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Hasler BP, Schulz CT, Pedersen SL. Sleep-Related Predictors of Risk for Alcohol Use and Related Problems in Adolescents and Young Adults. Alcohol Res 2024; 44:02. [PMID: 38500552 PMCID: PMC10948113 DOI: 10.35946/arcr.v44.1.02] [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: 03/20/2024] Open
Abstract
PURPOSE Growing evidence supports sleep and circadian rhythms as influencing alcohol use and the course of alcohol use disorder (AUD). Studying sleep/circadian-alcohol associations during adolescence and young adulthood may be valuable for identifying sleep/circadian-related approaches to preventing and/or treating AUD. This paper reviews current evidence for prospective associations between sleep/circadian factors and alcohol involvement during adolescence and young adulthood with an emphasis on the effects of sleep/circadian factors on alcohol use. SEARCH METHODS The authors conducted a literature search in PsycInfo, PubMed, and Web of Science using the search terms "sleep" and "alcohol" paired with "adolescent" or "adolescence" or "young adult" or "emerging adult," focusing on the title/abstract fields, and restricting to English-language articles. Next, the search was narrowed to articles with a prospective/longitudinal or experimental design, a sleep-related measure as a predictor, an alcohol-related measure as an outcome, and confirming a primarily adolescent and/or young adult sample. This step was completed by a joint review of candidate article abstracts by two of the authors. SEARCH RESULTS The initial search resulted in 720 articles. After review of the abstracts, the list was narrowed to 27 articles reporting on observational longitudinal studies and three articles reporting on intervention trials. Noted for potential inclusion were 35 additional articles that reported on studies with alcohol-related predictors and sleep-related outcomes, and/or reported on candidate moderators or mediators of sleep-alcohol associations. Additional articles were identified via review of relevant article reference lists and prior exposure based on the authors' previous work in this area. DISCUSSION AND CONCLUSIONS Overall, the review supports a range of sleep/circadian characteristics during adolescence and young adulthood predicting the development of alcohol use and/or alcohol-related problems. Although sleep treatment studies in adolescents and young adults engaging in regular and/or heavy drinking show that sleep can be improved in those individuals, as well as potentially reducing alcohol craving and alcohol-related consequences, no studies in any age group have yet demonstrated that improving sleep reduces drinking behavior. Notable limitations include relatively few longitudinal studies and only two experimental studies, insufficient consideration of different assessment timescales (e.g., day-to-day vs. years), insufficient consideration of the multidimensional nature of sleep, a paucity of objective measures of sleep and circadian rhythms, and insufficient consideration of how demographic variables may influence sleep/circadian-alcohol associations. Examining such moderators, particularly those related to minoritized identities, as well as further investigation of putative mechanistic pathways linking sleep/circadian characteristics to alcohol outcomes, are important next steps.
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Affiliation(s)
- Brant P Hasler
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Christina T Schulz
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Sarah L Pedersen
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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2
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Yousefzadehfard Y, Wechsler B, DeLorenzo C. Human circadian rhythm studies: Practical guidelines for inclusion/exclusion criteria and protocol. Neurobiol Sleep Circadian Rhythms 2022; 13:100080. [PMID: 35989718 PMCID: PMC9382328 DOI: 10.1016/j.nbscr.2022.100080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/03/2022] Open
Abstract
As interest in circadian rhythms and their effects continues to grow, there is an increasing need to perform circadian studies in humans. Although the constant routine is the gold standard for these studies, there are advantages to performing more naturalistic studies. Here, a review of protocols for such studies is provided along with sample inclusion and exclusion criteria. Sleep routines, drug use, shift work, and menstrual cycle are addressed as screening considerations. Regarding protocol, best practices for measuring melatonin, including light settings, posture, exercise, and dietary habits are described. The inclusion/exclusion recommendations and protocol guidelines are intended to reduce confounding variables in studies that do not involve the constant routine. Given practical limitations, a range of recommendations is provided from stringent to lenient. The scientific rationale behind these recommendations is discussed. However, where the science is equivocal, recommendations are based on empirical decisions made in previous studies. While not all of the recommendations listed may be practical in all research settings and with limited potential participants, the goal is to allow investigators to make well informed decisions about their screening procedures and protocol techniques and to improve rigor and reproducibility, in line with the objectives of the National Institutes of Health.
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Affiliation(s)
- Yashar Yousefzadehfard
- Center for Understanding Biology Using Imaging Technology, Department of Psychiatry, Stony Brook University, Stony Brook, NY, USA.,Department of Psychiatry, Texas Tech University Health Science Center, Midland, TX, USA
| | - Bennett Wechsler
- Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, USA
| | - Christine DeLorenzo
- Center for Understanding Biology Using Imaging Technology, Department of Psychiatry, Stony Brook University, Stony Brook, NY, USA
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3
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Ruby CL, Paye G, Fabi JL, Zhang J, Risinger MO, Palmer KN, Verbanes NM, D'Angelo A, Watts TM, Mabe L, Swartzwelder HS. Sex Differences in Photic Entrainment and Sensitivity to Ethanol-Induced Chronodisruption in Adult Mice After Adolescent Intermittent Ethanol Exposure. Alcohol Clin Exp Res 2018; 42:2144-2159. [PMID: 30102762 DOI: 10.1111/acer.13867] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/07/2018] [Indexed: 11/27/2022]
Abstract
BACKGROUND Evidence supports a role for the circadian system in alcohol use disorders, but the impact of adolescent alcohol exposure on circadian timing later in life is unknown. Acute ethanol (EtOH) attenuates circadian photic phase-resetting in adult, but not adolescent, rodents. However, nearly all studies have focused on males and it is unknown whether this adolescent-typical insensitivity to EtOH persists into adulthood after adolescent drinking. METHODS Circadian activity was monitored in C57BL/6J mice receiving adolescent intermittent EtOH (AIE) exposure (15% EtOH and water every other day throughout adolescence) or water alone followed by 24 days wherein EtOH was not available (washout). Mice then received a challenge dose of EtOH (1.5 g/kg, intraperitoneal) or saline 15 minutes prior to a 30-minute phase-delaying light pulse and then were released into constant darkness (DD). To control for possible phase-shifting by EtOH challenge alone, a separate group of mice underwent AIE exposure (or water-only) and washout and then received an EtOH or saline injection, but did not receive a light pulse prior to DD. RESULTS Striking sex differences in nearly all measures of circadian photic entrainment were observed during adolescence but AIE effects were subtle and few. Only EtOH-naïve adult male mice showed attenuated photic phase-shifts with EtOH challenge, while all other groups showed normal phase-resetting responses to light. AIE-exposed females showed a persistent delay in activity offset. CONCLUSIONS Adult male AIE-exposed mice retained adolescent-like insensitivity to EtOH-induced suppression of photic phase-resetting, suggesting AIE-induced "lock-in" of an adolescent behavioral phenotype. Adult AIE-exposed females showed delayed initiation of the rest phase. Our results also indicate that intermittent EtOH drinking has subtle effects on circadian activity in mice during adolescence that differ from previously reported effects on adult males. The observed sex differences in circadian activity, EtOH consumption and preference, and responses to EtOH challenge merit future mechanistic study.
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Affiliation(s)
- Christina L Ruby
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Gerneleh Paye
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Jason L Fabi
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Jiawen Zhang
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Megan O Risinger
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Kaitlyn N Palmer
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Natalie M Verbanes
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Ariana D'Angelo
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Tia M Watts
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Lauren Mabe
- Department of Biology , Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - H Scott Swartzwelder
- Department of Psychiatry and Behavioral Sciences , Duke University, Durham, North Carolina
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4
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De Nobrega AK, Lyons LC. Drosophila: An Emergent Model for Delineating Interactions between the Circadian Clock and Drugs of Abuse. Neural Plast 2017; 2017:4723836. [PMID: 29391952 PMCID: PMC5748135 DOI: 10.1155/2017/4723836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/13/2017] [Indexed: 01/12/2023] Open
Abstract
Endogenous circadian oscillators orchestrate rhythms at the cellular, physiological, and behavioral levels across species to coordinate activity, for example, sleep/wake cycles, metabolism, and learning and memory, with predictable environmental cycles. The 21st century has seen a dramatic rise in the incidence of circadian and sleep disorders with globalization, technological advances, and the use of personal electronics. The circadian clock modulates alcohol- and drug-induced behaviors with circadian misalignment contributing to increased substance use and abuse. Invertebrate models, such as Drosophila melanogaster, have proven invaluable for the identification of genetic and molecular mechanisms underlying highly conserved processes including the circadian clock, drug tolerance, and reward systems. In this review, we highlight the contributions of Drosophila as a model system for understanding the bidirectional interactions between the circadian system and the drugs of abuse, alcohol and cocaine, and illustrate the highly conserved nature of these interactions between Drosophila and mammalian systems. Research in Drosophila provides mechanistic insights into the corresponding behaviors in higher organisms and can be used as a guide for targeted inquiries in mammals.
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Affiliation(s)
- Aliza K. De Nobrega
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Lisa C. Lyons
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
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5
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Abstract
Reward-related learning, including that associated with drugs of abuse, is largely mediated by the dopaminergic mesolimbic pathway. Mesolimbic neurophysiology and motivated behavior, in turn, are modulated by the circadian timing system which generates ∼24-h rhythms in cellular activity. Both drug taking and seeking and mesolimbic dopaminergic neurotransmission can vary widely over the day. Moreover, circadian clock genes are expressed in ventral tegmental area dopaminergic cells and in mesolimbic target regions where they can directly modulate reward-related neurophysiology and behavior. There also exists a reciprocal influence between drug taking and circadian timing as the administration of drugs of abuse can alter behavioral rhythms and circadian clock gene expression in mesocorticolimbic structures. These interactions suggest that manipulations of the circadian timing system may have some utility in the treatment of substance abuse disorders. Here, the literature on bidirectional interactions between the circadian timing system and drug taking is briefly reviewed, and potential chronotherapeutic considerations for the treatment of addiction are discussed.
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6
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Ruby CL, Palmer KN, Zhang J, Risinger MO, Butkowski MA, Swartzwelder HS. Differential Sensitivity to Ethanol-Induced Circadian Rhythm Disruption in Adolescent and Adult Mice. Alcohol Clin Exp Res 2016; 41:187-196. [PMID: 27997028 DOI: 10.1111/acer.13275] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 10/19/2016] [Indexed: 12/29/2022]
Abstract
BACKGROUND Growing evidence supports a central role for the circadian system in alcohol use disorders, but few studies have examined this relationship during adolescence. In mammals, circadian rhythms are regulated by the suprachiasmatic nucleus, a biological clock whose timing is synchronized (reset) to the environment primarily by light (photic) input. Alcohol (ethanol [EtOH]) disrupts circadian timing in part by attenuating photic phase-resetting responses in adult rodents. However, circadian rhythms change throughout life and it is not yet known whether EtOH has similar effects on circadian regulation during adolescence. METHODS General circadian locomotor activity was monitored in male C57BL6/J mice beginning in adolescence (P27) or adulthood (P61) in a 12-hour light, 12-hour dark photocycle for ~2 weeks to establish baseline circadian activity measures. On the day of the experiment, mice received an acute injection of EtOH (1.5 g/kg, i.p.) or equal volume saline 15 minutes prior to a 30-minute light pulse at Zeitgeber Time 14 (2 hours into the dark phase) and then were released into constant darkness (DD) for ~2 weeks to assess phase-resetting responses. Control mice of each age-group received injections but no light pulse prior to DD. RESULTS While adults showed the expected decrease in photic phase-delays induced by acute EtOH, this effect was absent in adolescent mice. Adolescents also showed baseline differences in circadian rhythmicity compared to adults, including advanced photocycle entrainment, larger photic phase-delays, a shorter free-running (endogenous) circadian period, and greater circadian rhythm amplitude. CONCLUSIONS Collectively, our results indicate that adolescent mice are less sensitive to the effect of EtOH on circadian photic phase-resetting and that their daily activity rhythms are markedly different than those of adults.
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Affiliation(s)
- Christina L Ruby
- Department of Biology, Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Kaitlyn N Palmer
- Department of Biology, Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Jiawen Zhang
- Department of Biology, Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Megan O Risinger
- Department of Biology, Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - Melissa A Butkowski
- Department of Biology, Indiana University of Pennsylvania, Indiana, Pennsylvania
| | - H Scott Swartzwelder
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, North Carolina.,Neurobiology Research Laboratory, VA Medical Center, Durham, North Carolina
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7
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Burgess HJ, Emens JS. Circadian-Based Therapies for Circadian Rhythm Sleep-Wake Disorders. CURRENT SLEEP MEDICINE REPORTS 2016; 2:158-165. [PMID: 27990327 DOI: 10.1007/s40675-016-0052-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This review summarizes recent developments relevant to the treatment of circadian rhythm sleep-wake disorders. The clinical practice guidelines for the treatment of intrinsic circadian rhythm sleep-wake disorders is described, followed by recent treatment studies for delayed sleep-wake phase disorder, non-24 hour sleep-wake disorder, irregular sleep-wake disorder and shift work. New methods to estimate circadian phase, including home saliva collection to estimate the dim light melatonin onset, circadian questionnaires and general rules to guide light and exogenous melatonin treatments are described. New developments in light treatment are detailed, including light flashes during sleep and wearable light devices. Substances such as caffeine and alcohol, and devices such as electronic tablets are also considered for their potential to shift circadian timing. Finally, an update on melatonin supplements in the US is discussed, along with the controversy surrounding the use of melatonin supplements in patients with prediabetes or diabetes.
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Affiliation(s)
- Helen J Burgess
- Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, 1645 West Jackson Blvd., Suite 425, Chicago, Illinois 60612. Ph. 312-563-4785 Fax. 312-563-4900
| | - Jonathan S Emens
- Departments of Psychiatry & Medicine, Oregon Health & Science University, Portland VA Medical Center, 3710 SW US Veterans Hospital, Rd. P3-PULM, Portland, Oregon 97239. Ph. 503-402-2841 Fax. 503-273-5033
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8
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Burgess HJ, Rizvydeen M, Fogg LF, Keshavarzian A. A single dose of alcohol does not meaningfully alter circadian phase advances and phase delays to light in humans. Am J Physiol Regul Integr Comp Physiol 2016; 310:R759-65. [PMID: 26936778 PMCID: PMC4867406 DOI: 10.1152/ajpregu.00001.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/29/2016] [Indexed: 01/13/2023]
Abstract
Central circadian timing influences mental and physical health. Research in nocturnal rodents has demonstrated that when alcohol is consumed, it reaches the central hypothalamic circadian pacemaker (suprachiasmatic nuclei) and can directly alter circadian phase shifts to light. In two separate studies, we examined, for the first time, the effects of a single dose of alcohol on circadian phase advances and phase delays to light in humans. Two 23-day within-subjects placebo-controlled counterbalanced design studies were conducted. Both studies consisted of 6 days of fixed baseline sleep to stabilize circadian timing, a 2-day laboratory session, a 6-day break, and a repeat of 6 days of fixed sleep and a 2-day laboratory session. In the phase advance study (n= 10 light drinkers, 24-45 yr), the laboratory sessions consisted of a baseline dim light phase assessment, sleep episode, alcohol (0.6 g/kg) or placebo, 2-h morning bright light pulse, and final phase assessment. In the phase-delay study (n= 14 light drinkers, 22-44 yr), the laboratory sessions consisted of a baseline phase assessment, alcohol (0.8 g/kg) or placebo, 2-h late night bright light pulse, sleep episode, and final phase assessment. In both studies, alcohol either increased or decreased the observed phase shifts to light (interaction P≥ 0.46), but the effect of alcohol vs. placebo on phase shifts to light was always on average smaller than 30 min. Thus, no meaningful effects of a single dose of alcohol vs. placebo on circadian phase shifts to light in humans were observed.
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Affiliation(s)
- Helen J Burgess
- Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, Chicago, Illinois;
| | - Muneer Rizvydeen
- Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, Chicago, Illinois
| | - Louis F Fogg
- College of Nursing, Rush University Medical Center, Chicago, Illinois; and
| | - Ali Keshavarzian
- Department of Digestive Diseases, Rush University Medical Center, Chicago, Illinois
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9
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Udoh US, Valcin JA, Gamble KL, Bailey SM. The Molecular Circadian Clock and Alcohol-Induced Liver Injury. Biomolecules 2015; 5:2504-37. [PMID: 26473939 PMCID: PMC4693245 DOI: 10.3390/biom5042504] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/02/2015] [Accepted: 09/09/2015] [Indexed: 12/11/2022] Open
Abstract
Emerging evidence from both experimental animal studies and clinical human investigations demonstrates strong connections among circadian processes, alcohol use, and alcohol-induced tissue injury. Components of the circadian clock have been shown to influence the pathophysiological effects of alcohol. Conversely, alcohol may alter the expression of circadian clock genes and the rhythmic behavioral and metabolic processes they regulate. Therefore, we propose that alcohol-mediated disruption in circadian rhythms likely underpins many adverse health effects of alcohol that cut across multiple organ systems. In this review, we provide an overview of the circadian clock mechanism and showcase results from new studies in the alcohol field implicating the circadian clock as a key target of alcohol action and toxicity in the liver. We discuss various molecular events through which alcohol may work to negatively impact circadian clock-mediated processes in the liver, and contribute to tissue pathology. Illuminating the mechanistic connections between the circadian clock and alcohol will be critical to the development of new preventative and pharmacological treatments for alcohol use disorders and alcohol-mediated organ diseases.
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Affiliation(s)
- Uduak S Udoh
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
| | - Jennifer A Valcin
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
| | - Karen L Gamble
- Department of Psychiatry, Division of Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
| | - Shannon M Bailey
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
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10
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Summa KC, Jiang P, Fitzpatrick K, Voigt RM, Bowers SJ, Forsyth CB, Vitaterna MH, Keshavarzian A, Turek FW. Chronic Alcohol Exposure and the Circadian Clock Mutation Exert Tissue-Specific Effects on Gene Expression in Mouse Hippocampus, Liver, and Proximal Colon. Alcohol Clin Exp Res 2015; 39:1917-29. [PMID: 26332085 DOI: 10.1111/acer.12834] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 06/30/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Chronic alcohol exposure exerts numerous adverse effects, although the specific mechanisms underlying these negative effects on different tissues are not completely understood. Alcohol also affects core properties of the circadian clock system, and it has been shown that disruption of circadian rhythms confers vulnerability to alcohol-induced pathology of the gastrointestinal barrier and liver. Despite these findings, little is known of the molecular interactions between alcohol and the circadian clock system, especially regarding implications for tissue-specific susceptibility to alcohol pathologies. The aim of this study was to identify changes in expression of genes relevant to alcohol pathologies and circadian clock function in different tissues in response to chronic alcohol intake. METHODS Wild-type and circadian Clock(Δ19) mutant mice were subjected to a 10-week chronic alcohol protocol, after which hippocampal, liver, and proximal colon tissues were harvested for gene expression analysis using a custom-designed multiplex magnetic bead hybridization assay that provided quantitative assessment of 80 mRNA targets of interest, including 5 housekeeping genes and a predetermined set of 75 genes relevant for alcohol pathology and circadian clock function. RESULTS Significant alterations in expression levels attributable to genotype, alcohol, and/or a genotype by alcohol interaction were observed in all 3 tissues, with distinct patterns of expression changes observed in each. Of particular interest was the finding that a high proportion of genes involved in inflammation and metabolism on the array was significantly affected by alcohol and the Clock(Δ19) mutation in the hippocampus, suggesting a suite of molecular changes that may contribute to pathological change. CONCLUSIONS These results reveal the tissue-specific nature of gene expression responses to chronic alcohol exposure and the Clock(Δ19) mutation and identify specific expression profiles that may contribute to tissue-specific vulnerability to alcohol-induced injury in the brain, colon, and liver.
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Affiliation(s)
- Keith C Summa
- Center for Sleep & Circadian Biology, Department of Neurobiology, Northwestern University, Evanston, Illinois
| | - Peng Jiang
- Center for Sleep & Circadian Biology, Department of Neurobiology, Northwestern University, Evanston, Illinois
| | - Karrie Fitzpatrick
- Center for Sleep & Circadian Biology, Department of Neurobiology, Northwestern University, Evanston, Illinois
| | - Robin M Voigt
- Division of Digestive Diseases and Nutrition, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Samuel J Bowers
- Center for Sleep & Circadian Biology, Department of Neurobiology, Northwestern University, Evanston, Illinois
| | - Christopher B Forsyth
- Division of Digestive Diseases and Nutrition, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois.,Department of Biochemistry, Rush University Medical Center, Chicago, Illinois
| | - Martha H Vitaterna
- Center for Sleep & Circadian Biology, Department of Neurobiology, Northwestern University, Evanston, Illinois
| | - Ali Keshavarzian
- Division of Digestive Diseases and Nutrition, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois.,Department of Biochemistry, Rush University Medical Center, Chicago, Illinois.,Department of Pharmacology, Rush University Medical Center, Chicago, Illinois.,Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, Illinois.,Division of Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Science, Utrecht University, Utrecht, the Netherlands
| | - Fred W Turek
- Center for Sleep & Circadian Biology, Department of Neurobiology, Northwestern University, Evanston, Illinois
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11
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Parekh PK, Ozburn AR, McClung CA. Circadian clock genes: effects on dopamine, reward and addiction. Alcohol 2015; 49:341-9. [PMID: 25641765 DOI: 10.1016/j.alcohol.2014.09.034] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 12/17/2022]
Abstract
Addiction is a widespread public health issue with social and economic ramifications. Substance abuse disorders are often accompanied by disruptions in circadian rhythms including sleep/wake cycles, which can exacerbate symptoms of addiction and dependence. Additionally, genetic disturbance of circadian molecular mechanisms can predispose some individuals to substance abuse disorders. In this review, we will discuss how circadian genes can regulate midbrain dopaminergic activity and subsequently, drug intake and reward. We will also suggest future directions for research on circadian genes and drugs of abuse.
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12
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Prosser RA, Glass JD. Assessing ethanol's actions in the suprachiasmatic circadian clock using in vivo and in vitro approaches. Alcohol 2015; 49:321-339. [PMID: 25457753 DOI: 10.1016/j.alcohol.2014.07.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/07/2014] [Accepted: 07/09/2014] [Indexed: 12/18/2022]
Abstract
Research over the past decade has demonstrated substantial interactions between the circadian system and the processes through which alcohol affects behavior and physiology. Here we summarize the results of our collaborative efforts focused on this intersection. Using a combination of in vivo and in vitro approaches, we have shown that ethanol affects many aspects of the mammalian circadian system, both acutely as well as after chronic administration. Conversely, we have shown circadian influences on ethanol consumption. Importantly, we are beginning to delve into the cellular mechanisms associated with these effects. We are also starting to form a picture of the neuroanatomical bases for many of these actions. Finally, we put our current findings into perspective by suggesting new avenues of inquiry for our future efforts.
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13
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Thakkar MM, Sharma R, Sahota P. Alcohol disrupts sleep homeostasis. Alcohol 2015; 49:299-310. [PMID: 25499829 DOI: 10.1016/j.alcohol.2014.07.019] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 07/02/2014] [Accepted: 07/07/2014] [Indexed: 01/14/2023]
Abstract
Alcohol is a potent somnogen and one of the most commonly used "over the counter" sleep aids. In healthy non-alcoholics, acute alcohol decreases sleep latency, consolidates and increases the quality (delta power) and quantity of NREM sleep during the first half of the night. However, sleep is disrupted during the second half. Alcoholics, both during drinking periods and during abstinences, suffer from a multitude of sleep disruptions manifested by profound insomnia, excessive daytime sleepiness, and altered sleep architecture. Furthermore, subjective and objective indicators of sleep disturbances are predictors of relapse. Finally, within the USA, it is estimated that societal costs of alcohol-related sleep disorders exceeds $18 billion. Thus, although alcohol-associated sleep problems have significant economic and clinical consequences, very little is known about how and where alcohol acts to affect sleep. In this review, we have described our attempts to unravel the mechanism of alcohol-induced sleep disruptions. We have conducted a series of experiments using two different species, rats and mice, as animal models. We performed microdialysis, immunohistochemical, pharmacological, sleep deprivation and lesion studies which suggest that the sleep-promoting effects of alcohol may be mediated via alcohol's action on the mediators of sleep homeostasis: adenosine (AD) and the wake-promoting cholinergic neurons of the basal forebrain (BF). Alcohol, via its action on AD uptake, increases extracellular AD resulting in the inhibition of BF wake-promoting neurons. Since binge alcohol consumption is a highly prevalent pattern of alcohol consumption and disrupts sleep, we examined the effects of binge drinking on sleep-wakefulness. Our results suggest that disrupted sleep homeostasis may be the primary cause of sleep disruption observed following binge drinking. Finally, we have also shown that sleep disruptions observed during acute withdrawal, are caused due to impaired sleep homeostasis. In conclusion, we suggest that alcohol may disrupt sleep homeostasis to cause sleep disruptions.
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Affiliation(s)
- Mahesh M Thakkar
- Harry S. Truman Memorial Veterans Hospital, Columbia, MO 65201, USA; Department of Neurology, University of Missouri, Columbia, MO 65201, USA.
| | - Rishi Sharma
- Harry S. Truman Memorial Veterans Hospital, Columbia, MO 65201, USA; Department of Neurology, University of Missouri, Columbia, MO 65201, USA
| | - Pradeep Sahota
- Harry S. Truman Memorial Veterans Hospital, Columbia, MO 65201, USA; Department of Neurology, University of Missouri, Columbia, MO 65201, USA
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14
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Rosenwasser AM, McCulley WD, Fecteau M. Circadian activity rhythms and voluntary ethanol intake in male and female ethanol-preferring rats: effects of long-term ethanol access. Alcohol 2014; 48:647-55. [PMID: 25281289 DOI: 10.1016/j.alcohol.2014.07.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 06/12/2014] [Accepted: 07/01/2014] [Indexed: 01/13/2023]
Abstract
Chronic alcohol (ethanol) intake alters fundamental properties of the circadian clock. While previous studies have reported significant alterations in free-running circadian period during chronic ethanol access, these effects are typically subtle and appear to require high levels of intake. In the present study we examined the effects of long-term voluntary ethanol intake on ethanol consumption and free-running circadian period in male and female, selectively bred ethanol-preferring P and HAD2 rats. In light of previous reports that intermittent access can result in escalated ethanol intake, an initial 2-week water-only baseline was followed by either continuous or intermittent ethanol access (i.e., alternating 15-day epochs of ethanol access and ethanol deprivation) in separate groups of rats. Thus, animals were exposed to either 135 days of continuous ethanol access or to five 15-day access periods alternating with four 15-day periods of ethanol deprivation. Animals were maintained individually in running-wheel cages under continuous darkness throughout the experiment to allow monitoring of free-running activity and drinking rhythms, and 10% (v/v) ethanol and plain water were available continuously via separate drinking tubes during ethanol access. While there were no initial sex differences in ethanol drinking, ethanol preference increased progressively in male P and HAD2 rats under both continuous and intermittent-access conditions, and eventually exceeded that seen in females. Free-running period shortened during the initial ethanol-access epoch in all groups, but the persistence of this effect showed complex dependence on sex, breeding line, and ethanol-access schedule. Finally, while females of both breeding lines displayed higher levels of locomotor activity than males, there was little evidence for modulation of activity level by ethanol access. These results are consistent with previous findings that chronic ethanol intake alters free-running circadian period, and show further that the development of chronobiological tolerance to ethanol may vary by sex and genotype.
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Affiliation(s)
- Alan M Rosenwasser
- Department of Psychology, University of Maine, Orono, ME 04469, USA; School of Biology and Ecology, University of Maine, Orono, ME 04469, USA; Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME 04469, USA.
| | | | - Matthew Fecteau
- Department of Psychology, University of Maine, Orono, ME 04469, USA
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Logan RW, Williams WP, McClung CA. Circadian rhythms and addiction: mechanistic insights and future directions. Behav Neurosci 2014; 128:387-412. [PMID: 24731209 DOI: 10.1037/a0036268] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Circadian rhythms are prominent in many physiological and behavioral functions. Circadian disruptions either by environmental or molecular perturbation can have profound health consequences, including the development and progression of addiction. Both animal and humans studies indicate extensive bidirectional relationships between the circadian system and drugs of abuse. Addicted individuals display disrupted rhythms, and chronic disruption or particular chronotypes may increase the risk for substance abuse and relapse. Moreover, polymorphisms in circadian genes and an evening chronotype have been linked to mood and addiction disorders, and recent efforts suggest an association with the function of reward neurocircuitry. Animal studies are beginning to determine how altered circadian gene function results in drug-induced neuroplasticity and behaviors. Many studies suggest a critical role for circadian rhythms in reward-related pathways in the brain and indicate that drugs of abuse directly affect the central circadian pacemaker. In this review, we highlight key findings demonstrating the importance of circadian rhythms in addiction and how future studies will reveal important mechanistic insights into the involvement of circadian rhythms in drug addiction.
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Affiliation(s)
- Ryan W Logan
- Department of Psychiatry, University of Pittsburgh School of Medicine
| | - Wilbur P Williams
- Department of Psychiatry, University of Pittsburgh School of Medicine
| | - Colleen A McClung
- Department of Psychiatry, University of Pittsburgh School of Medicine
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16
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The role of clock in ethanol-related behaviors. Neuropsychopharmacology 2013; 38:2393-400. [PMID: 23722243 PMCID: PMC3799058 DOI: 10.1038/npp.2013.138] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 05/21/2013] [Accepted: 05/22/2013] [Indexed: 02/08/2023]
Abstract
Mice with a mutation in the Clock gene (ClockΔ19) exhibit increased preference for stimulant rewards and sucrose. They also have an increase in dopaminergic activity in the ventral tegmental area (VTA) and a general increase in glutamatergic tone that might underlie these behaviors. However, it is unclear if their phenotype would extend to a very different class of drug (ethanol), and if so, whether these systems might be involved in their response. Continuous access voluntary ethanol intake was evaluated in ClockΔ19 mutants and wild-type (WT) mice. We found that ClockΔ19 mice exhibited significantly increased ethanol intake in a two-bottle choice paradigm. Interestingly, this effect was more robust in female mice. Moreover, chronic ethanol experience resulted in a long-lasting decrease in VTA Clock expression. To determine the importance of VTA Clock expression in ethanol intake, we knocked down Clock expression in the VTA of WT mice via RNA interference. We found that reducing Clock expression in the VTA resulted in significantly increased ethanol intake similar to the ClockΔ19 mice. Interestingly, we also discovered that ClockΔ19 mice exhibit significantly augmented responses to the sedative effects of ethanol and ketamine, but not pentobarbital. However, their drinking behavior was not affected by acamprosate, an FDA-approved drug for the treatment of alcoholism, suggesting that their increased glutamatergic tone might underlie the increased sensitivity to the sedative/hypnotic properties of ethanol but not the rewarding properties of ethanol. Taken together, we have identified a significant role for Clock in the VTA as a negative regulator of ethanol intake and implicate the VTA dopamine system in this response.
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Filiano AN, Millender-Swain T, Johnson R, Young ME, Gamble KL, Bailey SM. Chronic ethanol consumption disrupts the core molecular clock and diurnal rhythms of metabolic genes in the liver without affecting the suprachiasmatic nucleus. PLoS One 2013; 8:e71684. [PMID: 23951220 PMCID: PMC3741117 DOI: 10.1371/journal.pone.0071684] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Accepted: 07/08/2013] [Indexed: 12/15/2022] Open
Abstract
Chronic ethanol consumption disrupts several metabolic pathways including β-oxidation and lipid biosynthesis, facilitating the development of alcoholic fatty liver disease. Many of these same metabolic pathways are directly regulated by cell autonomous circadian clocks, and recent studies suggest that disruption of daily rhythms in metabolism contributes to multiple common cardiometabolic diseases (including non-alcoholic fatty liver disease). However, it is not known whether ethanol disrupts the core molecular clock in the liver, nor whether this, in turn, alters rhythms in lipid metabolism. Herein, we tested the hypothesis that chronic ethanol consumption disrupts the molecular circadian clock in the liver and potentially changes the diurnal expression patterns of lipid metabolism genes. Consistent with previous studies, male C57BL/6J mice fed an ethanol-containing diet exhibited higher levels of liver triglycerides compared to control mice, indicating hepatic steatosis. Further, the diurnal oscillations of core clock genes (Bmal1, Clock, Cry1, Cry2, Per1, and Per2) and clock-controlled genes (Dbp, Hlf, Nocturnin, Npas2, Rev-erbα, and Tef) were altered in livers from ethanol-fed mice. In contrast, ethanol had only minor effects on the expression of core clock genes in the suprachiasmatic nucleus (SCN). These results were confirmed in Per2Luciferase knock-in mice, in which ethanol induced a phase advance in PER2::LUC bioluminescence oscillations in liver, but not SCN. Further, there was greater variability in the phase of PER2::LUC oscillations in livers from ethanol-fed mice. Ethanol consumption also affected the diurnal oscillations of metabolic genes, including Adh1, Cpt1a, Cyp2e1, Pck1, Pdk4, Ppargc1a, Ppargc1b and Srebp1c, in the livers of C57BL/6J mice. In summary, chronic ethanol consumption alters the function of the circadian clock in liver. Importantly, these results suggest that chronic ethanol consumption, at levels sufficient to cause steatosis, disrupts the core hepatic clock as well as the diurnal rhythms of key lipid metabolism genes.
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Affiliation(s)
- Ashley N. Filiano
- Department of Pathology-Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Telisha Millender-Swain
- Department of Pathology-Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Russell Johnson
- Department of Psychiatry-Division of Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Martin E. Young
- Department of Medicine-Division of Cardiovascular Diseases, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Karen L. Gamble
- Department of Psychiatry-Division of Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Shannon M. Bailey
- Department of Pathology-Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- * E-mail:
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McCulley WD, Ascheid S, Crabbe JC, Rosenwasser AM. Selective breeding for ethanol-related traits alters circadian phenotype. Alcohol 2013; 47:187-94. [PMID: 23414725 DOI: 10.1016/j.alcohol.2013.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 01/10/2013] [Accepted: 01/12/2013] [Indexed: 10/27/2022]
Abstract
Previous studies in mice and rats have shown that selective breeding for high and low ethanol preference results in divergence of circadian phenotype in the selected lines. These results indicate that some alleles influencing ethanol preference also contribute to circadian rhythm regulation. Selective breeding has also been used to produce lines of mice differing in a number of other ethanol-related traits, while studies of phenotypic and genetic correlation indicate that diverse ethanol-related traits are influenced by both shared and unshared genetics. In the present study, we examined several features of circadian activity rhythms in a mouse line selected for binge-like drinking and in mouse lines selected for high and low severity of ethanol withdrawal convulsions. Specifically, Experiment 1 compared High Drinking in the Dark (HDID-1) mice to their genetically heterogeneous progenitor line (HS/Npt), and Experiment 2 compared Withdrawal Seizure-Prone (WSP-2) and Withdrawal Seizure-Resistant (WSR-2) mice. Both line pairs displayed differences in their daily activity patterns under light-dark conditions. In addition, HDID-1 mice showed shorter free-running periods in constant light and less coherent activity rhythms across lighting conditions relative to HS/Npt controls, while WSP-2 mice showed longer free-running periods in constant darkness relative to WSR-2 mice. These results strengthen the evidence for genetic linkages between responsiveness to ethanol and circadian regulation, and extend this evidence to include ethanol-related phenotypes other than preference drinking. However, the present results also indicate that the nature of genetic correlations between and within phenotypic domains is highly complex.
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Rosenwasser AM, Fixaris MC. Chronobiology of alcohol: studies in C57BL/6J and DBA/2J inbred mice. Physiol Behav 2013; 110-111:140-7. [PMID: 23313401 DOI: 10.1016/j.physbeh.2013.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 11/02/2012] [Accepted: 01/06/2013] [Indexed: 12/18/2022]
Abstract
Human alcoholics display dramatic disruptions of circadian rhythms that may contribute to the maintenance of excessive drinking, thus creating a vicious cycle. While clinical studies cannot establish direct causal mechanisms, recent animal experiments have revealed bidirectional interactions between circadian rhythms and ethanol intake, suggesting that the chronobiological disruptions seen in human alcoholics are mediated in part by alterations in circadian pacemaker function. The present study was designed to further explore these interactions using C57BL/6J (B6) and DBA/2J (D2) inbred mice, two widely employed strains differing in both circadian and alcohol-related phenotypes. Mice were maintained in running-wheel cages with or without free-choice access to ethanol and exposed to a variety of lighting regimens, including standard light-dark cycles, constant darkness, constant light, and a "shift-lag" schedule consisting of repeated light-dark phase shifts. Relative to the standard light-dark cycle, B6 mice showed reduced ethanol intake in both constant darkness and constant light, while D2 mice showed reduced ethanol intake only in constant darkness. In contrast, shift-lag lighting failed to affect ethanol intake in either strain. Access to ethanol altered daily activity patterns in both B6 and D2 mice, and increased activity levels in D2 mice, but had no effects on other circadian parameters. Thus, the overall pattern of results was broadly similar in both strains, and consistent with previous observations that chronic ethanol intake alters circadian activity patterns while environmental perturbation of circadian rhythms modulates voluntary ethanol intake. These results suggest that circadian-based interventions may prove useful in the management of alcohol use disorders.
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Conroy DA, Hairston IS, Arnedt JT, Hoffmann RF, Armitage R, Brower KJ. Dim light melatonin onset in alcohol-dependent men and women compared with healthy controls. Chronobiol Int 2012; 29:35-42. [PMID: 22217099 PMCID: PMC4258345 DOI: 10.3109/07420528.2011.636852] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sleep disturbances in alcohol-dependent (AD) individuals may persist despite abstinence from alcohol and can influence the course of the disorder. Although the mechanisms of sleep disturbances of AD are not well understood and some evidence suggests dysregulation of circadian rhythms, dim light melatonin onset (DLMO) has not previously been assessed in AD versus healthy control (HC) individuals in a sample that varied by sex and race. The authors assessed 52 AD participants (mean ± SD age: 36.0 ± 11.0 yrs of age, 10 women) who were 3-12 wks since their last drink (abstinence: 57.9 ± 19.3 d) and 19 age- and sex-matched HCs (34.4 ± 10.6 yrs, 5 women). Following a 23:00-06:00 h at-home sleep schedule for at least 5 d and screening/baseline nights in the sleep laboratory, participants underwent a 3-h extension of wakefulness (02:00 h bedtime) during which salivary melatonin samples were collected every 30 min beginning at 19:30 h. The time of DLMO was the primary measure of circadian physiology and was assessed with two commonly used methodologies. There was a slower rate of rise and lower maximal amplitude of the melatonin rhythm in the AD group. DLMO varied by the method used to derive it. Using 3 pg/mL as threshold, no significant differences were found between the AD and HC groups. Using 2 standard deviations above the mean of the first three samples, the DLMO in AD occurred significantly later, 21:02 ± 00:41 h, than in HC, 20:44 ± 00:21 h (t = -2.4, p = .02). Although melatonin in the AD group appears to have a slower rate of rise, using well-established criteria to assess the salivary DLMO did not reveal differences between AD and HC participants. Only when capturing melatonin when it is already rising was DLMO found to be significantly delayed by a mean 18 min in AD participants. Future circadian analyses on alcoholics should account for these methodological caveats.
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Affiliation(s)
- Deirdre A Conroy
- Addiction Research Center, Department of Psychiatry, University of Michigan, Ann Arbor, Michigan 48109, USA.
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Brager AJ, Prosser RA, Glass JD. Circadian and acamprosate modulation of elevated ethanol drinking in mPer2 clock gene mutant mice. Chronobiol Int 2012; 28:664-72. [PMID: 21929298 DOI: 10.3109/07420528.2011.601968] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The PER2 clock gene modulates ethanol consumption, such that mutant mice not expressing functional mPer2 have altered circadian behavior that promotes higher ethanol intake and preference. Experiments were undertaken to characterize circadian-related behavioral effects of mPer2 deletion on ethanol intake and to explore how acamprosate (used to reduce alcohol dependence) alters diurnal patterns of ethanol intake. Male mPer2 mutant and WT (wild-type) mice were entrained to a 12:12 h light-dark (12L:12D) photocycle, and their locomotor and drinking activities were recorded. Circadian locomotor measurements confirmed that mPer2 mutants had an advanced onset of nocturnal activity of about 2 h relative to WTs, and an increased duration of nocturnal activity (p < .01). Also, mPer2 mutants preferred and consumed more ethanol and had more daily ethanol drinking episodes vs. WTs. Measurements of systemic ethanol using subcutaneous microdialysis confirmed the advanced rise in ethanol intake in the mPer2 mutants, with 24-h averages being ∼60 vs. ∼25 mM for WTs (p < .01). A 6-day regimen of single intraperitoneal (i.p.) acamprosate injections (300 mg/kg) at zeitgeber time (ZT) 10 did not alter the earlier onset of nocturnal ethanol drinking in the mPer2 mutants, but reduced the overall amplitude of drinking and preference (both p < .01). Acamprosate also reduced these parameters in WTs. These results suggest that elevated ethanol intake in mPer2 mutants may be a partial consequence of an earlier nighttime activity onset and increase in nocturnal drinking activity. The suppressive action of acamprosate on ethanol intake is not due to an altered diurnal pattern of drinking, but rather a decrease in the number of daily drinking bouts and amount of drinking per bout.
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Affiliation(s)
- Allison J Brager
- Department of Biological Sciences, Kent State University, Kent, Ohio 44242, USA
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Brager A, Prosser RA, Glass JD. Acamprosate-responsive brain sites for suppression of ethanol intake and preference. Am J Physiol Regul Integr Comp Physiol 2011; 301:R1032-43. [PMID: 21697518 DOI: 10.1152/ajpregu.00179.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acamprosate suppresses alcohol intake and craving in recovering alcoholics; however, the central sites of its action are unclear. To approach this question, brain regions responsive to acamprosate were mapped using acamprosate microimplants targeted to brain reward and circadian areas implicated in alcohol dependence. mPer2 mutant mice with nonfunctional mPer2, a circadian clock gene that gates endogenous timekeeping, were included, owing to their high levels of ethanol intake and preference. Male wild-type (WT) and mPer2 mutant mice received free-choice (15%) ethanol/water for 3 wk. The ethanol was withdrawn for 3 wk and then reintroduced to facilitate relapse. Four days before ethanol reintroduction, mice received bilateral blank or acamprosate-containing microimplants releasing ∼50 ng/day into reward [ventral tegmental (VTA), peduculopontine tegmentum (PPT), and nucleus accumbens (NA)] and circadian [intergeniculate leaflet (IGL) and suprachiasmatic nucleus (SCN)] areas. The hippocampus was also targeted. Circadian locomotor activity was measured throughout. Ethanol intake and preference were greater in mPer2 mutants than in wild-type (WT) mice (27 g·kg(-1)·day(-1) vs. 13 g·kg(-1)·day(-1) and 70% vs. 50%, respectively; both, P < 0.05). In WTs, acamprosate in all areas, except hippocampus, suppressed ethanol intake and preference (by 40-60%) during ethanol reintroduction. In mPer2 mutants, acamprosate in the VTA, PPT, and SCN suppressed ethanol intake and preference by 20-30%. These data are evidence that acamprosate's suppression of ethanol intake and preference are manifest through actions within major reward and circadian sites.
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Affiliation(s)
- Allison Brager
- Department of Biological Sciences, Kent State University, Kent, Ohio 44242, USA
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