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Xie X, Lu J, Ma T, Cheng Y, Woodson K, Bonifacio J, Bego K, Wang X, Wang J. Linking input- and cell-type-specific synaptic plasticity to the reinforcement of alcohol-seeking behavior. Neuropharmacology 2023; 237:109619. [PMID: 37290535 DOI: 10.1016/j.neuropharm.2023.109619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/15/2023] [Accepted: 05/27/2023] [Indexed: 06/10/2023]
Abstract
The reinforcement of voluntary alcohol-seeking behavior requires dopamine-dependent long-term synaptic plasticity in the striatum. Specifically, the long-term potentiation (LTP) of direct-pathway medium spiny neurons (dMSNs) in the dorsomedial striatum (DMS) promotes alcohol drinking. However, it remains unclear whether alcohol induces input-specific plasticity onto dMSNs and whether this plasticity directly drives instrumental conditioning. In this study, we found that voluntary alcohol intake selectively strengthened glutamatergic transmission from the medial prefrontal cortex (mPFC) to DMS dMSNs in mice. Importantly, mimicking this alcohol-induced potentiation by optogenetically self-stimulating mPFC→dMSN synapse with an LTP protocol was sufficient to drive the reinforcement of lever pressing in operant chambers. Conversely, induction of a post-pre spike timing-dependent LTD at this synapse time-locked to alcohol delivery during operant conditioning persistently decreased alcohol-seeking behavior. Our results establish a causal relationship between input- and cell-type-specific corticostriatal plasticity and the reinforcement of alcohol-seeking behavior. This provides a potential therapeutic strategy to restore normal cortical control of dysregulated basal ganglia circuitries in alcohol use disorder.
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Affiliation(s)
- Xueyi Xie
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Jiayi Lu
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Tengfei Ma
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Yifeng Cheng
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Kayla Woodson
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Jordan Bonifacio
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Kassidy Bego
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Xuehua Wang
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Jun Wang
- Department of Neuroscience and Experimental Therapeutics, School of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA.
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Konar-Nié M, Guzman-Castillo A, Armijo-Weingart L, Aguayo LG. Aging in nucleus accumbens and its impact on alcohol use disorders. Alcohol 2023; 107:73-90. [PMID: 36087859 DOI: 10.1016/j.alcohol.2022.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/01/2022] [Accepted: 08/04/2022] [Indexed: 02/06/2023]
Abstract
Ethanol is one of the most widely consumed drugs in the world and prolonged excessive ethanol intake might lead to alcohol use disorders (AUDs), which are characterized by neuroadaptations in different brain regions, such as in the reward circuitry. In addition, the global population is aging, and it appears that they are increasing their ethanol consumption. Although research involving the effects of alcohol in aging subjects is limited, differential effects have been described. For example, studies in human subjects show that older adults perform worse in tests assessing working memory, attention, and cognition as compared to younger adults. Interestingly, in the field of the neurobiological basis of ethanol actions, there is a significant dichotomy between what we know about the effects of ethanol on neurochemical targets in young animals and how it might affect them in the aging brain. To be able to understand the distinct effects of ethanol in the aging brain, the following questions need to be answered: (1) How does physiological aging impact the function of an ethanol-relevant region (e.g., the nucleus accumbens)? and (2) How does ethanol affect these neurobiological systems in the aged brain? This review discusses the available data to try to understand how aging affects the nucleus accumbens (nAc) and its neurochemical response to alcohol. The data show that there is little information on the effects of ethanol in aged mice and rats, and that many studies had considered 2-3-month-old mice as adults, which needs to be reconsidered since more recent literature defines 6 months as young adults and >18 months as an older mouse. Considering the actual relevance of an aged worldwide population and that this segment is drinking more frequently, it appears at least reasonable to explore how ethanol affects the brain in adult and aged models.
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Affiliation(s)
- Macarena Konar-Nié
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepcion, Concepcion, Chile.
| | - Alejandra Guzman-Castillo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepcion, Concepcion, Chile; Programa en Neurociencia, Psiquiatría y Salud Mental, Universidad de Concepción, Concepcion, Chile.
| | - Lorena Armijo-Weingart
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepcion, Concepcion, Chile; Programa en Neurociencia, Psiquiatría y Salud Mental, Universidad de Concepción, Concepcion, Chile.
| | - Luis Gerardo Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepcion, Concepcion, Chile; Programa en Neurociencia, Psiquiatría y Salud Mental, Universidad de Concepción, Concepcion, Chile.
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3
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Gimenez-Gomez P, Le T, Martin GE. Modulation of neuronal excitability by binge alcohol drinking. Front Mol Neurosci 2023; 16:1098211. [PMID: 36866357 PMCID: PMC9971943 DOI: 10.3389/fnmol.2023.1098211] [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] [Received: 11/14/2022] [Accepted: 01/19/2023] [Indexed: 02/16/2023] Open
Abstract
Drug use poses a serious threat to health systems throughout the world. The number of consumers rises every year being alcohol the drug of abuse most consumed causing 3 million deaths (5.3% of all deaths) worldwide and 132.6 million disability-adjusted life years. In this review, we present an up-to-date summary about what is known regarding the global impact of binge alcohol drinking on brains and how it affects the development of cognitive functions, as well as the various preclinical models used to probe its effects on the neurobiology of the brain. This will be followed by a detailed report on the state of our current knowledge of the molecular and cellular mechanisms underlying the effects of binge drinking on neuronal excitability and synaptic plasticity, with an emphasis on brain regions of the meso-cortico limbic neurocircuitry.
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Affiliation(s)
- Pablo Gimenez-Gomez
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, United States
- The Brudnick Neuropsychiatric Research Institute, Worcester, MA, United States
| | - Timmy Le
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, United States
- The Brudnick Neuropsychiatric Research Institute, Worcester, MA, United States
- Graduate Program in Neuroscience, Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA, United States
| | - Gilles E. Martin
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, United States
- The Brudnick Neuropsychiatric Research Institute, Worcester, MA, United States
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Griffin WC, Lopez MF, Woodward JJ, Becker HC. Alcohol dependence and the ventral hippocampal influence on alcohol drinking in male mice. Alcohol 2023; 106:44-54. [PMID: 36328184 PMCID: PMC9868110 DOI: 10.1016/j.alcohol.2022.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/26/2022] [Accepted: 10/26/2022] [Indexed: 11/07/2022]
Abstract
Examining neural circuits underlying persistent, heavy drinking provides insight into the neurobiological mechanisms driving alcohol use disorder. Facilitated by its connectivity with other parts of the brain such as the nucleus accumbens (NAc), the ventral hippocampus (vHC) supports many behaviors, including those related to reward seeking and addiction. These studies used a well-established mouse model of alcohol (ethanol) dependence. After surgery to infuse DREADD-expressing viruses (hM4Di, hM3Dq, or mCherry-only) into the vHC and position guide cannula above the NAc, male C57BL/6J mice were treated in the CIE drinking model that involved repeated cycles of chronic intermittent alcohol (CIE) vapor or air (CTL) exposure alternating with weekly test drinking cycles in which mice were offered alcohol (15% v/v) 2 h/day. Additionally, smaller groups of mice were evaluated for either cFos expression or glutamate release using microdialysis procedures. In CIE mice expressing inhibitory (hM4Di) DREADDs in the vHC, drinking increased as expected, but CNO (3 mg/kg intraperitoneally [i.p.]) given 30 min before testing did not alter alcohol intake. However, in CTL mice expressing hM4Di, CNO significantly increased alcohol drinking (∼30%; p < 0.05) to levels similar to the CIE mice. The vHC-NAc pathway was targeted by infusing CNO into the NAc (3 or 10 μM/side) 30 min before testing. CNO activation of the pathway in mice expressing excitatory (hM3Dq) DREADDs selectively reduced consumption in CIE mice back to CTL levels (∼35-45%; p < 0.05) without affecting CTL alcohol intake. Lastly, activating the vHC-NAc pathway increased cFos expression and evoked significant glutamate release from the vHC terminals in the NAc. These data indicate that reduced activity of the vHC increases alcohol consumption and that targeted, increased activity of the vHC-NAc pathway attenuates excessive drinking associated with alcohol dependence. Thus, these findings indicate that the vHC and its glutamatergic projections to the NAc are involved in excessive alcohol drinking.
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Affiliation(s)
- William C Griffin
- Charleston Alcohol Research Center, Department of Psychiatry and Behavioral Science, Medical University of South Carolina, Charleston, SC, United States.
| | - Marcelo F Lopez
- Charleston Alcohol Research Center, Department of Psychiatry and Behavioral Science, Medical University of South Carolina, Charleston, SC, United States
| | - John J Woodward
- Charleston Alcohol Research Center, Department of Psychiatry and Behavioral Science, Medical University of South Carolina, Charleston, SC, United States; Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Howard C Becker
- Charleston Alcohol Research Center, Department of Psychiatry and Behavioral Science, Medical University of South Carolina, Charleston, SC, United States; Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC 29425-0742, United States
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5
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Effects of ceftriaxone on ethanol drinking and GLT-1 expression in ethanol dependence and relapse drinking. Alcohol 2021; 92:1-9. [PMID: 33465464 DOI: 10.1016/j.alcohol.2021.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/11/2020] [Accepted: 01/12/2021] [Indexed: 12/26/2022]
Abstract
Repeated cycles of chronic intermittent ethanol (CIE) exposure increase voluntary consumption of alcohol (ethanol) in mice. Previous reports from our laboratory show that CIE increases extracellular glutamate in the nucleus accumbens (NAc) and that manipulating accumbal glutamate concentrations will alter ethanol drinking, indicating that glutamate homeostasis plays a crucial role in ethanol drinking in this model. A number of studies have shown that ceftriaxone increases GLT-1 expression, the major glutamate transporter, and that treatment with this antibiotic reduces ethanol drinking. The present studies examined the effects of ceftriaxone on ethanol drinking and GLT-1 in a mouse model of ethanol dependence and relapse drinking. The results show that ceftriaxone did not influence drinking at any dose in either ethanol-dependent or non-dependent mice. Further, ceftriaxone did not increase GLT-1 expression in the accumbens core or shell, with the exception of the ethanol-dependent mice receiving the highest dose of ceftriaxone. Interestingly, ethanol-dependent mice treated with only vehicle displayed reduced expression of GLT-1 in the accumbens shell and of the presynaptic mGlu2 receptor in the accumbens core. The reduced expression of the major glutamate transporter (GLT-1), as well as a receptor that regulates glutamate release (mGlu2), may help explain, at least in part, increased glutamatergic transmission in this model of ethanol dependence and relapse drinking.
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Alcohol. Alcohol 2021. [DOI: 10.1016/b978-0-12-816793-9.00001-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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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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Avchalumov Y, Piña-Crespo JC, Woodward JJ, Mandyam CD. Acute Ethanol Exposure Enhances Synaptic Plasticity in the Dorsal Striatum in Adult Male and Female Rats. Brain Plast 2020; 6:113-122. [PMID: 33680850 PMCID: PMC7903017 DOI: 10.3233/bpl-190097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Background: Acute (ex vivo) and chronic (in vivo) alcohol exposure induces neuroplastic changes in the dorsal striatum, a
critical region implicated in instrumental learning. Objective: Sex differences are evident in alcohol reward and reinforcement, with
female rats consuming higher amount of alcohol in operant paradigms compared to male rats. However, sex differences in
the neuroplastic changes produced by acute alcohol in the dorsal striatum have been unexplored. Methods: Using electrophysiological
recordings from dorsal striatal slices obtained from adult male and female rats, we investigated the effects of ex vivo ethanol
exposure on synaptic transmission and synaptic plasticity. Ethanol (44 mM) enhanced basal synaptic transmission in both
sexes. Ethanol also enhanced long-term potentiation in both sexes. Other measures of synaptic plasticity including paired-pulse
ratio were unaltered by ethanol in both sexes. Results: The results suggest that alterations in synaptic plasticity induced by acute
ethanol, at a concentration associated with intoxication, could play an important role in alcohol-induced experience-dependent
modification of corticostriatal circuits underlying the learning of goal-directed instrumental actions and formation of habits
mediating alcohol seeking and taking. Conclusions: Taken together, understanding the mechanism(s) underlying alcohol induced changes
in corticostriatal function may lead to the development of more effective therapeutic agents to reduce habitual drinking and
seeking associated with alcohol use disorders.
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Affiliation(s)
| | - Juan C Piña-Crespo
- Neuroscience Initiative, Sanford Burnham Prebys Medical Research Institute, La Jolla, CA, USA
| | - John J Woodward
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - 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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9
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Alhaddad H, Alasmari F, Alhamadani B, Wong W, Bell RL, Sari Y. Effects of chronic ethanol consumption on the expression of GLT-1 and neuroplasticity-related proteins in the nucleus accumbens of alcohol-preferring rats. Brain Res Bull 2020; 165:272-280. [PMID: 33075417 DOI: 10.1016/j.brainresbull.2020.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/25/2020] [Accepted: 10/09/2020] [Indexed: 11/26/2022]
Abstract
Chronic ethanol exposure induces impairments in CNS excitatory and inhibitory activity. These impairments are associated with glutamatergic dysfunction, including altered neuroplasticity. This study examined the effects of 6-week ethanol (15% and 30% v/v) consumption, by male alcohol-preferring P rats, on protein expression associated with neuroplasticity and glutamate transporter-1 (GLT-1) function. The latter regulates intra- and extra-synaptic glutamate levels. We focused on the shell and core subregions of the nucleus accumbens (Acb); i.e., shell (AcbSh) and core (AcbCo), for these measures. Chronic ethanol exposure increased the expression of BDNF, Arc and phosphorylated (p)-post-synaptic density protein-95 (p-PSD-95) in the AcbSh of P rats. Moreover, the ratio of phospho-neuronal nitric oxide synthase (p-nNOS) to total nNOS was also increased in the AcbSh. These changes in BDNF, Arc and p-nNOS/nNOS ratio were not observed in the AcbCo. Furthermore, chronic ethanol consumption reduced GLT-1 expression in the AcbSh. Alternatively, treatment with ceftriaxone (CEF), a known GLT-1 upregulator, abolished the effect of chronic ethanol consumption on BDNF expression in the AcbSh. Overall, the present findings confirm that chronic ethanol consumption modulates activity-associated synaptic proteins, including BDNF, Arc and nNOS in a subregion-specific (i.e., in the AcbSh but not AcbCo) manner. Thus, alterations in mesocorticolimbic glutamatergic homeostasis and neuroplasticity are possible functional targets for the treatment of alcohol use disorders.
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Affiliation(s)
- Hasan Alhaddad
- University of Toledo, College of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology and Experimental Therapeutics, Toledo, OH 43614, USA
| | - Fawaz Alasmari
- University of Toledo, College of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology and Experimental Therapeutics, Toledo, OH 43614, USA; Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Balsam Alhamadani
- University of Toledo, College of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology and Experimental Therapeutics, Toledo, OH 43614, USA
| | - Woonyen Wong
- University of Toledo, College of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology and Experimental Therapeutics, Toledo, OH 43614, USA
| | - Richard L Bell
- Department of Psychiatry and Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Youssef Sari
- University of Toledo, College of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology and Experimental Therapeutics, Toledo, OH 43614, USA.
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Cofresí RU, Bartholow BD, Piasecki TM. Evidence for incentive salience sensitization as a pathway to alcohol use disorder. Neurosci Biobehav Rev 2019; 107:897-926. [PMID: 31672617 PMCID: PMC6878895 DOI: 10.1016/j.neubiorev.2019.10.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 12/12/2022]
Abstract
The incentive salience sensitization (ISS) theory of addiction holds that addictive behavior stems from the ability of drugs to progressively sensitize the brain circuitry that mediates attribution of incentive salience (IS) to reward-predictive cues and its behavioral manifestations. In this article, we establish the plausibility of ISS as an etiological pathway to alcohol use disorder (AUD). We provide a comprehensive and critical review of evidence for: (1) the ability of alcohol to sensitize the brain circuitry of IS attribution and expression; and (2) attribution of IS to alcohol-predictive cues and its sensitization in humans and non-human animals. We point out gaps in the literature and how these might be addressed. We also highlight how individuals with different alcohol subjective response phenotypes may differ in susceptibility to ISS as a pathway to AUD. Finally, we discuss important implications of this neuropsychological mechanism in AUD for psychological and pharmacological interventions attempting to attenuate alcohol craving and cue reactivity.
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Affiliation(s)
- Roberto U Cofresí
- University of Missouri, Department of Psychological Sciences, Columbia, MO 65211, United States.
| | - Bruce D Bartholow
- University of Missouri, Department of Psychological Sciences, Columbia, MO 65211, United States
| | - Thomas M Piasecki
- University of Missouri, Department of Psychological Sciences, Columbia, MO 65211, United States
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11
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Gallegos S, Muñoz B, Araya A, Aguayo LG. High ethanol sensitive glycine receptors regulate firing in D1 medium spiny neurons in the nucleus accumbens. Neuropharmacology 2019; 160:107773. [PMID: 31521620 DOI: 10.1016/j.neuropharm.2019.107773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 09/03/2019] [Accepted: 09/06/2019] [Indexed: 12/21/2022]
Abstract
Inhibitory glycine receptors (GlyRs) are widely expressed in spinal cord and brain stem. They are also expressed in the nucleus Accumbens (nAc) where they have been implicated in the release of dopamine from the ventral tegmental area to the nAc in the presence of ethanol. One of the major types of neurons in the nAc are the Dopamine 1 receptor-expressing (D1+) medium spiny neurons (MSNs) that are activated when addictive drugs, like ethanol, are administrated. Thus, D1(+) MSNs are a relevant target for the study of ethanol effects. Here, using electrophysiological recordings, we report that GlyRs in D1(+) MSNs are highly sensitive to ethanol, with potentiation starting at 5 mM (26 ± 5%). Single channel recordings in D1(+) MSNs showed that 10 mM ethanol increased the open probability of the channel (0.22 ± 0.05 versus 0.66 ± 0.16), but did not affect channel conductance (~40 pS). A glycinergic mediated tonic current in D1(+) MSNs was potentiated by 10 and 50 mM ethanol causing a reduction in the excitability of these cells. A 34 ± 7% reduction in action potential firing was observed in these neurons in the presence of 50 mM ethanol. Interestingly, no effects of ethanol were detected in the presence of strychnine or in D1(-) MSNs in the nAc. These results indicate that GlyRs present in D1(+) MSNs are sensitive to low concentrations of ethanol, and that potentiation of this inhibitory current regulates the activation of nAc, acting as a homeostatic signal that would prevent over-activation of the reward system when drugs like ethanol are consumed.
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Affiliation(s)
- S Gallegos
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepcion, Concepcion, Chile
| | - B Muñoz
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepcion, Concepcion, Chile
| | - A Araya
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepcion, Concepcion, Chile
| | - L G Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepcion, Concepcion, Chile.
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12
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Ethanol Experience Enhances Glutamatergic Ventral Hippocampal Inputs to D1 Receptor-Expressing Medium Spiny Neurons in the Nucleus Accumbens Shell. J Neurosci 2019; 39:2459-2469. [PMID: 30692226 DOI: 10.1523/jneurosci.3051-18.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/11/2019] [Accepted: 01/15/2019] [Indexed: 02/05/2023] Open
Abstract
A growing number of studies implicate alterations in glutamatergic signaling within the reward circuitry of the brain during alcohol abuse and dependence. A key integrator of glutamatergic signaling in the reward circuit is the nucleus accumbens, more specifically, the dopamine D1 receptor-expressing medium spiny neurons (D1-MSNs) within this region, which have been implicated in the formation of dependence to many drugs of abuse including alcohol. D1-MSNs receive glutamatergic input from several brain regions; however, it is not currently known how individual inputs onto D1-MSNs are altered by alcohol experience. Here, we investigate input-specific adaptations in glutamatergic transmission in response to varying levels of alcohol experience. Virally mediated expression of Channelrhodopsin in ventral hippocampal (vHipp) glutamate neurons of male mice allowed for selective activation of vHipp to D1-MSN synapses. Therefore, we were able to compare synaptic adaptations in response to low and high alcohol experience in vitro and in vivo Alcohol experience enhanced glutamatergic activity and abolished LTD at vHipp to D1-MSN synapses. Following chronic alcohol experience, GluA2-lacking AMPARs, which are Ca permeable, were inserted into vHipp to D1-MSN synapses. These findings support the reversal of alcohol-induced insertion of Ca-permeable AMPARs and the enhancement of glutamatergic activity at vHipp to D1-MSNs as potential targets for intervention during early exposure to alcohol.SIGNIFICANCE STATEMENT Given the roles of the nucleus accumbens (NAc) in integrating cortical and allocortical information and in reward learning, it is vital to understand how inputs to this region are altered by drugs of abuse such as alcohol. The strength of excitatory inputs from the ventral hippocampus (vHipp) to the NAc has been positively associated with reward-related behaviors, but it is unclear whether or how ethanol affects these inputs. Here we show that vHipp-NAc synapses indeed are altered by ethanol exposure, with vHipp glutamatergic input to the NAc being enhanced following chronic ethanol experience. This work provides insight into ethanol-induced alterations of vHipp-NAc synapses and suggests that, similarly to drugs such as cocaine, the strengthening of these synapses promotes reward behavior.
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13
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Shillinglaw JE, Morrisett RA, Mangieri RA. Ethanol Modulates Glutamatergic Transmission and NMDAR-Mediated Synaptic Plasticity in the Agranular Insular Cortex. Front Pharmacol 2018; 9:1458. [PMID: 30618752 PMCID: PMC6305468 DOI: 10.3389/fphar.2018.01458] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/29/2018] [Indexed: 12/17/2022] Open
Abstract
The agranular insular cortex (AIC) has recently been investigated by the alcohol field because of its connectivity to and modulatory control over limbic and brainstem regions implicated in alcohol use disorder (AUD), and because it has shown involvement in animal models of alcohol drinking. Despite evidence of AIC involvement in AUD, there has not yet been an examination of whether ethanol modulates glutamatergic and γ-amino-butyric acid (GABA)ergic synaptic transmission and plasticity in the AIC. Characterizing how the synaptic transmission and plasticity states of AIC cortical processing neurons are modulated by acute ethanol will likely reveal the molecular targets by which chronic ethanol alters AIC function as alcohol drinking transitions from controlled to problematic. Therefore, we collected brain slices from ethanol-naïve adult male mice, obtained whole-cell recording configuration in layer 2/3 AIC pyramidal neurons, and bath-applied ethanol at pharmacologically relevant concentrations during electrophysiological assays of glutamatergic and GABAergic synaptic transmission and plasticity. We found that ethanol inhibited electrically evoked N-methyl-D-aspartate receptor (NMDAR)-mediated excitatory post-synaptic currents (EPSCs) in a concentration-related fashion, and had little effect on evoked α-amino-3-hydrox-5-methylisoxazole-4-propionic acid-type receptor (AMPAR)-mediated EPSCs. Ethanol had no effect on spontaneous excitatory post-synaptic currents (sEPSCs) or inhibitory GABAAR-mediated post-synaptic currents (sIPSCs). We found that synaptic conditioning (low-frequency stimulation for 15 min at 1 Hz) induced a form of long-term depression (LTD) of evoked AMPAR-mediated EPSCs. The ability to induce LTD was inhibited by a non-selective NMDAR antagonist (DL-2-amino-5-phosphonovaleric acid), and also by acute, intoxicating concentrations of ethanol. Taken together these data suggest that the glutamate, but not GABA system in the AIC is uniquely sensitive to ethanol, and that in particular NMDAR-mediated processes in the AIC may be disrupted by pharmacologically relevant concentrations of ethanol.
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Affiliation(s)
- Joel E Shillinglaw
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, United States
| | - Richard A Morrisett
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, United States
| | - Regina A Mangieri
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, United States
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Role of glutamatergic system and mesocorticolimbic circuits in alcohol dependence. Prog Neurobiol 2018; 171:32-49. [PMID: 30316901 DOI: 10.1016/j.pneurobio.2018.10.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/08/2018] [Accepted: 10/08/2018] [Indexed: 02/06/2023]
Abstract
Emerging evidence demonstrates that alcohol dependence is associated with dysregulation of several neurotransmitters. Alterations in dopamine, glutamate and gamma-aminobutyric acid release are linked to chronic alcohol exposure. The effects of alcohol on the glutamatergic system in the mesocorticolimbic areas have been investigated extensively. Several studies have demonstrated dysregulation in the glutamatergic systems in animal models exposed to alcohol. Alcohol exposure can lead to an increase in extracellular glutamate concentrations in mesocorticolimbic brain regions. In addition, alcohol exposure affects the expression and functions of several glutamate receptors and glutamate transporters in these brain regions. In this review, we discussed the effects of alcohol exposure on glutamate receptors, glutamate transporters and glutamate homeostasis in each area of the mesocorticolimbic system. In addition, we discussed the genetic aspect of alcohol associated with glutamate and reward circuitry. We also discussed the potential therapeutic role of glutamate receptors and glutamate transporters in each brain region for the treatment of alcohol dependence. Finally, we provided some limitations on targeting the glutamatergic system for potential therapeutic options for the treatment alcohol use disorders.
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15
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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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16
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Ferguson LB, Zhang L, Kircher D, Wang S, Mayfield RD, Crabbe JC, Morrisett RA, Harris RA, Ponomarev I. Dissecting Brain Networks Underlying Alcohol Binge Drinking Using a Systems Genomics Approach. Mol Neurobiol 2018; 56:2791-2810. [PMID: 30062672 PMCID: PMC6459809 DOI: 10.1007/s12035-018-1252-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/17/2018] [Indexed: 12/22/2022]
Abstract
Alcohol use disorder (AUD) is a complex psychiatric disorder with strong genetic and environmental risk factors. We studied the molecular perturbations underlying risky drinking behavior by measuring transcriptome changes across the neurocircuitry of addiction in a genetic mouse model of binge drinking. Sixteen generations of selective breeding for high blood alcohol levels after a binge drinking session produced global changes in brain gene expression in alcohol-naïve High Drinking in the Dark (HDID-1) mice. Using gene expression profiles to generate circuit-level hypotheses, we developed a systems approach that integrated regulation of gene coexpression networks across multiple brain regions, neuron-specific transcriptional signatures, and knowledgebase analytics. Whole-cell, voltage-clamp recordings from nucleus accumbens shell neurons projecting to the ventral tegmental area showed differential ethanol-induced plasticity in HDID-1 and control mice and provided support for one of the hypotheses. There were similarities in gene networks between HDID-1 mouse brains and postmortem brains of human alcoholics, suggesting that some gene expression patterns associated with high alcohol consumption are conserved across species. This study demonstrated the value of gene networks for data integration across biological modalities and species to study mechanisms of disease.
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Affiliation(s)
- Laura B Ferguson
- The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA.,The Institute for Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Lingling Zhang
- The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA
| | - Daniel Kircher
- The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA
| | - Shi Wang
- The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA
| | - R Dayne Mayfield
- The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA
| | - John C Crabbe
- Portland Alcohol Research Center, VA Portland Health Care System, Portland, OR, USA.,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - Richard A Morrisett
- The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA
| | - R Adron Harris
- The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA
| | - Igor Ponomarev
- The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA.
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17
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Renteria R, Buske TR, Morrisett RA. Long-term subregion-specific encoding of enhanced ethanol intake by D1DR medium spiny neurons of the nucleus accumbens. Addict Biol 2018; 23:689-698. [PMID: 28656742 DOI: 10.1111/adb.12526] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/10/2017] [Accepted: 05/03/2017] [Indexed: 12/22/2022]
Abstract
The nucleus accumbens (NAc) is a critical component of the mesocorticolimbic system and is involved in mediating the motivational and reinforcing aspects of ethanol consumption. Chronic intermittent ethanol (CIE) exposure is a reliable model to induce ethanol dependence and increase volitional ethanol consumption in mice. Following a CIE-induced escalation of ethanol consumption, NMDAR (N-methyl-D-aspartate receptor)-dependent long-term depression in D1 dopamine receptor expressing medium spiny neurons of the NAc shell was markedly altered with no changes in plasticity in D1 dopamine receptor medium spiny neurons from the NAc core. This disruption of plasticity persisted for up to 2 weeks after cessation of ethanol access. To determine if changes in AMPA receptor (AMPAR) composition contribute to this ethanol-induced neuroadaptation, we monitored the rectification of AMPAR excitatory postsynaptic currents (EPSCs). We observed a marked decrease in the rectification index in the NAc shell, suggesting the presence of GluA2-lacking AMPARs. There was no change in the amplitude of spontaneous EPSCs (sEPSCs), but there was a transient increase in sEPSC frequency in the NAc shell. Using the paired pulse ratio, we detected a similar transient increase in the probability of neurotransmitter release. With no change in sEPSC amplitude, the change in the rectification index suggests that GluA2-containing AMPARs are removed and replaced with GluA2-lacking AMPARs in the NAc shell. This CIE-induced alteration in AMPAR subunit composition may contribute to the loss of NMDAR-dependent long-term depression in the NAc shell and therefore may constitute a critical neuroadaptive response underlying the escalation of ethanol intake in the CIE model.
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Affiliation(s)
- Rafael Renteria
- Institute for Neuroscience; The University of Texas at Austin; Austin Texas USA
| | - Tavanna R. Buske
- The College of Pharmacy; The University of Texas at Austin; Austin Texas USA
| | - Richard A. Morrisett
- Institute for Neuroscience; The University of Texas at Austin; Austin Texas USA
- The College of Pharmacy; The University of Texas at Austin; Austin Texas USA
- Waggoner Center for Alcohol and Addiction Research; The University of Texas at Austin; Austin Texas USA
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18
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Abstract
Ionotropic glutamate receptors (AMPA, NMDA, and kainate receptors) play a central role in excitatory glutamatergic signaling throughout the brain. As a result, functional changes, especially long-lasting forms of plasticity, have the potential to profoundly alter neuronal function and the expression of adaptive and pathological behaviors. Thus, alcohol-related adaptations in ionotropic glutamate receptors are of great interest, since they could promote excessive alcohol consumption, even after long-term abstinence. Alcohol- and drug-related adaptations in NMDARs have been recently reviewed, while less is known about kainate receptor adaptations. Thus, we focus here on functional changes in AMPARs, tetramers composed of GluA1-4 subunits. Long-lasting increases or decreases in AMPAR function, the so-called long-term potentiation or depression, have widely been considered to contribute to normal and pathological memory states. In addition, a great deal has been learned about the acute regulation of AMPARs by signaling pathways, scaffolding and auxiliary proteins, intracellular trafficking, and other mechanisms. One important common adaptation is a shift in AMPAR subunit composition from GluA2-containing, calcium-impermeable AMPARs (CIARs) to GluA2-lacking, calcium-permeable AMPARs (CPARs), which is observed under a broad range of conditions including intoxicant exposure or intake, stress, novelty, food deprivation, and ischemia. This shift has the potential to facilitate AMPAR currents, since CPARs have much greater single-channel currents than CIARs, as well as faster AMPAR activation kinetics (although with faster inactivation) and calcium-related activity. Many tools have been developed to interrogate particular aspects of AMPAR signaling, including compounds that selectively inhibit CPARs, raising exciting translational possibilities. In addition, recent studies have used transgenic animals and/or optogenetics to identify AMPAR adaptations in particular cell types and glutamatergic projections, which will provide critical information about the specific circuits that CPARs act within. Also, less is known about the specific nature of alcohol-related AMPAR adaptations, and thus we use other examples that illustrate more fully how particular AMPAR changes might influence intoxicant-related behavior. Thus, by identifying alcohol-related AMPAR adaptations, the specific molecular events that underlie them, and the cells and projections in which they occur, we hope to better inform the development of new therapeutic interventions for addiction.
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Cuzon Carlson VC. GABA and Glutamate Synaptic Coadaptations to Chronic Ethanol in the Striatum. Handb Exp Pharmacol 2018; 248:79-112. [PMID: 29460153 DOI: 10.1007/164_2018_98] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Alcohol (ethanol) is a widely used and abused drug with approximately 90% of adults over the age of 18 consuming alcohol at some point in their lifetime. Alcohol exerts its actions through multiple neurotransmitter systems within the brain, most notably the GABAergic and glutamatergic systems. Alcohol's actions on GABAergic and glutamatergic neurotransmission have been suggested to underlie the acute behavioral effects of ethanol. The striatum is the primary input nucleus of the basal ganglia that plays a role in motor and reward systems. The effect of ethanol on GABAergic and glutamatergic neurotransmission within striatal circuitry has been thought to underlie ethanol taking, seeking, withdrawal and relapse. This chapter reviews the effects of ethanol on GABAergic and glutamatergic transmission, highlighting the dynamic changes in striatal circuitry from acute to chronic exposure and withdrawal.
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20
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Marszalek-Grabska M, Gibula-Bruzda E, Bodzon-Kulakowska A, Suder P, Gawel K, Talarek S, Listos J, Kedzierska E, Danysz W, Kotlinska JH. ADX-47273, a mGlu5 receptor positive allosteric modulator, attenuates deficits in cognitive flexibility induced by withdrawal from 'binge-like' ethanol exposure in rats. Behav Brain Res 2017; 338:9-16. [PMID: 29030082 DOI: 10.1016/j.bbr.2017.10.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 10/01/2017] [Accepted: 10/09/2017] [Indexed: 11/15/2022]
Abstract
Repeated exposure to and withdrawal from ethanol induces deficits in spatial reversal learning. Data indicate that metabotropic glutamate 5 (mGlu5) receptors are implicated in synaptic plasticity and learning and memory. These receptors functionally interact with N-methyl-d-aspartate (NMDA) receptors, and activation of one type results in the activation of the other. We examined whether (S)-(4-fluorophenyl)(3-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-piperidin-1-yl (ADX-47273), a positive allosteric modulator (PAM) of mGlu5 receptor, attenuates deficits in reversal learning induced by withdrawal (11-13days) from 'binge-like' ethanol input (5.0g/kg, i.g. for 5days) in the Barnes maze (a spatial learning) task in rats. We additionally examined the effects of ADX-47273 on the expression of the NMDA receptors subunit, GluN2B, in the hippocampus and prefrontal cortex, on the 13th day of ethanol withdrawal. Herein, withdrawal from repeated ethanol administration impaired reversal learning, but not the probe trial. Moreover, ADX-47273 (30mg/kg, i.p.) given prior to the first reversal learning trial for 3days in the Barnes maze, significantly enhanced performance in the ethanol-treated group. The 13th day of ethanol abstinence decreased the expression of the GluN2B subunit in the selected brain regions, but ADX-47273 administration increased it. In conclusion, positive allosteric modulation of mGlu5 receptors recovered spatial reversal learning impairment induced by withdrawal from 'binge-like' ethanol exposure. Such effect seems to be correlated with the mGlu5 receptors mediated potentiation of GluN2B-NMDA receptor mediated responses in the hippocampus and prefrontal cortex. Thus, our results emphasize the role of mGlu5 receptor PAM in the adaptive learning impaired by ethanol exposure.
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Affiliation(s)
| | - Ewa Gibula-Bruzda
- Department of Pharmacology and Pharmacodynamics, Medical University, Lublin, Poland
| | - Anna Bodzon-Kulakowska
- Department of Biochemistry and Neurobiology, AGH University of Science and Technology, Krakow, Poland
| | - Piotr Suder
- Department of Biochemistry and Neurobiology, AGH University of Science and Technology, Krakow, Poland
| | - Kinga Gawel
- Department of Pharmacology and Pharmacodynamics, Medical University, Lublin, Poland; Department of Experimental and Clinical Pharmacology, Medical University, Lublin, Poland
| | - Sylwia Talarek
- Department of Pharmacology and Pharmacodynamics, Medical University, Lublin, Poland
| | - Joanna Listos
- Department of Pharmacology and Pharmacodynamics, Medical University, Lublin, Poland
| | - Ewa Kedzierska
- Department of Pharmacology and Pharmacodynamics, Medical University, Lublin, Poland
| | | | - Jolanta H Kotlinska
- Department of Pharmacology and Pharmacodynamics, Medical University, Lublin, Poland.
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Ostroumov A, Dani JA. Convergent Neuronal Plasticity and Metaplasticity Mechanisms of Stress, Nicotine, and Alcohol. Annu Rev Pharmacol Toxicol 2017; 58:547-566. [PMID: 28977763 DOI: 10.1146/annurev-pharmtox-010617-052735] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Stress and tobacco smoking are risk factors for alcoholism, but the underlying neural mechanisms are not well understood. Although stress, nicotine, and alcohol have broad, individual effects in the brain, some of their actions converge onto the same mechanisms and circuits. Stress and nicotine augment alcohol-related behaviors, in part via modulation of alcohol-evoked neuronal plasticity and metaplasticity mechanisms. Stress modulates alcohol-evoked plasticity via the release of signaling molecules that influence synaptic transmission. Nicotine also activates some of the same signaling molecules, cells, and circuits, producing a convergence of both stress and nicotine onto common plasticity mechanisms that influence alcohol self-administration. We describe several forms of alcohol-induced plasticity, including classic Hebbian plasticity at glutamatergic synapses, and we highlight less appreciated forms, such as non-Hebbian and GABAergic synaptic plasticity. Risk factors such as stress and nicotine initiate lasting neural changes that modify subsequent alcohol-induced synaptic plasticity and increase the vulnerability to alcohol addiction.
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Affiliation(s)
- Alexey Ostroumov
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, Philadelphia, Pennsylvania 19104, USA; ,
| | - John A Dani
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, Philadelphia, Pennsylvania 19104, USA; ,
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22
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Mangieri RA, Maier EY, Buske TR, Lasek AW, Morrisett RA. Anaplastic Lymphoma Kinase Is a Regulator of Alcohol Consumption and Excitatory Synaptic Plasticity in the Nucleus Accumbens Shell. Front Pharmacol 2017; 8:533. [PMID: 28860990 PMCID: PMC5559467 DOI: 10.3389/fphar.2017.00533] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 07/31/2017] [Indexed: 01/12/2023] Open
Abstract
Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase recently implicated in biochemical, physiological, and behavioral responses to ethanol. Thus, manipulation of ALK signaling may represent a novel approach to treating alcohol use disorder (AUD). Ethanol induces adaptations in glutamatergic synapses onto nucleus accumbens shell (NAcSh) medium spiny neurons (MSNs), and putative targets for treating AUD may be validated for further development by assessing how their manipulation modulates accumbal glutamatergic synaptic transmission and plasticity. Here, we report that Alk knockout (AlkKO) mice consumed greater doses of ethanol, relative to wild-type (AlkWT) mice, in an operant self-administration model. Using ex vivo electrophysiology to examine excitatory synaptic transmission and plasticity at NAcSh MSNs that express dopamine D1 receptors (D1MSNs), we found that the amplitude of spontaneous excitatory post-synaptic currents (EPSCs) in NAcSh D1MSNs was elevated in AlkKO mice and in the presence of an ALK inhibitor, TAE684. Furthermore, when ALK was absent or inhibited, glutamatergic synaptic plasticity – long-term depression of evoked EPSCs – in D1MSNs was attenuated. Thus, loss of ALK activity in mice is associated with elevated ethanol consumption and enhanced excitatory transmission in NAcSh D1MSNs. These findings add to the mounting evidence of a relationship between excitatory synaptic transmission onto NAcSh D1MSNs and ethanol consumption, point toward ALK as one important molecular mediator of this interaction, and further validate ALK as a target for therapeutic intervention in the treatment of AUD.
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Affiliation(s)
- Regina A Mangieri
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, AustinTX, United States
| | - Esther Y Maier
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, AustinTX, United States
| | - Tavanna R Buske
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, AustinTX, United States
| | - Amy W Lasek
- Department of Psychiatry, University of Illinois at Chicago, ChicagoIL, United States
| | - Richard A Morrisett
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, AustinTX, United States
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Camacho A, Montalvo-Martinez L, Cardenas-Perez RE, Fuentes-Mera L, Garza-Ocañas L. Obesogenic diet intake during pregnancy programs aberrant synaptic plasticity and addiction-like behavior to a palatable food in offspring. Behav Brain Res 2017; 330:46-55. [DOI: 10.1016/j.bbr.2017.05.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 04/30/2017] [Accepted: 05/04/2017] [Indexed: 02/07/2023]
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24
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Förstera B, Muñoz B, Lobo MK, Chandra R, Lovinger DM, Aguayo LG. Presence of ethanol-sensitive glycine receptors in medium spiny neurons in the mouse nucleus accumbens. J Physiol 2017; 595:5285-5300. [PMID: 28524260 DOI: 10.1113/jp273767] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 05/05/2017] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS The nucleus accumbens (nAc) is involved in addiction-related behaviour caused by several drugs of abuse, including alcohol. Glycine receptors (GlyRs) are potentiated by ethanol and they have been implicated in the regulation of accumbal dopamine levels. We investigated the presence of GlyR subunits in nAc and their modulation by ethanol in medium spiny neurons (MSNs) of the mouse nAc. We found that the GlyR α1 subunit is preferentially expressed in nAc and is potentiated by ethanol. Our study shows that GlyR α1 in nAc is a new target for development of novel pharmacological tools for behavioural intervention in drug abuse. ABSTRACT Alcohol abuse causes major social, economic and health-related problems worldwide. Alcohol, like other drugs of abuse, increases levels of dopamine in the nucleus accumbens (nAc), facilitating behavioural reinforcement and substance abuse. Previous studies suggested that glycine receptors (GlyRs) are involved in the regulation of accumbal dopamine levels. Here, we investigated the presence of GlyRs in accumbal dopamine receptor medium spiny neurons (MSNs) of C57BL/6J mice, analysing mRNA expression levels and immunoreactivity of GlyR subunits, as well as ethanol sensitivity. We found that GlyR α1 subunits are expressed at higher levels than α2, α3 and β in the mouse nAc and were located preferentially in dopamine receptor 1 (DRD1)-positive MSNs. Interestingly, the glycine-evoked currents in dissociated DRD1-positive MSNs were potentiated by ethanol. Also, the potentiation of the GlyR-mediated tonic current by ethanol suggests that they modulate the excitability of DRD1-positive MSNs in nAc. This study should contribute to understanding the role of GlyR α1 in the reward system and might help to develop novel pharmacological therapies to treat alcoholism and other addiction-related and compulsive behaviours.
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Affiliation(s)
- B Förstera
- Department of Physiology, University of Concepcion, Concepcion, Chile
| | - B Muñoz
- Department of Physiology, University of Concepcion, Concepcion, Chile
| | - M K Lobo
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF II Rm 251, Baltimore, MD, 21201, USA
| | - R Chandra
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF II Rm 251, Baltimore, MD, 21201, USA
| | - D M Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - L G Aguayo
- Department of Physiology, University of Concepcion, Concepcion, Chile
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Dopamine Receptors Differentially Control Binge Alcohol Drinking-Mediated Synaptic Plasticity of the Core Nucleus Accumbens Direct and Indirect Pathways. J Neurosci 2017; 37:5463-5474. [PMID: 28473645 DOI: 10.1523/jneurosci.3845-16.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 04/24/2017] [Accepted: 04/25/2017] [Indexed: 12/18/2022] Open
Abstract
Binge alcohol drinking, a behavior characterized by rapid repeated alcohol intake, is most prevalent in young adults and is a risk factor for excessive alcohol consumption and alcohol dependence. Although the alteration of synaptic plasticity is thought to contribute to this behavior, there is currently little evidence that this is the case. We used drinking in the dark (DID) as a model of binge alcohol drinking to assess its effects on spike timing-dependent plasticity (STDP) in medium spiny neurons (MSNs) of the core nucleus accumbens (NAc) by combining patch-clamp recordings with calcium imaging and optogenetics. After 2 weeks of daily alcohol binges, synaptic plasticity was profoundly altered. STDP in MSNs expressing dopamine D1 receptors shifted from spike-timing-dependent long-term depression (tLTD), the predominant form of plasticity in naive male mice, to spike-timing-dependent long-term potentiation (tLTP) in DID mice, an effect that was totally reversed in the presence of 4 μm SCH23390, a dopamine D1 receptor antagonist. In MSNs presumably expressing dopamine D2 receptors, tLTP, the main form of plasticity in naive mice, was inhibited in DID mice. Interestingly, 1 μm sulpiride, a D2 receptor antagonist, restored tLTP. Although we observed no alterations of AMPA and NMDA receptor properties, we found that the AMPA/NMDA ratio increased at cortical and amygdaloid inputs but not at hippocampal inputs. Also, DID effects on STDP were accompanied by lower dendritic calcium transients. These data suggest that the role of dopamine in mediating the effects of binge alcohol drinking on synaptic plasticity of NAc MSNs differs markedly whether these neurons belong to the direct or indirect pathways.SIGNIFICANCE STATEMENT We examined the relationship between binge alcohol drinking and spike timing-dependent plasticity in nucleus accumbens (NAc) neurons. We found that repeated drinking bouts modulate differently synaptic plasticity in medium spiny neurons of the accumbens direct and indirect pathways. While timing-dependent long-term depression switches to long-term potentiation (LTP) in the former, timing-dependent LTP is inhibited in the latter. These effects are not accompanied by changes in AMPA and NMDA receptor properties at cortical, amygdaloid, and hippocampal synapses. Interestingly, dopamine D1 and D2 receptor antagonists have opposite effects on plasticity. Our data show that whether core NAc medium spiny neurons belong to the direct or indirect pathways determines the form of spike timing-dependent plasticity (STDP), the manner by which STDP responds to binge alcohol drinking, and its sensitivity to dopamine receptor antagonists.
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Scofield MD, Heinsbroek JA, Gipson CD, Kupchik YM, Spencer S, Smith ACW, Roberts-Wolfe D, Kalivas PW. The Nucleus Accumbens: Mechanisms of Addiction across Drug Classes Reflect the Importance of Glutamate Homeostasis. Pharmacol Rev 2017; 68:816-71. [PMID: 27363441 DOI: 10.1124/pr.116.012484] [Citation(s) in RCA: 358] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The nucleus accumbens is a major input structure of the basal ganglia and integrates information from cortical and limbic structures to mediate goal-directed behaviors. Chronic exposure to several classes of drugs of abuse disrupts plasticity in this region, allowing drug-associated cues to engender a pathologic motivation for drug seeking. A number of alterations in glutamatergic transmission occur within the nucleus accumbens after withdrawal from chronic drug exposure. These drug-induced neuroadaptations serve as the molecular basis for relapse vulnerability. In this review, we focus on the role that glutamate signal transduction in the nucleus accumbens plays in addiction-related behaviors. First, we explore the nucleus accumbens, including the cell types and neuronal populations present as well as afferent and efferent connections. Next we discuss rodent models of addiction and assess the viability of these models for testing candidate pharmacotherapies for the prevention of relapse. Then we provide a review of the literature describing how synaptic plasticity in the accumbens is altered after exposure to drugs of abuse and withdrawal and also how pharmacological manipulation of glutamate systems in the accumbens can inhibit drug seeking in the laboratory setting. Finally, we examine results from clinical trials in which pharmacotherapies designed to manipulate glutamate systems have been effective in treating relapse in human patients. Further elucidation of how drugs of abuse alter glutamatergic plasticity within the accumbens will be necessary for the development of new therapeutics for the treatment of addiction across all classes of addictive substances.
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Affiliation(s)
- M D Scofield
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina (M.D.S., J.A.H., S.S., D.R.-W., P.W.K.); Department of Psychology, Arizona State University, Tempe, Arizona (C.D.G.); Department of Neuroscience, Hebrew University, Jerusalem, Israel (Y.M.K.); and Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York (A.C.W.S.)
| | - J A Heinsbroek
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina (M.D.S., J.A.H., S.S., D.R.-W., P.W.K.); Department of Psychology, Arizona State University, Tempe, Arizona (C.D.G.); Department of Neuroscience, Hebrew University, Jerusalem, Israel (Y.M.K.); and Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York (A.C.W.S.)
| | - C D Gipson
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina (M.D.S., J.A.H., S.S., D.R.-W., P.W.K.); Department of Psychology, Arizona State University, Tempe, Arizona (C.D.G.); Department of Neuroscience, Hebrew University, Jerusalem, Israel (Y.M.K.); and Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York (A.C.W.S.)
| | - Y M Kupchik
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina (M.D.S., J.A.H., S.S., D.R.-W., P.W.K.); Department of Psychology, Arizona State University, Tempe, Arizona (C.D.G.); Department of Neuroscience, Hebrew University, Jerusalem, Israel (Y.M.K.); and Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York (A.C.W.S.)
| | - S Spencer
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina (M.D.S., J.A.H., S.S., D.R.-W., P.W.K.); Department of Psychology, Arizona State University, Tempe, Arizona (C.D.G.); Department of Neuroscience, Hebrew University, Jerusalem, Israel (Y.M.K.); and Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York (A.C.W.S.)
| | - A C W Smith
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina (M.D.S., J.A.H., S.S., D.R.-W., P.W.K.); Department of Psychology, Arizona State University, Tempe, Arizona (C.D.G.); Department of Neuroscience, Hebrew University, Jerusalem, Israel (Y.M.K.); and Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York (A.C.W.S.)
| | - D Roberts-Wolfe
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina (M.D.S., J.A.H., S.S., D.R.-W., P.W.K.); Department of Psychology, Arizona State University, Tempe, Arizona (C.D.G.); Department of Neuroscience, Hebrew University, Jerusalem, Israel (Y.M.K.); and Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York (A.C.W.S.)
| | - P W Kalivas
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina (M.D.S., J.A.H., S.S., D.R.-W., P.W.K.); Department of Psychology, Arizona State University, Tempe, Arizona (C.D.G.); Department of Neuroscience, Hebrew University, Jerusalem, Israel (Y.M.K.); and Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York (A.C.W.S.)
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27
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Li YJ, Ping XJ, Qi C, Shen F, Sun LL, Sun XW, Ge FF, Xing GG, Cui CL. Re-exposure to morphine-associated context facilitated long-term potentiation in the vSUB-NAc glutamatergic pathway via GluN2B-containing receptor activation. Addict Biol 2017; 22:435-445. [PMID: 26692025 DOI: 10.1111/adb.12343] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 09/29/2015] [Accepted: 11/04/2015] [Indexed: 12/28/2022]
Abstract
The glutamatergic projection from the ventral subiculum of the hippocampus (vSUB) to the nucleus accumbens (NAc) shell has been reported to play a key role in drug-related behavior. The GluN2B subunit of N-methyl-D-aspartate receptors (NMDARs) in the NAc can be selectively elevated after the retrieval of drug-conditioned memory. However, whether the increased GluN2B-containing NMDARs (GluN2B-NMDARs) are able to alter the synaptic plasticity of the vSUB-NAc glutamatergic pathway remains unclear. Here, we found that the long-term potentiation (LTP) in the vSUB-NAc pathway was facilitated and the GluN2B subunit protein level was elevated in synaptoneurosomes of the NAc shell, but not in the core, following morphine-induced conditioned place preference (CPP) expression in rats. The facilitated LTP was prevented by the GluN2B-NMDAR antagonist RO25-6981. Also, a neurochemical disconnection following microinjection of RO25-6981 into the NAc shell, plus microinfusion of GABA agonist baclofen and muscimol into the contralateral vSUB prevented the expression of morphine-induced CPP. These findings suggest that the retrieval of drug-associated memory potentiated synaptic plasticity in the vSUB-NAc pathway, which was dependent on GluN2B-NMDAR activation in the NAc shell. These findings provide a new explanation for the mechanisms that underlie the morphine-associated-context memory. The GluN2B-NMDARs may be regarded as a potential target for erasing morphine-related memory.
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Affiliation(s)
- Yi-Jing Li
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
| | - Xing-Jie Ping
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
| | - Chong Qi
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
| | - Fang Shen
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
| | - Lin-Lin Sun
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
| | - Xiao-Wei Sun
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
| | - Fei-Fei Ge
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
| | - Guo-Gang Xing
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
| | - Cai-Lian Cui
- Neuroscience Research Institute; Peking University; Beijing China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing China
- Key Laboratory for Neuroscience; Ministry of Education; Beijing China
- Key Laboratory for Neuroscience; Ministry of National Health and Family Planning Commission; Beijing China
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28
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Wills TA, Baucum AJ, Louderback KM, Chen Y, Pasek JG, Delpire E, Tabb DL, Colbran RJ, Winder DG. Chronic intermittent alcohol disrupts the GluN2B-associated proteome and specifically regulates group I mGlu receptor-dependent long-term depression. Addict Biol 2017; 22:275-290. [PMID: 26549202 PMCID: PMC4860359 DOI: 10.1111/adb.12319] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/31/2015] [Accepted: 09/11/2015] [Indexed: 02/03/2023]
Abstract
N-Methyl-d-aspartate receptors (NMDARs) are major targets of both acute and chronic alcohol, as well as regulators of plasticity in a number of brain regions. Aberrant plasticity may contribute to the treatment resistance and high relapse rates observed in alcoholics. Recent work suggests that chronic alcohol treatment preferentially modulates both the expression and subcellular localization of NMDARs containing the GluN2B subunit. Signaling through synaptic and extrasynaptic GluN2B-NMDARs has already been implicated in the pathophysiology of various other neurological disorders. NMDARs interact with a large number of proteins at the glutamate synapse, and a better understanding of how alcohol modulates this proteome is needed. We employed a discovery-based proteomic approach in subcellular fractions of hippocampal tissue from chronic intermittent alcohol (CIE)-exposed C57Bl/6J mice to gain insight into alcohol-induced changes in GluN2B signaling complexes. Protein enrichment analyses revealed changes in the association of post-synaptic proteins, including scaffolding, glutamate receptor and PDZ-domain binding proteins with GluN2B. In particular, GluN2B interaction with metabotropic glutamate (mGlu)1/5 receptor-dependent long-term depression (LTD)-associated proteins such as Arc and Homer 1 was increased, while GluA2 was decreased. Accordingly, we found a lack of mGlu1/5 -induced LTD while α1 -adrenergic receptor-induced LTD remained intact in hippocampal CA1 following CIE. These data suggest that CIE specifically disrupts mGlu1/5 -LTD, representing a possible connection between NMDAR and mGlu receptor signaling. These studies not only demonstrate a new way in which alcohol can modulate plasticity in the hippocampus but also emphasize the utility of this discovery-based proteomic approach to generate new hypotheses regarding alcohol-related mechanisms.
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Affiliation(s)
- Tiffany A. Wills
- Department of Cell Biology & Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Anthony J. Baucum
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202
| | | | - Yaoyi Chen
- Department of Biochemical Informatics, Vanderbilt University School of Medicine, Nashville TN 37232
| | - Johanna G. Pasek
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN 37232
| | - Eric Delpire
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN 37232
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville TN 37232
- J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville TN 37232
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville TN 37232
| | - David L. Tabb
- Department of Biochemical Informatics, Vanderbilt University School of Medicine, Nashville TN 37232
| | - Roger J. Colbran
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN 37232
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville TN 37232
- J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville TN 37232
| | - Danny G. Winder
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN 37232
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville TN 37232
- J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville TN 37232
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29
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Radke AK, Jury NJ, Kocharian A, Marcinkiewcz CA, Lowery-Gionta EG, Pleil KE, McElligott ZA, McKlveen JM, Kash TL, Holmes A. Chronic EtOH effects on putative measures of compulsive behavior in mice. Addict Biol 2017; 22:423-434. [PMID: 26687341 PMCID: PMC4916036 DOI: 10.1111/adb.12342] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 10/22/2015] [Accepted: 11/04/2015] [Indexed: 01/08/2023]
Abstract
Addictions, including alcohol use disorders, are characterized by the loss of control over drug seeking and consumption, but the neural circuits and signaling mechanisms responsible for the transition from controlled use to uncontrolled abuse remain incompletely understood. Prior studies have shown that 'compulsive-like' behaviors in rodents, for example, persistent responding for ethanol (EtOH) despite punishment, are increased after chronic exposure to EtOH. The main goal of the current study was to assess the effects of chronic intermittent EtOH (CIE) exposure on multiple, putative measures of compulsive-like EtOH seeking in C57BL/6 J mice. Mice were exposed to two or four weekly cycles of CIE and then, post-withdrawal, tested for progressive ratio responding for EtOH, sustained responding during signaled EtOH unavailability and (footshock) punished suppression of responding for EtOH. Results showed that mice exposed to CIE exhibited attenuated suppression of EtOH seeking during punishment, as compared with air-exposed controls. By contrast, CIE exposure affected neither punished food reward-seeking behavior, nor other putative measures of compulsive-like EtOH seeking. Ex vivo reverse transcription polymerase chain reaction analysis of brain tissue found reduced sensitivity to punished EtOH seeking after CIE exposure was accompanied by a significant increase in gene expression of the GluN1 and GluN2A subunits of the N-methyl-d-aspartate receptor, specifically in the medial orbitofrontal cortex. Moreover, slice electrophysiological analysis revealed increased N-methyl-d-aspartate receptor-mediated currents in the orbitofrontal cortex after CIE exposure in test-naïve mice. Collectively, the current findings add to the growing body of evidence demonstrating that chronic exposure to EtOH fosters resistance to punished EtOH seeking in association with adaptations in cortical glutamatergic transmission.
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Affiliation(s)
- Anna K. Radke
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD
| | - Nicholas J. Jury
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD
| | - Adrina Kocharian
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD
| | - Catherine A. Marcinkiewcz
- Bowles Center for Alcohol Studies and Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC
| | - Emily G. Lowery-Gionta
- Bowles Center for Alcohol Studies and Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC
| | - Kristen E. Pleil
- Bowles Center for Alcohol Studies and Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC
| | - Zoe A. McElligott
- Bowles Center for Alcohol Studies and Department of Psychiatry, UNC Chapel Hill School of Medicine, Chapel Hill, NC
| | - Jessica M. McKlveen
- Bowles Center for Alcohol Studies and Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC
| | - Thomas L. Kash
- Bowles Center for Alcohol Studies and Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD
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Uys JD, McGuier NS, Gass JT, Griffin WC, Ball LE, Mulholland PJ. Chronic intermittent ethanol exposure and withdrawal leads to adaptations in nucleus accumbens core postsynaptic density proteome and dendritic spines. Addict Biol 2016; 21:560-74. [PMID: 25787124 DOI: 10.1111/adb.12238] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Alcohol use disorder is a chronic relapsing brain disease characterized by the loss of ability to control alcohol (ethanol) intake despite knowledge of detrimental health or personal consequences. Clinical and pre-clinical models provide strong evidence for chronic ethanol-associated alterations in glutamatergic signaling and impaired synaptic plasticity in the nucleus accumbens (NAc). However, the neural mechanisms that contribute to aberrant glutamatergic signaling in ethanol-dependent individuals in this critical brain structure remain unknown. Using an unbiased proteomic approach, we investigated the effects of chronic intermittent ethanol (CIE) exposure on neuroadaptations in postsynaptic density (PSD)-enriched proteins in the NAc of ethanol-dependent mice. Compared with controls, CIE exposure significantly changed expression levels of 50 proteins in the PSD-enriched fraction. Systems biology and functional annotation analyses demonstrated that the dysregulated proteins are expressed at tetrapartite synapses and critically regulate cellular morphology. To confirm this latter finding, the density and morphology of dendritic spines were examined in the NAc core of ethanol-dependent mice. We found that CIE exposure and withdrawal differentially altered dendrite diameter and dendritic spine density and morphology. Through the use of quantitative proteomics and functional annotation, these series of experiments demonstrate that ethanol dependence produces neuroadaptations in proteins that modify dendritic spine morphology. In addition, these studies identified novel PSD-related proteins that contribute to the neurobiological mechanisms of ethanol dependence that drive maladaptive structural plasticity of NAc neurons.
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Affiliation(s)
- Joachim D. Uys
- Department of Cell and Molecular Pharmacology; Medical University of South Carolina; Charleston SC USA
| | - Natalie S. McGuier
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | - Justin T. Gass
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | - William C. Griffin
- Department of Psychiatry and Behavioral Sciences; Medical University of South Carolina; Charleston SC USA
| | - Lauren E. Ball
- Department of Cell and Molecular Pharmacology; Medical University of South Carolina; Charleston SC USA
| | - Patrick J. Mulholland
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
- Department of Psychiatry and Behavioral Sciences; Medical University of South Carolina; Charleston SC USA
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31
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Renteria R, Jeanes ZM, Mangieri RA, Maier EY, Kircher DM, Buske TR, Morrisett RA. Using In Vitro Electrophysiology to Screen Medications: Accumbal Plasticity as an Engram of Alcohol Dependence. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 126:441-65. [PMID: 27055622 DOI: 10.1016/bs.irn.2016.02.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The nucleus accumbens (NAc) is a central component of the mesocorticolimbic reward system. Increasing evidence strongly implicates long-term synaptic neuroadaptations in glutamatergic excitatory activity of the NAc shell and/or core medium spiny neurons in response to chronic drug and alcohol exposure. Such neuroadaptations likely play a critical role in the development and expression of drug-seeking behaviors. We have observed unique cell-type-specific bidirectional changes in NAc synaptic plasticity (metaplasticity) following acute and chronic intermittent ethanol exposure. Other investigators have also previously observed similar metaplasticity in the NAc following exposure to psychostimulants, opiates, and amazingly, even following an anhedonia-inducing experience. Considering that the proteome of the postsynaptic density likely contains hundreds of biochemicals, proteins and other components and regulators, we believe that there is a large number of potential molecular sites through which accumbal metaplasticity may be involved in chronic alcohol abuse. Many of our companion laboratories are now engaged in identifying and screening medications targeting candidate genes and its products previously linked to maladaptive alcohol phenotypes. We hypothesize that if manipulation of such target genes and their products change NAc plasticity, then that observation constitutes an important validation step for the development of novel therapeutics to treat alcohol dependence.
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Affiliation(s)
- R Renteria
- University of Texas at Austin, Austin, TX, United States
| | - Z M Jeanes
- University of Texas at Austin, Austin, TX, United States
| | - R A Mangieri
- University of Texas at Austin, Austin, TX, United States
| | - E Y Maier
- University of Texas at Austin, Austin, TX, United States
| | - D M Kircher
- University of Texas at Austin, Austin, TX, United States
| | - T R Buske
- University of Texas at Austin, Austin, TX, United States
| | - R A Morrisett
- University of Texas at Austin, Austin, TX, United States.
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32
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Renteria R, Maier EY, Buske TR, Morrisett RA. Selective alterations of NMDAR function and plasticity in D1 and D2 medium spiny neurons in the nucleus accumbens shell following chronic intermittent ethanol exposure. Neuropharmacology 2016; 112:164-171. [PMID: 26946430 DOI: 10.1016/j.neuropharm.2016.03.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Revised: 02/22/2016] [Accepted: 03/01/2016] [Indexed: 12/27/2022]
Abstract
A major mouse model widely adopted in recent years to induce pronounced ethanol intake is the ethanol vapor model known as "CIE" or "Chronic Intermittent Ethanol." One critical question concerning this model is whether the rapid induction of high blood ethanol levels for such short time periods is sufficient to induce alterations in N-methyl-d-aspartate receptor (NMDAR) function which may contribute to excessive ethanol intake. In this study, we determined whether such short term intermittent ethanol exposure modulates NMDAR function as well as other prominent electrophysiological properties and the expression of plasticity in both D1 (D1+) and D2 (D1-) dopamine receptor expressing medium spiny neurons (MSNs) in the nucleus accumbens (NAc) shell. To distinguish between the two subtypes of MSNs in the NAc we treated Drd1a-TdTomato transgenic mice with CIE vapor and electrophysiological recordings were conducted 24 h after the last vapor exposure. To investigate CIE induced alterations in plasticity, long-term depression (LTD) was induced by pairing low frequency stimulation (LFS) with post synaptic depolarization. In ethanol naïve mice, LFS induced synaptic depression (LTD) was apparent exclusively in D1+ MSNs. Whereas in slices prepared from CIE treated mice, LFS induced synaptic potentiation (LTP) in D1+ MSNs. Furthermore, following CIE exposure, LFS now produced LTD in D1- MSNs. We found that CIE exposure induced an increase in excitability in D1+ MSNs with no change in D1- MSNs. After CIE, we found a significant increase in spontaneous EPSCs (sEPSCs) frequency in D1+ but not D1- MSNs suggesting alterations in baseline α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) mediated signaling. CIE induced changes in NMDAR function were measured using the NMDA/AMPA ratio and input-output curves of isolated NMDAR currents. We observed a significant increase in NMDAR function in D1+ MSNs and a decrease in D1- MSNs after ethanol vapor exposure. The reversal of NMDAR function may account for the CIE induced alterations in the expression of plasticity. The cell type specific alterations in excitatory signaling in the NAc shell may constitute an important neuroadaptation necessary for the expression of increased ethanol consumption induced by intermittent ethanol vapor exposure. This article is part of the Special Issue entitled 'Ionotropic glutamate receptors'.
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Affiliation(s)
- Rafael Renteria
- Institute for Neuroscience, The University of Texas at Austin, Austin, TX, USA.
| | - Esther Y Maier
- The Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX, USA.
| | - Tavanna R Buske
- The Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX, USA.
| | - Richard A Morrisett
- Institute for Neuroscience, The University of Texas at Austin, Austin, TX, USA; The Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX, USA; Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, USA.
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Burnett EJ, Chandler LJ, Trantham-Davidson H. Glutamatergic plasticity and alcohol dependence-induced alterations in reward, affect and cognition. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:309-20. [PMID: 26341050 PMCID: PMC4679411 DOI: 10.1016/j.pnpbp.2015.08.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Revised: 07/29/2015] [Accepted: 08/27/2015] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Alcohol dependence is characterized by a reduction in reward threshold, development of a negative affective state, and significant cognitive impairments. Dependence-induced glutamatergic neuroadaptations in the neurocircuitry mediating reward, affect and cognitive function are thought to underlie the neural mechanism for these alterations. These changes serve to promote increased craving for alcohol and facilitate the development of maladaptive behaviors that promote relapse to alcohol drinking during periods of abstinence. OBJECTIVE To review the extant literature on the effects of chronic alcohol exposure on glutamatergic neurotransmission and its impact on reward, affect and cognition. RESULTS Evidence from a diverse set of studies demonstrates significant enhancement of glutamatergic activity following chronic alcohol exposure. In particular, up-regulation of GluN2B-containing NMDA receptor expression and function is a commonly observed phenomenon that likely reflects activity-dependent adaptive homeostatic plasticity. However, this observation as well as other glutamatergic neuroadaptations are often circuit and cell-type specific. DISCUSSION Dependence-induced alterations in glutamate signaling contribute to many of the symptoms experienced in addicted individuals and can persist well into abstinence. This suggests that they play an important role in the development of behaviors that increase the probability for relapse. As our understanding of the complexity of the neurocircuitry involved in the addictive process has advanced, it has become increasingly clear that investigations of cell-type and circuit-specific effects are required to gain a more comprehensive understanding of the glutamatergic adaptations and their functional consequences in alcohol addiction. CONCLUSION While pharmacological treatments for alcohol dependence and relapse targeting the glutamatergic system have shown great promise in preclinical models, more research is needed to uncover novel, possibly circuit-specific, therapeutic targets that exhibit improved efficacy and reduced side effects.
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Affiliation(s)
- Elizabeth J Burnett
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425.
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34
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Stankiewicz AM, Goscik J, Dyr W, Juszczak GR, Ryglewicz D, Swiergiel AH, Wieczorek M, Stefanski R. Novel candidate genes for alcoholism--transcriptomic analysis of prefrontal medial cortex, hippocampus and nucleus accumbens of Warsaw alcohol-preferring and non-preferring rats. Pharmacol Biochem Behav 2015; 139:27-38. [PMID: 26455281 DOI: 10.1016/j.pbb.2015.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 10/06/2015] [Accepted: 10/06/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Animal models provide opportunity to study neurobiological aspects of human alcoholism. Changes in gene expression have been implicated in mediating brain functions, including reward system and addiction. The current study aimed to identify genes that may underlie differential ethanol preference in Warsaw High Preferring (WHP) and Warsaw Low Preferring (WLP) rats. METHODS Microarray analysis comparing gene expression in nucleus accumbens (NAc), hippocampus (HP) and medial prefrontal cortex (mPFC) was performed in male WHP and WLP rats bred for differences in ethanol preference. RESULTS Differential and stable between biological repeats expression of 345, 254 and 129 transcripts in NAc, HP and mPFC was detected. Identified genes and processes included known mediators of ethanol response (Mx2, Fam111a, Itpr1, Gabra4, Agtr1a, LTP/LTD, renin-angiotensin signaling pathway), toxicity (Sult1c2a, Ces1, inflammatory response), as well as genes involved in regulation of important addiction-related brain systems such as dopamine, tachykinin or acetylcholine (Gng7, Tac4, Slc5a7). CONCLUSIONS The identified candidate genes may underlie differential ethanol preference in an animal model of alcoholism. COMMENT Names of genes are written in italics, while names of proteins are written in standard font. Names of human genes/proteins are written in all capital letters. Names of rodent genes/proteins are written in capital letter followed by small letters.
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Affiliation(s)
- Adrian M Stankiewicz
- Department of Animal Behaviour, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, 05-552 Jastrzebiec, Poland
| | - Joanna Goscik
- Software Department, Faculty of Computer Science, Bialystok University of Technology, 15-351 Bialystok, Poland
| | - Wanda Dyr
- Department of Pharmacology and Physiology of the Nervous System, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland
| | - Grzegorz R Juszczak
- Department of Animal Behaviour, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, 05-552 Jastrzebiec, Poland
| | - Danuta Ryglewicz
- First Department of Neurology, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland
| | - Artur H Swiergiel
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland; Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA71130, USA.
| | - Marek Wieczorek
- Department of Neurobiology, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Roman Stefanski
- Department of Pharmacology and Physiology of the Nervous System, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland
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35
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Ji X, Saha S, Martin GE. The origin of glutamatergic synaptic inputs controls synaptic plasticity and its modulation by alcohol in mice nucleus accumbens. Front Synaptic Neurosci 2015; 7:12. [PMID: 26257641 PMCID: PMC4507144 DOI: 10.3389/fnsyn.2015.00012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/06/2015] [Indexed: 01/08/2023] Open
Abstract
It is widely accepted that long-lasting changes of synaptic strength in the nucleus accumbens (NAc), a brain region involved in drug reward, mediate acute and chronic effects of alcohol. However, our understanding of the mechanisms underlying the effects of alcohol on synaptic plasticity is limited by the fact that the NAc receives glutamatergic inputs from distinct brain regions (e.g., the prefrontal cortex (PFCx), the amygdala and the hippocampus), each region providing different information (e.g., spatial, emotional and cognitive). Combining whole-cell patch-clamp recordings and the optogenetic technique, we examined synaptic plasticity, and its regulation by alcohol, at cortical, hippocampal and amygdala inputs in fresh slices of mouse tissue. We showed that the origin of synaptic inputs determines the basic properties of glutamatergic synaptic transmission, the expression of spike-timing dependent long-term depression (tLTD) and long-term potentiation (LTP) and long-term potentiation (tLTP) and their regulation by alcohol. While we observed both tLTP and tLTD at amygadala and hippocampal synapses, we showed that cortical inputs only undergo tLTD. Functionally, we provide evidence that acute Ethyl Alcohol (EtOH) has little effects on higher order information coming from the PFCx, while severely impacting the ability of emotional and contextual information to induce long-lasting changes of synaptic strength.
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Affiliation(s)
- Xincai Ji
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School Worcester, MA, USA
| | - Sucharita Saha
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School Worcester, MA, USA
| | - Gilles E Martin
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School Worcester, MA, USA
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Renteria R, Jeanes ZM, Morrisett RA. Ethanol attenuation of long-term depression in the nucleus accumbens can be overcome by activation of TRPV1 receptors. Alcohol Clin Exp Res 2015; 38:2763-9. [PMID: 25421513 DOI: 10.1111/acer.12542] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 08/06/2014] [Indexed: 01/08/2023]
Abstract
BACKGROUND Altered expression of synaptic plasticity within the nucleus accumbens (NAc) constitutes a critical neuroadaptive response to ethanol (EtOH) and other drugs of abuse. We have previously reported that N-methyl-D-aspartate receptor (NMDAR)-dependent long-term depression (LTD) is markedly affected by chronic intermittent ethanol exposure in vivo; however, endocannabinoid (eCB)-dependent synaptic depression, despite being very well-documented in the dorsal striatum, is much less well understood in the NAc. METHODS Whole cell patch clamp electrophysiology was used to investigate interactions between these different plasticity-induction systems. Excitatory postsynaptic currents (EPSCs) were measured in the NAc shell and NMDAR-LTD was induced by a pairing protocol (500 stimuli at 1 Hz stimulation [low-frequency stimulation (LFS)] paired with postsynaptic depolarization to -50 mV). AM251, a CB1 receptor antagonist, was used to determine whether this form of LTD is modulated by eCBs. To determine the effect of EtOH on a purely eCB-dependent response in the NAc, depolarization-induced suppression of excitation (DSE) was used in the presence of 40 mM EtOH. Finally, we determined whether the enhancement of eCB signaling with URB597, a fatty acid amide hydrolase inhibitor, and AM404, an anandamide re-uptake inhibitor would also modulate LFS LTD in the presence of NMDAR blockade or EtOH. RESULTS In the presence of AM251, the LFS pairing protocol resulted in NMDAR-dependent long-term potentiation that was blocked with either EtOH or DL-APV. We also found that DSE in the NAc shell was blocked by AM251 and suppressed by EtOH. Enhanced eCB signaling rescued NAc-LTD expression in the presence of EtOH through a distinct mechanism requiring activation of TRPV1 receptors. CONCLUSIONS EtOH modulation of synaptic plasticity in the NAc is dependent upon a complex interplay between NMDARs, eCBs, and TRPV1 receptors. These findings demonstrate a novel form of TRPV1-dependent LTD in the NAc shell that may be critical for EtOH dependence.
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Affiliation(s)
- Rafael Renteria
- Institute for Neuroscience, The College of Pharmacy, The University of Texas at Austin, Austin, Texas
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Neuroplasticity of A-type potassium channel complexes induced by chronic alcohol exposure enhances dendritic calcium transients in hippocampus. Psychopharmacology (Berl) 2015; 232:1995-2006. [PMID: 25510858 PMCID: PMC4426211 DOI: 10.1007/s00213-014-3835-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/25/2014] [Indexed: 10/24/2022]
Abstract
RATIONALE Chronic alcohol-induced cognitive impairments and maladaptive plasticity of glutamatergic synapses are well-documented. However, it is unknown if prolonged alcohol exposure affects dendritic signaling that may underlie hippocampal dysfunction in alcoholics. Back-propagation of action potentials (bAPs) into apical dendrites of hippocampal neurons provides distance-dependent signals that modulate dendritic and synaptic plasticity. The amplitude of bAPs decreases with distance from the soma that is thought to reflect an increase in the density of Kv4.2 channels toward distal dendrites. OBJECTIVE The aim of this study was to quantify changes in hippocampal Kv4.2 channel function and expression using electrophysiology, Ca(2+) imaging, and western blot analyses in a well-characterized in vitro model of chronic alcohol exposure. RESULTS Chronic alcohol exposure significantly decreased expression of Kv4.2 channels and KChIP3 in hippocampus. This reduction was associated with an attenuation of macroscopic A-type K(+) currents in CA1 neurons. Chronic alcohol exposure increased bAP-evoked Ca(2+) transients in the distal apical dendrites of CA1 pyramidal neurons. The enhanced bAP-evoked Ca(2+) transients induced by chronic alcohol exposure were not related to synaptic targeting of N-methyl-D-aspartate (NMDA) receptors or morphological adaptations in apical dendritic arborization. CONCLUSIONS These data suggest that chronic alcohol-induced decreases in Kv4.2 channel function possibly mediated by a downregulation of KChIP3 drive the elevated bAP-associated Ca(2+) transients in distal apical dendrites. Alcohol-induced enhancement of bAPs may affect metaplasticity and signal integration in apical dendrites of hippocampal neurons leading to alterations in hippocampal function.
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Frequency of alcohol consumption in humans; the role of metabotropic glutamate receptors and downstream signaling pathways. Transl Psychiatry 2015; 5:e586. [PMID: 26101849 PMCID: PMC4490281 DOI: 10.1038/tp.2015.70] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/13/2015] [Accepted: 04/23/2015] [Indexed: 12/18/2022] Open
Abstract
Rodent models implicate metabotropic glutamate receptors (mGluRs) and downstream signaling pathways in addictive behaviors through metaplasticity. One way mGluRs can influence synaptic plasticity is by regulating the local translation of AMPA receptor trafficking proteins via eukaryotic elongation factor 2 (eEF2). However, genetic variation in this pathway has not been examined with human alcohol use phenotypes. Among a sample of adults living in Detroit, Michigan (Detroit Neighborhood Health Study; n = 788; 83% African American), 206 genetic variants across the mGluR-eEF2-AMPAR pathway (including GRM1, GRM5, HOMER1, HOMER2, EEF2K, MTOR, EIF4E, EEF2, CAMK2A, ARC, GRIA1 and GRIA4) were found to predict number of drinking days per month (corrected P-value < 0.01) when considered as a set (set-based linear regression conducted in PLINK). In addition, a CpG site located in the 3'-untranslated region on the north shore of EEF2 (cg12255298) was hypermethylated in those who drank more frequently (P < 0.05). Importantly, the association between several genetic variants within the mGluR-eEF2-AMPAR pathway and alcohol use behavior (i.e., consumption and alcohol-related problems) replicated in the Grady Trauma Project (GTP), an independent sample of adults living in Atlanta, Georgia (n = 1034; 95% African American), including individual variants in GRM1, GRM5, EEF2, MTOR, GRIA1, GRIA4 and HOMER2 (P < 0.05). Gene-based analyses conducted in the GTP indicated that GRM1 (empirical P < 0.05) and EEF2 (empirical P < 0.01) withstood multiple test corrections and predicted increased alcohol consumption and related problems. In conclusion, insights from rodent studies enabled the identification of novel human alcohol candidate genes within the mGluR-eEF2-AMPAR pathway.
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Hu W, Morris B, Carrasco A, Kroener S. Effects of acamprosate on attentional set-shifting and cellular function in the prefrontal cortex of chronic alcohol-exposed mice. Alcohol Clin Exp Res 2015; 39:953-61. [PMID: 25903298 PMCID: PMC10782929 DOI: 10.1111/acer.12722] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/05/2015] [Indexed: 12/01/2022]
Abstract
BACKGROUND The medial prefrontal cortex (mPFC) inhibits impulsive and compulsive behaviors that characterize drug abuse and dependence. Acamprosate is the leading medication approved for the maintenance of abstinence, shown to reduce craving and relapse in animal models and human alcoholics. Whether acamprosate can modulate executive functions that are impaired by chronic ethanol (EtOH) exposure is unknown. Here we explored the effects of acamprosate on an attentional set-shifting task and tested whether these behavioral effects are correlated with modulation of glutamatergic synaptic transmission and intrinsic excitability of mPFC neurons. METHODS We induced alcohol dependence in mice via chronic intermittent EtOH (CIE) exposure in vapor chambers and measured changes in alcohol consumption in a limited access 2-bottle choice paradigm. Impairments of executive function were assessed in an attentional set-shifting task. Acamprosate was applied subchronically for 2 days during withdrawal before the final behavioral test. Alcohol-induced changes in cellular function of layer 5/6 pyramidal neurons, and the potential modulation of these changes by acamprosate, were measured using patch clamp recordings in brain slices. RESULTS Chronic EtOH exposure impaired cognitive flexibility in the attentional set-shifting task. Acamprosate improved overall performance and reduced perseveration. Recordings of mPFC neurons showed that chronic EtOH exposure increased use-dependent presynaptic transmitter release and enhanced postsynaptic N-methyl-D-aspartate receptor function. Moreover, CIE treatment lowered input resistance, and decreased the threshold and the after hyperpolarization of action potentials, suggesting chronic EtOH exposure also impacted membrane excitability of mPFC neurons. However, acamprosate treatment did not reverse these EtOH-induced changes cellular function. CONCLUSIONS Acamprosate improved attentional control of EtOH exposed animals, but did not alter the concurrent changes in synaptic transmission or membrane excitability of mPFC neurons, indicating that these changes are not the pharmacological targets of acamprosate in the recovery of mPFC functions affected by chronic EtOH exposure.
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Affiliation(s)
- Wei Hu
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas
| | - Brett Morris
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas
| | - Angelique Carrasco
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas
| | - Sven Kroener
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas
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Karkhanis AN, Rose JH, Huggins KN, Konstantopoulos JK, Jones SR. Chronic intermittent ethanol exposure reduces presynaptic dopamine neurotransmission in the mouse nucleus accumbens. Drug Alcohol Depend 2015; 150:24-30. [PMID: 25765483 PMCID: PMC4387104 DOI: 10.1016/j.drugalcdep.2015.01.019] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 12/28/2014] [Accepted: 01/14/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Increasing evidence suggests that chronic ethanol exposure decreases dopamine (DA) neurotransmission in the nucleus accumbens (NAc), contributing to a hypodopaminergic state during withdrawal. However, few studies have investigated adaptations in presynaptic DA terminals after chronic intermittent ethanol (CIE) exposure. In monkeys and rats, chronic ethanol exposure paradigms have been shown to increase DA uptake and D2 autoreceptor sensitivity. METHODS The current study examined the effects of ethanol on DA terminals in CIE exposed mice during two time-points after the cessation of CIE exposure. DA release and uptake were measured using fast scan cyclic voltammetry in NAc core slices from C57BL/6J mice, 0h and 72h following three weekly cycles (4 days of 16h ethanol vapor/8h room air/day+3 days withdrawal) of CIE vapor exposure. RESULTS Current results showed that DA release was reduced, uptake rates were increased, and inhibitory D2-type autoreceptor activity was augmented following CIE exposure in mice. CONCLUSIONS Overall, these CIE-induced adaptations in the accumbal DA system reduce DA signaling and therefore reveal several potential mechanisms contributing to a functional hypodopaminergic state during alcohol withdrawal.
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Zhang X, Feng ZJ, Chergui K. Induction of cannabinoid- and N-methyl-D-aspartate receptor-mediated long-term depression in the nucleus accumbens and dorsolateral striatum is region and age dependent. Int J Neuropsychopharmacol 2015; 18:pyu052. [PMID: 25618403 PMCID: PMC4360221 DOI: 10.1093/ijnp/pyu052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The adolescent brain is sensitive to experience-dependent plasticity and might be more vulnerable than the adult brain to the effects of some drugs of abuse. The factors that contribute to these differences are not fully identified. We have examined the ability of cannabinoids to induce a form of synaptic plasticity, long-term depression, in the nucleus accumbens and dorsolateral striatum of adolescent and adult mice. METHODS We measured field excitatory postsynaptic potentials/population spikes in brain slices. RESULTS We found that the cannabinoid receptor agonist WIN 55,212-2 (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone mesylate) induced long-term depression in the nucleus accumbens of adolescent but not adult mice and failed to induce long-term depression in the dorsolateral striatum of adolescent or adult mice. Similar results were obtained with the group I metabotropic glutamate receptor agonist (S)-3,5- dihydroxyphenylglycine, which has previously been shown to promote the release of endocannabinoids. These age-related differences were associated with reduced protein levels of the cannabinoid type 1 receptor and metabotropic glutamate receptor 1 in adult nucleus accumbens and dorsolateral striatum and with an increased tone of endocannabinoids in the dorsolateral striatum of adult mice. We also found that N-methyl-D-aspartate receptor-dependent long-term depression, which was induced in the nucleus accumbens of adolescent mice, was blunted in adult mice, possibly because of decreased levels of GluN1, the obligatory subunit of N-methyl-D-aspartate receptors. CONCLUSIONS This study identifies region- and age-specific differences in the ability of endogenous and exogenous cannabinoids, and of N-methyl-D-aspartate receptors, to induce long-term depression in the striatal complex. These observations might contribute to a better understanding of the increased sensitivity of the adolescent brain to drug induced-plasticity.
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Affiliation(s)
| | | | - Karima Chergui
- The Karolinska Institute, Department of Physiology and Pharmacology, Section of Molecular Neurophysiology, Von Eulers väg 8, 171 77 Stockholm, Sweden (Drs Zhang, Feng, and Chergui).
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Lovinger DM. Mechanisms of Neuroplasticity and Ethanol's Effects on Plasticity in the Striatum and Bed Nucleus of the Stria Terminalis. Alcohol Res 2015; 37:109-24. [PMID: 26259092 PMCID: PMC4476598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Long-lasting changes in synaptic function (i.e., synaptic plasticity) have long been thought to contribute to information storage in the nervous system. Although synaptic plasticity mainly has adaptive functions that allow the organism to function in complex environments, it is now clear that certain events or exposure to various substances can produce plasticity that has negative consequences for organisms. Exposure to drugs of abuse, in particular ethanol, is a life experience that can activate or alter synaptic plasticity, often resulting in increased drug seeking and taking and in many cases addiction.Two brain regions subject to alcohol's effects on synaptic plasticity are the striatum and bed nucleus of the stria terminalis (BNST), both of which have key roles in alcohol's actions and control of intake. The specific effects depend on both the brain region analyzed (e.g., specific subregions of the striatum and BNST) and the duration of ethanol exposure (i.e., acute vs. chronic). Plastic changes in synaptic transmission in these two brain regions following prolonged ethanol exposure are thought to contribute to excessive alcohol drinking and relapse to drinking. Understanding the mechanisms underlying this plasticity may lead to new therapies for treatment of these and other aspects of alcohol use disorder.
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Hampered long-term depression and thin spine loss in the nucleus accumbens of ethanol-dependent rats. Proc Natl Acad Sci U S A 2014; 111:E3745-54. [PMID: 25122682 DOI: 10.1073/pnas.1406768111] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Alcoholism involves long-term cognitive deficits, including memory impairment, resulting in substantial cost to society. Neuronal refinement and stabilization are hypothesized to confer resilience to poor decision making and addictive-like behaviors, such as excessive ethanol drinking and dependence. Accordingly, structural abnormalities are likely to contribute to synaptic dysfunctions that occur from suddenly ceasing the use of alcohol after chronic ingestion. Here we show that ethanol-dependent rats display a loss of dendritic spines in medium spiny neurons of the nucleus accumbens (Nacc) shell, accompanied by a reduction of tyrosine hydroxylase immunostaining and postsynaptic density 95-positive elements. Further analysis indicates that "long thin" but not "mushroom" spines are selectively affected. In addition, patch-clamp experiments from Nacc slices reveal that long-term depression (LTD) formation is hampered, with parallel changes in field potential recordings and reductions in NMDA-mediated synaptic currents. These changes are restricted to the withdrawal phase of ethanol dependence, suggesting their relevance in the genesis of signs and/or symptoms affecting ethanol withdrawal and thus the whole addictive cycle. Overall, these results highlight the key role of dynamic alterations in dendritic spines and their presynaptic afferents in the evolution of alcohol dependence. Furthermore, they suggest that the selective loss of long thin spines together with a reduced NMDA receptor function may affect learning. Disruption of this LTD could contribute to the rigid emotional and motivational state observed in alcohol dependence.
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Jeanes ZM, Buske TR, Morrisett RA. Cell type-specific synaptic encoding of ethanol exposure in the nucleus accumbens shell. Neuroscience 2014; 277:184-95. [PMID: 25003712 DOI: 10.1016/j.neuroscience.2014.06.063] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/19/2014] [Accepted: 06/24/2014] [Indexed: 12/22/2022]
Abstract
Synaptic alterations in the nucleus accumbens (NAc) are crucial for the aberrant reward-associated learning that forms the foundation of drug dependence. Altered glutamatergic synaptic plasticity, in particular, is thought to be a vital component of the neurobiological underpinnings of addictive behavior. The development of bacterial artificial chromosome-eGFP (enhanced green fluorescent protein) transgenic mice that express eGFP driven by endogenous D1 dopamine receptor (D1R) promoters has now allowed investigation of the cell type-specific synaptic modifications in the NAc in response to drugs of abuse. In this study, we used whole-cell ex vivo slice electrophysiology in Drd1-eGFP mice to investigate cell type-specific alterations in NAc synaptic plasticity following ethanol exposure. Electrophysiological recordings were made from eGFP-expressing medium spiny neurons (D1+ MSNs) and non-eGFP-expressing (putative D2 receptor-expressing) (D1- MSNs) from the shell subregion of the NAc. We observed low frequency-induced long-term depression (1Hz-LTD) of α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA)-mediated excitatory postsynaptic currents (EPSCs) solely in D1+ MSNs. However, 24h following four consecutive days of in vivo chronic intermittent ethanol (CIE) vapor exposure, 1-Hz LTD was conversely observed only in D1- MSNs, and now absent in D1+ MSNs. Complete recovery of the baseline plasticity phenotype in both cell types required a full 2 weeks of withdrawal from CIE vapor exposure. Thus, we observed a cell type specificity of synaptic plasticity in the NAc shell, as well as, a gradual recovery of the pre-ethanol exposure plasticity state following extended withdrawal. These changes highlight the adaptability of NAc shell MSNs to the effects of ethanol exposure and may represent critical neuroadaptations underlying the development of ethanol dependence.
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Affiliation(s)
- Z M Jeanes
- The Division of Pharmacology and Toxicology, The College of Pharmacy, The University of Texas at Austin, Austin, TX 78712-1074, United States
| | - T R Buske
- The Division of Pharmacology and Toxicology, The College of Pharmacy, The University of Texas at Austin, Austin, TX 78712-1074, United States
| | - R A Morrisett
- The Division of Pharmacology and Toxicology, The College of Pharmacy, The University of Texas at Austin, Austin, TX 78712-1074, United States; The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX 78712-0125, United States; The Institute for Molecular and Cellular Biology, The University of Texas at Austin, Austin, TX 78712-0125, United States; The Institute for Neuroscience, The University of Texas at Austin, Austin, TX 78712-0125, United States.
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45
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Griffin WC. Alcohol dependence and free-choice drinking in mice. Alcohol 2014; 48:287-93. [PMID: 24530006 DOI: 10.1016/j.alcohol.2013.11.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Revised: 11/04/2013] [Accepted: 11/21/2013] [Indexed: 02/04/2023]
Abstract
Alcohol dependence continues to be an important health concern and animal models are critical to furthering our understanding of this complex disease. A hallmark feature of alcoholism is a significant increase in alcohol drinking over time. While several different animal models of excessive alcohol (ethanol) drinking exist for mice and rats, a growing number of laboratories are using a model that combines chronic ethanol exposure procedures with voluntary ethanol drinking with mice as experimental subjects. Primarily, these studies use a chronic intermittent ethanol (CIE) exposure pattern to render mice dependent and a 2-h limited access procedure to evaluate drinking behavior. Compared to non-dependent mice that also drink ethanol, the ethanol-dependent mice demonstrate significant increases in voluntary ethanol drinking. The increased drinking significantly elevates blood and brain ethanol concentrations compared to the non-dependent control mice. Studies report that the increased drinking by dependent mice is driven by neuroadaptations in glutamatergic and corticotropin-releasing factor signaling in different brain regions known to be involved in alcohol-related behaviors. The dysregulation of these systems parallels findings in human alcoholics and treatments that demonstrate efficacy in alcoholics can also reduce drinking in this model. Moreover, preclinical findings have informed the development of human clinical trials, further highlighting the translational potential of the model. As a result of these features, the CIE exposure and free-choice drinking model is becoming more widely used and promises to provide more insight into mechanisms of excessive drinking that may be important for developing treatments for human alcoholics. The salient features and possible future considerations for CIE exposure and free-choice drinking in mice are discussed.
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Liang J, Marty VN, Mulpuri Y, Olsen RW, Spigelman I. Selective modulation of GABAergic tonic current by dopamine in the nucleus accumbens of alcohol-dependent rats. J Neurophysiol 2014; 112:51-60. [PMID: 24717351 DOI: 10.1152/jn.00564.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The nucleus accumbens (NAcc) is a key structure of the mesolimbic dopaminergic reward system and plays an important role in mediating alcohol-seeking behaviors. Alterations in glutamatergic and GABAergic signaling were recently demonstrated in the NAcc of rats after chronic intermittent ethanol (CIE) treatment, a model of alcohol dependence. Here we studied dopamine (DA) modulation of GABAergic signaling and how this modulation might be altered by CIE treatment. We show that the tonic current (I(tonic)) mediated by extrasynaptic γ-aminobutyric acid type A receptors (GABA(A)Rs) of medium spiny neurons (MSNs) in the NAcc core is differentially modulated by DA at concentrations in the range of those measured in vivo (0.01-1 μM), without affecting the postsynaptic kinetics of miniature inhibitory postsynaptic currents (mIPSCs). Use of selective D1 receptor (D1R) and D2 receptor (D2R) ligands revealed that I(tonic) potentiation by DA (10 nM) is mediated by D1Rs while I(tonic) depression by DA (0.03-1 μM) is mediated by D2Rs in the same MSNs. Addition of guanosine 5'-O-(2-thiodiphosphate) (GDPβS) to the recording pipettes eliminated I(tonic) decrease by the selective D2R agonist quinpirole (5 nM), leaving intact the quinpirole effect on mIPSC frequency. Recordings from CIE and vehicle control (CIV) MSNs during application of D1R agonist (SKF 38393, 100 nM) or D2R agonist (quinpirole, 2 nM) revealed that SKF 38393 potentiated I(tonic) to the same extent, while quinpirole reduced I(tonic) to a similar extent, in both groups of rats. Our data suggest that the selective modulatory effects of DA on I(tonic) are unaltered by CIE treatment and withdrawal.
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Affiliation(s)
- Jing Liang
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, California; and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Vincent N Marty
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, California; and
| | - Yatendra Mulpuri
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, California; and
| | - Richard W Olsen
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Igor Spigelman
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, California; and
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Acute and chronic effects of ethanol on learning-related synaptic plasticity. Alcohol 2014; 48:1-17. [PMID: 24447472 DOI: 10.1016/j.alcohol.2013.09.045] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 09/16/2013] [Accepted: 09/18/2013] [Indexed: 11/23/2022]
Abstract
Alcoholism is associated with acute and long-term cognitive dysfunction including memory impairment, resulting in substantial disability and cost to society. Thus, understanding how ethanol impairs cognition is essential for developing treatment strategies to dampen its adverse impact. Memory processing is thought to involve persistent, use-dependent changes in synaptic transmission, and ethanol alters the activity of multiple signaling molecules involved in synaptic processing, including modulation of the glutamate and gamma-aminobutyric acid (GABA) transmitter systems that mediate most fast excitatory and inhibitory transmission in the brain. Effects on glutamate and GABA receptors contribute to ethanol-induced changes in long-term potentiation (LTP) and long-term depression (LTD), forms of synaptic plasticity thought to underlie memory acquisition. In this paper, we review the effects of ethanol on learning-related forms of synaptic plasticity with emphasis on changes observed in the hippocampus, a brain region that is critical for encoding contextual and episodic memories. We also include studies in other brain regions as they pertain to altered cognitive and mental function. Comparison of effects in the hippocampus to other brain regions is instructive for understanding the complexities of ethanol's acute and long-term pharmacological consequences.
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48
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Tabakoff B, Hoffman PL. The neurobiology of alcohol consumption and alcoholism: an integrative history. Pharmacol Biochem Behav 2013; 113:20-37. [PMID: 24141171 PMCID: PMC3867277 DOI: 10.1016/j.pbb.2013.10.009] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 01/17/2023]
Abstract
Studies of the neurobiological predisposition to consume alcohol (ethanol) and to transition to uncontrolled drinking behavior (alcoholism), as well as studies of the effects of alcohol on brain function, started a logarithmic growth phase after the repeal of the 18th Amendment to the United States Constitution. Although the early studies were primitive by current technological standards, they clearly demonstrated the effects of alcohol on brain structure and function, and by the end of the 20th century left little doubt that alcoholism is a "disease" of the brain. This review traces the history of developments in the understanding of ethanol's effects on the most prominent inhibitory and excitatory systems of brain (GABA and glutamate neurotransmission). This neurobiological information is integrated with knowledge of ethanol's actions on other neurotransmitter systems to produce an anatomical and functional map of ethanol's properties. Our intent is limited in scope, but is meant to provide context and integration of the actions of ethanol on the major neurobiologic systems which produce reinforcement for alcohol consumption and changes in brain chemistry that lead to addiction. The developmental history of neurobehavioral theories of the transition from alcohol drinking to alcohol addiction is presented and juxtaposed to the neurobiological findings. Depending on one's point of view, we may, at this point in history, know more, or less, than we think we know about the neurobiology of alcoholism.
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Affiliation(s)
- Boris Tabakoff
- University of Colorado School of Medicine, MS8303, 12800 E. 19 Ave., Aurora, CO 80045 U.S.A
| | - Paula L. Hoffman
- University of Colorado School of Medicine, MS8303, 12800 E. 19 Ave., Aurora, CO 80045 U.S.A
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Mishra D, Chergui K. Ethanol inhibits excitatory neurotransmission in the nucleus accumbens of adolescent mice through GABAA and GABAB receptors. Addict Biol 2013; 18:605-13. [PMID: 21790906 DOI: 10.1111/j.1369-1600.2011.00350.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Age-related differences in various acute physiological and behavioral effects of alcohol have been demonstrated in humans and in other species. Adolescents are more sensitive to positive reinforcing properties of alcohol than adults, but the cellular mechanisms that underlie such a difference are not clearly established. We, therefore, assessed age differences in the ability of ethanol to modulate glutamatergic synaptic transmission in the mouse nucleus accumbens (NAc), a brain region importantly involved in reward mechanisms. We measured field excitatory postsynaptic potentials/population spikes (fEPSP/PS) in NAc slices from adolescent (22-30 days old) and adult (5-8 months old) male mice. We found that 50mM ethanol applied in the perfusion solution inhibits glutamatergic neurotransmission in the NAc of adolescent, but not adult, mice. This effect is blocked by the gamma-aminobutyric acid (GABA)A receptor antagonist bicuculline and by the GABAB receptor antagonist CGP 55845. Furthermore, bicuculline applied alone produces a stronger increase in the fEPSP/PS amplitude in adult mice than in adolescent mice. Activation of GABAA receptors with muscimol produces a stronger and longer lasting depression of neurotransmission in adolescent mice as compared with adult mice. Activation of GABAB receptors with SKF 97541 also depresses neurotransmission more strongly in adolescent than in adult mice. These results demonstrate that an increased GABA receptor function associated with a reduced inhibitory tone underlies the depressant action of ethanol on glutamatergic neurotransmission in the NAc of adolescent mice.
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Affiliation(s)
- Devesh Mishra
- The Karolinska Institute, Department of Physiology and Pharmacology, Section of Molecular Neurophysiology, Sweden.
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Cerovic M, d'Isa R, Tonini R, Brambilla R. Molecular and cellular mechanisms of dopamine-mediated behavioral plasticity in the striatum. Neurobiol Learn Mem 2013; 105:63-80. [PMID: 23827407 DOI: 10.1016/j.nlm.2013.06.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 06/20/2013] [Accepted: 06/23/2013] [Indexed: 12/25/2022]
Abstract
The striatum is the input structure of the basal ganglia system. By integrating glutamatergic signals from cortical and subcortical regions and dopaminergic signals from mesolimbic nuclei the striatum functions as an important neural substrate for procedural and motor learning as well as for reward-guided behaviors. In addition, striatal activity is significantly altered in pathological conditions in which either a loss of dopamine innervation (Parkinson's disease) or aberrant dopamine-mediated signaling (drug addiction and L-DOPA induced dyskinesia) occurs. Here we discuss cellular mechanisms of striatal synaptic plasticity and aspects of cell signaling underlying striatum-dependent behavior, with a major focus on the neuromodulatory action of the endocannabinoid system and on the role of the Ras-ERK cascade.
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Affiliation(s)
- Milica Cerovic
- School of Biosciences, Cardiff University, CF10 3AX Cardiff, UK
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