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Waldron MA, Jones HE, Rhinehart EM, Grisel JE. Sensitivity to the initial rewarding effects of alcohol: Influence of age, sex, and β-endorphin. ALCOHOL, CLINICAL & EXPERIMENTAL RESEARCH 2024; 48:667-679. [PMID: 38426214 DOI: 10.1111/acer.15281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 01/27/2024] [Accepted: 01/29/2024] [Indexed: 03/02/2024]
Abstract
BACKGROUND Alcohol use disorders (AUDs) are widespread, devastating and complex. About 20% of people who consume alcohol develop problem use, accounting for over 5% of worldwide deaths. While numerous animal models have facilitated understanding of the consequences of excessive drinking, translational models allow for experimental manipulation of factors thought to contribute to AUD liability. METHODS We employ a single-exposure conditioned place preference assay (SE-CPP) to investigate the influence of age, sex and the opioid peptide β-endorphin (bE) on the initial rewarding effects of ethanol, a strong predictor of AUDs. Adolescent (PND28-35) and adult (PND70-90) male and female, control C57BL/6J and bE-deficient mice were tested following a single injection of 1.5 g/kg of ethanol. Following the SE-CPP test, animals were deeply anesthetized, sacrificed, and perfused, and the brains were subsequently sectioned at 40 microns and processed for immunohistochemical localization of c-fos. One-sample, two-tailed t-tests were used to assess drug preference or aversion and the locomotor effects of alcohol. RESULTS In general, adults were more sensitive to the effects of alcohol than adolescents, and outcomes depended on sex and bE. For example, among females, adolescents were stimulated by the drug, but insensitive to locomotor effects as adults, while among males, adolescents were insensitive and adults sedated. Wild-type adolescents of both sexes failed to evince initial subjective reward from the drug, but bE-deficient adolescents, and all adult subjects, preferred a context once associated with ethanol over one that had been paired with saline. c-fos immunoreactivity in multiple brain regions was attenuated in bE-deficient animals, though influences of both sex and bE grew stronger with age. CONCLUSIONS This study demonstrates the utility of the SE-CPP paradigm for elucidating factors that contribute to the liability for AUDs, and supports the growing body of research that shows that sensitivity to the rewarding effects of alcohol changes during the course of development. Our results also suggest that developmental contributions are sex-dependent, and may also depend on the influence of endogenous opioid signaling.
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Affiliation(s)
- Madison A Waldron
- Department of Psychology, Neuroscience Program, Bucknell University, Lewisburg, Pennsylvania, USA
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
| | - Holly E Jones
- Department of Psychology, Neuroscience Program, Bucknell University, Lewisburg, Pennsylvania, USA
| | - Erin M Rhinehart
- Department of Biology, Susquehanna University, Selinsgrove, Pennsylvania, USA
| | - Judith E Grisel
- Department of Psychology, Neuroscience Program, Bucknell University, Lewisburg, Pennsylvania, USA
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Takahashi N, Akaike N, Nagamatsu T, Uchino H, Kudo Y. Effects of TND1128 (a 5-deazaflavin derivative), with self-redox ability, as a mitochondria activator on the mouse brain slice and its comparison with β-NMN. J Pharmacol Sci 2023; 151:93-109. [PMID: 36707184 DOI: 10.1016/j.jphs.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 11/22/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
We have no definitive treatment for dementia characterized by prolonged neuronal death due to the enormous accumulation of foreign matter, such as β-amyloid. Since Alzheimer's type dementia develops slowly, we may be able to delay the onset and improve neuronal dysfunction by enhancing the energy metabolism of individual neurons. TND1128, a derivative of 5-deazaflavin, is a chemical known to have an efficient self-redox ability. We expected TND1128 as an activator for mitochondrial energy synthesis. We used brain slices prepared from mice 22 ± 2 h pretreated with TND1128 or β-NMN. We measured Ca2+ concentrations in the cytoplasm ([Ca2+]cyt) and mitochondria ([Ca2+]mit) by using fluorescence Ca2+ indicators, Fura-4F, and X-Rhod-1, respectively, and examined the protective effects of drugs on [Ca2+]cyt and [Ca2+]mit overloading by repeating 80K exposure. TND1128 (0.01, 0.1, and 1 mg/kg s.c.) mitigates the dynamics of both [Ca2+]cyt and [Ca2+]mit in a dose-dependent manner. β-NMN (10, 30, and 100 mg/kg s.c.) also showed significant dose-dependent mitigating effects on [Ca2+]cyt, but the effect on the [Ca2+]mit dynamics was insignificant. We confirmed the mitochondria-activating potential of TND1128 in the present study. We expect TND1128 as a drug that rescues deteriorating neurons with aging or disease.
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Affiliation(s)
- Nanae Takahashi
- Department of Anesthesiology, Tokyo Medical University Hachioji Medical Center 1163 Tatemachi,Hachioji, Tokyo 193-0998, Japan.
| | - Norio Akaike
- Research Division for Clinical Pharmacology, Medical Corporation, Juryou Group, Kumamoto Kinoh Hospital, 6-8-1 Yamamuro, Kita-ku, Kumamoto 860-8518, Japan.
| | - Tomohisa Nagamatsu
- Laboratory of Curative Creation Study for Geriatric-diseases Prevention, Faculty of Pharmacological Sciences, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto, 860-0082, Japan.
| | - Hiroyuki Uchino
- Department of Anesthesiology, Tokyo Medical University, 6-7-1 Nishishinjuku, Sinjuku-ku, Tokyo 160-0023, Japan.
| | - Yoshihisa Kudo
- Department of Anesthesiology, Tokyo Medical University Hachioji Medical Center 1163 Tatemachi,Hachioji, Tokyo 193-0998, Japan.
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3
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Seemiller LR, Logue SF, Gould TJ. Inbred mouse strain differences in alcohol and nicotine addiction-related phenotypes from adolescence to adulthood. Pharmacol Biochem Behav 2022; 218:173429. [PMID: 35820468 DOI: 10.1016/j.pbb.2022.173429] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 06/18/2022] [Accepted: 07/06/2022] [Indexed: 11/20/2022]
Abstract
Understanding the genetic basis of a predisposition for nicotine and alcohol use across the lifespan is important for public health efforts because genetic contributions may change with age. However, parsing apart subtle genetic contributions to complex human behaviors is a challenge. Animal models provide the opportunity to study the effects of genetic background and age on drug-related phenotypes, while controlling important experimental variables such as amount and timing of drug exposure. Addiction research in inbred, or isogenic, mouse lines has demonstrated genetic contributions to nicotine and alcohol abuse- and addiction-related behaviors. This review summarizes inbred mouse strain differences in alcohol and nicotine addiction-related phenotypes including voluntary consumption/self-administration, initial sensitivity to the drug as measured by sedative, hypothermic, and ataxic effects, locomotor effects, conditioned place preference or place aversion, drug metabolism, and severity of withdrawal symptoms. This review also discusses how these alcohol and nicotine addiction-related phenotypes change from adolescence to adulthood.
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Affiliation(s)
- Laurel R Seemiller
- Department of Biobehavioral Health, Penn State University, University Park, PA, USA
| | - Sheree F Logue
- Department of Biobehavioral Health, Penn State University, University Park, PA, USA
| | - Thomas J Gould
- Department of Biobehavioral Health, Penn State University, University Park, PA, USA.
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4
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Lodha J, Brocato E, Wolstenholme JT. Areas of Convergence and Divergence in Adolescent Social Isolation and Binge Drinking: A Review. Front Behav Neurosci 2022; 16:859239. [PMID: 35431830 PMCID: PMC9009335 DOI: 10.3389/fnbeh.2022.859239] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
Adolescence is a critical developmental period characterized by enhanced social interactions, ongoing development of the frontal cortex and maturation of synaptic connections throughout the brain. Adolescents spend more time interacting with peers than any other age group and display heightened reward sensitivity, impulsivity and diminished inhibitory self-control, which contribute to increased risky behaviors, including the initiation and progression of alcohol use. Compared to adults, adolescents are less susceptible to the negative effects of ethanol, but are more susceptible to the negative effects of stress, particularly social stress. Juvenile exposure to social isolation or binge ethanol disrupts synaptic connections, dendritic spine morphology, and myelin remodeling in the frontal cortex. These structural effects may underlie the behavioral and cognitive deficits seen later in life, including social and memory deficits, increased anxiety-like behavior and risk for alcohol use disorders (AUD). Although the alcohol and social stress fields are actively investigating the mechanisms through which these effects occur, significant gaps in our understanding exist, particularly in the intersection of the two fields. This review will highlight the areas of convergence and divergence in the fields of adolescent social stress and ethanol exposure. We will focus on how ethanol exposure or social isolation stress can impact the development of the frontal cortex and lead to lasting behavioral changes in adulthood. We call attention to the need for more mechanistic studies and the inclusion of the evaluation of sex differences in these molecular, structural, and behavioral responses.
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Affiliation(s)
- Jyoti Lodha
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Emily Brocato
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Jennifer T. Wolstenholme
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
- VCU Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
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5
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Bent MAM, Pais AC, Wolstenholme JT. Comparing behavior following binge ethanol in adolescent and adult DBA/2 J mice. Behav Brain Res 2022; 419:113703. [PMID: 34864163 PMCID: PMC8765084 DOI: 10.1016/j.bbr.2021.113703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 11/06/2021] [Accepted: 12/01/2021] [Indexed: 01/20/2023]
Abstract
The adolescent brain undergoes maturation in areas critically involved in reward, addiction, and memory. Adolescents consume alcohol more than any other drug, typically in a binge-like manner. While adults also binge on alcohol, the adolescent brain is more susceptible to ethanol-related damages due to its ongoing development, which may result in persistent behavioral and physical changes, including differences in myelination in the frontal cortex. Sex also impacts ethanol metabolism and addiction progression, suggesting females are more sensitive than males. This study addressed memory, sociability, ethanol sensitivity, and myelin gene expression changes due to binge ethanol, sex, and age. DBA/2 J males and females were exposed to intermittent binge ethanol (4 g/kg, i.g.) from postnatal day (PND) 29-42 or as adults from PND 64-77. Age groups were tested for behaviors at the early phase (24 h - 7 days) and late phase (starting 3 weeks) after the last dose. Adult prefrontal cortex was collected at both phases. Adolescent ethanol impaired late phase memory while adult ethanol showed no impairment. Meanwhile, adolescent males showed early phase tolerance to ethanol-induced locomotor activation, while adult females showed tolerance at both phases. Adult-treated mice displayed reductions in social interaction. Adult ethanol decreased Mal expression, a gene involved in myelin integrity, at the early phase. No differences in myelin gene expression were observed at the late phase. Thus, adolescent binge ethanol more severely impacts memory and myelin gene expression compared to adult exposure, while adult mice display ethanol-induced reductions in social interaction and tolerance to ethanol's locomotor activation.
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Affiliation(s)
- Maria Alexis M. Bent
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA
| | - A. Christian Pais
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA,,VCU Alcohol Research Center, Virginia Commonwealth University, Richmond, VA
| | - Jennifer T. Wolstenholme
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA,,VCU Alcohol Research Center, Virginia Commonwealth University, Richmond, VA
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Transcranial direct current stimulation (tDCS) reduces motivation to drink ethanol and reacquisition of ethanol self-administration in female mice. Sci Rep 2022; 12:198. [PMID: 34997004 PMCID: PMC8741977 DOI: 10.1038/s41598-021-03940-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 11/24/2021] [Indexed: 12/02/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) is an emerging noninvasive brain neuromodulation technique aimed at relieving symptoms associated with psychiatric disorders, including addiction. The goal of the present study was to better identify which phase of alcohol-related behavior (hedonic effect, behavioral sensitization, self-administration, or motivation to obtain the drug) might be modulated by repeated anodal tDCS over the frontal cortex (0.2 mA, 20 min, twice a day for 5 consecutive days), using female mice as a model. Our data showed that tDCS did not modulate the hedonic effects of ethanol as assessed by a conditioned place preference test (CPP) or the expression of ethanol-induced behavioral sensitization. Interestingly, tDCS robustly reduced reacquisition of ethanol consumption (50% decrease) following extinction of self-administration in an operant paradigm. Furthermore, tDCS significantly decreased motivation to drink ethanol on a progressive ratio schedule (30% decrease). Taken together, our results show a dissociation between the effects of tDCS on “liking” (hedonic aspect; no effect in the CPP) and “wanting” (motivation; decreased consumption on a progressive ratio schedule). Our tDCS procedure in rodents will allow us to better understand its mechanisms of action in order to accelerate its use as a complementary and innovative tool to help alcohol-dependent patients maintain abstinence or reduce ethanol intake.
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7
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Hoffman JL, Faccidomo S, Saunders BL, Taylor SM, Kim M, Hodge CW. Inhibition of AMPA receptors (AMPARs) containing transmembrane AMPAR regulatory protein γ-8 with JNJ-55511118 shows preclinical efficacy in reducing chronic repetitive alcohol self-administration. Alcohol Clin Exp Res 2021; 45:1424-1435. [PMID: 34086361 DOI: 10.1111/acer.14639] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/27/2021] [Accepted: 05/14/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND A prominent therapeutic indication for alcohol use disorder (AUD) is reduction in chronic repetitive alcohol use. Glutamate α-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPARs) regulate chronic alcohol self-administration in preclinical models. Recent evidence indicates that the expression and function of AMPARs require the transmembrane AMPAR regulatory protein γ-8 (TARP γ-8). This study evaluated the preclinical efficacy of JNJ-55511118, a novel, selective, high-affinity inhibitor of TARP γ-8-bound AMPARs, in reducing chronic operant alcohol self-administration. METHODS Separate groups of male and female C57BL/6J mice (n = 8/sex/group) were trained to lever press for sweetened alcohol (9% v/v + sucrose 2% w/v) or sucrose only (2% w/v) in operant conditioning chambers using an FR-4 schedule of reinforcement. After a 40-day baseline, JNJ-55511118 (0, 1, and 10 mg/kg, p.o.) was administered in randomized order 1 h before self-administration sessions. Parameters of operant behavior including response rate, total reinforcers, and head entries in the drinking troughs were computer recorded. RESULTS During baseline, responding to alcohol, but not sucrose, was greater in female than male mice. In male mice, both doses of JNJ-55511118 decreased multiple parameters of alcohol self-administration but did not reduce behavior-matched sucrose-only self-administration. JNJ-55511118 had no effect on sweetened alcohol or sucrose self-administration in female mice. Subsequent tests of motor function showed that the lowest effective dose of JNJ-55511118 (1 mg/kg) had no effect on open-field activity in male mice. CONCLUSIONS This study shows for the first time that TARP γ-8-bound AMPARs regulate a behavioral pathology associated with addiction. The preclinical efficacy of JNJ-55511118 in reducing alcohol self-administration in male mice suggests that inhibition of TARP γ-8-bound AMPARs is a novel and highly significant neural target for developing medications to treat AUD and other forms of addiction.
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Affiliation(s)
- Jessica L Hoffman
- Bowles Center for Alcohol Studies, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sara Faccidomo
- Bowles Center for Alcohol Studies, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Psychiatry, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Briana L Saunders
- Bowles Center for Alcohol Studies, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Seth M Taylor
- Bowles Center for Alcohol Studies, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Michelle Kim
- Bowles Center for Alcohol Studies, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Clyde W Hodge
- Bowles Center for Alcohol Studies, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Psychiatry, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Ferreira SEMM, Soares LM, Lira CR, Yokoyama TS, Engi SA, Cruz FC, Leão RM. Ethanol-induced locomotor sensitization: Neuronal activation in the nucleus accumbens and medial prefrontal cortex. Neurosci Lett 2021; 749:135745. [PMID: 33610663 DOI: 10.1016/j.neulet.2021.135745] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 12/31/2022]
Abstract
Ethanol consumption may promote neuroplasticity and alterations in synapses, resulting in modifications in neuronal activity. Here, we treated male Swiss mice with ethanol (2.2 g/kg) or saline once per day for 21 consecutive days. Nine days after the last ethanol administration, they received a challenge injection of ethanol or saline, and we assessed locomotor activity. After the behavioral analysis, we evaluated neuronal activation in the medial Prefrontal Cortex (Cingulate, Prelimbic, and Infralimbic) and the Nucleus Accumbens (Shell and Core) using Fos/DAB immunohistochemistry. In another group of animals, we performed the quantitative analysis of the ARC and PSD-95 protein levels by Western blotting in the medial prefrontal cortex and nucleus accumbens brain areas. Repeated ethanol administration produced locomotor sensitization, accompanied by an increase in the nucleus accumbens shell's activation but not core. Furthermore, the ethanol pretreatment reduced ARC expression in the nucleus accumbens and medial prefrontal cortex. Our results suggest the participation of the nucleus accumbens shell in ethanol behavioral sensitization and add new pieces of evidence that neuroplasticity in synapses may contribute to the mechanism underlying this behavior.
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Affiliation(s)
- Sara Emi M M Ferreira
- Department of Bioregulation Sciences, Health Sciences Institute, Federal University of Bahia, UFBA, Brazil; Graduate Program in Pharmacy, Federal University of Bahia, UFBA, Brazil
| | - Leonardo M Soares
- Department of Bioregulation Sciences, Health Sciences Institute, Federal University of Bahia, UFBA, Brazil
| | - Clarice R Lira
- Department of Bioregulation Sciences, Health Sciences Institute, Federal University of Bahia, UFBA, Brazil; Graduate Program in Pharmacy, Federal University of Bahia, UFBA, Brazil
| | - Thais S Yokoyama
- Pharmacology Department, São Paulo Federal University, UNIFESP, Brazil
| | - Sheila A Engi
- Pharmacology Department, São Paulo Federal University, UNIFESP, Brazil
| | - Fábio C Cruz
- Pharmacology Department, São Paulo Federal University, UNIFESP, Brazil
| | - Rodrigo M Leão
- Department of Bioregulation Sciences, Health Sciences Institute, Federal University of Bahia, UFBA, Brazil; Graduate Program in Pharmacy, Federal University of Bahia, UFBA, Brazil; Pharmacology Department, Biomedical Sciences Institute, Federal University of Uberlândia, UFU, Brazil.
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Reduced sedation and increased ethanol consumption in knock-in mice expressing an ethanol insensitive alpha 2 subunit of the glycine receptor. Neuropsychopharmacology 2021; 46:528-536. [PMID: 32357359 PMCID: PMC8026987 DOI: 10.1038/s41386-020-0689-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/20/2020] [Accepted: 04/23/2020] [Indexed: 01/24/2023]
Abstract
Previous studies have shown the presence of several subunits of the inhibitory glycine receptor (GlyR) in the reward system, specifically in medium spiny neurons (MSNs) of the nucleus Accumbens (nAc). It was suggested that GlyR α1 subunits regulate nAc excitability and ethanol consumption. However, little is known about the role of the α2 subunit in the adult brain since it is a subunit highly expressed during early brain development. In this study, we used genetically modified mice with a mutation (KR389-390AA) in the intracellular loop of the GlyR α2 subunit which results in a heteromeric α2β receptor that is insensitive to ethanol. Using this mouse model denoted knock-in α2 (KI α2), our electrophysiological studies showed that neurons in the adult nAc expressed functional KI GlyRs that were rather insensitive to ethanol when compared with WT GlyRs. In behavioral tests, the KI α2 mice did not show any difference in basal motor coordination, locomotor activity, or conditioned place preference compared with WT littermate controls. In terms of ethanol response, KI α2 male mice recovered faster from the administration of ataxic and sedative doses of ethanol. Furthermore, KI α2 mice consumed higher amounts of ethanol in the first days of the drinking in the dark protocol, as compared with WT mice. These results show that the α2 subunit is important for the potentiation of GlyRs in the adult brain and this might result in reduced sedation and increased ethanol consumption.
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Pharmacological inhibition of glycogen synthase kinase 3 increases operant alcohol self-administration in a manner associated with altered pGSK-3β, protein interacting with C kinase and GluA2 protein expression in the reward pathway of male C57BL/6J mice. Behav Pharmacol 2020; 31:15-26. [PMID: 31503067 DOI: 10.1097/fbp.0000000000000501] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Glycogen synthase kinase 3 (GSK-3) is a constitutively active serine-threonine kinase that regulates numerous signaling pathways and has been implicated in neurodegenerative and neuropsychiatric diseases. Alcohol exposure increases GSK-3β (ser9) phosphorylation (pGSK-3β); however, few studies have investigated whether GSK-3 regulates the positive reinforcing effects of alcohol, which drive repetitive drug use. To address this goal, male C57BL/6J mice were trained to lever press on a fixed-ratio 4 schedule of sweetened alcohol or sucrose-only reinforcement in operant conditioning chambers. The GSK-3 inhibitor CHIR 99021 (0-10 mg/kg, i.p.) was injected 45 minutes prior to self-administration sessions. After completion of the self-administration dose-effect curve, potential locomotor effects of the GSK-3 inhibitor were assessed. To determine molecular efficacy, CHIR 99021 (10 mg/kg, i.p.) was evaluated on pGSK-3β, GSK-3β, protein interacting with C kinase (PICK1), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluA2 subunit protein expression in amygdala, nucleus accumbens (NAcb), and frontal cortex. Results showed that CHIR 99021 (10 mg/kg) dose-dependently increased alcohol reinforced responding with no effect on sucrose self-administration or locomotor activity. CHIR 99021 (10 mg/kg) significantly decreased pGSK-3β expression in all brain regions tested, reduced PICK1 and increased GluA2 total expression only in the NAcb. We conclude that GSK-3 inhibition increased the reinforcing effects of alcohol in mice. This was associated with reduced pGSK-3β and PICK1, and increased GluA2 expression. Given prior results showing that AMPA receptor activity regulates alcohol self-administration, we propose that signaling through the GSK-3/PICK1/GluA2 molecular pathway drives the positive reinforcing effects of the drug, which are required for abuse liability.
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11
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Galaj E, Barrera E, Morris D, Ma YY, Ranaldi R. Aberrations in Incentive Learning and Responding to Heroin in Male Rats After Adolescent or Adult Chronic Binge-Like Alcohol Exposure. Alcohol Clin Exp Res 2020; 44:1214-1223. [PMID: 32311102 DOI: 10.1111/acer.14341] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/08/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE Binge drinking is a serious problem among adolescents and young adults despite its adverse consequences on the brain and behavior. One area that remains poorly understood concerns the impact of chronic intermittent ethanol (CIE) exposure on incentive learning. METHODS Here, we examined the effects of CIE exposure during different developmental stages on conditioned approach and conditioned reward learning in rats experiencing acute or protracted withdrawal from alcohol. Two or 21 days after adolescent or adult CIE exposure, male rats were exposed to pairings of a light stimulus (CS) and food pellets for 3 consecutive daily sessions (30 CS-food pellet pairings per session). This was followed by conditioned approach testing measuring responses (food trough head entries) to the CS-only presentations and by conditioned reward testing measuring responses on a lever producing the CS and on another producing a tone. We then measured behavioral sensitization to repeated injections of heroin (2 mg/kg/d for 9 days). RESULTS Adolescent and adult alcohol-treated rats showed significantly impaired conditioned reward learning regardless of withdrawal period (acute or prolonged). We found no evidence of changes to conditioned approach learning after adolescent or adult exposure to CIE. Finally, in addition to producing long-term impairments in incentive learning, CIE exposure enhanced locomotor activity in response to heroin and had no effect on behavioral sensitization to heroin regardless of age and withdrawal period. CONCLUSIONS Our work sets a framework for identifying CIE-induced alterations in incentive learning and inducing susceptibility to subsequent opioid effects.
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Affiliation(s)
- Ewa Galaj
- From the, Molecular Targets and Medication Discovery Branch, (EG), National Institute on Drug Abuse Intramural Research Program, Baltimore, Maryland, USA
| | - Eddy Barrera
- Department of Psychology, (EB, DM, RR), Queens College, City University of New York, Flushing, New York, USA
| | - Debra Morris
- Department of Psychology, (EB, DM, RR), Queens College, City University of New York, Flushing, New York, USA
| | - Yao-Ying Ma
- Department of Pharmacology and Toxicology, (Y-YM), Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Robert Ranaldi
- Department of Psychology, (EB, DM, RR), Queens College, City University of New York, Flushing, New York, USA
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12
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Wu R, Liu J, Wang K, Huang Y, Zhang Y, Li JX. Effects of a trace amine-associated receptor 1 agonist RO 5263397 on ethanol-induced behavioral sensitization. Behav Brain Res 2020; 390:112641. [PMID: 32407821 DOI: 10.1016/j.bbr.2020.112641] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 03/29/2020] [Accepted: 04/01/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Alcohol dependence is a chronic and severe health problem which puts a heavy burden on society. Alcohol activates mesolimbic dopamine circuity to achieve its reinforcing effect. While TAAR1 is critically involved in the modulation of dopamine, there is little evidence indicating that TAAR1 could play a role in behavioral effects of ethanol. METHODS By using the animal model of behavioral sensitization induced by ethanol in mice, the present study was performed to investigate whether the activation of TAAR1 would affect the behavioral plasticity of ethanol. RESULTS Repeated administration with ethanol induced a significant increased locomotion in WT mice with females showing higher level of sensitization to ethanol than male mice. The TAAR1 agonist RO5263397 significantly decreased the expression of ethanol-induced behavioral sensitization both in male and female WT mice (0.1 and 0.32 mg/kg). Repeated RO5263397 exposure also prevented the development of behavioral sensitization to ethanol both in male and female WT mice. Moreover, while TAAR1-KO mice developed normal levels of ethanol-induced behavioral sensitization, RO5263397 did not affect this behavior in TAAR1-KO mice. CONCLUSIONS These results indicated that the TAAR1 agonist RO5263397 negatively regulated the expression and development of ethanol-elicited behavioral sensitization in WT but not in TAAR1-KO mice. The present study suggests that TAAR1 is probably involved in certain addiction-like effects of alcohol and could be a useful drug target for the development of new medications to treat alcohol dependence.
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Affiliation(s)
- Ruyan Wu
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, NY, United States; School of Medicine, Yangzhou University, Yangzhou, China
| | - Jianfeng Liu
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, NY, United States
| | - Kaixuan Wang
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, NY, United States
| | - Yufei Huang
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, NY, United States
| | - Yanan Zhang
- Research Triangle Institute, NC, United States
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, NY, United States.
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Carrara-Nascimento PF, Hoffmann LB, Flório JC, Planeta CS, Camarini R. Effects of Ethanol Exposure During Adolescence or Adulthood on Locomotor Sensitization and Dopamine Levels in the Reward System. Front Behav Neurosci 2020; 14:31. [PMID: 32210774 PMCID: PMC7067700 DOI: 10.3389/fnbeh.2020.00031] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/13/2020] [Indexed: 12/02/2022] Open
Abstract
Behavioral sensitization is a process of neuroadaptation characterized by a gradual increase in motor behaviors. The major neural substrates involved in the behavioral sensitization lie on the dopaminergic mesocorticolimbic pathway, which is still under development during adolescence. To investigate age-differences in ethanol behavioral sensitization and dopamine levels in distinct brain regions of the reward system, adolescent and adult mice were repeatedly pretreated with saline or ethanol (2.0 g/kg i.p.) during 15 consecutive days and challenged with saline or ethanol 5 days after pretreatment. Dopamine and its metabolites were measured in tissue samples of the prefrontal cortex (PFC), nucleus accumbens (NAc) and striatum by HPLC analysis. While repeated ethanol administration resulted in the development of locomotor sensitization in both adult and adolescent mice, only the adults expressed sensitization to a subsequent ethanol challenge injection. Neurochemical results showed reduced dopamine levels in adolescents compared to adults. Specifically, mice pretreated with ethanol during adolescence displayed lower dopamine levels in the PFC compared to the respective adult group in response to an ethanol challenge injection, and preadolescent mice exhibited lower dopamine levels in the NAc following an acute ethanol treatment compared to adults. These findings suggest that adolescent mice are not only less sensitive to the expression of ethanol-induced sensitization than adults, but also show lower dopamine content after ethanol exposition in the PFC and NAc.
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Affiliation(s)
| | - Lucas Barbosa Hoffmann
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Jorge Camilo Flório
- Departmento de Patologia, Escola de Medicina Veterinária, Universidade de São Paulo, São Paulo, Brazil
| | - Cleopatra Silva Planeta
- Laboratório de Neuropsicofarmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, Brazil
| | - Rosana Camarini
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
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14
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Matonda-Ma-Nzuzi T, Didone V, Seutin V, Tirelli E, Quertemont E. Investigating the reciprocal relationships between locomotor sensitization to ethanol and PTSD-like clusters in DBA/2J mice. Behav Brain Res 2019; 368:111909. [PMID: 30986492 DOI: 10.1016/j.bbr.2019.111909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 03/15/2019] [Accepted: 04/11/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD) are two conditions that co-occur frequently. The mechanistic explanations of this co-morbidity are still unclear. The goal of this study was twofold. First to investigate whether PTSD reduces the threshold for the acquisition of ethanol sensitization in an animal model of PTSD. Then to investigate whether ethanol sensitization modulates the expression of PTSD. METHODS 152 female inbred DBA/2 J mice were submitted to an inescapable footshock paradigm to induce a PTSD-like condition (PTSDLC) and to a paradigm of locomotor sensitization to ethanol. In a first experiment, mice were submitted to the PTSDLC and then repeatedly injected with either saline, 1 g/kg ethanol or 2 g/kg ethanol. Their sensitization to the locomotor stimulant effects of ethanol was then tested in an open field. In a second experiment, mice were first sensitized to the locomotor stimulant effects of ethanol and then tested for their behavioral response to PTSDLC. RESULTS In the first experiment, PTSDLC failed to induce a significant locomotor sensitization at the subthreshold dose of 1 g/kg ethanol. However, with 2 g/kg ethanol, a stronger ethanol sensitization was observed in mice submitted to the footshock relative to the control group. In the second experiment, ethanol sensitization increased only some of the behavioral clusters of PTSDLC, namely the fear generalization in a new context. CONCLUSION PTSDLC did not reduce the dose threshold for the acquisition of ethanol sensitization but strengthened the development of ethanol sensitization with effective doses. This suggests that PTSD might interact with one of the mechanisms underlying the development of alcohol sensitization. When the relationship between ethanol sensitization and PTSDLC is tested in the reverse direction, the present study only shows a significant effect of ethanol administration on the "sensitized fear" PTSD cluster.
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Affiliation(s)
- Thierry Matonda-Ma-Nzuzi
- Psychology & Neuroscience of Cognition - PsyNCogn, Liège University, Belgium; Laboratory of Neurophysiology, GIGA Neurosciences, all at Liège University, B-4000, Sart Tilman, Liège, Belgium; Département de psychiatrie, Faculté de médecine, Université de Kinshasa, Democratic Republic of the Congo
| | - Vincent Didone
- Psychology & Neuroscience of Cognition - PsyNCogn, Liège University, Belgium
| | - Vincent Seutin
- Laboratory of Neurophysiology, GIGA Neurosciences, all at Liège University, B-4000, Sart Tilman, Liège, Belgium
| | - Ezio Tirelli
- Psychology & Neuroscience of Cognition - PsyNCogn, Liège University, Belgium
| | - Etienne Quertemont
- Psychology & Neuroscience of Cognition - PsyNCogn, Liège University, Belgium.
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15
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Stevenson RA, Hoffman JL, Maldonado-Devincci AM, Faccidomo S, Hodge CW. MGluR5 activity is required for the induction of ethanol behavioral sensitization and associated changes in ERK MAP kinase phosphorylation in the nucleus accumbens shell and lateral habenula. Behav Brain Res 2019; 367:19-27. [PMID: 30914307 DOI: 10.1016/j.bbr.2019.03.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/21/2019] [Accepted: 03/21/2019] [Indexed: 11/26/2022]
Abstract
Metabotropic glutamate receptor subtype-5 (mGluR5) activity regulates a variety of behavioral pathologies associated with alcohol addiction. The main goal of this study was to determine if mGluR5 regulates the induction of ethanol-induced locomotor sensitization, which is a model of experience-dependent plasticity following initial exposure to drugs of abuse. The extracellular signal-regulated kinase (ERK1/2) pathway is downstream of mGluR5 and implicated in alcohol addiction; however, its role in sensitization remains unexplored. We sought to determine if mGluR5-mediated changes in ethanol-induced sensitization are associated with changes in ERK1/2 phosphorylation (pERK1/2) in specific brain regions. Adult male DBA/2 J mice were tested for acute locomotor response to ethanol (0 or 2 g/kg, IP) followed by a 9-day induction period in which the mGluR5 antagonist MPEP (0 or 30 mg/kg, IP) was administered prior to ethanol (0 or 2.5 g/kg, IP). One day later, ethanol (2 g/kg) produced a robust within- and between-group increase in locomotor activity, indicating sensitization in mice that received MPEP (0 mg/kg) during induction. MPEP (30 mg/kg) treatment during induction resulted in locomotor response to ethanol (2 g/kg) challenge that was equivalent to an acute response, indicating full blockade of sensitization. Sensitization was associated with increased pERK1/2 immunoreactivity (IR) in nucleus accumbens shell (AcbSh) and a reduction in lateral habenula (LHb), both of which were blocked by MPEP treatment during induction. Sensitization was also associated with mGluR5-independent increases in pERK1/2 IR in the nucleus accumbens core and decreases in the dentate gyrus and lateral septum. These data indicate that mGluR5 activity is required for the induction of ethanol locomotor sensitization and associated changes in ERK1/2 phosphorylation in the AcbSh and LHb, which raises the hypothesis that mGluR5-mediated cell signaling in these brain regions may mediate the induction of sensitization. Elucidating mechanisms of sensitization may increase understanding of how ethanol hijacks behavioral functions during the development of addiction.
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Affiliation(s)
- Rebekah A Stevenson
- Center for Alcohol Studies, Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States; Department of Biology, Bucknell University, Lewisburg, PA, 17837, United States
| | - Jessica L Hoffman
- Center for Alcohol Studies, Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States
| | - Antoniette M Maldonado-Devincci
- Center for Alcohol Studies, Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States; Department of Psychology, North Carolina A&T State University, Greensboro, NC, 27411, United States
| | - Sara Faccidomo
- Center for Alcohol Studies, Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States
| | - Clyde W Hodge
- Center for Alcohol Studies, Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States.
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16
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Sun W, Li X, Tang C, An L. Acute Low Alcohol Disrupts Hippocampus-Striatum Neural Correlate of Learning Strategy by Inhibition of PKA/CREB Pathway in Rats. Front Pharmacol 2018; 9:1439. [PMID: 30574089 PMCID: PMC6291496 DOI: 10.3389/fphar.2018.01439] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 11/22/2018] [Indexed: 11/30/2022] Open
Abstract
The hippocampus and striatum guide place-strategy and response-strategy learning, respectively, and they have dissociable roles in memory systems, which could compensate in case of temporary or permanent damage. Although acute alcohol (AA) treatment had been shown to have adverse effects on hippocampal function, whether it causes the functional compensation and the underlying mechanisms is unknown. In this study, rats treated with a low dose of AA avoided a hippocampus-dependent spatial strategy, instead preferring a striatum-dependent response strategy. Consistently, the learning-induced increase in hippocampal, but not striatal, pCREB was rendered less pronounced due to diminished activity of pPKA, but not pERK or pCaMKII. As rats approached the turn-decision area, Sp-cAMP, a PKA activator, was found to mitigate the inhibitory effect of AA on intra- and cross-structure synchronized neuronal oscillations, and rescue response-strategy bias and spatial learning deficits. Our study provides strong evidence of the critical link between neural couplings and strategy selection. Moreover, the PKA/CREB-signaling pathway is involved in the suppressive effect of AA on neural correlates of place-learning strategy. The novel important evidence provided here shows the functional couplings between the hippocampus and striatum in spatial learning processing and suggests possible avenues for therapeutic intervention.
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Affiliation(s)
- Wei Sun
- Medical College of Acupuncture-Moxibustion and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiaoliang Li
- Medical College of Acupuncture-Moxibustion and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Chunzhi Tang
- Medical College of Acupuncture-Moxibustion and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Lei An
- Medical College of Acupuncture-Moxibustion and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China.,College of Acupuncture-Moxibustion and Orthopedics, Guiyang University of Chinese Medicine, Guiyang, China.,Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada
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17
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Nona CN, Hendershot CS, Lê AD. Behavioural sensitization to alcohol: Bridging the gap between preclinical research and human models. Pharmacol Biochem Behav 2018; 173:15-26. [DOI: 10.1016/j.pbb.2018.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 07/31/2018] [Accepted: 08/07/2018] [Indexed: 12/28/2022]
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18
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Santos-Rocha JB, Rae M, Teixeira AMA, Teixeira SA, Munhoz CD, Muscará MN, Marcourakis T, Szumlinski KK, Camarini R. Involvement of neuronal nitric oxide synthase in cross-sensitization between chronic unpredictable stress and ethanol in adolescent and adult mice. Alcohol 2018; 68:71-79. [PMID: 29525685 DOI: 10.1016/j.alcohol.2017.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 09/22/2017] [Accepted: 10/18/2017] [Indexed: 01/05/2023]
Abstract
The peculiar neurochemical profile of the adolescent brain renders it differently susceptible to several stimuli, including stress and/or drug exposure. Among several stress mediators, nitric oxide (NO) has a role in stress responses. We have demonstrated that adolescent mice are less sensitive to ethanol-induced sensitization than adult mice. The present study investigated whether chronic unpredictable stress (CUS) induces behavioral sensitization to ethanol in adolescent and adult Swiss mice, and investigated the influence of Ca2+-dependent nitric oxide synthase (NOS) activity in the phenomenon. Adolescent and adult mice were exposed to repeated 1.8 g/kg ethanol or CUS and challenged with saline or ethanol. A neuronal nitric oxide synthase (nNOS) inhibitor, 7-nitroindazole (7NI), was administered along with ethanol and CUS to test its effects on behavioral sensitization. Both adolescent and adult mice displayed cross-sensitization between CUS and ethanol in adult mice, with adolescents showing a lower degree of sensitization than adults. nNOS inhibition by 7NI reduced both ethanol sensitization and cross-sensitization. All age differences in the Ca2+-dependent NOS activity in the hippocampus and prefrontal cortex were in the direction of greater activity in adults than in adolescents. Adolescents showed lower sensitivity to cross-sensitization between CUS and ethanol, and the nitric oxide (NO) system seems to have a pivotal role in ethanol-induced behavioral sensitization and cross-sensitization in both adolescent and adult mice.
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Affiliation(s)
| | - Mariana Rae
- Departmento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, 05508-900, Brazil
| | | | - Simone Aparecida Teixeira
- Departmento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, 05508-900, Brazil
| | - Carolina Demarchi Munhoz
- Departmento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, 05508-900, Brazil
| | - Marcelo Nicolas Muscará
- Departmento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, 05508-900, Brazil
| | - Tania Marcourakis
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, SP, 05508-000, Brazil
| | - Karen K Szumlinski
- Department of Psychological and Brain Sciences, Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106-9660, United States
| | - Rosana Camarini
- Departmento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, 05508-900, Brazil.
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19
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Hendershot CS, Nona CN. A Review of Developmental Considerations in Human Laboratory Alcohol Research. CURRENT ADDICTION REPORTS 2017; 4:364-378. [PMID: 29326866 DOI: 10.1007/s40429-017-0173-8] [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] [Indexed: 10/18/2022]
Abstract
PURPOSE OF REVIEW Human laboratory studies involving alcohol administration have generated critical knowledge about individual differences in risk for alcohol use disorder (AUD), but have primarily involved adult populations and cross-sectional research designs. Ethical constraints have largely precluded human laboratory alcohol research in adolescence, and prospective studies have been rare. This paper provides an overview of developmental considerations in human laboratory alcohol research, with a focus on studies conducted with youth. RECENT FINDINGS Recent human laboratory studies from Europe and Canada have examined aspects of alcohol response during late adolescence, while recent survey studies from the United States have highlighted methods for circumventing alcohol administration in studies of adolescents. SUMMARY Across several decades of research, exceedingly few laboratory studies have examined developmental differences in alcohol responses or utilized prospective designs. Efforts to prioritize prospective research would further clarify the role of alcohol sensitivity traits as predictors or markers of AUD onset and progression.
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Affiliation(s)
- Christian S Hendershot
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Christina N Nona
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
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20
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Wolstenholme JT, Mahmood T, Harris GM, Abbas S, Miles MF. Intermittent Ethanol during Adolescence Leads to Lasting Behavioral Changes in Adulthood and Alters Gene Expression and Histone Methylation in the PFC. Front Mol Neurosci 2017; 10:307. [PMID: 29018328 PMCID: PMC5622951 DOI: 10.3389/fnmol.2017.00307] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/12/2017] [Indexed: 01/23/2023] Open
Abstract
Adolescents primarily consume alcohol in binges, which can be particularly harmful to the developing frontal cortex and increase risk for an adult alcohol use disorder. We conducted a study investigating immediate and long lasting changes to the prefrontal cortex (PFC) transcriptome to determine the molecular mechanisms underlying adult ethanol behavioral sensitivity following binge ethanol in adolescence. DBA/2J mice were orally dosed with 4 g/kg ethanol intermittently from day 29 to 42. Adolescent mice were tested for anxiety-like behavior and ethanol sensitivity using the loss of righting reflex task. As adults, mice were tested for cognitive changes using the novel object recognition task, ethanol-induced anxiolysis and ethanol sensitivity. Adolescent binge ethanol altered ethanol sensitivity in young mice and led to lasting memory deficits in the object recognition test and greater ethanol sensitivity in adulthood. Using genomic profiling of transcripts in the PFC, we found that binge ethanol reduced myelin-related gene expression and altered chromatin modifying genes involved in histone demethylation at H3K9 and H3K36. We hypothesize that ethanol's actions on histone methylation may be a switch for future transcriptional changes that underlie the behavioral changes lasting into adulthood.
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Affiliation(s)
- Jennifer T Wolstenholme
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States.,VCU Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Tariq Mahmood
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Guy M Harris
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Shahroze Abbas
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Michael F Miles
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States.,VCU Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States.,Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA, United States
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21
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Effects of environmental enrichment upon ethanol-induced conditioned place preference and pre-frontal BDNF levels in adolescent and adult mice. Sci Rep 2017; 7:8574. [PMID: 28819238 PMCID: PMC5561235 DOI: 10.1038/s41598-017-08795-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 07/18/2017] [Indexed: 01/04/2023] Open
Abstract
Environmental enrichment (EE) provides a non-pharmacological tool to alter drug-induced reward, yet its effects on ethanol-induced reward remain controversial. We analyzed adolescent vs. adult (mice) differences in the influence of EE on ethanol-induced conditioned place preference (CPP). The effects of these treatments on brain-derived neurotrophic factor (BDNF) levels in the prefrontal cortex were examined in a separate group of animals. Ethanol-induced CPP was found in adults, and it was similar in EE and in animals reared under standard housing conditions (SC). Adolescents kept under EE, but not those in SC, exhibited CPP. Among SC, but not among EE, adolescents, BDNF levels were significantly lower in those treated with ethanol than in those given vehicle. These results indicate that, compared to adults, adolescent exhibited reduced sensitivity to ethanol’s rewarding effects, yet the youth but not the adults exhibited sensitivity to the promoting effect of EE upon CPP by ethanol. Ethanol significantly reduced BDNF levels in adolescents reared under standard housing conditions, but not in adult mice nor in adolescents given EE housing conditions. The present results add to the plethora of adolescent-specific responses to ethanol or to environmental stimuli that may put the youth at risk for escalation of ethanol intake.
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22
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Oxytocin reduces alcohol consumption in prairie voles. Physiol Behav 2017; 179:411-421. [PMID: 28716609 DOI: 10.1016/j.physbeh.2017.07.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/12/2017] [Accepted: 07/13/2017] [Indexed: 11/23/2022]
Abstract
Alcohol use disorder (AUD) negatively affects millions of people every year in the United States, and effective treatments for AUD are still needed. The neuropeptide oxytocin has shown promise for reducing alcohol drinking in mice and rats. Because oxytocin also plays a key role in complex prosocial behaviors like bonding and attachment, we tested the effect of oxytocin on alcohol drinking in prairie voles, a species that both consumes high amounts of alcohol and forms oxytocin dependent social bonds in a manner similar to humans. Oxytocin treatment (1.0, 3.0, and 10.0mg/kg, i.p.) reduced alcohol consumption in male and female prairie voles in animals that had access to 15% ethanol vs water every other day for 12 alcohol drinking sessions. In animals with continuous access to 15% alcohol and water, oxytocin (3.0mg/kg) reduced alcohol consumption only in the first hour of access after treatment, with no significant effects on consumption over the 24-hr period. In an open field locomotor test, oxytocin (1.0, 3.0, and 10.0mg/kg, i.p.) did not affect overall locomotor activity; however, ethanol (2g/kg, i.p.) increased locomotor activity in males and females, and produced anxiolytic effects (increased time in the center of an open field) in females only. Because prairie voles have been shown to match the alcohol consumption of their cage mate, we evaluated the relationship between cage mates' alcohol drinking. There was an overall pattern of social facilitation (consumption by one cage mate predicted consumption by the other cage mate); however, we found significant individual differences across cages in which many cages did not show significant matching, and, in some cases one cage mate's consumption negatively predicted the other cage mate's consumption. Overall, our data provide support for the potential of oxytocin as a treatment to reduce alcohol consumption.
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23
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Carrara-Nascimento PF, Hoffmann LB, Contó MB, Marcourakis T, Camarini R. Ethanol Sensitization during Adolescence or Adulthood Induces Different Patterns of Ethanol Consumption without Affecting Ethanol Metabolism. Front Behav Neurosci 2017; 11:46. [PMID: 28386220 PMCID: PMC5362622 DOI: 10.3389/fnbeh.2017.00046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 02/28/2017] [Indexed: 11/13/2022] Open
Abstract
In previous study, we demonstrated that ethanol preexposure may increase ethanol consumption in both adolescent and adult mice, in a two-bottle choice model. We now questioned if ethanol exposure during adolescence results in changes of consumption pattern using a three-bottle choice procedure, considering drinking-in-the-dark and alcohol deprivation effect as strategies for ethanol consumption escalation. We also analyzed aldehyde dehydrogenase (ALDH) activity as a measurement of ethanol metabolism. Adolescent and adult Swiss mice were treated with saline (SAL) or 2.0 g/kg ethanol (EtOH) during 15 days (groups: Adolescent-SAL, Adolescent-EtOH, Adult-SAL and Adult-EtOH). Five days after the last injection, mice were exposed to the three-bottle choice protocol using sucrose fading procedure (4% + sucrose vs. 8%–15% ethanol + sucrose vs. water + sucrose) for 2 h during the dark phase. Sucrose was faded out from 8% to 0%. The protocol was composed of a 6-week acquisition period, followed by four withdrawals and reexposures. Both adolescent and adult mice exhibited ethanol behavioral sensitization, although the magnitude of sensitization in adolescents was lower than in adults. Adolescent-EtOH displayed an escalation of 4% ethanol consumption during acquisition that was not observed in Adult-EtOH. Moreover, Adult-EtOH consumed less 4% ethanol throughout all the experiment and less 15% ethanol in the last reexposure period than Adolescent-EtOH. ALDH activity varied with age, in which older mice showed higher ALDH than younger ones. Ethanol pretreatment or the pattern of consumption did not have influence on ALDH activity. Our data suggest that ethanol pretreatment during adolescence but not adulthood may influence the pattern of ethanol consumption toward an escalation in ethanol consumption at low dose, without exerting an impact on ALDH activity.
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Affiliation(s)
- Priscila F Carrara-Nascimento
- Laboratory of Neurochemistry and Behavioral Pharmacology, Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo São Paulo, Brazil
| | - Lucas B Hoffmann
- Laboratory of Neurochemistry and Behavioral Pharmacology, Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo São Paulo, Brazil
| | - Marcos B Contó
- Laboratory of Neurochemistry and Behavioral Pharmacology, Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo São Paulo, Brazil
| | - Tania Marcourakis
- Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, Universidade de São Paulo São Paulo, Brazil
| | - Rosana Camarini
- Laboratory of Neurochemistry and Behavioral Pharmacology, Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo São Paulo, Brazil
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24
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Camarini R, Pautassi RM. Behavioral sensitization to ethanol: Neural basis and factors that influence its acquisition and expression. Brain Res Bull 2016; 125:53-78. [PMID: 27093941 DOI: 10.1016/j.brainresbull.2016.04.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 12/29/2022]
Abstract
Ethanol-induced behavioral sensitization (EBS) was first described in 1980, approximately 10 years after the phenomenon was described for psychostimulants. Ethanol acts on γ-aminobutyric acid (GABA) and glutamate receptors as an allosteric agonist and antagonist, respectively, but it also affects many other molecular targets. The multiplicity of factors involved in the behavioral and neurochemical effects of ethanol and the ensuing complexity may explain much of the apparent disparate results, found across different labs, regarding ethanol-induced behavioral sensitization. Although the mesocorticolimbic dopamine system plays an important role in EBS, we provide evidence of the involvement of other neurotransmitter systems, mainly the glutamatergic, GABAergic, and opioidergic systems. This review also analyses the neural underpinnings (e.g., induction of cellular transcription factors such as cyclic adenosine monophosphate response element binding protein and growth factors, such as the brain-derived neurotrophic factor) and other factors that influence the phenomenon, including age, sex, dose, and protocols of drug administration. One of the reasons that make EBS an attractive phenomenon is the assumption, firmly based on empirical evidence, that EBS and addiction-related processes have common molecular and neural basis. Therefore, EBS has been used as a model of addiction processes. We discuss the association between different measures of ethanol-induced reward and EBS. Parallels between the pharmacological basis of EBS and acute motor effects of ethanol are also discussed.
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Affiliation(s)
- Rosana Camarini
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, Brazil.
| | - Ricardo Marcos Pautassi
- Instituto de Investigaciones Médicas M. y M. Ferreyra, Córdoba (IMMF-CONICET-Universidad Nacional de Córdoba), Universidad Nacional de Córdoba, Argentina
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25
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Cannabinoid CB1 receptor inhibition blunts adolescent-typical increased binge alcohol and sucrose consumption in male C57BL/6J mice. Pharmacol Biochem Behav 2016; 143:11-7. [PMID: 26800788 DOI: 10.1016/j.pbb.2016.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 01/26/2023]
Abstract
Increased binge alcohol consumption has been reported among adolescents as compared to adults in both humans and rodent models, and has been associated with serious long-term health consequences. However, the neurochemical mechanism for age differences in binge drinking between adolescents and adults has not been established. The present study was designed to evaluate the mechanistic role of the cannabinoid CB1 receptor in adolescent and adult binge drinking. Binge consumption was established in adolescent and adult male C57BL/6J mice by providing access to 20% alcohol or 1% sucrose for 4h every other day. Pretreatment with the CB1 antagonist/inverse agonist AM-251 (0, 1, 3, and 10mg/kg) in a Latin square design dose-dependently reduced adolescent alcohol consumption to adult levels without altering adult intake. AM-251 (3mg/kg) also reduced adolescent but not adult sucrose consumption. Adolescent reductions in alcohol and sucrose were not associated with alterations in open-field locomotor activity or thigmotaxis. These findings point to age differences in CB1 receptor activity as a functional mediator of adolescent-typical increased binge drinking as compared to adults. Developmental alterations in endocannabinoid signaling in the adolescent brain may therefore be responsible for the drinking phenotype seen in this age group.
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Vilenne A, Quertemont E. Explicit and Implicit Positive Alcohol Expectancies in Problem and Non-Problem Drinkers: Differences Across Age Groups from Young Adolescence to Adulthood. Front Psychol 2015; 6:1773. [PMID: 26635680 PMCID: PMC4646978 DOI: 10.3389/fpsyg.2015.01773] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/04/2015] [Indexed: 11/13/2022] Open
Abstract
Aims: Recent studies with animal models showed that the stimulant and sedative effects of alcohol change during the adolescent period. In humans, the stimulant effects of ethanol are most often indirectly recorded through the measurement of explicit and implicit alcohol effect expectancies. However, it is unknown how such implicit and explicit expectancies evolve with age in humans during adolescence. Methods: Adolescent (13–16 year old), young adult (17–18 year old), and adult (35–55 year old) participants were recruited. On the basis of their score on the Alcohol Use Disorder Identification Test (AUDIT), they were classified as non-problem (AUDIT ≤ 7) or problem (AUDIT ≥ 11) drinkers. The participants completed the Alcohol Expectancy Questionnaire (AEQ) and performed two unipolar Implicit Association Test (IAT) to assess implicit associations between alcohol and the concepts of “stimulation” and “sedation”. Results: Problem drinkers from the three age groups reported significantly higher positive alcohol expectancies than non-problem drinkers on all AEQ subscales. Positive alcohol explicit expectancies also gradually decreased with age, with adolescent problem drinkers reporting especially high positive expectancies. This effect was statistically significant for all positive expectancies, with the exception of relaxation expectancies that were only close to statistical significance. In contrast, stimulation and sedation alcohol implicit associations were not significantly different between problem and non-problem drinkers and did not change with age. Conclusion: These results indicate that explicit positive alcohol effect expectancies predict current alcohol consumption levels, especially in adolescents. Positive alcohol expectancies also gradually decrease with age in the three cross-sectional groups of adolescents, young adults, and adults. This effect might be related to changes in the physiological response to alcohol.
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Affiliation(s)
- Aurélie Vilenne
- Département Psychologie, Cognition et Comportement, Université de Liège Liège, Belgium
| | - Etienne Quertemont
- Département Psychologie, Cognition et Comportement, Université de Liège Liège, Belgium
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Higher long-lasting ethanol sensitization after adolescent ethanol exposure in mice. Psychopharmacology (Berl) 2014; 231:1821-9. [PMID: 24317444 DOI: 10.1007/s00213-013-3376-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 11/24/2013] [Indexed: 10/25/2022]
Abstract
RATIONALE Due to their maturing brain, adolescents are suggested to be more vulnerable to the long-term consequences of chronic alcohol use. Increased sensitization to the stimulant effects of ethanol is a possible consequence of ethanol exposure during adolescence. OBJECTIVES The aim of this study was to characterize the long-term alterations in the stimulant effects of ethanol and in the rate of ethanol sensitization in mice pre-exposed to ethanol during adolescence in comparison to mice pre-exposed to ethanol in adulthood. METHODS Adolescent and adult female Swiss mice were injected with saline or ethanol (2.5 or 4 g/kg) during 14 consecutive days. After a 3-week period of ethanol abstinence, mice were tested as adults before and after a second exposure to daily repeated ethanol injections. RESULTS All mice pre-exposed to ethanol as adults or adolescents showed higher stimulant effects when re-exposed to ethanol 3 weeks later. However, this enhanced sensitivity to the stimulant effects of ethanol was of significantly higher magnitude in mice repeatedly injected with high ethanol doses (4 g/kg) during adolescence. Furthermore, the increased expression of ethanol stimulant effects in these mice was maintained even after a second procedure of ethanol sensitization. CONCLUSIONS Adolescence is a critical period for the development of a sensitization to ethanol stimulant properties providing that high intermittent ethanol doses are administered. These results might contribute to explain the relationship between age at first alcohol use and risks of later alcohol problems and highlight the dangers of repeated consumption of high alcohol amounts in young adolescents.
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Acevedo MB, Pautassi RM, Spear NE, Spear LP. Age-dependent effects of stress on ethanol-induced motor activity in rats. Psychopharmacology (Berl) 2013; 230:389-98. [PMID: 23775530 PMCID: PMC3859917 DOI: 10.1007/s00213-013-3163-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 05/27/2013] [Indexed: 01/28/2023]
Abstract
RATIONALE It is important to study age-related differences that may put adolescents at risk for alcohol-related problems. Adolescents seem less sensitive to the aversive effects of ethanol than adults. Less is known of appetitive effects of ethanol and stress modulation of these effects. OBJECTIVES This study aims to describe the effects of acute social or restraint stress on ethanol-precipitated locomotor activity (LMA), in adolescent and adult rats. Effects of activation of the kappa system on ethanol-induced LMA were also evaluated. METHODS Adolescent or adult rats were restrained for 90 min, exposed to social deprivation stress for 90 or 180 min or administered with the kappa agonist U62,066E before being given ethanol, and assessed for LMA. RESULTS Adolescents were significantly more sensitive to the stimulating, and less sensitive to the sedative, effects of ethanol than adults. Basal locomotion was significantly increased by social deprivation stress in adult, but not in adolescent, rats. U62,066E significantly reduced basal and ethanol-induced locomotion in the adolescents. Corticosterone and progesterone levels were significantly higher in adolescents than in adults. CONCLUSIONS Adolescents exhibit greater sensitivity to ethanol-induced LMA and reduced sensitivity to ethanol-induced motor sedation than adult rats. Ethanol's effects on motor activity were not affected by acute stress. Unlike adults, adolescents were insensitive to acute restraint and social deprivation stress but exhibited motor depression after activation of the endogenous kappa opioid receptor system.
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Affiliation(s)
- María Belén Acevedo
- Instituto de Investigación Médica M. y M. Ferreyra (CONICET-UNC), Córdoba, C.P 5016, Argentina
| | - Ricardo Marcos Pautassi
- Instituto de Investigación Médica M. y M. Ferreyra (CONICET-UNC), Córdoba, C.P 5016, Argentina,Facultad de Psicología, Universidad Nacional de Córdoba, Córdoba, C.P 5000, Argentina,Corresponding author: Instituto de Investigación Médica M. y M. Ferreyra (INIMEC – CONICET), Friuli 2434, Córdoba, C.P 5016, T.E. 54-351-4681465, FAX 54-351-4695163, Argentina;
| | - Norman E. Spear
- Center for Development and Behavioral Neuroscience, Binghamton University, Binghamton, NY 13902-6000, USA
| | - Linda P. Spear
- Center for Development and Behavioral Neuroscience, Binghamton University, Binghamton, NY 13902-6000, USA
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Quoilin C, Didone V, Tirelli E, Quertemont E. Chronic tolerance to ethanol-induced sedation: implication for age-related differences in locomotor sensitization. Alcohol 2013; 47:317-22. [PMID: 23566528 DOI: 10.1016/j.alcohol.2013.01.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 01/28/2013] [Accepted: 01/31/2013] [Indexed: 01/18/2023]
Abstract
The adolescent brain has been suggested to be particularly sensitive to ethanol-induced neuroadaptations, which in turn could increase the risk of youths for alcohol abuse and dependence. Sensitization to the locomotor stimulant effects of ethanol has often been used as an animal model of ethanol-induced neuroadaptations. Previously, we showed that young mice were more sensitive than adults to the locomotor sensitization induced by high ethanol doses. However, this effect could be due to age-related differences in chronic tolerance to the sedative effects of ethanol. The aim of the present study is to assess chronic tolerance to the sedative effects of ethanol in weaning 21-day-old (P21), adolescent 35-day-old (P35) and adult 63-day-old (P63) female Swiss mice. After a daily injection of saline or 4 g/kg ethanol during 6 consecutive days, all P21, P35 and P63 mice were injected with 4 g/kg ethanol and submitted to the loss of righting reflex procedure. Our results confirm that the sensitivity to the acute sedative effects of ethanol gradually increases with age. Although this schedule of ethanol injections induces significant age-related differences in ethanol sensitization, it did not reveal significant differences between P21, P35 and P63 mice in the development of a chronic ethanol tolerance to its sedative effects. The present results show that age-related differences in the development of ethanol sensitization cannot be explained by differences in chronic ethanol tolerance to its sedative effects. More broadly, they do not support the idea that ethanol-induced sensitization is a by-product of chronic ethanol tolerance.
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Hay RA, Jennings JH, Zitzman DL, Hodge CW, Robinson DL. Specific and nonspecific effects of naltrexone on goal-directed and habitual models of alcohol seeking and drinking. Alcohol Clin Exp Res 2013; 37:1100-10. [PMID: 23398292 DOI: 10.1111/acer.12081] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 12/04/2012] [Indexed: 11/29/2022]
Abstract
BACKGROUND The opioid-receptor antagonist naltrexone (NTX) reduces goal-directed alcohol drinking in rats presumably by blunting alcohol reward. However, different operant conditioning behavior can be produced by different reinforcement schedules, with goal-directed operant behavior being more sensitive to changes in reward value than less flexible, habit-associated models. We tested the hypothesis that NTX more effectively reduces alcohol drinking and seeking in a goal-directed than in a habit-associated operant model, and more effectively reduces alcohol versus sucrose self-administration, consistent with diminished alcohol reward. METHODS Rats were trained to self-administer 10% alcohol or 1.5% sucrose in a lever-press task and then underwent a within-subject assessment of NTX (0.1 to 1 mg/kg) effects on operant behavior. A fixed-ratio (FR5) reinforcement schedule was used to model goal-directed behavior, and a variable-interval (VI30) schedule was used to model habitual behavior. RESULTS As predicted, NTX reduced fluid deliveries earned by the FR5-alcohol group significantly more than all other groups. However, NTX reduced lever presses during self-administration sessions in VI30-trained rats without reducing earned deliveries, due to the low contingency between rate of pressing and fluid deliveries under that schedule. Interestingly, when fluid delivery was withheld (extinction), NTX reduced reward-seeking in all rats. Finally, NTX blocked reinstatement of reward-seeking upon presentation of 0.2 ml alcohol or sucrose and associated cues in the FR5-trained but not VI30-trained rats. CONCLUSIONS NTX reduced goal-directed alcohol drinking compared with other operant conditions. In addition, NTX blocked reinstatement of reward-seeking in rats trained on the goal-directed FR5 reinforcement schedule but not in rats trained on the habit-like VI30 reinforcement schedule. However, NTX also exerted nonspecific effects on reward-seeking that were revealed under low-effort contingency conditions or absence of reward. Together, these data support the hypothesis that NTX is less effective in conditioning models that are more habit-associated.
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Affiliation(s)
- Rachel A Hay
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, NC 27599-7178, USA
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Moore EM, Forrest RD, Boehm SL. Genotype modulates age-related alterations in sensitivity to the aversive effects of ethanol: an eight inbred strain analysis of conditioned taste aversion. GENES, BRAIN, AND BEHAVIOR 2013; 12:70-7. [PMID: 23171343 PMCID: PMC3553292 DOI: 10.1111/gbb.12004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 10/18/2012] [Accepted: 11/15/2012] [Indexed: 02/04/2023]
Abstract
Adolescent individuals display altered behavioral sensitivity to ethanol, which may contribute to the increased ethanol consumption seen in this age-group. However, genetics also exert considerable influence on both ethanol intake and sensitivity. Currently there is little research assessing the combined influence of developmental and genetic alcohol sensitivities. Sensitivity to the aversive effects of ethanol using a conditioned taste aversion (CTA) procedure was measured during both adolescence (P30) and adulthood (P75) in eight inbred mouse strains (C57BL/6J, DBA/2J, 129S1/SvImJ, A/J, BALB/cByJ, BTBR T(+) tf/J, C3H/HeJ and FVB/NJ). Adolescent and adult mice were water deprived, and subsequently provided with access to 0.9% (v/v) NaCl solution for 1 h. Immediately following access mice were administered ethanol (0, 1.5, 2.25 and 3 g/kg, ip). This procedure was repeated in 72 h intervals for a total of five CTA trials. Sensitivity to the aversive effects of ethanol was highly dependent upon both strain and age. Within an inbred strain, adolescent animals were consistently less sensitive to the aversive effects of ethanol than their adult counterparts. However, the dose of ethanol required to produce an aversion response differed as a function of both age and strain.
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Affiliation(s)
- Eileen M. Moore
- Center for Development and Behavioral Neuroscience, Department of Psychology, Binghamton University – SUNY Binghamton, 4400 Vestal Parkway East, Binghamton, NY 13902, USA
- Indiana Alcohol Research Center, Psychobiology of Addictions, Department of Psychology, Purdue School of Science, IUPUI, 402 N. Blackford Street, LD 124, Indianapolis, IN 46202, USA
| | - Robert D. Forrest
- Indiana Alcohol Research Center, Psychobiology of Addictions, Department of Psychology, Purdue School of Science, IUPUI, 402 N. Blackford Street, LD 124, Indianapolis, IN 46202, USA
| | - Stephen L. Boehm
- Indiana Alcohol Research Center, Psychobiology of Addictions, Department of Psychology, Purdue School of Science, IUPUI, 402 N. Blackford Street, LD 124, Indianapolis, IN 46202, USA
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Nona CN, Guirguis S, Nobrega JN. Susceptibility to ethanol sensitization is differentially associated with changes in pCREB, trkB and BDNF mRNA expression in the mouse brain. Behav Brain Res 2013; 242:25-33. [PMID: 23291223 DOI: 10.1016/j.bbr.2012.12.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 12/16/2012] [Accepted: 12/21/2012] [Indexed: 11/30/2022]
Abstract
Repeated exposure to ethanol in mice induces behavioural sensitization, a progressive increase in locomotor activity that is common to drugs of abuse. Not all mice however show sensitization to ethanol. The goal of the present study was to examine whether variability in the sensitization response to ethanol (EtOH) is differentially associated with regional brain changes in specific molecular markers associated with neuroplasticity, namely BDNF and its receptor trkB, and levels of phosphorylated cyclic AMP-regulated element-binding protein (pCREB), 14 days after withdrawal from chronic, intermittent EtOH exposure. Male DBA/2NCrl mice received 7 biweekly EtOH (2.2g/kg, i.p.) or saline (SAL) injections and were classified as Sensitized or Non-sensitized on the basis of final locomotor activity (LMA) scores. Brains were removed two weeks later for immunohistochemical and in situ hybridization analyses. Compared to SAL-treated and Non-sensitized mice, Sensitized animals showed a higher number of pCREB-immunoreactive cells in the nucleus accumbens shell (+68% and +50%, respectively) and in the bed nucleus of the stria terminalis (+61% and 46%, respectively), whereas SAL and Non-sensitized groups did not differ from each other. A different pattern was seen when BDNF and trkB mRNA levels were analyzed in the same groups. Non-sensitized mice displayed lower BDNF mRNA in several brain areas and significantly lower trkB levels throughout the brain when compared to either the Sensitized or to SAL groups, which did not differ from each other. These results indicate that sensitization to EtOH is differentially associated with increased pCREB levels in specific brain areas. The observed decrease in BDNF and trkB mRNA in the Non-sensitized group suggests the possibility that EtOH may have neurotoxic effects in a subpopulation of mice, which might in turn prevent the development of behavioural sensitization. The lack of a difference in BDNF and trkB mRNA expression between Sensitized and SAL mice suggests that EtOH sensitization may be mediated by mechanisms different from those mediating sensitization to other psychostimulants.
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Affiliation(s)
- Christina N Nona
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
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Hayes DM, Fee JR, McCown TJ, Knapp DJ, Breese GR, Cubero I, Carvajal F, Lerma-Cabrera JM, Navarro M, Thiele TE. Neuropeptide Y signaling modulates the expression of ethanol-induced behavioral sensitization in mice. Addict Biol 2012; 17:338-50. [PMID: 21762289 DOI: 10.1111/j.1369-1600.2011.00336.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neuropeptide Y (NPY) and protein kinase A (PKA) have been implicated in neurobiological responses to ethanol. We have previously reported that mutant mice lacking normal production of the RIIβ subunit of PKA (RIIβ-/- mice) show enhanced sensitivity to the locomotor stimulant effects of ethanol and increased behavioral sensitization relative to littermate wild-type RIIβ+/+ mice. We now report that RIIβ-/- mice also show increased NPY immunoreactivity in the nucleus accumbens (NAc) core and the ventral striatum relative to RIIβ+/+ mice. These observations suggest that elevated NPY signaling in the NAc and/or striatum may contribute to the increased sensitivity to ethanol-induced behavioral sensitization that is a characteristic of RIIβ-/- mice. Consistently, NPY-/- mice failed to display ethanol-induced behavioral sensitization that was evident in littermate NPY+/+ mice. To examine more directly the role of NPY in the locomotor stimulant effects of ethanol, we infused a recombinant adeno-associated virus (rAAV) into the region of the NAc core of DBA/2J mice. The rAAV-fibronectin (FIB)-NPY(13-36) vector expresses and constitutively secretes the NPY fragment NPY(13-36) (a selective Y(2) receptor agonist) from infected cells in vivo. Mice treated with the rAAV-FIB-NPY(13-36) vector exhibited reduced expression of ethanol-induced behavioral sensitization compared with mice treated with a control vector. Taken together, the current data provide the first evidence that NPY signaling in the NAc core and the Y(2) receptor modulate ethanol-induced behavioral sensitization.
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Affiliation(s)
- Dayna M Hayes
- Department of Psychology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, NC, USA
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Spanos M, Besheer J, Hodge CW. Increased sensitivity to alcohol induced changes in ERK Map kinase phosphorylation and memory disruption in adolescent as compared to adult C57BL/6J mice. Behav Brain Res 2012; 230:158-66. [PMID: 22348893 DOI: 10.1016/j.bbr.2012.02.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 01/31/2012] [Accepted: 02/06/2012] [Indexed: 12/18/2022]
Abstract
Adolescence is a critical period of brain development that is accompanied by increased probability of risky behavior, such as alcohol use. Emerging research indicates that adolescents are differentially sensitive to the behavioral effects of acute ethanol as compared to adults but the neurobiological mechanisms of this effect remain to be fully elucidated. This study was designed to evaluate effects of acute ethanol on extracellular signal-regulated kinase phosphorylation (p-ERK1/2) in mesocorticolimbic brain regions. We also sought to determine if age-specific effects of ethanol on p-ERK1/2 are associated with ethanol-induced behavioral deficits on acquisition of the hippocampal-dependent novel object recognition (NOR) test. Adolescent and adult C57BL/6J mice were administered acute ethanol (0 0.5, 1, or 3g/kg, i.p.). Brains were removed 30-min post injection and processed for analysis of p-ERK1/2 immunoreactivity (IR). Additional groups of mice were administered ethanol (0 or 1g/kg) prior to the NOR test. Analysis of p-ERK1/2 IR showed that untreated adolescent mice had significantly higher levels of p-ERK1/2 IR in the nucleus accumbens shell, basolateral amygdala (BLA), central amygdala (CeA), and medial prefrontal cortex (mPFC) as compared to adults. Ethanol (1g/kg) selectively reduced p-ERK1/2 IR in the dentate gyrus and increased p-ERK1/2 IR in the BLA only in adolescent mice. Ethanol (3g/kg) produced the same effects on p-ERK1/2 IR in both age groups with increases in CeA and mPFC, but a decrease in the dentate gyrus, as compared to age-matched saline controls. Pretreatment with ethanol (1g/kg) disrupted performance on the NOR test specifically in adolescents, which corresponds with the ethanol-induced inhibition of p-ERK1/2 IR in the hippocampus. These data show that adolescent mice have differential expression of basal p-ERK1/2 IR in mesocorticolimbic brain regions. Acute ethanol produces a unique set of changes in ERK1/2 phosphorylation in the adolescent brain that are associated with disruption of hippocampal-dependent memory acquisition.
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Affiliation(s)
- Marina Spanos
- Neurobiology Curriculum, School of Medicine, University of North Carolina at Chapel Hill, Thurston-Bowles Building, CB #7178, Chapel Hill, NC 27599, United States
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Effects of ethanol administration on corticosterone levels in adolescent and adult rats. Alcohol 2012; 46:29-36. [PMID: 21917408 DOI: 10.1016/j.alcohol.2011.08.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 08/01/2011] [Accepted: 08/03/2011] [Indexed: 01/12/2023]
Abstract
Adolescent humans and rodents have been shown to consume more alcohol than their adult counterparts. Given that corticosterone (CORT) has been shown to be related to the intake of several drugs of abuse, this study assessed the ontogenetic effects of low-moderate doses of ethanol on CORT increases and recovery. Despite no significant differences in baseline (home cage) CORT levels, CORT responses to ethanol were greater in females than in males and in adult females than in adolescent females; males, however, showed less marked age differences in CORT levels after ethanol consumption. Adolescent blood ethanol concentrations (BECs) were lower than those of adults, although these BEC differences appear insufficient to account for the ontogenetic differences in CORT levels. Collectively, these findings suggest that it is unlikely that age differences in CORT elevations provide a major contribution to the ontogenetic differences in alcohol intake seen between adolescents and adults.
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Developmental differences in ethanol-induced sensitization using postweanling, adolescent, and adult Swiss mice. Psychopharmacology (Berl) 2012; 219:1165-77. [PMID: 21881875 DOI: 10.1007/s00213-011-2453-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 08/10/2011] [Indexed: 02/01/2023]
Abstract
RATIONALE The maturing adolescent brain has been suggested to be more sensitive than the adult brain to ethanol-induced neuroadaptations. In animal studies, sensitization to the stimulant effects of ethanol is used to study the vulnerability to chronic ethanol-induced neurobehavioral alterations. OBJECTIVES The aim of the present study was to systematically characterize age-dependent changes in the development and expression of the sensitization to the stimulant effects of a range of ethanol doses in female Swiss mice. Three ages were studied: 21-day-old mice (postweanlings), 35-day-old mice (adolescents), and 63-day-old mice (adults). METHODS Postweanling, adolescent, and adult mice were daily injected with saline or various ethanol doses (1.5 to 4 g/kg) for 7 days. They were then tested for acute and sensitized locomotor activity. RESULTS Postweanling and adolescent mice were more sensitive than adult mice to the acute stimulant effects of ethanol. In adult mice, daily injections of ethanol at doses between 2.5 and 4 g/kg led to significant sensitization. Higher ethanol doses (3.5 and 4 g/kg) were required to induce sensitization in postweanling and adolescent mice. However, younger mice showed ethanol sensitization of higher magnitude. CONCLUSIONS Young mice develop very strong ethanol sensitization at doses that mimic binge drinking in humans. These results might explain why early ethanol drinking during adolescence is related to a higher prevalence of subsequent alcohol disorders.
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Kliethermes CL, Heberlein U. Insulin attenuates the acquisition and expression of ethanol-induced locomotor sensitization in DBA/2J mice. Life Sci 2011; 89:968-74. [PMID: 22056372 DOI: 10.1016/j.lfs.2011.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 09/06/2011] [Accepted: 10/13/2011] [Indexed: 10/15/2022]
Abstract
AIM Ethanol-induced locomotor sensitization is a behavioral manifestation of physiological responses to repeated ethanol exposures. While ethanol exerts direct effects on multiple neurotransmitter systems in the brain, ethanol-induced changes in metabolic state, including acute hyperglycemia and inhibition of insulin signaling, also have plausible roles in the expression of ethanol-related behaviors through direct and indirect effects on brain function. The current experiments examined whether insulin administration or the resultant hypoglycemia might attenuate the development of sensitization to the locomotor stimulant effect of ethanol. MAIN METHODS Male and female DBA/2J mice received daily injections of 5 or 10 IU/kg insulin before or after a stimulating dose of ethanol and subsequent testing in an automated activity monitor. Blood glucose levels were determined upon the completion of the experiments. KEY FINDINGS Insulin injected prior to ethanol blunted the acute stimulant response as well as the acquisition and expression of locomotor sensitization, while insulin given after ethanol did not affect the development of the sensitized response. In a separate experiment, mice given glucose concurrently with insulin developed ethanol-induced locomotor sensitization normally. SIGNIFICANCE These experiments suggest that insulin attenuates the development of ethanol-induced locomotor sensitization, and that blood glucose levels can largely account for this effect. Further studies of the role of ethanol-induced metabolic states should provide novel information on the expression of ethanol-related behaviors.
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Pietropaolo S, Crusio WE. Strain-dependent changes in acoustic startle response and its plasticity across adolescence in mice. Behav Genet 2011; 39:623-31. [PMID: 19641985 DOI: 10.1007/s10519-009-9291-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 07/15/2009] [Indexed: 01/06/2023]
Abstract
Acoustic startle response and its plasticity, e.g., habituation and prepulse inhibition (PPI), have been extensively investigated, being altered in several neuropsychiatric disorders. Yet, little is known about the expression of startle-related behaviors during adolescence, a critical phase in the development of a variety of major neuropsychiatric pathologies. The present study investigated for the first time startle behaviors across adolescence in male mice of the inbred strains C57BL/6J and DBA/2J. Pre-pubertal (4 weeks of age) mice displayed reduced startle reactivity and altered PPI compared to adult animals (8 weeks of age), but these effects were observed only in the C57BL/6J strain. Strain differences were also clearly detected for startle response, habituation, and PPI. All effects were modulated by the intensity of the pulse stimulus and were not confounded by differences in anxiety levels. Our data demonstrate that genetic factors and the early adolescent phase are critically important considerations in the design of mouse models of neuropsychiatric disturbances.
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Affiliation(s)
- Susanna Pietropaolo
- Centre de Neurosciences Intégratives et Cognitives UMR 5228, Université de Bordeaux and CNRS, Bat B2, Avenue des Facultés, 33405 Talence Cedex, France
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Carrara-Nascimento PF, Griffin WC, Pastrello DM, Olive MF, Camarini R. Changes in extracellular levels of glutamate in the nucleus accumbens after ethanol-induced behavioral sensitization in adolescent and adult mice. Alcohol 2011; 45:451-60. [PMID: 21570797 DOI: 10.1016/j.alcohol.2011.01.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 01/20/2011] [Accepted: 01/24/2011] [Indexed: 12/25/2022]
Abstract
Repeated administration of low doses of ethanol gradually increases locomotor responses to ethanol in adult Swiss mice. This phenomenon is known as behavioral sensitization. However, we have shown that adolescent Swiss mice show either behavioral tolerance or no sensitization after repeated ethanol injections. Although the mesolimbic dopamine system has been extensively implicated in behavioral sensitization, several studies have demonstrated an important role of glutamatergic transmission in this phenomenon. In addition, relatively few studies have examined the role of developmental factors in behavioral sensitization to ethanol. To examine the relationship between age differences in behavioral sensitization to ethanol and the neurochemical adaptations related to glutamate within nucleus accumbens (NAc), in vivo microdialysis was conducted in adolescent and adult Swiss mice treated with ethanol (1.8 g/kg) or saline for 15 days and subsequently challenged with an acute dose (1.8 g/kg) of ethanol 6 days later. Consistent with previous findings, only adult mice demonstrated evidence of behavioral sensitization. However, ethanol-treated adolescent mice demonstrated a 196.1 ± 40.0% peak increase in extracellular levels of glutamate in the NAc after ethanol challenge in comparison with the basal values, whereas ethanol-treated adult mice demonstrated a 52.2 ± 6.2% reduction in extracellular levels of glutamate in the NAc after ethanol challenge. These observations suggest an age-dependent inverse relationship between behavioral and glutamatergic responses to repeated ethanol exposure.
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Holstein SE, Spanos M, Hodge CW. Adolescent C57BL/6J mice show elevated alcohol intake, but reduced taste aversion, as compared to adult mice: a potential behavioral mechanism for binge drinking. Alcohol Clin Exp Res 2011; 35:1842-51. [PMID: 21575017 DOI: 10.1111/j.1530-0277.2011.01528.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Binge alcohol drinking during adolescence is a serious health problem that may increase future risk of an alcohol use disorder. Although there are several different procedures by which to preclinically model binge-like alcohol intake, limited-access procedures offer the advantage of achieving high voluntary alcohol intake and pharmacologically relevant blood alcohol concentrations (BACs). Therefore, in the current study, developmental differences in binge-like alcohol drinking using a limited-access cycling procedure were examined. In addition, as alcohol drinking has been negatively correlated with sensitivity to the aversive properties of alcohol, we examined developmental differences in sensitivity to an alcohol-induced conditioned taste aversion (CTA). METHODS Binge-like alcohol consumption was investigated in adolescent (4 weeks) and adult (10 weeks) male C57BL/6J mice for 2 to 4 h/d for 16 days. Developmental differences in sensitivity to an alcohol-induced CTA were examined in adolescent and adult mice, with saline or alcohol (3 or 4 g/kg) repeatedly paired with the intake of a novel tastant (NaCl). RESULTS Adolescent mice showed a significant increase in alcohol intake as compared to adults, with adolescents achieving higher BACs and increasing alcohol consumption over successive cycles of the binge procedure. Conversely, adolescent mice exhibited a dose-dependent reduction in sensitivity to the aversive properties of alcohol, as compared to adult mice, with adolescent mice failing to develop a CTA to 3 g/kg alcohol. Finally, extinction of an alcohol CTA was observed following conditioning with a higher dose of alcohol in adolescent, versus adult, mice. CONCLUSIONS These results indicate that adolescent mice consume more alcohol, per kilogram body weight, than adults in a binge-like model of alcohol drinking and demonstrate a blunted sensitivity to the conditioned aversive effects of alcohol. Overall, this supports a behavioral framework by which heightened binge alcohol intake during adolescence occurs, in part, via a reduced sensitivity to the aversive properties of alcohol.
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Affiliation(s)
- Sarah E Holstein
- Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7178, USA
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Melón LC, Boehm SL. Role of genotype in the development of locomotor sensitization to alcohol in adult and adolescent mice: comparison of the DBA/2J and C57BL/6J inbred mouse strains. Alcohol Clin Exp Res 2011; 35:1351-60. [PMID: 21410489 DOI: 10.1111/j.1530-0277.2011.01471.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Animal models that explore differential sensitivity to the effects of acute and repeated exposure of alcohol (ethanol) may be influenced by both the developmental and genetic profile of the population. Therefore, we sought to compare the influence of ontogeny on sensitivity to ethanol-induced locomotor stimulation and on the induction of locomotor sensitization to this effect across 2 inbred strains of mice; the ethanol consuming C57BL/6J and the ethanol avoiding DBA/2J strains. METHODS C57BL/6J and DBA/2J adults (postnatal day [PD] 60 to 80) and adolescents (PD 30±2) were assessed for basal activity, acute response to 2.0 g/kg ethanol, and the expression of locomotor sensitization following repeated administration of 2.5, 3.0, or 3.5 g/kg ethanol. RESULTS Basal activity was different across development for the C57BL/6J, but not DBA/2J, with adult B6 mice showing persistently greater baseline activity. Adolescents of both strains were more sensitive than adults to acute ethanol-induced locomotor stimulation; adults exhibited a decrease in their acute response across the testing session. Adolescent DBA/2J mice developed less ethanol sensitization compared to adults, with significant sensitization observed only following repeated administration of the lowest ethanol dose (2.5 g/kg), whereas DBA/2J adults sensitized to all doses. Age did not influence the development of ethanol sensitization for the C57BL/6J strain, as both adults and adolescents displayed a sensitized response following all ethanol doses. CONCLUSIONS These results suggest that the developmental pattern of locomotor sensitivity to ethanol is unique to the genotypic profile of the animal model.
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Affiliation(s)
- Laverne C Melón
- Center for Developmental and Behavioral Neuroscience, Department of Psychology, Binghamton University, Binghamton, NY, USA.
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Quoilin C, Didone V, Tirelli E, Quertemont E. Ontogeny of the stimulant and sedative effects of ethanol in male and female Swiss mice: gradual changes from weaning to adulthood. Psychopharmacology (Berl) 2010; 212:501-12. [PMID: 20683582 DOI: 10.1007/s00213-010-1971-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Accepted: 07/21/2010] [Indexed: 11/27/2022]
Abstract
RATIONALE The adolescent period is characterized by a specific sensitivity to the effects of alcohol, which is believed to contribute to the enhanced risks of alcohol dependence when drinking is initiated early during adolescence. In adolescent rodents, while the reduced sensitivity to the sedative effects of ethanol has been well characterized, its stimulant effects have not yet been extensively studied. OBJECTIVES The present study characterized the development of the stimulant and the sedative effects of acute ethanol in male and female Swiss mice from weaning to early adulthood and tested whether both effects are interrelated. METHODS In a first experiment, mice aged 21, 28, 35, 42, and 60 days were injected with various ethanol doses and tested for ethanol-induced locomotor activity. In an independent experiment, mice of the same groups of age were injected with 4 g/kg ethanol and ethanol-induced sedation was quantified with the loss of righting reflex procedure. RESULTS In male and female mice, the stimulant effects of ethanol gradually decreased, whereas its sedative effects increased with age. When the sedation was statistically controlled using a covariance analysis, the differences between adult and juvenile mice in the locomotor stimulation were significantly reduced. CONCLUSIONS From weaning to early adulthood, the acute stimulant and sedative effects of ethanol show gradual changes that are similar in male and female mice. Although the initial tolerance to the sedative effects of ethanol contributes to the changes in ethanol-induced locomotor activity, young mice also show a higher sensitivity to the stimulant effects of ethanol.
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Affiliation(s)
- Caroline Quoilin
- Centre de Neurosciences Cognitives et Comportementales, Université de Liège, Boulevard du Rectorat 5/B32, 4000, Liège, Belgium
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Acevedo MB, Molina JC, Nizhnikov ME, Spear NE, Pautassi RM. High ethanol dose during early adolescence induces locomotor activation and increases subsequent ethanol intake during late adolescence. Dev Psychobiol 2010; 52:424-40. [PMID: 20373327 DOI: 10.1002/dev.20444] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Adolescent initiation of ethanol consumption is associated with subsequent heightened probability of ethanol use disorders. The present study examined the relationship between motivational sensitivity to ethanol initiation in adolescent rats and later ethanol intake. Experiment 1 determined that ethanol induces locomotor activation shortly after administration but not if tested at a later post-administration interval. In Experiment 2, adolescent rats were assessed for ethanol-induced locomotor activation on postnatal Day 28. These animals were then evaluated for ethanol-mediated conditioned taste aversion and underwent a 16-day-long ethanol intake protocol. Ethanol-mediated aversive effects were unrelated to ethanol locomotor stimulation or subsequent ethanol consumption patterns. Ethanol intake during late adolescence was greatest in animals initiated to ethanol earliest at postnatal Day 28. Females that were more sensitive to ethanol's locomotor-activating effects showed a transient increase in ethanol self-administration. Blood ethanol concentrations during initiation were not related to ethanol-induced locomotor activation. Adolescent rats appeared sensitive to the locomotor-stimulatory effects of ethanol. Even brief ethanol exposure during adolescence may promote later ethanol intake.
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Affiliation(s)
- María Belén Acevedo
- Instituto de Investigación Médica M. y M., Ferreyra (INIMEC-CONICET), Córdoba C.P 5000, Argentina
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Moore EM, Linsenbardt DN, Melón LC, Boehm SL. Ontogenetic differences in adolescent and adult C57BL/6J and DBA/2J mice: anxiety-like, locomotor, and consummatory behaviors. Dev Psychobiol 2010; 53:141-56. [PMID: 20886536 DOI: 10.1002/dev.20501] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2009] [Revised: 08/16/2010] [Accepted: 08/17/2010] [Indexed: 11/11/2022]
Abstract
Adolescence is a highly conserved period during which mammals undergo a number of hormonal, biological, and behavioral changes [Spear [2000] Neurosci. Biobehav. Rev. 24: 417-463]. Ethical constraints limit the research that can be done in human adolescents. Rodents provide a useful model of at least some of the features of adolescence, including increases in body growth, differences in sleep/wake, and eating patterns, as well as differences in risk-taking, novelty seeking, and exploratory behaviors. Much of the available developmental research has utilized rats; however, the use of inbred mouse strains provides a unique means to assess the genetic factors involved in behavioral differences during adolescence. We assessed differences between adults and adolescents in anxiety-like, locomotor, and consummatory behaviors using two commonly used inbred strains of mice, the DBA/2J and C57BL/6J strains. Age and genotype-dependent differences were found in all three behaviors measured, suggesting both factors are important determinants of behavior in mice.
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Affiliation(s)
- Eileen M Moore
- Department of Psychology, Indiana University-Purdue University, 402 N Blackford St, LD 124, Indianapolis, IN 46202, USA
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Pautassi RM, Camarini R, Quadros IM, Miczek KA, Israel Y. Genetic and environmental influences on ethanol consumption: perspectives from preclinical research. Alcohol Clin Exp Res 2010; 34:976-87. [PMID: 20374217 DOI: 10.1111/j.1530-0277.2010.01172.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Alcohol use disorders (abuse and dependence, AUD) are multifactorial phenomena, depending on the interplay of environmental and genetic variables. METHOD This review describes current developments in animal research that may help (a) develop gene therapies for the treatment of alcoholism, (b) understand the permissive role of stress on ethanol intake, and (c) elucidate why exposure to ethanol early in life is associated with a greater risk of AUD. RESULTS The polymorphisms found in liver alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) affect the elimination of ethanol and the susceptibility to ethanol intake. A highly active ADH protects against alcoholism, an effect related to a presteady state burst in arterial acetaldehyde. Social stressors, such as repeated early maternal separation or social defeat, exert a permissive effect on ethanol intake, perhaps by altering the normal development of the hypothalamic-pituitary-adrenal axis. Ethanol exposure during gestation, infancy, or adolescence increases the likelihood of AUD later in life. Early perception of ethanol's positive and negative (anti-anxiety) reinforcing effects may play a role in this phenomenon. CONCLUSIONS The review underscores the advantages of using preclinical animal models of AUD and highlights points of intersection between the topics to help design a more integrated approach for the study of alcohol-related problems.
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Affiliation(s)
- Ricardo M Pautassi
- Instituto de Investigaciones Médicas M. y M. Ferreyra (INIMEC-CONICET), Argentina.
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Moore EM, Mariani JN, Linsenbardt DN, Melón LC, Boehm SL. Adolescent C57BL/6J (but not DBA/2J) mice consume greater amounts of limited-access ethanol compared to adults and display continued elevated ethanol intake into adulthood. Alcohol Clin Exp Res 2010; 34:734-42. [PMID: 20102570 DOI: 10.1111/j.1530-0277.2009.01143.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Alcohol use is common during the adolescent period, a time at which a number of crucial neurobiological, hormonal, and behavioral changes occur (Spear, 2000). In order to more fully understand the complex interaction between alcohol use and these age-typical neurobiological changes, animal models must be utilized. Rodents experience a developmental period similar to that of adolescence. Although rat models have shown striking adolescent-specific differences in sensitivity to ethanol, little work has been done in mice despite the fact that the C57BL/6J (B6) and DBA2/J (D2) mice have been shown to markedly differ in ethanol preference drinking and exhibit widely different sensitivities to ethanol. METHODS The current study examined ethanol intake in adolescent and adult B6 and D2 mice using a limited access alcohol exposure paradigm called Drinking in the Dark (DID). Additionally, the effect of adolescent (or adult) ethanol exposure on subsequent adult ethanol intake was examined by re-exposing the mice to the same paradigm once the adolescents reached adulthood. We hypothesized that adolescent (P25-45) mice would exhibit greater binge-like alcohol intake compared to adults (P60-80), and that B6 mice would exhibit greater binge-like alcohol intake compared to D2 mice. Moreover, we predicted that relative difference in binge-like alcohol intake between adolescents and adults would be greater in D2 mice. RESULTS Adolescent B6 mice consumed more ethanol than adults in the DID model. There was no difference between adolescent and adult D2 mice. CONCLUSIONS This work adds to the literature suggesting that adolescents will consume more ethanol than adults and that this exposure can result in altered adult intake. However, this effect seems largely dependent upon genotype. Future work will continue to examine age-related differences in ethanol intake, preference, and sensitivity in inbred mouse strains.
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Affiliation(s)
- Eileen M Moore
- Center for Development and Behavioral Neuroscience, Department of Psychology, Binghamton University-SUNY, Binghamton, New York, USA
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Schramm-Sapyta NL, Walker QD, Caster JM, Levin ED, Kuhn CM. Are adolescents more vulnerable to drug addiction than adults? Evidence from animal models. Psychopharmacology (Berl) 2009; 206:1-21. [PMID: 19547960 PMCID: PMC3025448 DOI: 10.1007/s00213-009-1585-5] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Accepted: 05/26/2009] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND RATIONALE Epidemiological evidence suggests that people who begin experimenting with drugs of abuse during early adolescence are more likely to develop substance use disorders (SUDs), but this correlation does not guarantee causation. Animal models, in which age of onset can be tightly controlled, offer a platform for testing causality. Many animal models address drug effects that might promote or discourage drug intake and drug-induced neuroplasticity. METHODS We have reviewed the preclinical literature to investigate whether adolescent rodents are differentially sensitive to rewarding, reinforcing, aversive, locomotor, and withdrawal-induced effects of drugs of abuse. RESULTS AND CONCLUSIONS The rodent model literature consistently suggests that the balance of rewarding and aversive effects of drugs of abuse is tipped toward reward in adolescence. However, increased reward does not consistently lead to increased voluntary intake: age effects on voluntary intake are drug and method specific. On the other hand, adolescents are consistently less sensitive to withdrawal effects, which could protect against compulsive drug seeking. Studies examining neuronal function have revealed several age-related effects but have yet to link these effects to vulnerability to SUDs. Taken together, the findings suggest factors which may promote recreational drug use in adolescents, but evidence relating to pathological drug-seeking behavior is lacking. A call is made for future studies to address this gap using behavioral models of pathological drug seeking and for neurobiologic studies to more directly link age effects to SUD vulnerability.
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Linsenbardt DN, Moore EM, Gross CD, Goldfarb KJ, Blackman LC, Boehm SL. Sensitivity and tolerance to the hypnotic and ataxic effects of ethanol in adolescent and adult C57BL/6J and DBA/2J mice. Alcohol Clin Exp Res 2009; 33:464-76. [PMID: 19120054 PMCID: PMC2736547 DOI: 10.1111/j.1530-0277.2008.00857.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND There is considerable research examining differences in adolescent and adult sensitivity and tolerance to ethanol related behavioral phenotypes. However, the available published data has almost exclusively assessed these behaviors in outbred rats. The present study was conducted using the alcohol preferring inbred mouse strain C57BL/6J (B6) and the alcohol nonpreferring inbred mouse strain DBA/2J (D2) to determine if differences in the sedative and ataxic effects of ethanol exist between adolescents and adults, and to determine whether there are any genetic influences involved therein. METHODS Adolescent and adult mice of each sex and genotype were given intraperitoneal (i.p.) injections of ethanol (1.5, 1.75, or 4.0 g/kg) or saline and assessed for the loss of righting reflex (LORR) or hind footslips on the balance beam apparatus. These animals were then tested for the development of tolerance to these behaviors on subsequent days. RESULTS Despite evident pharmacokinetic differences, D2 adolescents were found to be relatively less sensitive to ethanol's hypnotic actions than their adult D2 counterparts. Adolescent and adult B6 animals did not differ. Furthermore, although adult animals appeared to develop significantly greater degrees of tolerance to ethanol-induced hypnosis compared with adolescents, these effects were likely in part related to differences in ethanol absorption/metabolism across time. Taking into account pharmacokinetic differences and the overall poor performance of male adults, adolescent animals were found to be equally if not more sensitive to the motor incoordinating (ataxic) effects of ethanol. Overall, tolerance to these effects varied by age and genotype but appeared to be related to changes in ethanol pharmacokinetics rather than strict behavioral sensitivity. CONCLUSION The current work suggests that adolescent B6 and D2 inbred mice exhibit ontogenetic differences in sensitivity to ethanol's hypnotic and ataxic effects. Importantly, in some cases age differences emerge as a function of differential ethanol pharmacokinetics. These results extend the current literature examining this critical developmental period in mice and illustrate the benefits of comparing ethanol related developmental differences in different genetic mouse populations.
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Affiliation(s)
- David N Linsenbardt
- Center for Development and Behavioral Neuroscience, Department of Psychology, Binghamton University, Binghamton, New York 13902, USA.
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Didone V, Quoilin C, Tirelli E, Quertemont E. Parametric analysis of the development and expression of ethanol-induced behavioral sensitization in female Swiss mice: effects of dose, injection schedule, and test context. Psychopharmacology (Berl) 2008; 201:249-60. [PMID: 18685830 DOI: 10.1007/s00213-008-1266-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Accepted: 07/19/2008] [Indexed: 12/31/2022]
Abstract
RATIONALE Repeated administrations of ethanol induce a progressive and enduring increase in its locomotor stimulant effects, a phenomenon termed behavioral sensitization that has not been systematically characterized. OBJECTIVE The aim of the present studies was to characterize the development and expression of ethanol sensitization in female Swiss mice by examining (1) the doses of ethanol that induce behavioral sensitization, (2) the doses of acute ethanol challenges that are necessary to express behavioral sensitization, (3) the effects of the intervals between administrations, and (4) the context dependency of ethanol sensitization. MATERIALS AND METHODS Mice were i.p. injected for 8 days with various ethanol doses, and locomotion was recorded for 5 min. Two days after the last sensitization session, ethanol sensitization was tested in 30-min test sessions. RESULTS Mice repeatedly injected with 2.5 g/kg ethanol showed a progressive (200-300%) increase in locomotor activity. In response to a 2.5 g/kg ethanol challenge, the mice repeatedly treated with doses above 1.5 g/kg showed a significant sensitization. Following the induction of sensitization with the maximally effective sensitizing dose (2.5 g/kg), mice showed greater activation after challenges with 1.5, 2.0, 2.5, and 3.0 g/kg ethanol. The intervals (24, 48, or 96 h) between ethanol injections did not affect the induction or expression of sensitization. Finally, sensitization to 2.5 g/kg ethanol was expressed regardless of the context in which it was induced. CONCLUSIONS Female Swiss mice develop a robust context-independent sensitization after repeated ethanol injections at all doses above 1.5 g/kg, including highly sedative doses such as 4 g/kg.
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Affiliation(s)
- Vincent Didone
- Centre de Neurosciences Cognitives et Comportementales, Université de Liège, Boulevard du Rectorat 5/B32, 4000, Liège, Belgium
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Abstract
Although drugs of abuse have different chemical structures and interact with different protein targets, all appear to usurp common neuronal systems that regulate reward and motivation. Addiction is a complex disease that is thought to involve drug-induced changes in synaptic plasticity due to alterations in cell signaling, gene transcription, and protein synthesis. Recent evidence suggests that drugs of abuse interact with and change a common network of signaling pathways that include a subset of specific protein kinases. The best studied of these kinases are reviewed here and include extracellular signal-regulated kinase, cAMP-dependent protein kinase, cyclin-dependent protein kinase 5, protein kinase C, calcium/calmodulin-dependent protein kinase II, and Fyn tyrosine kinase. These kinases have been implicated in various aspects of drug addiction including acute drug effects, drug self-administration, withdrawal, reinforcement, sensitization, and tolerance. Identifying protein kinase substrates and signaling pathways that contribute to the addicted state may provide novel approaches for new pharmacotherapies to treat drug addiction.
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Affiliation(s)
- Anna M Lee
- Ernest Gallo Clinic and Research Center, Department of Neurology, University of California at San Francisco, Emeryville, CA 94608, USA
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