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Clites BL, Frohock B, Koury EJ, Andersen EC, Pierce JT. Natural variation in protein kinase D modifies alcohol sensitivity in Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.09.598102. [PMID: 38895441 PMCID: PMC11185769 DOI: 10.1101/2024.06.09.598102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Differences in naïve alcohol sensitivity between individuals are a strong predictor of later life alcohol use disorders (AUD). However, the genetic bases for alcohol sensitivity (beyond ethanol metabolism) and pharmacological approaches to modulate alcohol sensitivity remain poorly understood. We used a high-throughput behavioral screen to measure acute behavioral sensitivity to alcohol, a model of intoxication, in a genetically diverse set of over 150 wild strains of the nematode Caenorhabditis elegans. We performed a genome-wide association study to identify loci that underlie natural variation in alcohol sensitivity. We identified five quantitative trait loci (QTL) and further show that variants in the C. elegans ortholog of protein kinase D, dkf-2, likely underlie the chromosome V QTL. We found that resistance to intoxication was conferred by dkf-2 loss-of-function mutations as well as partly by a PKD inhibitor in a dkf-2-dependent manner. Protein kinase D might represent a conserved, druggable target to modify alcohol sensitivity with application towards AUD.
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Affiliation(s)
- Benjamin L Clites
- Waggoner Center for Alcohol & Addiction Research, Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin TX
| | - Brooke Frohock
- Waggoner Center for Alcohol & Addiction Research, Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin TX
| | - Emily J Koury
- Department of Biology, Johns Hopkins University, Baltimore MD
| | - Erik C Andersen
- Department of Biology, Johns Hopkins University, Baltimore MD
| | - Jonathan T Pierce
- Waggoner Center for Alcohol & Addiction Research, Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin TX
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2
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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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Alcohol Use Disorder: Neurobiology and Therapeutics. Biomedicines 2022; 10:biomedicines10051192. [PMID: 35625928 PMCID: PMC9139063 DOI: 10.3390/biomedicines10051192] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 02/04/2023] Open
Abstract
Alcohol use disorder (AUD) encompasses the dysregulation of multiple brain circuits involved in executive function leading to excessive consumption of alcohol, despite negative health and social consequences and feelings of withdrawal when access to alcohol is prevented. Ethanol exerts its toxicity through changes to multiple neurotransmitter systems, including serotonin, dopamine, gamma-aminobutyric acid, glutamate, acetylcholine, and opioid systems. These neurotransmitter imbalances result in dysregulation of brain circuits responsible for reward, motivation, decision making, affect, and the stress response. Despite serious health and psychosocial consequences, this disorder still remains one of the leading causes of death globally. Treatment options include both psychological and pharmacological interventions, which are aimed at reducing alcohol consumption and/or promoting abstinence while also addressing dysfunctional behaviours and impaired functioning. However, stigma and social barriers to accessing care continue to impact many individuals. AUD treatment should focus not only on restoring the physiological and neurological impairment directly caused by alcohol toxicity but also on addressing psychosocial factors associated with AUD that often prevent access to treatment. This review summarizes the impact of alcohol toxicity on brain neurocircuitry in the context of AUD and discusses pharmacological and non-pharmacological therapies currently available to treat this addiction disorder.
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Eduardo PMC, Abrahao KP. Food composition can influence how much alcohol your animal model drinks: A mini-review about the role of isoflavones. Alcohol Clin Exp Res 2021; 46:6-12. [PMID: 34779005 DOI: 10.1111/acer.14741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/28/2021] [Accepted: 11/09/2021] [Indexed: 02/05/2023]
Abstract
Standard laboratory diets used have similar concentrations of proteins, carbohydrates and fat, but the concentration of some micronutrients can vary considerably. For example, the concentration of isoflavones can vary between 20 mg and 600 mg per gram of diet. Exposure to different concentrations of isoflavones interacts with alcohol (EtOH) intake, thereby influencing the results of alcohol research. In this mini-review, we describe correlations between isoflavone concentrations and alcohol intake based on data from previously published work. Although the administration of low doses of isoflavones can decrease alcohol intake in rats, there is a positive correlation between the isoflavone content in diets and alcohol intake in mice. This interaction seems to depend on the dose, route of administration, and time of exposure to isoflavones and may be related to specific neurobiological mechanisms. The literature also indicates that isoflavones can interact with some of alcohol's molecular targets and with neural pathways crucial to the alcohol reward process. Given these findings, more attention should be given to the different types of laboratory diets used in alcohol studies to allow better comparison and replication of animal research.
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Affiliation(s)
- P M C Eduardo
- Departamento de Psicobiologia, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - K P Abrahao
- Departamento de Psicobiologia, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
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5
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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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6
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Müller TE, Fontana BD, Bertoncello KT, Franscescon F, Mezzomo NJ, Canzian J, Stefanello FV, Parker MO, Gerlai R, Rosemberg DB. Understanding the neurobiological effects of drug abuse: Lessons from zebrafish models. Prog Neuropsychopharmacol Biol Psychiatry 2020; 100:109873. [PMID: 31981718 DOI: 10.1016/j.pnpbp.2020.109873] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 01/01/2023]
Abstract
Drug abuse and brain disorders related to drug comsumption are public health problems with harmful individual and social consequences. The identification of therapeutic targets and precise pharmacological treatments to these neuropsychiatric conditions associated with drug abuse are urgently needed. Understanding the link between neurobiological mechanisms and behavior is a key aspect of elucidating drug abuse-related targets. Due to various molecular, biochemical, pharmacological, and physiological features, the zebrafish (Danio rerio) has been considered a suitable vertebrate for modeling complex processes involved in drug abuse responses. In this review, we discuss how the zebrafish has been successfully used for modeling neurobehavioral phenotypes related to drug abuse and review the effects of opioids, cannabinoids, alcohol, nicotine, and psychedelic drugs on the central nervous system (CNS). Moreover, we summarize recent advances in zebrafish-based studies and outline potential advantages and limitations of the existing zebrafish models to explore the neurochemical bases of drug abuse and addiction. Finally, we discuss how the use of zebrafish models may present fruitful approaches to provide valuable clinically translatable data.
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Affiliation(s)
- Talise E Müller
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil.
| | - Barbara D Fontana
- Brain and Behaviour Laboratory, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Old St Michael's Building, Portsmouth PO1 2DT, UK
| | - Kanandra T Bertoncello
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil
| | - Francini Franscescon
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil
| | - Nathana J Mezzomo
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Pharmacology, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil
| | - Julia Canzian
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil
| | - Flavia V Stefanello
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil
| | - Matthew O Parker
- Brain and Behaviour Laboratory, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Old St Michael's Building, Portsmouth PO1 2DT, UK
| | - Robert Gerlai
- Department of Psychology, University of Toronto, Mississauga, Canada; Department of Cell and Systems Biology, University of Toronto, Canada
| | - Denis B Rosemberg
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; The International Zebrafish Neuroscience Research Consortium (ZNRC), 309 Palmer Court, Slidell, LA 70458, USA.
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Zhao H, Xue Q, Li C, Wang Q, Han S, Zhou Y, Yang T, Xie Y, Fu H, Lu C, Meng F, Zhang M, Zhang Y, Wu X, Wu S, Zhuo M, Xu H. Upregulation of Beta4 subunit of BK Ca channels in the anterior cingulate cortex contributes to mechanical allodynia associated anxiety-like behaviors. Mol Brain 2020; 13:22. [PMID: 32070382 PMCID: PMC7029562 DOI: 10.1186/s13041-020-0555-z] [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] [Received: 12/16/2019] [Accepted: 01/19/2020] [Indexed: 12/02/2022] Open
Abstract
The anterior cingulate cortex (ACC) serves as a critical hub for the anxiety and pain perception. The large-conductance Ca2+-activated potassium channels, or BKCa channels, are ubiquitously expressed throughout the central nervous system including the cingulate cortex. However, what changes of cortical BKCa channels undergo in the ACC remains unknown in pain-related anxiety. In the present study, a significant upregulation of synaptic and non-synaptic BKCa channel accessory β4 subunits in the ACC was accompanied with pain-associated anxiety-like behaviors in the chronic compression of multiple dorsal root ganglia (mCCD) of the rat. NS1619, an opener of BKCa channels, significantly rescued the alteration of fAHP and AP duration of ACC pyramidal neurons in mCCD rats. The mRNA expression of BKCa β4 subunits was extremely upregulated in the ACC after mCCD with the increased amount of both synaptic and non-synaptic BKCa β4 subunit protein. Meanwhile, NS1619 reversed the enhanced AMPA receptor-mediated spontaneous excitatory postsynaptic current (sEPSC) frequency and the attenuated PPR of ACC neurons in mCCD rats. Local activation of BKCa channels in the ACC reversed mechanical allodynia and anxiety-like behaviors. These results suggest that the upregulation of postsynaptic and presynaptic BKCa β4 subunit may contribute to neuronal hyperexcitability and the enhanced synaptic transmission in the ACC in neuropathic pain state, and then may result in anxiety-like behavior induced by neuropathic pain.
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Affiliation(s)
- Huan Zhao
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China.,Center for Neuron and Disease, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.,Department of Anesthesiology, Heze Municipal Hospital, Heze, 274031, Shandong, China
| | - Qian Xue
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Cong Li
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China.,Department of Anesthesiology, Heze Municipal Hospital, Heze, 274031, Shandong, China.,Shandong First Medcial University & Shandong Academy of Medical Sciences, Taian, 271000, Shandong, China
| | - Qingchuan Wang
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China.,Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Shichao Han
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Yongsheng Zhou
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Tao Yang
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Yingli Xie
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Hao Fu
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Changbo Lu
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Fancheng Meng
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Ming Zhang
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Yan Zhang
- Department of Anesthesiology, Heze Municipal Hospital, Heze, 274031, Shandong, China
| | - Xianglong Wu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Shengxi Wu
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Min Zhuo
- Center for Neuron and Disease, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.,Department of Phsyiology, University of Toronto, Toronto, Canada
| | - Hui Xu
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China. .,Center for Neuron and Disease, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
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8
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BK channel clustering is required for normal behavioral alcohol sensitivity in C. elegans. Sci Rep 2019; 9:10224. [PMID: 31308408 PMCID: PMC6629859 DOI: 10.1038/s41598-019-46615-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 07/02/2019] [Indexed: 02/05/2023] Open
Abstract
The large conductance, calcium- and voltage-activated potassium channel, known as the BK channel, is one of the central proteins that mediate alcohol intoxication and tolerance across species. Although ethanol targets BK channels through direct interaction, how ethanol-mediated BK channel activation causes behavioral intoxication is poorly understood. In. C. elegans, loss of function in SLO-1, the BK channel ortholog, confers profound ethanol resistance in movement and egg-laying behaviors. Here, we show that depletion of SLO-1 channels clustered at the active zones with no change in the overall channel expression level results in locomotory resistance to the intoxicating effect of ethanol, equivalent to that of slo-1 loss-of-function mutants. Likewise, depletion of clustered SLO-1 channels in the sarcolemma and neurons leads to ethanol-resistant egg-laying behavior. By contrast, reduction in the overall SLO-1 channel level by over 70% causes only moderate ethanol resistance in movement, and minimal, if any, resistance in egg laying. Our findings strongly suggest that behavioral ethanol sensitivity is conferred by local, but not global, depression of excitability via clustered BK channels. Given that clustered BK channels are functionally coupled to, and localize near, calcium channels, ethanol may mediate its behavioral effects by targeting BK channels and their coupled calcium channels.
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9
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Kaewphaleuk T, Watanapa WB, Panich U. Ethanol enhances endothelial ionic currents and nitric oxide release via intermediate-conductance calcium-activated potassium channel. Life Sci 2019; 228:21-29. [PMID: 31026455 DOI: 10.1016/j.lfs.2019.04.052] [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: 02/15/2019] [Revised: 04/17/2019] [Accepted: 04/22/2019] [Indexed: 12/29/2022]
Abstract
AIMS Ethanol is known to induce NO release and coronary vasorelaxation. Evidence suggests that K+ channels, especially a Ca2+-activated K+ channel (KCa), may regulate endothelial NO production. We aimed to investigate the ethanol effect on K+ currents in human coronary artery endothelial cells (HCAECs), identify the K+ channel type/subtype and signaling pathway involved, and demonstrate the relevance to ethanol-induced NO release. MAIN METHODS Ionic currents of cultured HCAECs were studied using whole-cell patch clamp technique. NO production were measured using the fluorescent probe, 2,3-diaminonaphthalene. KEY FINDINGS We found that ethanol significantly potentiated HCAEC current (maximal increase to 155.68 ± 18.93%, 20 mM ethanol, +80 mV; mean ± SEM, n = 9). Ethanol-induced current was significantly inhibited by blockers of IKCa or SKCa (intermediate- or small-conductance KCa), but not by blocking other K+ channels. When other known HCAEC channels were inhibited except IKCa, 20 mM ethanol significantly increased IKCa current to 198 ± 25.11% (n = 6), but it could not enhance SKCa current that was similarly isolated. Moreover, ethanol-induced NO release was prevented by blocking IKCa channel, adenosine A2A receptor (A2AR), Gs protein, or protein kinase A (PKA). SIGNIFICANCE This study was the first to demonstrate that acute ethanol exposure could activate endothelial IKCa channel, via A2AR-Gs-PKA signaling, leading to increased whole-cell current and NO release, which could be an important mechanism underlying ethanol-induced NO release and vasodilation.
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Affiliation(s)
- Thanaporn Kaewphaleuk
- Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Wattana B Watanapa
- Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
| | - Uraiwan Panich
- Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
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10
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Morel C, Montgomery S, Han MH. Nicotine and alcohol: the role of midbrain dopaminergic neurons in drug reinforcement. Eur J Neurosci 2018; 50:2180-2200. [PMID: 30251377 DOI: 10.1111/ejn.14160] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/31/2018] [Accepted: 08/20/2018] [Indexed: 12/11/2022]
Abstract
Nicotine and alcohol addiction are leading causes of preventable death worldwide and continue to constitute a huge socio-economic burden. Both nicotine and alcohol perturb the brain's mesocorticolimbic system. Dopamine (DA) neurons projecting from the ventral tegmental area (VTA) to multiple downstream structures, including the nucleus accumbens, prefrontal cortex, and amygdala, are highly involved in the maintenance of healthy brain function. VTA DA neurons play a crucial role in associative learning and reinforcement. Nicotine and alcohol usurp these functions, promoting reinforcement of drug taking behaviors. In this review, we will first describe how nicotine and alcohol individually affect VTA DA neurons by examining how drug exposure alters the heterogeneous VTA microcircuit and network-wide projections. We will also examine how coadministration or previous exposure to nicotine or alcohol may augment the reinforcing effects of the other. Additionally, this review briefly summarizes the role of VTA DA neurons in nicotine, alcohol, and their synergistic effects in reinforcement and also addresses the remaining questions related to the circuit-function specificity of the dopaminergic system in mediating nicotine/alcohol reinforcement and comorbidity.
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Affiliation(s)
- Carole Morel
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sarah Montgomery
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ming-Hu Han
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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11
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Scott LL, Iyer S, Philpo AE, Avalos MN, Wu NS, Shi T, Prakash BA, Nguyen TT, Mihic SJ, Aldrich RW, Pierce JT. A Novel Peptide Restricts Ethanol Modulation of the BK Channel In Vitro and In Vivo. J Pharmacol Exp Ther 2018; 367:282-290. [PMID: 30158242 DOI: 10.1124/jpet.118.251918] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/20/2018] [Indexed: 12/13/2022] Open
Abstract
Alcohol is a widely used and abused substance. A major unresolved issue in the alcohol research field is determining which of the many alcohol target proteins identified to date is responsible for shaping each specific alcohol-related behavior. The large-conductance, calcium- and voltage-activated potassium channel (BK channel) is a conserved target of ethanol. Genetic manipulation of the highly conserved BKα channel influences alcohol-related behaviors across phylogenetically diverse species that include worm, fly, mouse, and man. A pharmacological tool that prevents alcohol's action at a single target, like the BK channel, would complement genetic approaches in the quest to define the behavioral consequences of alcohol at each target. To identify agents that specifically modulate the action of ethanol at the BK channel, we executed a high-throughput phagemid-display screen in combination with a Caenorhabditis elegans behavioral genetics assay. This screen selected a novel nonapeptide, LS10, which moderated acute ethanol intoxication in a BK channel-humanized C. elegans strain without altering basal behavior. LS10's action in vivo was dependent upon BK channel functional activity. Single-channel electrophysiological recordings in vitro showed that preincubation with a submicromolar concentration of LS10 restricted ethanol-induced changes in human BKα channel gating. In contrast, no substantial changes in basal human BKα channel function were observed after LS10 application. The results obtained with the LS10 peptide provide proof-of-concept evidence that a combined phagemid-display/behavioral genetics screening approach can provide novel tools for understanding the action of alcohol at the BK channel and how this, in turn, exerts influence over central nervous system function.
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Affiliation(s)
- Luisa L Scott
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Sangeetha Iyer
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Ashley E Philpo
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Melva N Avalos
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Natalie S Wu
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Ted Shi
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Brooke A Prakash
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Thanh-Tu Nguyen
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - S John Mihic
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Richard W Aldrich
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Jonathan T Pierce
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
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12
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Shipston MJ. Control of anterior pituitary cell excitability by calcium-activated potassium channels. Mol Cell Endocrinol 2018; 463:37-48. [PMID: 28596131 DOI: 10.1016/j.mce.2017.06.003] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/02/2017] [Accepted: 06/02/2017] [Indexed: 01/01/2023]
Abstract
In anterior pituitary endocrine cells, large (BK), small (SK) and intermediate (IK) conductance calcium activated potassium channels are key determinants in shaping cellular excitability in a cell type- and context-specific manner. Indeed, these channels are targeted by multiple signaling pathways that stimulate or inhibit cellular excitability. BK channels can, paradoxically, both promote electrical bursting as well as terminate bursting and spiking dependent upon intrinsic BK channel properties and proximity to voltage gated calcium channels in somatotrophs, lactotrophs and corticotrophs. In contrast, SK channels are predominantly activated by calcium released from intracellular IP3-sensitive calcium stores and mediate membrane hyperpolarization in cells including gonadotrophs and corticotrophs. IK channels are predominantly expressed in corticotrophs where they limit membrane excitability. A major challenge for the future is to determine the cell-type specific molecular composition of calcium-activated potassium channels and how they control anterior pituitary hormone secretion as well as other calcium-dependent processes.
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Affiliation(s)
- Michael J Shipston
- Centre for Integrative Physiology, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh, EH89XD, UK.
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13
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Abrahao KP, Salinas AG, Lovinger DM. Alcohol and the Brain: Neuronal Molecular Targets, Synapses, and Circuits. Neuron 2017; 96:1223-1238. [PMID: 29268093 PMCID: PMC6566861 DOI: 10.1016/j.neuron.2017.10.032] [Citation(s) in RCA: 247] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/30/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
Abstract
Ethanol is one of the most commonly abused drugs. Although environmental and genetic factors contribute to the etiology of alcohol use disorders, it is ethanol's actions in the brain that explain (1) acute ethanol-related behavioral changes, such as stimulant followed by depressant effects, and (2) chronic changes in behavior, including escalated use, tolerance, compulsive seeking, and dependence. Our knowledge of ethanol use and abuse thus relies on understanding its effects on the brain. Scientists have employed both bottom-up and top-down approaches, building from molecular targets to behavioral analyses and vice versa, respectively. This review highlights current progress in the field, focusing on recent and emerging molecular, cellular, and circuit effects of the drug that impact ethanol-related behaviors. The focus of the field is now on pinpointing which molecular effects in specific neurons within a brain region contribute to behavioral changes across the course of acute and chronic ethanol exposure.
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Affiliation(s)
- Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - Armando G Salinas
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA.
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14
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Kuntamallappanavar G, Dopico AM. BK β1 subunit-dependent facilitation of ethanol inhibition of BK current and cerebral artery constriction is mediated by the β1 transmembrane domain 2. Br J Pharmacol 2017; 174:4430-4448. [PMID: 28940182 DOI: 10.1111/bph.14046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/11/2017] [Accepted: 09/14/2017] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Ethanol at concentrations obtained in the circulation during moderate-heavy episodic drinking (30-60 mM) causes cerebral artery constriction in several species, including humans. In rodents, ethanol-induced cerebral artery constriction results from ethanol inhibition of large conductance voltage/Ca2+i -gated K+ (BK) channels in cerebral artery myocytes. Moreover, the smooth muscle-abundant BK β1 accessory subunit is required for ethanol to inhibit cerebral artery myocyte BK channels under physiological Ca2+i and voltages and thus constrict cerebral arteries. The molecular bases of these ethanol actions remain unknown. Here, we set to identify the BK β1 region(s) that mediates ethanol-induced inhibition of cerebral artery myocyte BK channels and eventual arterial constriction. EXPERIMENTAL APPROACH We used protein biochemistry, patch-clamp on engineered channel subunits, reversible cDNA permeabilization of KCNMB1 K/O mouse arteries and artery in vitro pressurization. KEY RESULTS Ethanol inhibition of BK current was facilitated by β1 but not β4 subunits. Furthermore, only BK complexes containing β chimeras with β1 transmembrane (TM) domains on a β4 background or with a β1 TM2 domain on a β4 background displayed ethanol responses identical to those of BK complexes including wild-type β1. Moreover, β1 TM2 itself but not other β regions were necessary for ethanol-induced cerebral artery constriction. CONCLUSIONS AND IMPLICATIONS BK β1 TM2 is necessary for this subunit to enable ethanol-induced inhibition of myocyte BK channels and cerebral artery constriction at physiological Ca2+ and voltages. Thus, novel agents that target β1 TM2 may be considered to counteract ethanol-induced cerebral artery constriction and associated cerebrovascular conditions.
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Affiliation(s)
- Guruprasad Kuntamallappanavar
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Alex M Dopico
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, USA
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15
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Alcohol Regulates BK Surface Expression via Wnt/β-Catenin Signaling. J Neurosci 2017; 36:10625-10639. [PMID: 27733613 DOI: 10.1523/jneurosci.0491-16.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 07/27/2016] [Indexed: 12/26/2022] Open
Abstract
It has been suggested that drug tolerance represents a form of learning and memory, but this has not been experimentally established at the molecular level. We show that a component of alcohol molecular tolerance (channel internalization) from rat hippocampal neurons requires protein synthesis, in common with other forms of learning and memory. We identify β-catenin as a primary necessary protein. Alcohol increases β-catenin, and blocking accumulation of β-catenin blocks alcohol-induced internalization in these neurons. In transfected HEK293 cells, suppression of Wnt/β-catenin signaling blocks ethanol-induced internalization. Conversely, activation of Wnt/β-catenin reduces BK current density. A point mutation in a putative glycogen synthase kinase phosophorylation site within the S10 region of BK blocks internalization, suggesting that Wnt/β-catenin directly regulates alcohol-induced BK internalization via glycogen synthase kinase phosphorylation. These findings establish de novo protein synthesis and Wnt/β-catenin signaling as critical in mediating a persistent form of BK molecular alcohol tolerance establishing a commonality with other forms of long-term plasticity. SIGNIFICANCE STATEMENT Alcohol tolerance is a key step toward escalating alcohol consumption and subsequent dependence. Our research aims to make significant contributions toward novel, therapeutic approaches to prevent and treat alcohol misuse by understanding the molecular mechanisms of alcohol tolerance. In our current study, we identify the role of a key regulatory pathway in alcohol-induced persistent molecular changes within the hippocampus. The canonical Wnt/β-catenin pathway regulates BK channel surface expression in a protein synthesis-dependent manner reminiscent of other forms of long-term hippocampal neuronal adaptations. This unique insight opens the possibility of using clinically tested drugs, targeting the Wnt/β-catenin pathway, for the novel use of preventing and treating alcohol dependency.
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16
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Inenaga K, Ono K, Hitomi S, Kuroki A, Ujihara I. Thirst sensation and oral dryness following alcohol intake. JAPANESE DENTAL SCIENCE REVIEW 2017; 53:78-85. [PMID: 28725298 PMCID: PMC5501731 DOI: 10.1016/j.jdsr.2016.12.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 09/28/2016] [Accepted: 12/08/2016] [Indexed: 01/18/2023] Open
Abstract
Substantial acute and chronic intakes of alcohol or ethanol (EtOH) severely influence oral sensations, such as thirst and oral dryness (dry mouth, xerostomia). Thirst sensation and oral dryness are primarily caused by the activation of neurons in brain regions, including the circumventricular organs and hypothalamus, which are referred to as the dipsogenic center, and by a decrease in salivary secretion, respectively. The sensation of thirst experienced after heavy-alcohol drinking is widely regarded as a consequence of EtOH-induced diuresis; however, EtOH in high doses induces anti-diuresis. Recently, it has been proposed that the ethanol metabolite acetaldehyde induces thirst via two distinct processes in the central nervous system from EtOH-induced diuresis, based on the results of animal experiments. The present review describes new insights regarding the induction mechanism of thirst sensation and oral dryness after drinking alcohol.
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Affiliation(s)
- Kiyotoshi Inenaga
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan
| | - Kentaro Ono
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan
| | - Suzuro Hitomi
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan
| | - Ayu Kuroki
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan
| | - Izumi Ujihara
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan
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17
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Shah A, Zuo W, Kang S, Li J, Fu R, Zhang H, Bekker A, Ye JH. The lateral habenula and alcohol: Role of glutamate and M-type potassium channels. Pharmacol Biochem Behav 2017. [PMID: 28624587 DOI: 10.1016/j.pbb.2017.06.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Alcohol use disorder (AUD) or alcoholism is a chronic relapsing disorder. Our knowledge of alcoholism hinges on our understanding of its effects on the brain. This review will center on the effects of alcohol in the lateral habenula (LHb), an epithalamic structure that connects the forebrain with the midbrain and encodes aversive signaling. Like many addictive drugs, alcohol has both rewarding and aversive properties. While alcohol's euphoric property is believed to be important for the initiation of drinking, increasing evidence suggests that alcohol's negative affect plays a critical role in excessive drinking and alcohol dependence. During withdrawal and abstinence, alcoholics often experience anxiety and depressions, both of which have been implicated in relapse drinking. This review focuses on the recent accumulation of knowledge about the effects of acute and chronic alcohol exposure on the activity of and synaptic transmissions on LHb neurons, as well as the effects of manipulation of LHb function on alcohol consumption and related behaviors. Recent evidence highlights a critical role for the LHb in AUD and related psychiatric ailments. Multidisciplinary work in animals collectively suggests that LHb function and activity, including M-type potassium channels and glutamatergic transmission are altered by acute and repeated chronic alcohol exposure. We will also discuss how functional, pharmacological, and chemogenetic manipulation of the LHb affects ethanol drinking and psychiatric disorders occurring in animals withdrawn from chronic alcohol exposure. Conceivable mechanisms behind these effects and their potential as targets for therapies will also be discussed.
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Affiliation(s)
- Avi Shah
- Department of Anesthesiology, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA; Department of Pharmacology, Physiology and Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Wanhong Zuo
- Department of Anesthesiology, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA; Department of Pharmacology, Physiology and Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Seungwoo Kang
- Department of Anesthesiology, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA; Department of Pharmacology, Physiology and Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Jing Li
- Department of Anesthesiology, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA; Department of Pharmacology, Physiology and Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Rao Fu
- Department of Anesthesiology, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA; Department of Pharmacology, Physiology and Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Haifeng Zhang
- Department of Anesthesiology, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA; Department of Pharmacology, Physiology and Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Alex Bekker
- Department of Anesthesiology, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA; Department of Pharmacology, Physiology and Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Jiang-Hong Ye
- Department of Anesthesiology, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA; Department of Pharmacology, Physiology and Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA.
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18
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Behavioral Deficits Following Withdrawal from Chronic Ethanol Are Influenced by SLO Channel Function in Caenorhabditis elegans. Genetics 2017; 206:1445-1458. [PMID: 28546434 DOI: 10.1534/genetics.116.193102] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 04/29/2017] [Indexed: 01/03/2023] Open
Abstract
Symptoms of withdrawal from chronic alcohol use are a driving force for relapse in alcohol dependence. Thus, uncovering molecular targets to lessen their severity is key to breaking the cycle of dependence. Using the nematode Caenorhabditis elegans, we tested whether one highly conserved ethanol target, the large-conductance, calcium-activated potassium channel (known as the BK channel or Slo1), modulates ethanol withdrawal. Consistent with a previous report, we found that C. elegans displays withdrawal-related behavioral impairments after cessation of chronic ethanol exposure. We found that the degree of impairment is exacerbated in worms lacking the worm BK channel, SLO-1, and is reduced by selective rescue of this channel in the nervous system. Enhanced SLO-1 function, via gain-of-function mutation or overexpression, also dramatically reduced behavioral impairment during withdrawal. Consistent with these results, we found that chronic ethanol exposure decreased SLO-1 expression in a subset of neurons. In addition, we found that the function of a distinct, conserved Slo family channel, SLO-2, showed an inverse relationship to withdrawal behavior, and this influence depended on SLO-1 function. Together, our findings show that modulation of either Slo family ion channel bidirectionally regulates withdrawal behaviors in worm, supporting further exploration of the Slo family as targets for normalizing behaviors during alcohol withdrawal.
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19
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Bukiya AN, Dopico AM. Common structural features of cholesterol binding sites in crystallized soluble proteins. J Lipid Res 2017; 58:1044-1054. [PMID: 28420706 DOI: 10.1194/jlr.r073452] [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: 11/29/2016] [Revised: 04/12/2017] [Indexed: 01/24/2023] Open
Abstract
Cholesterol-protein interactions are essential for the architectural organization of cell membranes and for lipid metabolism. While cholesterol-sensing motifs in transmembrane proteins have been identified, little is known about cholesterol recognition by soluble proteins. We reviewed the structural characteristics of binding sites for cholesterol and cholesterol sulfate from crystallographic structures available in the Protein Data Bank. This analysis unveiled key features of cholesterol-binding sites that are present in either all or the majority of sites: i) the cholesterol molecule is generally positioned between protein domains that have an organized secondary structure; ii) the cholesterol hydroxyl/sulfo group is often partnered by Asn, Gln, and/or Tyr, while the hydrophobic part of cholesterol interacts with Leu, Ile, Val, and/or Phe; iii) cholesterol hydrogen-bonding partners are often found on α-helices, while amino acids that interact with cholesterol's hydrophobic core have a slight preference for β-strands and secondary structure-lacking protein areas; iv) the steroid's C21 and C26 constitute the "hot spots" most often seen for steroid-protein hydrophobic interactions; v) common "cold spots" are C8-C10, C13, and C17, at which contacts with the proteins were not detected. Several common features we identified for soluble protein-steroid interaction appear evolutionarily conserved.
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Affiliation(s)
- Anna N Bukiya
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38103
| | - Alejandro M Dopico
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38103
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20
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Ethanol-Sensitive Pacemaker Neurons in the Mouse External Globus Pallidus. Neuropsychopharmacology 2017; 42:1070-1081. [PMID: 27827370 PMCID: PMC5506786 DOI: 10.1038/npp.2016.251] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 10/26/2016] [Accepted: 10/27/2016] [Indexed: 11/27/2022]
Abstract
Although ethanol is one of the most widely used drugs, we still lack a full understanding of which neuronal subtypes are affected by this drug. Pacemaker neurons exert powerful control over brain circuit function, but little is known about ethanol effects on these types of neurons. Neurons in the external globus pallidus (GPe) generate pacemaker activity that controls basal ganglia, circuitry associated with habitual and compulsive drug use. We performed patch-clamp recordings from GPe neurons and found that bath application of ethanol dose-dependently decreased the firing rate of low-frequency GPe neurons, but did not alter the firing of high-frequency neurons. GABA or glutamate receptor antagonists did not block the ethanol effect. The GPe is comprised of a heterogeneous population of neurons. We used Lhx6-EGFP and Npas1-tdTm mice strains to identify low-frequency neurons. Lhx6 and Npas1 neurons exhibited decreased firing with ethanol, but only Npas1 neurons were sensitive to 10 mM ethanol. Large-conductance voltage and Ca2+-activated K+ (BK) channel have a key role in the ethanol effect on GPe neurons, as the application of BK channel inhibitors blocked the ethanol-induced firing decrease. Ethanol also increased BK channel open probability measured in single-channel recordings from Npas1-tdTm neurons. In addition, in vivo electrophysiological recordings from GPe showed that ethanol decreased the firing of a large subset of low-frequency neurons. These findings indicate how selectivity of ethanol effects on pacemaker neurons can occur, and enhance our understanding of the mechanisms contributing to acute ethanol effects on the basal ganglia.
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21
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Lovinger DM, Alvarez VA. Alcohol and basal ganglia circuitry: Animal models. Neuropharmacology 2017; 122:46-55. [PMID: 28341206 DOI: 10.1016/j.neuropharm.2017.03.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 03/16/2017] [Accepted: 03/20/2017] [Indexed: 01/18/2023]
Abstract
Brain circuits that include the cortex and basal ganglia make up the bulk of the forebrain, and influence behaviors related to almost all aspects of affective, cognitive and sensorimotor functions. The learning of new actions as well as association of existing action repertoires with environmental events are key functions of this circuitry. Unfortunately, the cortico-basal ganglia circuitry is also the target for all drugs of abuse, including alcohol. This makes the circuitry susceptible to the actions of chronic alcohol exposure that impairs circuit function in ways that contribute to cognitive dysfunction and drug use disorders. In the present review, we describe the connectivity and functions of the associative, limbic and sensorimotor cortico-basal ganglia circuits. We then review the effects of acute and chronic alcohol exposure on circuit function. Finally, we review studies examining the roles of the different circuits and circuit elements in alcohol use and abuse. We attempt to synthesize information from a variety of studies in laboratory animals and humans to generate hypotheses about how the three circuits interact with each other and with the other brain circuits during exposure to alcohol and during the development of alcohol use disorders. This article is part of the Special Issue entitled "Alcoholism".
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Affiliation(s)
- David M Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, United States.
| | - Veronica A Alvarez
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, United States
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22
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Latorre R, Castillo K, Carrasquel-Ursulaez W, Sepulveda RV, Gonzalez-Nilo F, Gonzalez C, Alvarez O. Molecular Determinants of BK Channel Functional Diversity and Functioning. Physiol Rev 2017; 97:39-87. [DOI: 10.1152/physrev.00001.2016] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Large-conductance Ca2+- and voltage-activated K+ (BK) channels play many physiological roles ranging from the maintenance of smooth muscle tone to hearing and neurosecretion. BK channels are tetramers in which the pore-forming α subunit is coded by a single gene ( Slowpoke, KCNMA1). In this review, we first highlight the physiological importance of this ubiquitous channel, emphasizing the role that BK channels play in different channelopathies. We next discuss the modular nature of BK channel-forming protein, in which the different modules (the voltage sensor and the Ca2+ binding sites) communicate with the pore gates allosterically. In this regard, we review in detail the allosteric models proposed to explain channel activation and how the models are related to channel structure. Considering their extremely large conductance and unique selectivity to K+, we also offer an account of how these two apparently paradoxical characteristics can be understood consistently in unison, and what we have learned about the conduction system and the activation gates using ions, blockers, and toxins. Attention is paid here to the molecular nature of the voltage sensor and the Ca2+ binding sites that are located in a gating ring of known crystal structure and constituted by four COOH termini. Despite the fact that BK channels are coded by a single gene, diversity is obtained by means of alternative splicing and modulatory β and γ subunits. We finish this review by describing how the association of the α subunit with β or with γ subunits can change the BK channel phenotype and pharmacology.
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Affiliation(s)
- Ramon Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Karen Castillo
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Willy Carrasquel-Ursulaez
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Romina V. Sepulveda
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Fernando Gonzalez-Nilo
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Carlos Gonzalez
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Osvaldo Alvarez
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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Developmental Ethanol Exposure Leads to Long-Term Deficits in Attention and Its Underlying Prefrontal Circuitry. eNeuro 2016; 3:eN-NWR-0267-16. [PMID: 27844059 PMCID: PMC5099605 DOI: 10.1523/eneuro.0267-16.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 10/18/2016] [Accepted: 10/22/2016] [Indexed: 11/21/2022] Open
Abstract
Chronic prenatal exposure to ethanol can lead to a spectrum of teratogenic outcomes that are classified in humans as fetal alcohol spectrum disorders (FASD). One of the most prevalent and persistent neurocognitive components of FASD is attention deficits, and it is now thought that these attention deficits differ from traditional attention deficit hyperactivity disorder (ADHD) in their quality and response to medication. However, the neuronal mechanisms underlying attention deficits in FASD are not well understood. We show here that after developmental binge-pattern ethanol exposure, adult mice exhibit impaired performance on the five-choice serial reaction time test for visual attention, with lower accuracy during initial training and a higher rate of omissions under challenging conditions of high attention demand. Whole-cell electrophysiology experiments in these same mice find dysregulated pyramidal neurons in layer VI of the medial prefrontal cortex, which are critical for normal attention performance. Layer VI neurons show decreased intrinsic excitability and increased responses to stimulation of both nicotinic acetylcholine receptors and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptors. Moreover, although nicotinic acetylcholine responses correlate with performance on the five-choice task in control mice, these relationships are completely disrupted in mice exposed to ethanol during development. These findings demonstrate a novel outcome of developmental binge-pattern ethanol exposure and suggest that persistent alterations to the function of prefrontal layer VI neurons play an important mechanistic role in attention deficits associated with FASD.
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Kuntamallappanavar G, Dopico AM. Alcohol modulation of BK channel gating depends on β subunit composition. J Gen Physiol 2016; 148:419-440. [PMID: 27799321 PMCID: PMC5089933 DOI: 10.1085/jgp.201611594] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 10/14/2016] [Indexed: 01/01/2023] Open
Abstract
In most mammalian tissues, Ca2+i/voltage-gated, large conductance K+ (BK) channels consist of channel-forming slo1 and auxiliary (β1-β4) subunits. When Ca2+i (3-20 µM) reaches the vicinity of BK channels and increases their activity at physiological voltages, β1- and β4-containing BK channels are, respectively, inhibited and potentiated by intoxicating levels of ethanol (50 mM). Previous studies using different slo1s, lipid environments, and Ca2+i concentrations-all determinants of the BK response to ethanol-made it impossible to determine the specific contribution of β subunits to ethanol action on BK activity. Furthermore, these studies measured ethanol action on ionic current under a limited range of stimuli, rendering no information on the gating processes targeted by alcohol and their regulation by βs. Here, we used identical experimental conditions to obtain single-channel and macroscopic currents of the same slo1 channel ("cbv1" from rat cerebral artery myocytes) in the presence and absence of 50 mM ethanol. First, we assessed the role five different β subunits (1,2,2-IR, 3-variant d, and 4) in ethanol action on channel function. Thus, two phenotypes were identified: (1) ethanol potentiated cbv1-, cbv1+β3-, and cbv1+β4-mediated currents at low Ca2+i while inhibiting current at high Ca2+i, the potentiation-inhibition crossover occurring at 20 µM Ca2+i; (2) for cbv1+β1, cbv1+wt β2, and cbv1+β2-IR, this crossover was shifted to ∼3 µM Ca2+i Second, applying Horrigan-Aldrich gating analysis on both phenotypes, we show that ethanol fails to modify intrinsic gating and the voltage-dependent parameters under examination. For cbv1, however, ethanol (a) drastically increases the channel's apparent Ca2+ affinity (nine-times decrease in Kd) and (b) very mildly decreases allosteric coupling between Ca2+ binding and channel opening (C). The decreased Kd leads to increased channel activity. For cbv1+β1, ethanol (a) also decreases Kd, yet this decrease (two times) is much smaller than that of cbv1; (b) reduces C; and (c) decreases coupling between Ca2+ binding and voltage sensing (parameter E). Decreased allosteric coupling leads to diminished BK activity. Thus, we have identified critical gating modifications that lead to the differential actions of ethanol on slo1 with and without different β subunits.
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Affiliation(s)
- Guruprasad Kuntamallappanavar
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38103
| | - Alex M Dopico
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38103
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Cochet-Escartin O, Carter JA, Chakraverti-Wuerthwein M, Sinha J, Collins EMS. Slo1 regulates ethanol-induced scrunching in freshwater planarians. Phys Biol 2016; 13:055001. [DOI: 10.1088/1478-3975/13/5/055001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Dopico AM, Bukiya AN, Kuntamallappanavar G, Liu J. Modulation of BK Channels by Ethanol. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 128:239-79. [PMID: 27238266 PMCID: PMC5257281 DOI: 10.1016/bs.irn.2016.03.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In alcohol-naïve systems, ethanol (<100mM) exposure of calcium-gated BK channels perturbs physiology and behavior. Brief (several minutes) ethanol exposure usually leads to increased BK current, which results from ethanol interaction with a pocket mapped to the BK channel-forming slo1 protein cytosolic tail domain. The importance of this region in ethanol-induced intoxication has been independently supported by an unbiased screen of Caenorhabditis elegans slo1 mutants. However, ethanol-induced BK activation is not universal as refractoriness and inhibition have been reported. The final effect depends on many factors, including intracellular calcium levels, slo1 isoform, BK beta subunit composition, posttranslational modification of BK proteins, channel lipid microenvironment, and type of ethanol administration. Studies in Drosophila melanogaster, C. elegans, and rodents show that protracted/repeated ethanol administration leads to tolerance to ethanol-induced modification of BK-driven physiology and behavior. Unveiling the mechanisms underlying tolerance is of major importance, as tolerance to ethanol has been proposed as predictor of risk for alcoholism.
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Affiliation(s)
- A M Dopico
- College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States.
| | - A N Bukiya
- College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - G Kuntamallappanavar
- College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - J Liu
- College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States
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Hoshi T, Heinemann SH. Modulation of BK Channels by Small Endogenous Molecules and Pharmaceutical Channel Openers. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 128:193-237. [PMID: 27238265 DOI: 10.1016/bs.irn.2016.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Voltage- and Ca(2+)-activated K(+) channels of big conductance (BK channels) are abundantly found in various organs and their relevance for smooth muscle tone and neuronal signaling is well documented. Dysfunction of BK channels is implicated in an array of human diseases involving many organs including the nervous, pulmonary, cardiovascular, renal, and urinary systems. In humans a single gene (KCNMA1) encodes the pore-forming α subunit (Slo1) of BK channels, but the channel properties are variable because of alternative splicing, tissue- and subcellular-specific auxiliary subunits (β, γ), posttranslational modifications, and a multitude of endogenous signaling molecules directly affecting the channel function. Initiatives to develop drugs capable of activating BK channels (channel openers) therefore need to consider the tissue-specific variability of BK channel structure and the potential interference with endogenously produced regulatory factors. The atomic structural basis of BK channel function is only beginning to be revealed. However, building on detailed knowledge of BK channel function, including its single-channel characteristics, voltage- and Ca(2+) dependence of channel gating, and modulation by diffusible messengers, a multi-tier allosteric model of BK channel gating (Horrigan and Aldrich (HA) model) has become a valuable tool in studying modulation of the channel. Using the conceptual framework of the HA model, we here review the functional impact of endogenous modulatory factors and select small synthetic compounds that regulate BK channel activity. Furthermore, we devise experimental approaches for studying BK channel-drug interactions with the aim to classify BK-modulating substances according to their molecular mode of action.
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Affiliation(s)
- T Hoshi
- University of Pennsylvania, Philadelphia, PA, United States.
| | - S H Heinemann
- Friedrich Schiller University Jena & Jena University Hospital, Jena, Germany
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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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Xie C, Liu HW, Pan N, Ding JP, Yao J. The residue I257 at S4-S5 linker in KCNQ1 determines KCNQ1/KCNE1 channel sensitivity to 1-alkanols. Acta Pharmacol Sin 2016; 37:124-33. [PMID: 26725740 DOI: 10.1038/aps.2015.133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/10/2015] [Indexed: 01/03/2023] Open
Abstract
AIM KCNQ1 and KCNE1 form a complex in human ventricular cardiomyocytes, which are important in maintaining a normal heart rhythm. In the present study we investigated the effects of a homologous series of 1-alkanols on KCNQ1/KCNE1 channels expressed in Xenopus oocytes. METHODS ECG recording was made in rats injected with ethanol-containing solution (0.3 mL, ip). Human KCNQ1 channel and its auxiliary subunit KCNE1 were heterologously coexpressed in Xenopus oocytes, which were superfused with ND96 solution; 1-alkanols (ethanol, 1-butanol and 1-hexanol) were delivered through a gravity-driven perfusion device. The slow-delayed rectifier potassium currents IKs (KCNQ1/KCNE1 currents) were recorded using a two-electrode voltage clamp method. Site-directed mutations (I257A) were made in KCNQ1. RESULTS In ECG recordings, a low concentration of ethanol (3%, v/v) slightly increased the heart rate of rats, whereas the higher concentrations of ethanol (10%, 50%, v/v) markedly reduced it. In oocytes coexpressing KCNQ1/KCNE1 channels, ethanol, 1-butanol and 1-hexanol dose-dependently inhibited IKs currents with IC50 values of 80, 11 and 2.7 mmol/L, respectively. Furthermore, the 1-alkanols blocked the KCNQ1 channel in both open and closed states, and a four-state model could adequately explain the effects of 1-alkanols on the closed-state channel block. Moreover, the mutation of I257A at the intracellular loop between S4 and S5 in KCNQ1 greatly decreased the sensitivity to 1-alkanols; and the IC50 values of ethanol, 1-butanol and 1-hexanol were increased to 634, 414 and 7.4 mmol/L, respectively. The mutation also caused the ablation of closed-state channel block. CONCLUSION These findings provide new insight into the intricate mechanisms of the blocking effects of ethanol on the KCNQ1 channel.
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Kreifeldt M, Cates-Gatto C, Roberts AJ, Contet C. BK Channel β1 Subunit Contributes to Behavioral Adaptations Elicited by Chronic Intermittent Ethanol Exposure. Alcohol Clin Exp Res 2015; 39:2394-402. [PMID: 26578345 DOI: 10.1111/acer.12911] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 09/16/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Large conductance, calcium- and voltage-activated potassium (BK) channels regulate neuronal excitability and neurotransmission. They can be directly activated by ethanol (EtOH) and they may be implicated in EtOH dependence. In this study, we sought to determine the influence of the auxiliary β1 and β4 subunits on EtOH metabolism, acute sensitivity to EtOH intoxication, acute functional tolerance, chronic tolerance, and handling-induced convulsions during withdrawal. METHODS Motor coordination, righting reflex, and body temperature were evaluated in BK β1 and β4 knockout, heterozygous, and wild-type mice following acute EtOH administration. Chronic tolerance and physical dependence were induced by chronic intermittent inhalation of EtOH vapor. RESULTS Constitutive deficiency in BK β1 or β4 subunits did not alter the clearance rate of EtOH, acute sensitivity to EtOH-induced ataxia, sedation, and hypothermia, nor acute functional tolerance to ataxia. BK β1 deletion reduced chronic tolerance to sedation and abolished chronic tolerance to hypothermia, while BK β4 deletion did not affect these adaptations to chronic EtOH exposure. Finally, the absence of BK β1 accelerated the appearance, while the absence of BK β4 delayed the resolution, of the hyperexcitable state associated with EtOH withdrawal. CONCLUSIONS Altogether, the present findings reveal the critical role of BK β1 in behavioral adaptations to prolonged, repeated EtOH intoxication.
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Affiliation(s)
- Max Kreifeldt
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California
| | - Chelsea Cates-Gatto
- Molecular and Cellular Neuroscience Department, The Scripps Research Institute, La Jolla, California
| | - Amanda J Roberts
- Molecular and Cellular Neuroscience Department, The Scripps Research Institute, La Jolla, California
| | - Candice Contet
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California
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Chang J, Fedinec AL, Kuntamallappanavar G, Leffler CW, Bukiya AN, Dopico AM. Endothelial Nitric Oxide Mediates Caffeine Antagonism of Alcohol-Induced Cerebral Artery Constriction. J Pharmacol Exp Ther 2015; 356:106-15. [PMID: 26555891 DOI: 10.1124/jpet.115.229054] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/05/2015] [Indexed: 12/31/2022] Open
Abstract
Despite preventive education, the combined consumption of alcohol and caffeine (particularly from "energy drinks") continues to rise. Physiologic perturbations by separate intake of ethanol and caffeine have been widely documented. However, the biologic actions of the alcohol-caffeine combination and their underlying subcellular mechanisms have been scarcely studied. Using intravital microscopy on a closed-cranial window and isolated, pressurized vessels, we investigated the in vivo and in vitro action of ethanol-caffeine mixtures on cerebral arteries from rats and mice, widely recognized models to address cerebrovascular pathophysiology and pharmacology. Caffeine at concentrations found in human circulation after ingestion of one to two cups of coffee (10 µM) antagonized the endothelium-independent constriction of cerebral arteries evoked by ethanol concentrations found in blood during moderate-heavy alcohol intoxication (40-70 mM). Caffeine antagonism against alcohol was similar whether evaluated in vivo or in vitro, suggesting independence of systemic factors and drug metabolism, but required a functional endothelium. Moreover, caffeine protection against alcohol increased nitric oxide (NO•) levels over those found in the presence of ethanol alone, disappeared upon blocking NO• synthase, and could not be detected in pressurized cerebral arteries from endothelial nitric-oxide synthase knockout (eNOS(-/-)) mice. Finally, incubation of de-endothelialized cerebral arteries with the NO• donor sodium nitroprusside (10 µM) fully restored the protective effect of caffeine. This study demonstrates for the first time that caffeine antagonizes ethanol-induced cerebral artery constriction and identifies endothelial NO• as the critical caffeine effector on smooth muscle targets. Conceivably, situations that perturb endothelial function and/or NO• availability will critically alter caffeine antagonism of alcohol-induced cerebrovascular constriction without significantly disrupting endothelium-independent, alcohol-induced cerebral artery constriction itself.
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Affiliation(s)
- Jennifer Chang
- Department of Pharmacology (J.C., G.K., A.N.B., A.M.D.) and Department of Physiology (A.L.F., C.W.L.), College of Medicine, Health Science Center, University of Tennessee, Memphis, Tennessee
| | - Alexander L Fedinec
- Department of Pharmacology (J.C., G.K., A.N.B., A.M.D.) and Department of Physiology (A.L.F., C.W.L.), College of Medicine, Health Science Center, University of Tennessee, Memphis, Tennessee
| | - Guruprasad Kuntamallappanavar
- Department of Pharmacology (J.C., G.K., A.N.B., A.M.D.) and Department of Physiology (A.L.F., C.W.L.), College of Medicine, Health Science Center, University of Tennessee, Memphis, Tennessee
| | - Charles W Leffler
- Department of Pharmacology (J.C., G.K., A.N.B., A.M.D.) and Department of Physiology (A.L.F., C.W.L.), College of Medicine, Health Science Center, University of Tennessee, Memphis, Tennessee
| | - Anna N Bukiya
- Department of Pharmacology (J.C., G.K., A.N.B., A.M.D.) and Department of Physiology (A.L.F., C.W.L.), College of Medicine, Health Science Center, University of Tennessee, Memphis, Tennessee
| | - Alex M Dopico
- Department of Pharmacology (J.C., G.K., A.N.B., A.M.D.) and Department of Physiology (A.L.F., C.W.L.), College of Medicine, Health Science Center, University of Tennessee, Memphis, Tennessee
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Korpi ER, den Hollander B, Farooq U, Vashchinkina E, Rajkumar R, Nutt DJ, Hyytiä P, Dawe GS. Mechanisms of Action and Persistent Neuroplasticity by Drugs of Abuse. Pharmacol Rev 2015; 67:872-1004. [DOI: 10.1124/pr.115.010967] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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