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Costa BY, Santos LG, Marianno P, Rae M, de Almeida MG, de Brito MC, Eichler R, Camarini R. Carbetocin Inhibits Behavioral Sensitization to Ethanol in Male and Female Mice, Independent of Corticosterone Levels. Toxics 2023; 11:893. [PMID: 37999545 PMCID: PMC10674331 DOI: 10.3390/toxics11110893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 10/17/2023] [Accepted: 10/27/2023] [Indexed: 11/25/2023]
Abstract
Oxytocin (OXT), a pro-social peptide, is increasingly recognized as a potential protective substance against drug addiction. In the context of ethanol, previous research has shown OXT's properties in reducing self-administration, alleviating motor impairment in rodents, and reducing craving in humans. However, its role in behavioral sensitization, a neuroadaptive response resulting from repeated drug exposure linked to an increased drug incentive, remains unexplored. OXT is recognized for its role in regulating the hypothalamic-pituitary-adrenal (HPA) axis, in which corticosterone is acknowledged as a significant factor in the development of behavioral sensitization. This study aimed to investigate the effects of carbetocin (CBT), an analogue of OXT, on the expression of behavioral sensitization to ethanol and the concurrent alterations in plasma corticosterone levels in male and female Swiss mice. We also aimed to confirm previous studies on OXT's impact on ethanol consumption in male mice, but with a focus on CBT, using the two-bottle choice model and the drinking in the dark (DID) methodology. For the sensitization study, the mice received either ethanol (1.8 g/kg, i.p.) or saline treatments daily for 15 consecutive days, followed by treatment with carbetocin (0.64 mg/kg, i.p.) or a vehicle for 6 days. Subsequently, on day 22, all the animals underwent an ethanol challenge to assess the expression of behavioral sensitization. The plasma corticosterone levels were measured on days 21 and 22. The CBT effectively prevented the expression of ethanol-induced behavioral sensitization in both male and female subjects, with no alterations having been detected in their corticosterone levels. In the ethanol consumption study, following an initial phase of ethanol acquisition, the male mice underwent a 6-day treatment with CBT i.p. or saline before being re-exposed to ethanol. We also found a reduction in their ethanol consumption due to the CBT treatment. In conclusion, carbetocin emerges as a promising and effective intervention for mitigating ethanol-induced behavioral sensitization and reducing ethanol intake, highlighting its potential significance in alcohol addiction treatment.
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Affiliation(s)
- Beatriz Yamada Costa
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo 05508-900, Brazil; (B.Y.C.); (P.M.); (M.R.); (M.C.d.B.); (R.E.)
| | - Luana Gasparini Santos
- School of Pharmaceutical Sciences, Universidade de São Paulo, São Paulo 05508-900, Brazil;
| | - Priscila Marianno
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo 05508-900, Brazil; (B.Y.C.); (P.M.); (M.R.); (M.C.d.B.); (R.E.)
| | - Mariana Rae
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo 05508-900, Brazil; (B.Y.C.); (P.M.); (M.R.); (M.C.d.B.); (R.E.)
| | - Marina Gomes de Almeida
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo 05508-900, Brazil; (B.Y.C.); (P.M.); (M.R.); (M.C.d.B.); (R.E.)
| | - Malcon Carneiro de Brito
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo 05508-900, Brazil; (B.Y.C.); (P.M.); (M.R.); (M.C.d.B.); (R.E.)
| | - Rosângela Eichler
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo 05508-900, Brazil; (B.Y.C.); (P.M.); (M.R.); (M.C.d.B.); (R.E.)
| | - Rosana Camarini
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo 05508-900, Brazil; (B.Y.C.); (P.M.); (M.R.); (M.C.d.B.); (R.E.)
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Nonoguchi HA, Jin M, Narreddy R, Kouo TWS, Nayak M, Trenet W, Mandyam CD. Progenitor Cells Play a Role in Reinstatement of Ethanol Seeking in Adult Male and Female Ethanol Dependent Rats. Int J Mol Sci 2023; 24:12233. [PMID: 37569609 PMCID: PMC10419311 DOI: 10.3390/ijms241512233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/19/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Female and male glial fibrillary acidic protein-thymidine kinase (GFAP-TK) transgenic rats were made ethanol dependent via a six-week chronic intermittent ethanol vapor (CIE) and ethanol drinking (ED) procedure. During the last week of CIE, a subset of male and female TK rats was fed valcyte to ablate dividing progenitor cells and continued the diet until the end of this study. Following week six, all CIE rats experienced two weeks of forced abstinence from CIE-ED, after which they experienced relapse to drinking, extinction, and reinstatement of ethanol seeking sessions. CIE increased ED in female and male rats, with females having higher ethanol consumption during CIE and relapse sessions compared with males. In both sexes, valcyte reduced the levels of Ki-67-labeled progenitor cells in the subgranular zone of the dentate gyrus and did not alter the levels in the medial prefrontal cortex (mPFC). Valcyte increased ED during relapse, increased lever responses during extinction and, interestingly, enhanced latency to extinguish ethanol-seeking behaviors in males. Valcyte reduced the reinstatement of ethanol-seeking behaviors triggered by ethanol cues in females and males. Reduced seeking by valcyte was associated with the normalization of cytokines and chemokines in plasma isolated from trunk blood, indicating a role for progenitor cells in peripheral inflammatory responses. Reduced seeking by valcyte was associated with increases in tight junction protein claudin-5 and oligodendrogenesis in the dentate gyrus and reduction in microglial activity in the dentate gyrus and mPFC in females and males, demonstrating a role for progenitor cells in the dentate gyrus in dependence-induced endothelial and microglial dysfunction. These data suggest that progenitor cells born during withdrawal and abstinence from CIE in the dentate gyrus are aberrant and could play a role in strengthening ethanol memories triggered by ethanol cues via central and peripheral immune responses.
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Affiliation(s)
| | - Michael Jin
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | | | | | | | - Wulfran Trenet
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Chitra D. Mandyam
- VA San Diego Healthcare System, San Diego, CA 92161, USA
- Department of Anesthesiology, University of California San Diego, San Diego, CA 92161, USA
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Galbo LK, Davenport AT, Epperly PM, Daunais JB, Stinson BT, Czoty PW. Social dominance in monkeys: Lack of effect on ethanol self-administration during schedule induction. Alcohol 2022; 98:1-7. [PMID: 34728320 DOI: 10.1016/j.alcohol.2021.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 10/10/2021] [Accepted: 10/11/2021] [Indexed: 02/03/2023]
Abstract
Nonhuman primate models of alcohol use disorder (AUD) frequently utilize schedule-induced polydipsia to initiate ethanol drinking. Previous research has demonstrated that specific characteristics of drinking during the final phase of induction, in which monkeys consume 1.5 g/kg of ethanol per day, can predict whether monkeys become heavy or light drinkers when they subsequently have free access to ethanol (22 hours per day; Baker, Farro, Gonzales, Helms, & Grant, 2017; Grant et al., 2008). A monkey's position in the social dominance hierarchy is another factor associated with ethanol drinking in nonhuman primates; lower social status is associated with higher ethanol intakes. In the present study, characteristics of drinking during induction were measured in 12 male cynomolgus monkeys living in three established social groups (4 monkeys per group). All monkeys were induced to consume water, then increasing doses of ethanol (0.5, 1.0, and 1.5 g/kg) for 30 sessions per dose using a 300-s fixed-time schedule of food pellet delivery. Drinking sessions occurred five days per week and monkeys were group-housed on the other two days. Contrary to our hypothesis that subordinate monkeys would show characteristics of drinking during the last phase of induction that were predictive of later heavy drinking, no significant differences were observed between dominant and subordinate monkeys in any phase of induction. When ethanol availability was subsequently increased to 22 hours per day for 5 weeks, the intakes of subordinate- and dominant-ranked monkeys diverged, with higher intakes on average in subordinates. Several factors unique to the conditions of induction may have obscured any influence of social rank, including the limited duration of sessions and limited maximal ethanol intake. The data support the conclusion that the effects of social rank on ethanol consumption require unrestricted access to ethanol.
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Deal A, Cooper N, Kirse HA, Uneri A, Raab-Graham K, Weiner JL, Solberg Woods LC. Early life stress induces hyperactivity but not increased anxiety-like behavior or ethanol drinking in outbred heterogeneous stock rats. Alcohol 2021; 91:41-51. [PMID: 33321179 PMCID: PMC8767639 DOI: 10.1016/j.alcohol.2020.11.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/10/2020] [Accepted: 11/30/2020] [Indexed: 01/26/2023]
Abstract
Early life stress is known to impact vulnerability to psychopathological disorders in adulthood, including anxiety and alcohol use disorder (AUD), but the mechanisms underlying susceptibility to these outcomes are not fully understood. In the current study, we used adolescent social isolation (ASI) to determine whether Heterogeneous Stock (HS) rats, an outbred model used for genetic fine-mapping, could be used to study the genetics contributing to ASI-induced anxiety- and AUD-like behavior. We isolated (ASI) or group-housed (adolescent group-housed; AGH) 64 male HS rats at 4 weeks of age. After 5 weeks in these housing conditions, multiple anxiety and coping/despair-like behaviors were measured. All rats were then individually housed and assessed for voluntary ethanol self-administration. At euthanasia, synaptoneurosomes were isolated from a subset of brains to examine the expression of two proteins associated with alcohol drinking-related behaviors, GluA1 and SK2, in the dorsal (dHC) and ventral hippocampus (vHC). We found that ASI increased hyperactivity in the open field test relative to AGH, with no changes in other anxiety-like behaviors. Surprisingly, ASI rats demonstrated decreased immobility and increased climbing in the forced swim test relative to AGH. In contrast to prior studies by us and others, we found no difference in self-administration of 20% ethanol, with decreased ethanol self-administration in ASI relative to AGH rats at higher ethanol concentrations. Furthermore, while ASI in Long-Evans rats resulted in decreased SK2 expression in vHC synaptosomes, no differences were seen in vHC synaptosomes for SK2 or GluA1 in HS rats. These results demonstrate that HS rats are protected against many of the negative effects previously seen in response to ASI, namely anxiety-like behavior and increased ethanol self-administration. The current work suggests that a lack of change in SK2 and GluA1 expression levels in the vHC may play a role in conferring this protection.
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Affiliation(s)
- Aaron Deal
- Department of Internal Medicine, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC, 27157, United States.
| | - Nicholas Cooper
- Department of Internal Medicine, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC, 27157, United States.
| | - Haley Ann Kirse
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC, 27157, United States.
| | - Ayse Uneri
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC, 27157, United States.
| | - Kimberly Raab-Graham
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC, 27157, United States.
| | - Jeffrey L Weiner
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC, 27157, United States.
| | - Leah C Solberg Woods
- Department of Internal Medicine, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC, 27157, United States.
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Sona Khan M, Trenet W, Xing N, Sibley B, Abbas M, al-Rashida M, Rauf K, Mandyam CD. A Novel Sulfonamide, 4-FS, Reduces Ethanol Drinking and Physical Withdrawal Associated With Ethanol Dependence. Int J Mol Sci 2020; 21:E4411. [PMID: 32575871 PMCID: PMC7352747 DOI: 10.3390/ijms21124411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/13/2020] [Accepted: 06/17/2020] [Indexed: 01/11/2023] Open
Abstract
Carbonic anhydrase (CA) is abundant in glial cells in the brain and CA type II isoform (CA II) activity in the hippocampus plays an important role in buffering extracellular pH transients produced by neural activity. Chronic ethanol exposure results in respiratory and metabolic acidosis, producing shifts in extracellular pH in the brain and body. These neurophysiological changes by ethanol are hypothesized to contribute to the continued drinking behavior and physical withdrawal behavior in subjects consuming ethanol chronically. We explored whether chronic ethanol self-administration (ethanol drinking, 10% v/v; ED) without or under the influence of chronic intermittent ethanol vapor (CIE-ED) experience alters the expression of CA II in the hippocampus. Postmortem hippocampal tissue analyses demonstrated that CA II levels were enhanced in the hilus region of the hippocampus in ED and CIE-ED rats. We used a novel molecule-4-fluoro-N-(4-sulfamoylphenyl) benzenesulfonamide (4-FS)-a selective CA II inhibitor, to determine whether CA II plays a role in ethanol self-administration in ED and CIE-ED rats and physical withdrawal behavior in CIE-ED rats. 4-FS (20 mg/kg, i.p.) reduced ethanol self-administration in ED rats and physical withdrawal behavior in CIE-ED rats. Postmortem hippocampal tissue analyses demonstrated that 4-FS reduced CA II expression in ED and CIE-ED rats to control levels. In parallel, 4-FS enhanced GABAA receptor expression, reduced ratio of glutamatergic GluN2A/2B receptors and enhanced the expression of Fos, a marker of neuronal activation in the ventral hippocampus in ED rats. These findings suggest that 4-FS enhanced GABAergic transmission and increased activity of neurons of inhibitory phenotypes. Taken together, these findings support the role of CA II in assisting with negative affective behaviors associated with moderate to severe alcohol use disorders (AUD) and that CA II inhibitors are a potential therapeutic target to reduce continued drinking and somatic withdrawal symptoms associated with moderate to severe AUD.
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Affiliation(s)
- Muhammad Sona Khan
- Abbottabad Campus, COMSATS University Islamabad, Abbottabad, Khyber Pakhtunkhawa 22060, Pakistan;
- VA San Diego Healthcare System, San Diego, CA 92161, USA; (W.T.); (N.X.); (B.S.)
- Department of Anesthesiology, University of California San Diego, San Diego, CA 92161, USA
| | - Wulfran Trenet
- VA San Diego Healthcare System, San Diego, CA 92161, USA; (W.T.); (N.X.); (B.S.)
| | - Nancy Xing
- VA San Diego Healthcare System, San Diego, CA 92161, USA; (W.T.); (N.X.); (B.S.)
| | - Britta Sibley
- VA San Diego Healthcare System, San Diego, CA 92161, USA; (W.T.); (N.X.); (B.S.)
| | - Muzaffar Abbas
- Department of Pharmacy, Capital University of Science & Technology, Islamabad 44000, Pakistan;
| | - Mariya al-Rashida
- Department of Chemistry, Forman Christian College, A Chartered University, Ferozepur Road, Lahore 54600, Pakistan;
| | - Khalid Rauf
- Abbottabad Campus, COMSATS University Islamabad, Abbottabad, Khyber Pakhtunkhawa 22060, Pakistan;
| | - Chitra D. Mandyam
- VA San Diego Healthcare System, San Diego, CA 92161, USA; (W.T.); (N.X.); (B.S.)
- Department of Anesthesiology, University of California San Diego, San Diego, CA 92161, USA
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Somkuwar SS, Mandyam CD. Individual Differences in Ethanol Drinking and Seeking Behaviors in Rats Exposed to Chronic Intermittent Ethanol Vapor Exposure is Associated with Altered CaMKII Autophosphorylation in the Nucleus Accumbens Shell. Brain Sci 2019; 9:brainsci9120367. [PMID: 31835746 PMCID: PMC6955871 DOI: 10.3390/brainsci9120367] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 11/16/2022] Open
Abstract
Chronic intermittent ethanol vapor exposure (CIE) in rodents produces reliable and high blood ethanol concentration and behavioral symptoms associated with moderate to severe alcohol use disorder (AUD)—for example, escalation of operant ethanol self-administration, a feature suggestive of transition from recreational to addictive use, is a widely replicated behavior in rats that experience CIE. Herein, we present evidence from a subset of rats that do not demonstrate escalation of ethanol self-administration following seven weeks of CIE. These low responders (LR) maintain low ethanol self-administration during CIE, demonstrate lower relapse to drinking during abstinence and reduced reinstatement of ethanol seeking triggered by ethanol cues when compared with high responders (HR). We examined the blood ethanol levels in LR and HR rats during CIE and show higher levels in LR compared with HR. We also examined peak corticosterone levels during CIE and show that LR rats have higher levels compared with HR rats. Lastly, we evaluated the levels of Ca2+/calmodulin-dependent protein kinase II (CaMKII) in the nucleus accumbens shell and reveal that the activity of CaMKII, which is autophosphorylated at site Tyr-286, is significantly reduced in HR rats compared with LR rats. These findings demonstrate that dysregulation of the hypothalamic–pituitary–adrenal axis activity and plasticity-related proteins regulating molecular memory in the nucleus accumbens shell are associated with higher ethanol-drinking and -seeking in HR rats. Future mechanistic studies should evaluate CaMKII autophosphorylation-dependent remodeling of glutamatergic synapses in the ventral striatum as a plausible mechanism for the CIE-induced enhanced ethanol drinking and seeking behaviors.
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Affiliation(s)
| | - Chitra D Mandyam
- VA San Diego Healthcare System, San Diego, CA 92161, USA
- Department of Anesthesiology, University of California San Diego, San Diego, CA 92161, USA
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Bocarsly ME, da Silva E Silva D, Kolb V, Luderman KD, Shashikiran S, Rubinstein M, Sibley DR, Dobbs LK, Alvarez VA. A Mechanism Linking Two Known Vulnerability Factors for Alcohol Abuse: Heightened Alcohol Stimulation and Low Striatal Dopamine D2 Receptors. Cell Rep 2019; 29:1147-1163.e5. [PMID: 31665630 PMCID: PMC6880649 DOI: 10.1016/j.celrep.2019.09.059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/10/2019] [Accepted: 09/18/2019] [Indexed: 12/21/2022] Open
Abstract
Alcohol produces both stimulant and sedative effects in humans and rodents. In humans, alcohol abuse disorder is associated with a higher stimulant and lower sedative responses to alcohol. Here, we show that this association is conserved in mice and demonstrate a causal link with another liability factor: low expression of striatal dopamine D2 receptors (D2Rs). Using transgenic mouse lines, we find that the selective loss of D2Rs on striatal medium spiny neurons enhances sensitivity to ethanol stimulation and generates resilience to ethanol sedation. These mice also display higher preference and escalation of ethanol drinking, which continues despite adverse outcomes. We find that striatal D1R activation is required for ethanol stimulation and that this signaling is enhanced in mice with low striatal D2Rs. These data demonstrate a link between two vulnerability factors for alcohol abuse and offer evidence for a mechanism in which low striatal D2Rs trigger D1R hypersensitivity, ultimately leading to compulsive-like drinking.
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Affiliation(s)
- Miriam E Bocarsly
- Laboratory on the Neurobiology of Compulsive Behaviors, NIAAA, NIH, Bethesda, MD, USA; NIGMS, IRP, NIH, Bethesda, MD, USA
| | | | - Vanessa Kolb
- Laboratory on the Neurobiology of Compulsive Behaviors, NIAAA, NIH, Bethesda, MD, USA
| | | | - Sannidhi Shashikiran
- Laboratory on the Neurobiology of Compulsive Behaviors, NIAAA, NIH, Bethesda, MD, USA
| | - Marcelo Rubinstein
- INGEBI, CONICET, and FCEN, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - David R Sibley
- Molecular Neuropharmacology Section, NINDS, IRP, NIH, Bethesda, MD, USA
| | - Lauren K Dobbs
- Laboratory on the Neurobiology of Compulsive Behaviors, NIAAA, NIH, Bethesda, MD, USA; Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA
| | - Veronica A Alvarez
- Laboratory on the Neurobiology of Compulsive Behaviors, NIAAA, NIH, Bethesda, MD, USA; Center on Compulsive Behaviors, IRP, NIH, Bethesda, MD, USA; NIDA, IRP, NIH, Bethesda, MD, USA.
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Abstract
Study Objectives To assess the risks associated with the use of alcohol as a "sleep aid," we evaluated tolerance development to pre-sleep ethanol's sedative-hypnotic effects, and subsequent ethanol dose escalation. Methods Volunteers, 21-55 years old, with insomnia in otherwise good medical and psychiatric health and no history of alcoholism or drug abuse participated. In experiment 1 (n = 24) 0.0, 0.3, or 0.6 g/kg (n = 8 per dose) ethanol was administered before sleep and 8-hour nocturnal polysomnograms (NPSGs) were collected. In experiment 2, after six nights pretreatment with ethanol 0.45 g/kg (n = 6) versus placebo (n = 6), choice of pre-sleep ethanol or placebo was assessed over seven choice nights. Results The 0.6 g/kg ethanol dose increased total sleep time and stage 3-4 sleep on night 2, but these effects were lost by night 6 (p < .05). Six nights of ethanol pretreatment produced on the choice nights more self-administered ethanol refills than the placebo pretreatment (p < .03). Conclusions These are the first data to explicitly show the risks associated with the use of alcohol as a "sleep aid" among people with insomnia. Initially, a moderate dose of ethanol improved NPSG sleep, which was lost by night 6. Tolerance was associated with enhanced self-administration of pre-sleep ethanol.
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Affiliation(s)
- Timothy Roehrs
- Sleep Disorders and Research Center, Henry Ford Health System, Detroit, MI
- Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, MI
| | - Thomas Roth
- Sleep Disorders and Research Center, Henry Ford Health System, Detroit, MI
- Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, MI
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Lebourgeois S, González-Marín MC, Jeanblanc J, Naassila M, Vilpoux C. Effect of N-acetylcysteine on motivation, seeking and relapse to ethanol self-administration. Addict Biol 2018; 23:643-652. [PMID: 28557352 DOI: 10.1111/adb.12521] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 03/10/2017] [Accepted: 04/11/2017] [Indexed: 02/06/2023]
Abstract
Alcohol use disorder is a chronic and highly relapsing disorder, characterized by a loss of control over alcohol consumption and craving. Several studies suggest a key role of glutamate in this disorder. In recent years, the modulation of cystine/glutamate exchange via the xc- system has emerged as a new therapeutic alternative for reducing the excitatory glutamatergic transmission observed after ethanol self-administration in both rats and humans. The objective of this study was to determine whether a treatment with N-acetylcysteine (NAC), a cystine prodrug, could reduce ethanol self-administration, ethanol-seeking behavior and reacquisition of ethanol self-administration. Male Long Evans rats were trained to self-administer 20 percent ethanol in operant cages for several weeks. Once the consumption surpassed 1 g of ethanol/kg body weight/15 minutes, the effect of an acute intraperitoneal injection of NAC (0, 25, 50 or 100 mg/kg) 1 hour before the beginning of each test was evaluated on different aspects of the operant self-administration behavior. We demonstrated antimotivational properties of NAC (100 mg/kg), as ethanol-reinforced responding was reduced in a fixed ratio (-35 percent) and in a progressive ratio schedule (-81 percent). NAC also reduced ethanol-seeking behavior (-77 percent) evaluated as extinction responding in a single extinction session. NAC was able to reduce reacquisition in rats that were abstinent for 17 days, while NAC had no effect on ethanol relapse in rats previously exposed to six extinction sessions. Overall, our results demonstrate that NAC limits motivation, seeking behavior and reacquisition in rats, making it a potential new treatment for the maintenance of abstinence.
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Affiliation(s)
- Sophie Lebourgeois
- INSERM ERI-24 GRAP, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé (CURS); Université de Picardie Jules Verne; France
| | - María Carmen González-Marín
- INSERM ERI-24 GRAP, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé (CURS); Université de Picardie Jules Verne; France
| | - Jerome Jeanblanc
- INSERM ERI-24 GRAP, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé (CURS); Université de Picardie Jules Verne; France
| | - Mickael Naassila
- INSERM ERI-24 GRAP, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé (CURS); Université de Picardie Jules Verne; France
| | - Catherine Vilpoux
- INSERM ERI-24 GRAP, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Centre Universitaire de Recherche en Santé (CURS); Université de Picardie Jules Verne; France
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Jimenez VA, Porcu P, Morrow AL, Grant KA. Adaptations in Basal and Hypothalamic-Pituitary-Adrenal-Activated Deoxycorticosterone Responses Following Ethanol Self-administration in Cynomolgus Monkeys. Front Endocrinol (Lausanne) 2017; 8:19. [PMID: 28220108 PMCID: PMC5292619 DOI: 10.3389/fendo.2017.00019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/18/2017] [Indexed: 11/13/2022] Open
Abstract
Acute ethanol activates the hypothalamic-pituitary-adrenal (HPA) axis, while long-term exposure results in a blunted neuroendocrine state, particularly with regards to the primary endpoint, cortisol, the primary glucocorticoid produced in the adrenal cortex. However, it is unknown if this dampened neuroendocrine status also influences other adrenocortical steroids. Plasma concentration of the mineralocorticoid and neuroactive steroid precursor deoxycorticosterone (DOC) is altered by pharmacological challenges of the HPA axis in cynomolgus monkeys. The present study investigated HPA axis regulation of circulating DOC concentration over the course of ethanol (4% w/v) induction and self-administration in non-human primates (Macaca fasciculata, n = 10). Plasma DOC, measured by radioimmunoassay, was compared at baseline (ethanol naïve), during schedule-induced polydipsia, and following 6-months of 22 h/day access to ethanol and water. The schedule induction of ethanol drinking did not alter basal DOC levels but selectively dampened the DOC response to pharmacological challenges aimed at the anterior pituitary (ovine corticotrophin-releasing hormone) and adrenal gland (post-dexamethasone adrenocorticotropin hormone), while pharmacological inhibition of central opioid receptors with naloxone greatly enhanced the DOC response during induction. Following 6 months of ethanol self-administration, basal DOC levels were increased more than twofold, while responses to each of the challenges normalized somewhat but remained significantly different than baseline. These data show that HPA axis modulation of the neuroactive steroid precursor DOC is markedly altered by the schedule induction of ethanol drinking and long-term voluntary ethanol self-administration. The consequences of chronic ethanol consumption on HPA axis regulation of DOC point toward allostatic modification of hypothalamic and adrenal function.
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Affiliation(s)
- Vanessa A. Jimenez
- Oregon National Primate Research Center, Division of Neuroscience, Beaverton, OR, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - Patrizia Porcu
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Neuroscience Institute, National Research Council of Italy (CNR), Cagliari, Italy
| | - A. Leslie Morrow
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kathleen A. Grant
- Oregon National Primate Research Center, Division of Neuroscience, Beaverton, OR, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
- *Correspondence: Kathleen A. Grant,
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11
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Vengeliene V, Olevska A, Spanagel R. Long-lasting effect of NMDA receptor antagonist memantine on ethanol-cue association and relapse. J Neurochem 2015; 135:1080-5. [PMID: 26342155 DOI: 10.1111/jnc.13350] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/20/2015] [Accepted: 08/28/2015] [Indexed: 12/13/2022]
Abstract
It is well known that the glutamatergic system plays a crucial role in alcohol addiction and especially in relapse-like behaviour. However, results of clinical studies on compounds that influence the activity of the glutamatergic system have been disappointing so far. The aim of our study was to establish treatment conditions under which the N-methyl-d-aspartate receptor (NMDAR) antagonist memantine may produce more reliable treatment effect with respect to alcohol relapse-like behaviour. For this purpose, male Wistar rats were trained to associate several discrete stimuli with ethanol delivery. Thereafter, half of the animals received a brief memory reactivation session followed by two administrations of 20 mg/kg of memantine, while the other half received the same treatment without memory reactivation. Afterwards, a cue-induced ethanol-seeking behaviour test was performed followed by repeated extinction sessions and a reacquisition test. Our data show that administration of memantine reduced responding on the ethanol-associated lever in a cue-induced ethanol-seeking test. This reduction did not depend on whether or not a memory reactivation session was introduced prior to memantine administration. Following extinction, however, reacquisition of ethanol self-administration was only impaired in the group where memantine was given after a short memory reactivation session, showing that this schedule of drug administration produced a long-lasting disruption of the association between the conditioned stimuli and the delivery of ethanol. In conclusion, we show that memantine disrupted the drug-cue association, which consequently interfered with relapse-like behaviour supporting the possibility that memantine is a treatment option for alcoholism. Our data supports the possibility that memantine is a treatment option for alcoholism. However, the effectiveness of this drug seems to lie in its ability to disrupt conditioned behaviours and should be given in conjunction with exposure to conditioned drug stimuli.
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Affiliation(s)
- Valentina Vengeliene
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, Heidelberg University, Mannheim, Germany
| | - Anastasia Olevska
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, Heidelberg University, Mannheim, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, Heidelberg University, Mannheim, Germany
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12
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Jimenez VA, Helms CM, Cornea A, Meshul CK, Grant KA. An ultrastructural analysis of the effects of ethanol self-administration on the hypothalamic paraventricular nucleus in rhesus macaques. Front Cell Neurosci 2015; 9:260. [PMID: 26236193 PMCID: PMC4500925 DOI: 10.3389/fncel.2015.00260] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 06/23/2015] [Indexed: 01/29/2023] Open
Abstract
A bidirectional relationship between stress and ethanol exists whereby stressful events are comorbid with problematic ethanol use and prolonged ethanol exposure results in adaptations of the physiological stress response. Endocrine response to stress is initiated in the hypothalamic paraventricular nucleus (PVN) with the synthesis and release of corticotropin-releasing hormone (CRH) and arginine-vasopressin (AVP). Alterations in CRH and AVP following long-term ethanol exposure in rodents is well demonstrated, however little is known about the response to ethanol in primates or the mechanisms of adaptation. We hypothesized that long-term ethanol self-administration in nonhuman primates would lead to ultrastructural changes in the PVN underlying adaptation to chronic ethanol. Double-label immunogold electron microscopy (EM) was used to measure presynaptic gamma-aminobutyric acid (GABA) and glutamate density within synaptic terminals contacting CRH- and AVP-immunoreactive dendrites. Additionally, pituitary-adrenal hormones (ACTH, cortisol, DHEA-s and aldosterone) under two conditions (low and mild stress) were compared before and after self-administration. All hormones were elevated in response to the mild stressor independent of ethanol consumption. The presynaptic glutamate density in recurrent (i.e., intra-hypothalamic) CRH terminals was highly related to ethanol intake, and may be a permissive factor in increased drinking due to stress. Conversely, glutamate density within recurrent AVP terminals showed a trend-level increase following ethanol, but was not related to average daily consumption. Glutamate density in non-recurrent AVP terminals was related to aldosterone under the low stress condition while GABAergic density in this terminal population was related to water consumption. The results reveal distinct populations of presynaptic terminals whose glutamatergic or GABAergic density were uniquely related to water and ethanol consumption and circulating hormones.
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Affiliation(s)
- Vanessa A Jimenez
- Behavioral Neuroscience, Oregon Health and Science University Portland, OR, USA ; Division of Neuroscience, Oregon National Primate Research Center Beaverton, OR, USA
| | - Christa M Helms
- Division of Neuroscience, Oregon National Primate Research Center Beaverton, OR, USA
| | - Anda Cornea
- Division of Neuroscience, Oregon National Primate Research Center Beaverton, OR, USA
| | - Charles K Meshul
- Behavioral Neuroscience, Oregon Health and Science University Portland, OR, USA ; Research Services, Veterans Affairs Medical Center Portland, OR, USA
| | - Kathleen A Grant
- Behavioral Neuroscience, Oregon Health and Science University Portland, OR, USA ; Division of Neuroscience, Oregon National Primate Research Center Beaverton, OR, USA
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13
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Ortega-Álvaro A, Ternianov A, Aracil-Fernández A, Navarrete F, García-Gutiérrez MS, Manzanares J. Role of cannabinoid CB2 receptor in the reinforcing actions of ethanol. Addict Biol 2015; 20:43-55. [PMID: 23855434 DOI: 10.1111/adb.12076] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This study examines the role of the cannabinoid CB2 receptor (CB2 r) on the vulnerability to ethanol consumption. The time-related and dose-response effects of ethanol on rectal temperature, handling-induced convulsions (HIC) and blood ethanol concentrations were evaluated in CB2 KO and wild-type (WT) mice. The reinforcing properties of ethanol were evaluated in conditioned place preference (CPP), preference and voluntary ethanol consumption and oral ethanol self-administration. Water-maintained behavior schedule was performed to evaluate the degree of motivation induced by a natural stimulus. Preference for non-alcohol tastants assay was performed to evaluate the differences in taste sensitivity. Tyrosine hydroxylase (TH) and μ-opioid receptor gene expressions were also measured in the ventral tegmental area and nucleus accumbens (NAcc), respectively. CB2 KO mice presented increased HIC score, ethanol-CPP, voluntary ethanol consumption and preference, acquisition of ethanol self-administration, and increased motivation to drink ethanol compared with WT mice. No differences were found between genotypes in the water-maintained behavior schedule or preference for non-alcohol tastants. Naïve CB2 KO mice presented increased μ-opioid receptor gene expression in NAcc. Acute ethanol administration (1-2 g/kg) increased TH and μ-opioid receptor gene expressions in CB2 KO mice, whereas the lower dose of ethanol decreased TH gene expression in WT mice. These results suggest that deletion of the CB2 r gene increased preference for and vulnerability to ethanol consumption, at least in part, by increased ethanol-induced sensitivity of the TH and μ-opioid receptor gene expressions in mesolimbic neurons. Future studies will determine the role of CB2 r as a target for the treatment of problems related with alcohol consumption.
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Affiliation(s)
- Antonio Ortega-Álvaro
- Unidad de Neuropsicofarmacología Traslacional; Complejo Hospitalario Universitario de Albacete; Albacete Spain
| | - Alexander Ternianov
- Unidad de Neuropsicofarmacología Traslacional; Complejo Hospitalario Universitario de Albacete; Albacete Spain
| | - Auxiliadora Aracil-Fernández
- Instituto de Neurociencias; Universidad Miguel Hernández-CSIC; San Juan de Alicante Alicante Spain
- Red Temática de Investigación Cooperativa en Salud (RETICS-Trastornos Adictivos); Instituto de Salud Carlos III, MICINN and FEDER; Madrid Spain
| | - Francisco Navarrete
- Instituto de Neurociencias; Universidad Miguel Hernández-CSIC; San Juan de Alicante Alicante Spain
- Red Temática de Investigación Cooperativa en Salud (RETICS-Trastornos Adictivos); Instituto de Salud Carlos III, MICINN and FEDER; Madrid Spain
| | - Maria Salud García-Gutiérrez
- Instituto de Neurociencias; Universidad Miguel Hernández-CSIC; San Juan de Alicante Alicante Spain
- Red Temática de Investigación Cooperativa en Salud (RETICS-Trastornos Adictivos); Instituto de Salud Carlos III, MICINN and FEDER; Madrid Spain
| | - Jorge Manzanares
- Instituto de Neurociencias; Universidad Miguel Hernández-CSIC; San Juan de Alicante Alicante Spain
- Red Temática de Investigación Cooperativa en Salud (RETICS-Trastornos Adictivos); Instituto de Salud Carlos III, MICINN and FEDER; Madrid Spain
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14
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Helms CM, Rau A, Shaw J, Stull C, Gonzales SW, Grant KA. The effects of age at the onset of drinking to intoxication and chronic ethanol self-administration in male rhesus macaques. Psychopharmacology (Berl) 2014; 231:1853-61. [PMID: 24448900 PMCID: PMC3969395 DOI: 10.1007/s00213-013-3417-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 12/19/2013] [Indexed: 11/27/2022]
Abstract
RATIONALE Consumption of alcohol begins during late adolescence in a majority of humans, and the greatest drinking occurs at 18-25 years then decreases with age. OBJECTIVES The present study measured the differences in ethanol intake in relation to age at the onset of ethanol access among nonhuman primates to control for self-selection in humans and isolate age effects on heavy drinking. METHODS Male rhesus macaques were assigned first access to ethanol during late adolescence (n = 8), young adulthood (n = 8), or early middle age (n = 11). The monkeys were induced to drink ethanol (4 % w/v in water) in increasing doses (water then 0.5, 1.0, 1.5 g/kg ethanol) using a fixed-time (FT) 300-s schedule of food delivery, followed by 22 h/day concurrent access to ethanol and water for 12 months. Age-matched controls consumed isocaloric maltose-dextrin solution yoked to the late adolescents expected to be rapidly maturing (n = 4). RESULTS Young adult monkeys had the greatest daily ethanol intake and blood-ethanol concentration (BEC). Only late adolescents escalated their intake (ethanol, not water) during the second compared to the first 6 months of access. On average, plasma testosterone level was consistent with age differences in maturation and tended to increase throughout the experiment more for control than ethanol-drinking adolescent monkeys. CONCLUSIONS Young adulthood in nonhuman primates strongly disposes toward heavy drinking, which is independent of sociocultural factors present in humans. Ethanol drinking to intoxication during the critical period of late adolescence is associated with escalation to heavy drinking.
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Affiliation(s)
- Christa M. Helms
- Oregon Health & Science University, Oregon National Primate Research Center
| | - Andrew Rau
- Oregon Health & Science University, Oregon National Primate Research Center
| | - Jessica Shaw
- Oregon Health & Science University, Oregon National Primate Research Center
| | - Cara Stull
- Oregon Health & Science University, Oregon National Primate Research Center
| | - Steven W. Gonzales
- Oregon Health & Science University, Oregon National Primate Research Center
| | - Kathleen A. Grant
- Oregon Health & Science University, Oregon National Primate Research Center
- Oregon Health & Science University, Department of Behavioral Neuroscience
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15
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Bass CE, Grinevich VP, Gioia D, Day-Brown JD, Bonin KD, Stuber GD, Weiner JL, Budygin EA. Optogenetic stimulation of VTA dopamine neurons reveals that tonic but not phasic patterns of dopamine transmission reduce ethanol self-administration. Front Behav Neurosci 2013; 7:173. [PMID: 24324415 PMCID: PMC3840465 DOI: 10.3389/fnbeh.2013.00173] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/05/2013] [Indexed: 01/16/2023] Open
Abstract
There is compelling evidence that acute ethanol exposure stimulates ventral tegmental area (VTA) dopamine cell activity and that VTA-dependent dopamine release in terminal fields within the nucleus accumbens plays an integral role in the regulation of ethanol drinking behaviors. Unfortunately, due to technical limitations, the specific temporal dynamics linking VTA dopamine cell activation and ethanol self-administration are not known. In fact, establishing a causal link between specific patterns of dopamine transmission and ethanol drinking behaviors has proven elusive. Here, we sought to address these gaps in our knowledge using a newly developed viral-mediated gene delivery strategy to selectively express Channelrhodopsin-2 (ChR2) on dopamine cells in the VTA of wild-type rats. We then used this approach to precisely control VTA dopamine transmission during voluntary ethanol drinking sessions. The results confirmed that ChR2 was selectively expressed on VTA dopamine cells and delivery of blue light pulses to the VTA induced dopamine release in accumbal terminal fields with very high temporal and spatial precision. Brief high frequency VTA stimulation induced phasic patterns of dopamine release in the nucleus accumbens. Lower frequency stimulation, applied for longer periods mimicked tonic increases in accumbal dopamine. Notably, using this optogenetic approach in rats engaged in an intermittent ethanol drinking procedure, we found that tonic, but not phasic, stimulation of VTA dopamine cells selectively attenuated ethanol drinking behaviors. Collectively, these data demonstrate the effectiveness of a novel viral targeting strategy that can be used to restrict opsin expression to dopamine cells in standard outbred animals and provide the first causal evidence demonstrating that tonic activation of VTA dopamine neurons selectively decreases ethanol self-administration behaviors.
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Affiliation(s)
- Caroline E Bass
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo Buffalo, NY, USA
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16
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Rodd ZA, Bell RL, Oster SM, Toalston JE, Pommer TJ, McBride WJ, Murphy JM. Serotonin-3 receptors in the posterior ventral tegmental area regulate ethanol self-administration of alcohol-preferring (P) rats. Alcohol 2010; 44:245-55. [PMID: 20682192 PMCID: PMC4516283 DOI: 10.1016/j.alcohol.2010.01.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 12/10/2009] [Accepted: 01/04/2010] [Indexed: 10/19/2022]
Abstract
Several studies indicated the involvement of serotonin-3 ([5-hydroxy tryptamine] 5-HT(3)) receptors in regulating alcohol-drinking behavior. The objective of this study was to determine the involvement of 5-HT(3) receptors within the ventral tegmental area (VTA) in regulating ethanol self-administration by alcohol-preferring (P) rats. Standard two-lever operant chambers (Coulbourn Instruments, Allentown, PA) were used to examine the effects of seven consecutive bilateral microinfusions of ICS 205-930 (ICS), a 5-HT(3) receptor antagonist, directly into the posterior VTA on the acquisition and maintenance of 15% (vol/vol) ethanol self-administration. P rats readily acquired ethanol self-administration by the fourth session. The three highest doses (0.125, 0.25, and 1.25 microg) of ICS prevented acquisition of ethanol self-administration. During the acquisition postinjection period, all rats treated with ICS demonstrated higher responding on the ethanol lever, with the highest dose producing the greatest effect. In contrast, during the maintenance phase, the three highest doses (0.75, 1.0, and 1.25 microg) of ICS significantly increased responding on the ethanol lever; after the 7-day dosing regimen, responding on the ethanol lever returned to control levels. Microinfusion of ICS into the posterior VTA did not alter the low responding on the water lever and did not alter saccharin (0.0125% wt/v) self-administration. Microinfusion of ICS into the anterior VTA did not alter ethanol self-administration. Overall, the results of this study suggest that 5-HT(3) receptors in the posterior VTA of the P rat may be involved in regulating ethanol self-administration. In addition, chronic operant ethanol self-administration and/or repeated treatments with a 5-HT(3) receptor antagonist may alter neuronal circuitry within the posterior VTA.
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Affiliation(s)
- Zachary A Rodd
- Department of Psychiatry, Institute of Psychiatric Research, Indiana School of Medicine, Indianapolis, USA.
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17
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Hodge CW, Miles MF, Sharko AC, Stevenson RA, Hillmann JR, Lepoutre V, Besheer J, Schroeder JP. The mGluR5 antagonist MPEP selectively inhibits the onset and maintenance of ethanol self-administration in C57BL/6J mice. Psychopharmacology (Berl) 2006; 183:429-38. [PMID: 16292590 PMCID: PMC2854492 DOI: 10.1007/s00213-005-0217-y] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Accepted: 09/22/2005] [Indexed: 01/18/2023]
Abstract
RATIONALE Many of the biochemical, physiological, and behavioral effects of ethanol are known to be mediated by ionotropic glutamate receptors. Emerging evidence implicates metabotropic glutamate receptors (mGluRs) in the biobehavioral effects of ethanol and other drugs of abuse, but there is little information regarding the role of mGluRs in the reinforcing effects of ethanol. MATERIALS AND METHODS Male C57BL/6J mice were trained to lever-press on a concurrent fixed ratio 1 schedule of ethanol (10% v/v) vs water reinforcement during 16-h sessions. Effects of mGluR1, mGluR2/3, and mGluR5 antagonists were then tested on parameters of ethanol self-administration behavior. RESULTS The mGluR5 antagonist MPEP (1-10 mg/kg, i.p.) dose-dependently reduced ethanol-reinforced responding but had no effect on concurrent water-reinforced responding. Analysis of the temporal pattern of responding showed that MPEP reduced ethanol-reinforced responding during peak periods of behavior occurring during the early hours of the dark cycle. Further analysis showed that MPEP reduced the number of ethanol response bouts and bout-response rate. MPEP also produced a 13-fold delay in ethanol response onset (i.e., latency to the first response) with no corresponding effect on water response latency or locomotor activity. The mGluR1 antagonist CPCCOEt (1-10 mg/kg, i.p.) or the mGluR2/3 antagonist LY 341495 (1-30 mg/kg, i.p.) failed to alter ethanol- or water-reinforced responding. CONCLUSIONS These data indicate that mGlu5 receptors selectively regulate the onset and maintenance of ethanol self-administration in a manner that is consistent with reduction in ethanol's reinforcement function.
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Affiliation(s)
- Clyde W Hodge
- Department of Psychiatry, Bowles Center for Alcohol Studies School of Medicine, CB#7178, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7178, USA.
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