors has not been well explored. METHODS Male Long-Evans rats were trained either to drink EtOH under the intermittent 2-bottle-choice protocol or to self-administer EtOH in operant chambers under fixed-ratio-3 schedules. Changes in drinking behaviors induced by the bilateral infusion into the RMTg of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), an agonist of AMPA-type glutamate receptors, or muscimol, an agonist of GABAA receptors, were measured. RESULTS Consumption and preference for EtOH, numbers of active lever pressing, and head entrance to the EtOH port were all significantly decreased upon activation of the RMTg by the infusion of AMPA, but were increased upon inhibition of the RMTg by the infusion of muscimol. By contrast, intra-RMTg infusion of these agents did not change sucrose consumption. CONCLUSIONS These data show for the first time that EtOH-drinking and EtOH-seeking behaviors of rats changed inversely with RMTg function, supporting the idea that the RMTg plays a crucial role in EtOH-drinking behaviors.
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Affiliation(s)
- Rao Fu
- Department of Anesthesiology, Pharmacology and Physiology, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Wanhong Zuo
- Department of Anesthesiology, Pharmacology and Physiology, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Danielle Gregor
- Department of Anesthesiology, Pharmacology and Physiology, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Jing Li
- Department of Anesthesiology, Pharmacology and Physiology, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Dennis Grech
- Department of Anesthesiology, Pharmacology and Physiology, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Jiang-Hong Ye
- Department of Anesthesiology, Pharmacology and Physiology, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
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10
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O’Tousa DS, Warnock KT, Matson LM, Namjoshi OA, Halcomb ME, Cook J, Grahame NJ, June HL. Triple monoamine uptake inhibitors demonstrate a pharmacologic association between excessive drinking and impulsivity in high-alcohol-preferring (HAP) mice. Addict Biol 2015; 20:236-47. [PMID: 24118509 PMCID: PMC3984927 DOI: 10.1111/adb.12100] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Approximately 30% of current drinkers in the United States drink excessively, and are referred to as problem/hazardous drinkers. These individuals, who may not meet criteria for alcohol abuse or dependence, comprise binge, heavy drinkers, or both. Given their high prevalence, interventions that reduce the risk of binge and heavy drinking have important public health implications. Impulsivity has been repeatedly associated with excessive drinking in the clinical literature. As impulsivity is correlated with, and may play a critical role in, the initiation and maintenance of excessive drinking, this behavior may be an important target for therapeutic intervention. Hence, a better understanding of pharmacological treatments capable of attenuating excessive drinking and impulsivity may markedly improve clinical outcomes. The high-alcohol-preferring (HAP) mice represent a strong rodent model to study the relationship between impulsivity and excessive alcohol drinking, as recent evidence indicates they consume high levels of alcohol throughout their active cycle and are innately impulsive. Using this model, the present study demonstrates that the triple monoamine uptake inhibitors (TUIs) amitifadine and DOV 102, 677 effectively attenuate binge drinking, heavy drinking assessed via a 24-hour free-choice assay, and impulsivity measured by the delay discounting procedure. In contrast, 3-PBC, a GABA-A α1 preferring ligand with mixed agonist-antagonist properties, attenuates excessive drinking without affecting impulsivity. These findings suggest that in HAP mice, monoamine pathways may predominate as a common mechanism underlying impulsivity and excessive drinking, while the GABAergic system may be more salient in regulating excessive drinking. We further propose that TUIs such as amitifadine and DOV 102, 677 may be used to treat the co-occurrence of impulsivity and excessive drinking.
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Affiliation(s)
- David S. O’Tousa
- Department of Psychology, Indiana University-Purdue University, Indianapolis, IN 46202
| | - Kaitlin T. Warnock
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC 20060, USA
| | - Liana M. Matson
- Department of Psychology, Indiana University-Purdue University, Indianapolis, IN 46202
| | - Ojas A. Namjoshi
- Department of Chemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - Meredith E. Halcomb
- Department of Psychology, Indiana University-Purdue University, Indianapolis, IN 46202
| | - James Cook
- Department of Chemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - Nicholas J. Grahame
- Department of Psychology, Indiana University-Purdue University, Indianapolis, IN 46202
| | - Harry L. June
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC 20060, USA
- Department of Pharmacology, Howard University College of Medicine, Washington, DC 20060, USA
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11
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Involvement of dopamine D2 receptors in addictive-like behaviour for acetaldehyde. PLoS One 2014; 9:e99454. [PMID: 24926837 PMCID: PMC4057173 DOI: 10.1371/journal.pone.0099454] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 05/14/2014] [Indexed: 12/29/2022] Open
Abstract
Acetaldehyde, the first metabolite of ethanol, is active in the central nervous system, where it exerts motivational properties. Acetaldehyde is able to induce drinking behaviour in operant-conflict paradigms that resemble the core features of the addictive phenotype: drug-intake acquisition and maintenance, drug-seeking, relapse and drug use despite negative consequences. Since acetaldehyde directly stimulates dopamine neuronal firing in the mesolimbic system, the aim of this study was the investigation of dopamine D2-receptors' role in the onset of the operant drinking behaviour for acetaldehyde in different functional stages, by the administration of two different D2-receptor agonists, quinpirole and ropinirole. Our results show that acetaldehyde was able to induce and maintain a drug-taking behaviour, displaying an escalation during training, and a reinstatement behaviour after 1-week forced abstinence. Acetaldehyde operant drinking behaviour involved D2-receptor signalling: in particular, quinpirole administration at 0.03 mg/kg, induced a significant decrease in the number of lever presses both in extinction and in relapse. Ropinirole, administered at 0.03 mg/kg during extinction, did not produce any modification but, when administered during abstinence, induced a strong decrease in acetaldehyde intake in the following relapse session. Taken together, our data suggest that acetaldehyde exerts its own motivational properties, involving the dopaminergic transmission: indeed, activation of pre-synaptic D2-receptors by quinpirole, during extinction and relapse, negatively affects operant behaviour for acetaldehyde, likely decreasing acetaldehyde-induced dopamine release. The activation of post-synaptic D2-receptors by ropinirole, during abstinence, decreases the motivation to the consecutive reinstatement of acetaldehyde drinking behaviour, likely counteracting the reduction in the dopaminergic tone typical of withdrawal. These data further strengthen the evidence that acetaldehyde may play a crucial role as mediator of ethanol's central effects.
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12
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Warnock KT, Yang AR, Yi HS, June HL, Kelly T, Basile AS, Skolnick P, June HL. Amitifadine, a triple monoamine uptake inhibitor, reduces binge drinking and negative affect in an animal model of co-occurring alcoholism and depression symptomatology. Pharmacol Biochem Behav 2012; 103:111-8. [PMID: 22884707 PMCID: PMC3537915 DOI: 10.1016/j.pbb.2012.07.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 07/25/2012] [Accepted: 07/27/2012] [Indexed: 01/08/2023]
Abstract
The co-occurrence of alcoholism and depression is highly prevalent and difficult to treat. In an animal model of binge drinking that exhibits abstinence-induced behaviors reminiscent of negative affective states, the triple monoamine uptake inhibitor, amitifadine, produced a selective, dose dependent attenuation of binge drinking. Amitifadine also reversed abstinence-induced increases in the intracranial self-stimulation threshold, a model of anhedonia, and immobility in the forced swim test, reflecting behavioral despair. In view of the safety profile of amitifadine in humans, including low risk for weight gain, lack of sexual side effects, and low potential for abuse, we hypothesize that amitifadine will be effective in treating co-occurring alcoholism and depression.
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Affiliation(s)
- Kaitlin T. Warnock
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC 20060, USA
| | - Andrew R.S.T. Yang
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC 20060, USA
| | - Heon S. Yi
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC 20060, USA
| | - Harry L. June
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC 20060, USA
| | - Tim Kelly
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC 20060, USA
| | | | - Phil Skolnick
- DOV Pharmaceutical, Inc., Somerset, N.J., 08873, USA
| | - Harry L. June
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC 20060, USA
- Department of Pharmacology, Howard University College of Medicine Washington, DC 20060, USA
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