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Lovinger DM, Roberto M. Synaptic Effects Induced by Alcohol. Curr Top Behav Neurosci 2023:10.1007/7854_2022_412. [PMID: 36765015 PMCID: PMC11104446 DOI: 10.1007/7854_2022_412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Ethanol (EtOH) has effects on numerous cellular molecular targets, and alterations in synaptic function are prominent among these effects. Acute exposure to EtOH activates or inhibits the function of proteins involved in synaptic transmission, while chronic exposure often produces opposing and/or compensatory/homeostatic effects on the expression, localization, and function of these proteins. Interactions between different neurotransmitters (e.g., neuropeptide effects on release of small molecule transmitters) can also influence both acute and chronic EtOH actions. Studies in intact animals indicate that the proteins affected by EtOH also play roles in the neural actions of the drug, including acute intoxication, tolerance, dependence, and the seeking and drinking of EtOH. The present chapter is an update of our previous Lovinger and Roberto (Curr Top Behav Neurosci 13:31-86, 2013) chapter and reviews the literature describing these acute and chronic synaptic effects of EtOH with a focus on adult animals and their relevance for synaptic transmission, plasticity, and behavior.
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Affiliation(s)
- David M Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism (NIAAA), Rockville, MD, USA
| | - Marisa Roberto
- Molecular Medicine Department, Scripps Research Institute, La Jolla, CA, USA.
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Sauton P, Deschamps C, Jeanblanc V, Pierrefiche O, Jeanblanc J, Naassila M. Interstrain differences in voluntary binge-like drinking behavior and in two acute ethanol injections-induced synaptic plasticity deficits in rats. Addict Biol 2021; 26:e12992. [PMID: 33331070 DOI: 10.1111/adb.12992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/14/2022]
Abstract
Propensity to drink alcohol and to initiate binge drinking behavior is driven by genetic factors. Recently, we proposed an original animal model useful in the study of voluntary binge-like drinking (BD) in outbred Long-Evans rats by combining intermittent access to 20% ethanol in a two-bottle choice (IA2BC) paradigm to 15-min daily sessions of 20% ethanol operant self-administration. We sought to compare three strains of outbred rats (Long-Evans, Sprague-Dawley, and Wistar) in our BD model. Because we found different propensity to BD between strains, we also sought to test interstrain differences using another procedure of two acute ethanol exposures known to alter long-term depression of hippocampal synaptic plasticity. Our results demonstrate that in both IA2BC and operant procedures, the Long-Evans strain consumed the highest, Wistar the lowest amount of ethanol, and the Sprague-Dawley was intermediate. Long-Evans rats were also the fastest consuming with the shortest time to reach 50% of their maximum consumption in 15 min. When we tested the acute effects of ethanol, long-term depression in hippocampus was abolished specifically in Long-Evans rats with no impact in the two other strains. Thus, our study reveals that the Long-Evans strain is the ideal strain in our recently developed animal model useful in the study of BD. In addition, with the other paradigm of forced acute ethanol exposure, the Long-Evans strain displayed an increase in sensitivity to the deleterious effect of BD on hippocampal synaptic plasticity. Further studies are needed in order to investigate why Long-Evans rats are more prone to BD.
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Affiliation(s)
- Pierre Sauton
- INSERM UMR 1247 – Research Group on Alcohol & Pharmacodependences (GRAP) Université de Picardie Jules Verne Amiens France
| | - Chloé Deschamps
- INSERM UMR 1247 – Research Group on Alcohol & Pharmacodependences (GRAP) Université de Picardie Jules Verne Amiens France
| | - Virginie Jeanblanc
- Animal Facility PlatAnN Université de Picardie Jules Verne Amiens France
| | - Olivier Pierrefiche
- INSERM UMR 1247 – Research Group on Alcohol & Pharmacodependences (GRAP) Université de Picardie Jules Verne Amiens France
| | - Jérôme Jeanblanc
- INSERM UMR 1247 – Research Group on Alcohol & Pharmacodependences (GRAP) Université de Picardie Jules Verne Amiens France
| | - Mickael Naassila
- INSERM UMR 1247 – Research Group on Alcohol & Pharmacodependences (GRAP) Université de Picardie Jules Verne Amiens France
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Abstract
Alcohol is one of the oldest pharmacological agents used for its sedative/hypnotic effects, and alcohol abuse and alcohol use disorder (AUD) continues to be major public health issue. AUD is strongly indicated to be a brain disorder, and the molecular and cellular mechanism/s by which alcohol produces its effects in the brain are only now beginning to be understood. In the brain, synaptic plasticity or strengthening or weakening of synapses, can be enhanced or reduced by a variety of stimulation paradigms. Synaptic plasticity is thought to be responsible for important processes involved in the cellular mechanisms of learning and memory. Long-term potentiation (LTP) is a form of synaptic plasticity, and occurs via N-methyl-D-aspartate type glutamate receptor (NMDAR or GluN) dependent and independent mechanisms. In particular, NMDARs are a major target of alcohol, and are implicated in different types of learning and memory. Therefore, understanding the effect of alcohol on synaptic plasticity and transmission mediated by glutamatergic signaling is becoming important, and this will help us understand the significant contribution of the glutamatergic system in AUD. In the first part of this review, we will briefly discuss the mechanisms underlying long term synaptic plasticity in the dorsal striatum, neocortex and the hippocampus. In the second part we will discuss how alcohol (ethanol, EtOH) can modulate long term synaptic plasticity in these three brain regions, mainly from neurophysiological and electrophysiological studies. Taken together, understanding the mechanism(s) underlying alcohol induced changes in brain function may lead to the development of more effective therapeutic agents to reduce AUDs.
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Affiliation(s)
| | - Chitra D Mandyam
- VA San Diego Healthcare System, San Diego, CA, USA.,Department of Anesthesiology, University of California San Diego, San Diego, CA, USA
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González‐Marín MDC, Coune F, Naassila M. Vulnerability to ethanol sensitization predicts higher intake and motivation to self-administer ethanol: Proof of the incentive salience sensitization theory? Addict Biol 2020; 25:e12833. [PMID: 31762127 DOI: 10.1111/adb.12833] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/16/2019] [Accepted: 09/09/2019] [Indexed: 12/28/2022]
Abstract
Ethanol-induced behavioral sensitization (EIBS) is thought to play a key role in addiction. However, whether EIBS is linked to an increase in the motivation to self-administerethanol in an operant paradigm has never been demonstrated, and thus, the motivational sensitization theory (increase in drug wanting) has not been yet confirmed. We investigated using the operant ethanol self-administrationparadigm if the motivation to self-administerethanol (breakpoint) is increased in female mice prone to develop EIBS. Outbred female Swiss mice were treated once a day with 2.5-g ethanol per kilogram during 10 days and challenged with the same dose of ethanol 7 days later. EIBS-pronegroup was characterized by a significant increase in locomotion between the challenge day and day 1. When the difference was not significant, mice were considered as the "EIBS-resistant"group. Mice were then trained to nose poke for a 20% ethanol solution reinforcer under a FR1 and then a FR-2schedule of reinforcement. Motivation was assessed more directly with a progressive ratio schedule. Our results show that there is a positive correlation between EIBS and both the level of intake and motivation. Interestingly, acquisition of ethanol self-administrationwas faster in sensitized mice that also display a quick and long-lastingincrease in ethanol intake together with a lack of effect of alcohol challenge on c-Fosexpression restricted to the dorsolateral striatum. These results further support that EIBS vulnerability is crucial in the development of addictive behaviors and suggest a potential link with habit learning processes.
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Affiliation(s)
| | - Fabien Coune
- INSERM UMR 1247—Research Group on Alcohol and Pharmacodependences (GRAP) Université de Picardie Jules Verne Amiens France
| | - Mickaël Naassila
- INSERM UMR 1247—Research Group on Alcohol and Pharmacodependences (GRAP) Université de Picardie Jules Verne Amiens France
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Peñasco S, Rico-Barrio I, Puente N, Fontaine CJ, Ramos A, Reguero L, Gerrikagoitia I, de Fonseca FR, Suarez J, Barrondo S, Aretxabala X, García Del Caño G, Sallés J, Elezgarai I, Nahirney PC, Christie BR, Grandes P. Intermittent ethanol exposure during adolescence impairs cannabinoid type 1 receptor-dependent long-term depression and recognition memory in adult mice. Neuropsychopharmacology 2020; 45:309-318. [PMID: 31569197 PMCID: PMC6901552 DOI: 10.1038/s41386-019-0530-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 08/23/2019] [Accepted: 09/17/2019] [Indexed: 12/11/2022]
Abstract
Binge drinking is a significant problem in adolescent populations, and because of the reciprocal interactions between ethanol (EtOH) consumption and the endocannabinoid (eCB) system, we sought to determine if adolescent EtOH intake altered the localization and function of the cannabinoid 1 (CB1) receptors in the adult brain. Adolescent mice were exposed to a 4-day-per week drinking in the dark (DID) procedure for a total of 4 weeks and then tested after a 2-week withdrawal period. Field excitatory postsynaptic potentials (fEPSPs), evoked by medial perforant path (MPP) stimulation in the dentate gyrus molecular layer (DGML), were significantly smaller. Furthermore, unlike control animals, CB1 receptor activation did not depress fEPSPs in the EtOH-exposed animals. We also examined a form of excitatory long-term depression that is dependent on CB1 receptors (eCB-eLTD) and found that it was completely lacking in the animals that consumed EtOH during adolescence. Histological analyses indicated that adolescent EtOH intake significantly reduced the CB1 receptor distribution and proportion of immunopositive excitatory synaptic terminals in the medial DGML. Furthermore, there was decreased binding of [35S]guanosine-5*-O-(3-thiotriphosphate) ([35S] GTPγS) and the guanine nucleotide-binding (G) protein Gαi2 subunit in the EtOH-exposed animals. Associated with this, there was a significant increase in monoacylglycerol lipase (MAGL) mRNA and protein in the hippocampus of EtOH-exposed animals. Conversely, deficits in eCB-eLTD and recognition memory could be rescued by inhibiting MAGL with JZL184. These findings indicate that repeated exposure to EtOH during adolescence leads to long-term deficits in CB1 receptor expression, eCB-eLTD, and reduced recognition memory, but that these functional deficits can be restored by treatments that increase endogenous 2-arachidonoylglycerol.
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Affiliation(s)
- Sara Peñasco
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Vizcaya, Spain
| | - Irantzu Rico-Barrio
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Vizcaya, Spain
| | - Nagore Puente
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Vizcaya, Spain
| | - Christine J Fontaine
- Division of Medical Sciences, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Almudena Ramos
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Vizcaya, Spain
| | - Leire Reguero
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Vizcaya, Spain
| | - Inmaculada Gerrikagoitia
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Vizcaya, Spain
| | - Fernando Rodríguez de Fonseca
- Hospital Regional Universitario de Málaga, Instituto de Investigación Biomédica de Málaga (IBIMA), 29010, Málaga, Spain
| | - Juan Suarez
- Hospital Regional Universitario de Málaga, Instituto de Investigación Biomédica de Málaga (IBIMA), 29010, Málaga, Spain
| | - Sergio Barrondo
- Department of Pharmacology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, CIBERSAM, Paseo de la Universidad 7, Vitoria-Gasteiz, Alava, 01006, Vitoria-Gasteiz, Spain
| | - Xabier Aretxabala
- Department of Neurosciences, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Araba, Spain
| | - Gontzal García Del Caño
- Department of Neurosciences, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Paseo de la Universidad 7, 01006, Vitoria-Gasteiz, Araba, Spain
| | - Joan Sallés
- Department of Pharmacology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, CIBERSAM, Paseo de la Universidad 7, Vitoria-Gasteiz, Alava, 01006, Vitoria-Gasteiz, Spain
| | - Izaskun Elezgarai
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Vizcaya, Spain
| | - Patrick C Nahirney
- Division of Medical Sciences, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Brian R Christie
- Division of Medical Sciences, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Pedro Grandes
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain.
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Vizcaya, Spain.
- Division of Medical Sciences, University of Victoria, Victoria, BC, V8P 5C2, Canada.
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Long-term exposure to daily ethanol injections in DBA/2J and Swiss mice: Lessons for the interpretation of ethanol sensitization. PLoS One 2019; 14:e0214696. [PMID: 31721780 PMCID: PMC6853325 DOI: 10.1371/journal.pone.0214696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 10/27/2019] [Indexed: 11/19/2022] Open
Abstract
Most mice ethanol sensitization studies focused on neurobiology at the expense of its behavioral characterization. Furthermore, relatively short ethanol exposures (10 to 20 injections) were used in these studies. The first aim of the present study is to better characterize the development and expression of ethanol sensitization after an extended exposure of 45 daily injections. In some previous studies, mice were classified as "respondent" and "resistant" to ethanol sensitization. The second aim of the present study is to test the long-term reliability of such categorizations and the consequences of their use on the interpretation of the ethanol sensitization results. Swiss and DBA/2J female mice received 45 consecutive daily ethanol administrations (respectively 2.5 and 2.0 g/kg) and their locomotor activity was daily recorded to test the development of ethanol sensitization. At the end of the procedure, a challenge test assessed the inter-group ethanol sensitization.The results of the present study show that ethanol sensitization continues to develop beyond 20 days to reach maximal levels after about 25 injections in DBA/2J mice and 40 injections in Swiss mice, although the core phase of the development of ethanol sensitization occurred in both strains during the first 20 days. Remarkably, ethanol sensitization after such a long daily ethanol treatment resulted in both an upward shift of the magnitude of ethanol stimulant effects and a prolongation of these effects in time (up to 30 minutes). Mice classified as "resistant to ethanol sensitization" according to previous studies developed very significant levels of ethanol sensitization when tested after 45 ethanol injections and are best described as showing a delayed development of ethanol sensitization. Furthermore, mice classified as respondent or resistant to ethanol sensitization also differ in their acute response to ethanol, such that it is difficult to ascertain whether these classifications are specifically related to the sensitization process.
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Lovinger DM, Abrahao KP. Synaptic plasticity mechanisms common to learning and alcohol use disorder. ACTA ACUST UNITED AC 2018; 25:425-434. [PMID: 30115764 PMCID: PMC6097767 DOI: 10.1101/lm.046722.117] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/21/2018] [Indexed: 11/24/2022]
Abstract
Alcohol use disorders include drinking problems that span a range from binge drinking to alcohol abuse and dependence. Plastic changes in synaptic efficacy, such as long-term depression and long-term potentiation are widely recognized as mechanisms involved in learning and memory, responses to drugs of abuse, and addiction. In this review, we focus on the effects of chronic ethanol (EtOH) exposure on the induction of synaptic plasticity in different brain regions. We also review findings indicating that synaptic plasticity occurs in vivo during EtOH exposure, with a focus on ex vivo electrophysiological indices of plasticity. Evidence for effects of EtOH-induced or altered synaptic plasticity on learning and memory and EtOH-related behaviors is also reviewed. As this review indicates, there is much work needed to provide more information about the molecular, cellular, circuit, and behavioral consequences of EtOH interactions with synaptic plasticity mechanisms.
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Affiliation(s)
- David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA
| | - Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA
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Abrahao KP, Salinas AG, Lovinger DM. Alcohol and the Brain: Neuronal Molecular Targets, Synapses, and Circuits. Neuron 2017; 96:1223-1238. [PMID: 29268093 PMCID: PMC6566861 DOI: 10.1016/j.neuron.2017.10.032] [Citation(s) in RCA: 243] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/30/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
Abstract
Ethanol is one of the most commonly abused drugs. Although environmental and genetic factors contribute to the etiology of alcohol use disorders, it is ethanol's actions in the brain that explain (1) acute ethanol-related behavioral changes, such as stimulant followed by depressant effects, and (2) chronic changes in behavior, including escalated use, tolerance, compulsive seeking, and dependence. Our knowledge of ethanol use and abuse thus relies on understanding its effects on the brain. Scientists have employed both bottom-up and top-down approaches, building from molecular targets to behavioral analyses and vice versa, respectively. This review highlights current progress in the field, focusing on recent and emerging molecular, cellular, and circuit effects of the drug that impact ethanol-related behaviors. The focus of the field is now on pinpointing which molecular effects in specific neurons within a brain region contribute to behavioral changes across the course of acute and chronic ethanol exposure.
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Affiliation(s)
- Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - Armando G Salinas
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA.
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