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Domi A, Cadeddu D, Lucente E, Gobbo F, Edvardsson C, Petrella M, Jerlhag E, Ericson M, Söderpalm B, Adermark L. Pre- and postsynaptic signatures in the prelimbic cortex associated with "alcohol use disorder" in the rat. Neuropsychopharmacology 2024; 49:1851-1860. [PMID: 38755284 DOI: 10.1038/s41386-024-01887-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/20/2024] [Accepted: 05/07/2024] [Indexed: 05/18/2024]
Abstract
The transition to alcohol use disorder (AUD) involves persistent neuroadaptations in executive control functions primarily regulated by the medial prefrontal cortex. However, the neurophysiological correlates to behavioral manifestations of AUD are not fully defined. The association between cortical neuroadaptations and behavioral manifestations of addiction was studied using a multi-symptomatic operant model based on the DSM-5 diagnostic criteria for AUD. This model aimed to characterize an AUD-vulnerable and AUD-resistant subpopulation of outbred male Wistar rats and was combined with electrophysiological measurements in the prelimbic cortex (PL). Mirroring clinical observations, rats exhibited individual variability in their vulnerability to develop AUD-like behavior, including motivation to seek for alcohol (crit 1), increased effort to obtain the substance (crit 2), and continued drinking despite negative consequences (crit 3). Only a small subset of rats met all the aforementioned AUD criteria (3 crit, AUD-vulnerable), while a larger fraction was considered AUD-resilient (0 crit). The development of AUD-like behavior was characterized by disruptions in glutamatergic synaptic activity, involving decreased frequency of spontaneous excitatory postsynaptic currents (sEPSCs) and heightened intrinsic excitability in layers 2/3 PL pyramidal neurons. These alterations were concomitant with a significant impairment in the ability of mGlu2/3 receptors to negatively regulate glutamate release in the PL but not in downstream regions like the basolateral amygdala or nucleus accumbens core. In conclusion alterations in PL synaptic activity were strongly associated with individual addiction scores, indicating their role as potential markers of the behavioral manifestations linked to AUD psychopathology.
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Affiliation(s)
- Ana Domi
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 90, Sweden.
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 45, Sweden.
| | - Davide Cadeddu
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 90, Sweden
| | - Erika Lucente
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 90, Sweden
| | - Francesco Gobbo
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9JZ, UK
| | - Christian Edvardsson
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 90, Sweden
| | - Michele Petrella
- Linköping University, Department of Biomedical and Clinical Sciences, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences, Linköping, Sweden
| | - Elisabet Jerlhag
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 90, Sweden
| | - Mia Ericson
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 90, Sweden
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 45, Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 45, Sweden
- The Clinic for Addiction and Dependency, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Louise Adermark
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 90, Sweden
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, 413 45, Sweden
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Silva-Cardoso GK, N’Gouemo P. Inhibition of the Sodium-Calcium Exchanger Reverse Mode Activity Reduces Alcohol Consumption in Rats. Int J Mol Sci 2024; 25:4132. [PMID: 38612942 PMCID: PMC11012417 DOI: 10.3390/ijms25074132] [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: 03/10/2024] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 04/14/2024] Open
Abstract
Excessive and uncontrolled consumption of alcohol can cause alcohol use disorder (AUD), but its pharmacological mechanisms are not fully understood. Inhibiting the reverse mode activity of the sodium-calcium exchanger (NCX) can reduce the risk of alcohol withdrawal seizures, suggesting that NCX could play a role in controlling alcohol consumption. Here, we investigated how two potent inhibitors of NCX reverse mode activity, SN-6 (NCX1) and KB-R7943 (NCX3), affect voluntary alcohol consumption in adult male and female rats using the intermittent alcohol access two-bottle choice paradigm. Initially, animals were trained to drink 7.5% ethanol and water for four weeks before administering SN-6 and KB-R7934. Afterward, their alcohol intake, preference, and water intake were recorded 2 and 24 h after exposure to water and 7.5% ethanol. SN-6 significantly reduced alcohol consumption by 48% in male and 36% in female rats without affecting their water intake. Additionally, SN-6 significantly reduced alcohol preference in females by 27%. However, KB-R7943 reduced alcohol consumption by 42% in female rats and did not affect alcohol preference or water intake. These findings suggest that alcohol exposure increased NCX reverse activity, and targeting NCX1 could be an effective strategy for reducing alcohol consumption in subjects susceptible to withdrawal seizures.
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Affiliation(s)
| | - Prosper N’Gouemo
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA;
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Silva-Cardoso GK, N'Gouemo P. Influence of Inherited Seizure Susceptibility on Intermittent Voluntary Alcohol Consumption and Alcohol Withdrawal Seizures in Genetically Epilepsy-Prone Rats (GEPR-3s). Brain Sci 2024; 14:188. [PMID: 38391762 PMCID: PMC10886844 DOI: 10.3390/brainsci14020188] [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: 01/30/2024] [Revised: 02/10/2024] [Accepted: 02/15/2024] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND The link between epilepsy and alcohol consumption is complex, with conflicting reports. To enhance our understanding of this link, we conducted a study to determine how inherited seizure susceptibility affects voluntary alcohol consumption and influences alcohol withdrawal seizures in male and female genetically epilepsy-prone rats (GEPR-3s) compared to Sprague Dawley (SD) rats. METHODS In the first experiment, animals were given access to two bottles simultaneously, one containing water and the other 7.5%, 15%, or 30% (v/v) alcohol three times a week for each dose after acclimation to drinking water. In a second experiment, animals were tested for acoustically evoked alcohol seizures 24 h after the last session of voluntary alcohol consumption. RESULTS Analysis revealed that GEPR-3s (males and females) had lower alcohol intake and preference than SD rats, particularly at lower alcohol concentrations. However, female GEPR-3s consumed more alcohol and had a higher alcohol preference than males. Furthermore, withdrawal from voluntary alcohol consumption facilitated the onset and duration of seizures in GEPR-3s. CONCLUSIONS Our study suggests that genetic seizure susceptibility in GEPR-3s is negatively associated with alcohol consumption. However, withdrawal from low to moderate amounts of alcohol intake can promote epileptogenesis in the epileptic GEPR-3s.
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Affiliation(s)
- Gleice Kelli Silva-Cardoso
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA
| | - Prosper N'Gouemo
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA
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Mulholland PJ, Padula AE, Wilhelm LJ, Park B, Grant KA, Ferguson BM, Cervera-Juanes R. Cross-species epigenetic regulation of nucleus accumbens KCNN3 transcripts by excessive ethanol drinking. Transl Psychiatry 2023; 13:364. [PMID: 38012158 PMCID: PMC10682415 DOI: 10.1038/s41398-023-02676-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 11/29/2023] Open
Abstract
The underlying genetic and epigenetic mechanisms driving functional adaptations in neuronal excitability and excessive alcohol intake are poorly understood. Small-conductance Ca2+-activated K+ (KCa2 or SK) channels encoded by the KCNN family of genes have emerged from preclinical studies as a key contributor to alcohol-induced functional neuroadaptations in alcohol-drinking monkeys and alcohol-dependent mice. Here, this cross-species analysis focused on KCNN3 DNA methylation, gene expression, and single nucleotide polymorphisms, including alternative promoters in KCNN3, that could influence surface trafficking and function of KCa2 channels. Bisulfite sequencing analysis of the nucleus accumbens tissue from alcohol-drinking monkeys and alcohol-dependent mice revealed a differentially methylated region in exon 1A of KCNN3 that overlaps with a predicted promoter sequence. The hypermethylation of KCNN3 in the accumbens paralleled an increase in the expression of alternative transcripts that encode apamin-insensitive and dominant-negative KCa2 channel isoforms. A polymorphic repeat in macaque KCNN3 encoded by exon 1 did not correlate with alcohol drinking. At the protein level, KCa2.3 channel expression in the accumbens was significantly reduced in very heavy-drinking monkeys. Together, our cross-species findings on epigenetic dysregulation of KCNN3 represent a complex mechanism that utilizes alternative promoters to potentially impact the firing of accumbens neurons. Thus, these results provide support for hypermethylation of KCNN3 as a possible key molecular mechanism underlying harmful alcohol intake and alcohol use disorder.
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Affiliation(s)
- Patrick J Mulholland
- Department of Neuroscience, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Audrey E Padula
- Department of Neuroscience, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Larry J Wilhelm
- Department of Translational Neuroscience, Atrium Health Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Byung Park
- Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Kathleen A Grant
- Department of Neurosciences, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97006, USA
| | - Betsy M Ferguson
- Department of Neurosciences, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97006, USA
| | - Rita Cervera-Juanes
- Department of Translational Neuroscience, Atrium Health Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA.
- Center for Precision Medicine, Atrium Health Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA.
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Juanes RC, Mulholland P, Padula A, Wilhelm L, Park B, Grant K, Ferguson B. Cross-species epigenetic regulation of nucleus accumbens KCNN3 transcripts by excessive ethanol drinking. RESEARCH SQUARE 2023:rs.3.rs-3315122. [PMID: 37790552 PMCID: PMC10543433 DOI: 10.21203/rs.3.rs-3315122/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The underlying genetic and epigenetic mechanisms driving functional adaptations in neuronal excitability and excessive alcohol intake are poorly understood. Small-conductance Ca2+-activated K+ (KCa2 or SK) channels encoded by the KCNN family of genes have emerged from preclinical studies as a key contributor to alcohol-induced functional neuroadaptations in alcohol-drinking monkeys and alcohol dependent mice. Here, this cross-species analysis focused on KCNN3 DNA methylation, gene expression, and single nucleotide polymorphisms including alternative promoters in KCNN3 that could influence surface trafficking and function of KCa2 channels. Bisulfite sequencing analysis of the nucleus accumbens tissue from alcohol-drinking monkeys and alcohol dependent mice revealed a differentially methylated region in exon 1A of KCNN3 that overlaps with a predicted promoter sequence. The hypermethylation of KCNN3 in the accumbens paralleled an increase in expression of alternative transcripts that encode apamin-insensitive and dominant-negative KCa2 channel isoforms. A polymorphic repeat in macaque KCNN3 encoded by exon 1 did not correlate with alcohol drinking. At the protein level, KCa2.3 channel expression in the accumbens was significantly reduced in very heavy drinking monkeys. Together, our cross-species findings on epigenetic dysregulation of KCNN3 represent a complex mechanism that utilizes alternative promoters to impact firing of accumbens neurons. Thus, these results provide support for hypermethylation of KCNN3 as a possible key molecular mechanism underlying harmful alcohol intake and alcohol use disorder.
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Affiliation(s)
| | | | | | | | | | | | - Betsy Ferguson
- Oregon Health & Sciences University/Oregon National Primate Research Center
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6
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Zhang M, Luo Y, Wang J, Sun Y, Xie B, Zhang L, Cong B, Ma C, Wen D. Roles of nucleus accumbens shell small-conductance calcium-activated potassium channels in the conditioned fear freezing. J Psychiatr Res 2023; 163:180-194. [PMID: 37216772 DOI: 10.1016/j.jpsychires.2023.05.057] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 04/27/2023] [Accepted: 05/15/2023] [Indexed: 05/24/2023]
Abstract
BACKGROUND Posttraumatic stress disorder (PTSD), a psychiatric disorder caused by stressful events, is characterized by long-lasting fear memory. The nucleus accumbens shell (NAcS) is a key brain region that regulates fear-associated behavior. Small-conductance calcium-activated potassium channels (SK channels) play a key role in regulating the excitability of NAcS medium spiny neurons (MSNs) but their mechanisms of action in fear freezing are unclear. METHOD We established an animal model of traumatic memory using conditioned fear freezing paradigm, and investigated the alterations in SK channels of NAc MSNs subsequent to fear conditioning in mice. We then utilized an adeno-associated virus (AAV) transfection system to overexpress the SK3 subunit and explore the function of the NAcS MSNs SK3 channel in conditioned fear freezing. RESULTS Fear conditioning activated NAcS MSNs with enhanced excitability and reduced the SK channel-mediated medium after-hyperpolarization (mAHP) amplitude. The expression of NAcS SK3 were also reduced time-dependently. The overexpression of NAcS SK3 impaired conditioned fear consolidation without affecting conditioned fear expression, and blocked fear conditioning-induced alterations in NAcS MSNs excitability and mAHP amplitude. Additionally, the amplitudes of mEPSC, AMPAR/NMDAR ratio, and membrane surface GluA1/A2 expression in NAcS MSNs was increased by fear conditioning and returned to normal levels upon SK3 overexpression, indicating that fear conditioning-induced decrease of SK3 expression caused postsynaptic excitation by facilitating AMPAR transmission to the membrane. CONCLUSION These findings show that the NAcS MSNs SK3 channel plays a critical role in conditioned fear consolidation and that it may influence PTSD pathogenesis, making it a potential therapeutic target against PTSD.
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Affiliation(s)
- Minglong Zhang
- College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Hebei Province, Shijiazhuang, 050017, PR China
| | - Yixiao Luo
- Hunan Province People's Hospital, The First-Affiliated Hospital of Hunan Normal University, Changsha, 410081, PR China
| | - Jian Wang
- College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Hebei Province, Shijiazhuang, 050017, PR China
| | - Yufei Sun
- College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Hebei Province, Shijiazhuang, 050017, PR China
| | - Bing Xie
- College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Hebei Province, Shijiazhuang, 050017, PR China
| | - Ludi Zhang
- College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Hebei Province, Shijiazhuang, 050017, PR China
| | - Bin Cong
- College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Hebei Province, Shijiazhuang, 050017, PR China
| | - Chunling Ma
- College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Hebei Province, Shijiazhuang, 050017, PR China.
| | - Di Wen
- College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Hebei Province, Shijiazhuang, 050017, PR China.
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Manz KM, Brady LJ, Calipari ES, Grueter BA. Accumbal Histamine Signaling Engages Discrete Interneuron Microcircuits. Biol Psychiatry 2023; 93:1041-1052. [PMID: 34953589 PMCID: PMC9012818 DOI: 10.1016/j.biopsych.2021.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Central histamine (HA) signaling modulates diverse cortical and subcortical circuits throughout the brain, including the nucleus accumbens (NAc). The NAc, a key striatal subregion directing reward-related behavior, expresses diverse HA receptor subtypes that elicit cellular and synaptic plasticity. However, the neuromodulatory capacity of HA within interneuron microcircuits in the NAc remains unknown. METHODS We combined electrophysiology, pharmacology, voltammetry, and optogenetics in male transgenic reporter mice to determine how HA influences microcircuit motifs controlled by parvalbumin-expressing fast-spiking interneurons (PV-INs) and tonically active cholinergic interneurons (CINs) in the NAc shell. RESULTS HA enhanced CIN output through an H2 receptor (H2R)-dependent effector pathway requiring Ca2+-activated small-conductance K+ channels, with a small but discernible contribution from H1Rs and synaptic H3Rs. While PV-IN excitability was unaffected by HA, presynaptic H3Rs decreased feedforward drive onto PV-INs via AC-cAMP-PKA (adenylyl cyclase-cyclic adenosine monophosphate-protein kinase A) signaling. H3R-dependent plasticity was differentially expressed at mediodorsal thalamus and prefrontal cortex synapses onto PV-INs, with mediodorsal thalamus synapses undergoing HA-induced long-term depression. These effects triggered downstream shifts in PV-IN- and CIN-controlled microcircuits, including near-complete collapse of mediodorsal thalamus-evoked feedforward inhibition and increased mesoaccumbens dopamine release. CONCLUSIONS HA targets H1R, H2R, and H3Rs in the NAc shell to engage synapse- and cell type-specific mechanisms that bidirectionally regulate PV-IN and CIN microcircuit activity. These findings extend the current conceptual framework of HA signaling and offer critical insight into the modulatory potential of HA in the brain.
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Affiliation(s)
- Kevin M Manz
- Medical Scientist Training Program, Vanderbilt University, Nashville, Tennessee; Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee.
| | - Lillian J Brady
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee
| | - Erin S Calipari
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee; Department of Pharmacology, Vanderbilt University, Nashville, Tennessee
| | - Brad A Grueter
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee; Department of Pharmacology, Vanderbilt University, Nashville, Tennessee; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee; Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee.
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Nimitvilai-Roberts S, Gioia D, Lopez MF, Glaser CM, Woodward JJ. Chronic intermittent ethanol exposure differentially alters the excitability of neurons in the orbitofrontal cortex and basolateral amygdala that project to the dorsal striatum. Neuropharmacology 2023; 228:109463. [PMID: 36792030 PMCID: PMC10006395 DOI: 10.1016/j.neuropharm.2023.109463] [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: 11/08/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/15/2023]
Abstract
Alcohol use disorder is associated with altered neuron function including those in orbitofrontal cortex (OFC) and basolateral amygdala (BLA) that send glutamatergic inputs to areas of the dorsal striatum (DS) that mediate goal and habit directed actions. Previous studies reported that chronic intermittent (CIE) exposure to ethanol alters the electrophysiological properties of OFC and BLA neurons, although projection targets for these neurons were not identified. In this study, we used male and female mice and recorded current-evoked spiking of retrobead labeled DS-projecting OFC and BLA neurons in the same animals following air or CIE treatment. DS-projecting OFC neurons were hyperexcitable 3- and 7-days following CIE exposure and spiking returned to control levels after 14 days of withdrawal. In contrast, firing was decreased in DS-projecting BLA neurons at 3-days withdrawal, increased at 7- and 14-days and returned to baseline at 28 days post-CIE. CIE exposure enhanced the amplitude and frequency of spontaneous excitatory postsynaptic currents (sEPSCs) of DS-projecting OFC neurons but had no effect on inhibitory postsynaptic currents (sIPSCs). In DS-projecting BLA neurons, the amplitude and frequency of sIPSCs was enhanced 3 days post-CIE with no change in sEPSCs while at 7-days post-withdrawal, sEPSC amplitude and frequency were increased and sIPSCs had returned to normal. Finally, in CIE-treated mice, acute ethanol no longer inhibited spike firing of DS-projecting OFC and BLA neurons. Overall, these results suggest that CIE-induced changes in the excitability of DS-projecting OFC and BLA neurons could underlie deficits in behavioral control often observed in alcohol-dependent individuals.
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Affiliation(s)
| | - Dominic Gioia
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Marcelo F Lopez
- Department of Psychiatry and Behavioral Sciences, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Christina M Glaser
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - John J Woodward
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA; Department of Psychiatry and Behavioral Sciences, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, 29425, USA.
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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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10
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Zahra A, Liu R, Han W, Meng H, Wang Q, Wang Y, Campbell SL, Wu J. K Ca-Related Neurological Disorders: Phenotypic Spectrum and Therapeutic Indications. Curr Neuropharmacol 2023; 21:1504-1518. [PMID: 36503451 PMCID: PMC10472807 DOI: 10.2174/1570159x21666221208091805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/21/2022] [Accepted: 07/23/2022] [Indexed: 12/14/2022] Open
Abstract
Although potassium channelopathies have been linked to a wide range of neurological conditions, the underlying pathogenic mechanism is not always clear, and a systematic summary of clinical manifestation is absent. Several neurological disorders have been associated with alterations of calcium-activated potassium channels (KCa channels), such as loss- or gain-of-function mutations, post-transcriptional modification, etc. Here, we outlined the current understanding of the molecular and cellular properties of three subtypes of KCa channels, including big conductance KCa channels (BK), small conductance KCa channels (SK), and the intermediate conductance KCa channels (IK). Next, we comprehensively reviewed the loss- or gain-of-function mutations of each KCa channel and described the corresponding mutation sites in specific diseases to broaden the phenotypic-genotypic spectrum of KCa-related neurological disorders. Moreover, we reviewed the current pharmaceutical strategies targeting KCa channels in KCa-related neurological disorders to provide new directions for drug discovery in anti-seizure medication.
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Affiliation(s)
- Aqeela Zahra
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
- Department of Zoology, University of Sialkot, Sialkot 51310, Pakistan
| | - Ru Liu
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Wenzhe Han
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Hui Meng
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Qun Wang
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - YunFu Wang
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Susan L. Campbell
- Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Jianping Wu
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
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Price ME, McCool BA. Chronic Alcohol Dysregulates Glutamatergic Function in the Basolateral Amygdala in a Projection-and Sex-Specific Manner. Front Cell Neurosci 2022; 16:857550. [PMID: 35496915 PMCID: PMC9050109 DOI: 10.3389/fncel.2022.857550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Chronic intermittent ethanol and withdrawal (CIE/WD) produces alcohol dependence, facilitates anxiety-like behavior, and increases post-CIE alcohol intake. The basolateral amygdala (BLA) is one of several brain regions that regulates anxiety-like behavior and alcohol intake through downstream projections to the nucleus accumbens (NAC) and bed nucleus of the stria terminalis (BNST), respectively. Previous studies revealed that CIE/WD induces input- and sex-specific adaptations to glutamatergic function in the BLA. The BLA receives information from two distinct input pathways. Glutamatergic afferents from medial structures like the thalamus and prefrontal cortex enter the BLA through the stria terminalis whereas lateral cortical structures like the anterior insula cortex enter the BLA through the external capsule. CIE/WD increases presynaptic glutamatergic function at stria terminalis synapses and postsynaptic function at external capsule synapses. Previous studies sampled neurons throughout the BLA, but did not distinguish between projection-specific populations. The current study investigated BLA neurons that project to the NAC (BLA-NAC neurons) or the BNST (BLA-BNST neurons) as representative “reward” and “aversion” BLA neurons, and showed that CIE/WD alters glutamatergic function and excitability in a projection- and sex-specific manner. CIE/WD increases glutamate release from stria terminalis inputs only onto BLA-BNST neurons. At external capsule synapses, CIE/WD increases postsynaptic glutamatergic function in male BLA-NAC neurons and female BLA-BNST neurons. Subsequent experiments demonstrated that CIE/WD enhanced the excitability of male BLA-NAC neurons and BLA-BNST neurons in both sexes when glutamatergic but not GABAergic function was intact. Thus, CIE/WD-mediated increased glutamatergic function facilitates hyperexcitability in male BLA-NAC neurons and BLA-BNST neurons of both sexes.
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Affiliation(s)
- Michaela E. Price
- Neuroscience and Alcohol Research Training Programs, Wake Forest School of Medicine, Winston-Salem, NC, United States
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Brian A. McCool
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, United States
- *Correspondence: Brian A. McCool,
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12
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Bilateral transcranial direct current stimulation attenuated symptoms of alcohol use disorder: A systematic review and meta-analysis. Prog Neuropsychopharmacol Biol Psychiatry 2021; 108:110160. [PMID: 33147505 DOI: 10.1016/j.pnpbp.2020.110160] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Alcohol use disorder is one of the common substance use disorders leading to mental and health problems. Despite the potential positive effects of transcranial direct current stimulation (tDCS) on symptoms of various substance use disorder, how specific tDCS protocols effectively influence on individuals with alcohol use disorder is still controversial. This systematic review and meta-analysis investigated beneficial effects of tDCS on symptoms of alcohol use disorder. METHOD Eighteen total studies met our inclusion criteria, and we used 25 total comparisons from the qualified studies for the data synthesis. We estimated effect sizes by quantifying changes in alcohol craving and consumption between active tDCS protocol and sham groups. In addition, three moderator variable analyses determined whether tDCS effects on symptoms of alcohol use disorder were different based on (a) bilateral versus unilateral tDCS protocols, (b) specific targeted regions, and (c) multiple sessions versus single session of tDCS protocols. RESULTS Random-effects model meta-analysis revealed small positive tDCS effects on alcohol craving and consumption. Specifically, bilateral tDCS protocols significantly reduced alcohol craving, and further anodal tDCS on right dorsolateral prefrontal cortex (DLPFC) and cathodal tDCS on left DLPFC revealed significant positive effects. The multiple sessions of tDCS protocols showed better effects on reducing alcohol craving. CONCLUSIONS The current findings suggested that bilateral tDCS protocols including anodal tDCS on right DLPFC and cathodal tDCS on left DLPFC with multiple sessions may effectively improve tDCS effects on symptoms of alcohol use disorder.
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Dwivedi D, Bhalla US. Physiology and Therapeutic Potential of SK, H, and M Medium AfterHyperPolarization Ion Channels. Front Mol Neurosci 2021; 14:658435. [PMID: 34149352 PMCID: PMC8209339 DOI: 10.3389/fnmol.2021.658435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/13/2021] [Indexed: 12/19/2022] Open
Abstract
SK, HCN, and M channels are medium afterhyperpolarization (mAHP)-mediating ion channels. The three channels co-express in various brain regions, and their collective action strongly influences cellular excitability. However, significant diversity exists in the expression of channel isoforms in distinct brain regions and various subcellular compartments, which contributes to an equally diverse set of specific neuronal functions. The current review emphasizes the collective behavior of the three classes of mAHP channels and discusses how these channels function together although they play specialized roles. We discuss the biophysical properties of these channels, signaling pathways that influence the activity of the three mAHP channels, various chemical modulators that alter channel activity and their therapeutic potential in treating various neurological anomalies. Additionally, we discuss the role of mAHP channels in the pathophysiology of various neurological diseases and how their modulation can alleviate some of the symptoms.
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Affiliation(s)
- Deepanjali Dwivedi
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bengaluru, India.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States.,Stanley Center at the Broad, Cambridge, MA, United States
| | - Upinder S Bhalla
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bengaluru, India
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14
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Cao J, Meitzen J. Perinatal activation of ER α and ER β but not GPER-1 masculinizes female rat caudate-putamen medium spiny neuron electrophysiological properties. J Neurophysiol 2021; 125:2322-2338. [PMID: 33978486 DOI: 10.1152/jn.00063.2021] [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] [Indexed: 01/01/2023] Open
Abstract
Exposure to steroid sex hormones such as 17β-estradiol (estradiol) during early life potentially permanently masculinize neuron electrophysiological phenotype. In rodents, one crucial component of this developmental process occurs in males, with estradiol aromatized in the brain from testes-sourced testosterone. However, it is unknown whether most neuron electrophysiological phenotypes are altered by this early masculinization process, including medium spiny neurons (MSNs) of the rat caudate-putamen. MSNs are the predominant and primary output neurons of the caudate-putamen and exhibit increased intrinsic excitability in females compared to males. Here, we hypothesize that since perinatal estradiol exposure occurs in males, then a comparable exposure in females to estradiol or its receptor agonists would be sufficient to induce masculinization. To test this hypothesis, we injected perinatal female rats with estradiol or its receptor agonists and then later assessed MSN electrophysiology. Female and male rats on postnatal day 0 and 1 were systemically injected with either vehicle, estradiol, the estrogen receptor (ER)α agonist PPT, the ERβ agonist DPN, or the G-protein-coupled receptor 1 (GPER-1) agonist G1. On postnatal days 19 ± 2, MSN electrophysiological properties were assessed using whole cell patch clamp recordings. Estradiol exposure abolished increased intrinsic excitability in female compared to male MSNs. Exposure to either an ERα or ERβ agonist masculinized female MSN evoked action potential firing rate properties, whereas exposure to an ERβ agonist masculinized female MSN inward rectification properties. Exposure to ER agonists minimally impacted male MSN electrophysiological properties. These findings indicate that perinatal estradiol exposure masculinizes MSN electrophysiological phenotype via activation of ERα and ERβ.NEW & NOTEWORTHY This study is the first to demonstrate that estradiol and estrogen receptor α and β stimulation during early development sexually differentiates the electrophysiological properties of caudate-putamen medium spiny neurons, the primary output neuron of the striatal regions. Overall, this evidence provides new insight into the neuroendocrine mechanism by which caudate-putamen neuron electrophysiology is sexually differentiated and demonstrates the powerful action of early hormone exposure upon individual neuron electrophysiology.
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Affiliation(s)
- Jinyan Cao
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina
| | - John Meitzen
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina.,Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina.,Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina
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15
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McCoy MT, Jayanthi S, Cadet JL. Potassium Channels and Their Potential Roles in Substance Use Disorders. Int J Mol Sci 2021; 22:1249. [PMID: 33513859 PMCID: PMC7865894 DOI: 10.3390/ijms22031249] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/12/2023] Open
Abstract
Substance use disorders (SUDs) are ubiquitous throughout the world. However, much remains to be done to develop pharmacotherapies that are very efficacious because the focus has been mostly on using dopaminergic agents or opioid agonists. Herein we discuss the potential of using potassium channel activators in SUD treatment because evidence has accumulated to support a role of these channels in the effects of rewarding drugs. Potassium channels regulate neuronal action potential via effects on threshold, burst firing, and firing frequency. They are located in brain regions identified as important for the behavioral responses to rewarding drugs. In addition, their expression profiles are influenced by administration of rewarding substances. Genetic studies have also implicated variants in genes that encode potassium channels. Importantly, administration of potassium agonists have been shown to reduce alcohol intake and to augment the behavioral effects of opioid drugs. Potassium channel expression is also increased in animals with reduced intake of methamphetamine. Together, these results support the idea of further investing in studies that focus on elucidating the role of potassium channels as targets for therapeutic interventions against SUDs.
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Affiliation(s)
| | | | - Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program, Baltimore, MD 21224, USA; (M.T.M.); (S.J.)
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16
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Avchalumov Y, Oliver RJ, Trenet W, Heyer Osorno RE, Sibley BD, Purohit DC, Contet C, Roberto M, Woodward JJ, Mandyam CD. Chronic ethanol exposure differentially alters neuronal function in the medial prefrontal cortex and dentate gyrus. Neuropharmacology 2020; 185:108438. [PMID: 33333103 DOI: 10.1016/j.neuropharm.2020.108438] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 12/06/2020] [Accepted: 12/09/2020] [Indexed: 12/28/2022]
Abstract
Alterations in the function of prefrontal cortex (PFC) and hippocampus have been implicated in underlying the relapse to alcohol seeking behaviors in humans and animal models of moderate to severe alcohol use disorders (AUD). Here we used chronic intermittent ethanol vapor exposure (CIE), 21d protracted abstinence following CIE (21d AB), and re-exposure to one vapor session during protracted abstinence (re-exposure) to evaluate the effects of chronic ethanol exposure on basal synaptic function, neuronal excitability and expression of key synaptic proteins that play a role in neuronal excitability in the medial PFC (mPFC) and dentate gyrus (DG). CIE consistently enhanced excitability of layer 2/3 pyramidal neurons in the mPFC and granule cell neurons in the DG. In the DG, this effect persisted during 21d AB. Re-exposure did not enhance excitability, suggesting resistance to vapor-induced effects. Analysis of action potential kinetics revealed that altered afterhyperpolarization, rise time and decay time constants are associated with the altered excitability during CIE, 21d AB and re-exposure. Molecular adaptations that may underlie increases in neuronal excitability under these different conditions were identified. Quantitative polymerase chain reaction of large-conductance potassium (BK) channel subunit mRNA in PFC and DG tissue homogenates did not show altered expression patterns of BK subunits. Western blotting demonstrates enhanced phosphorylation of Ca2⁺/calmodulin-dependent protein kinase II (CaMKII), and reduced phosphorylation of glutamate receptor GluN2A/2B subunits. These results suggest a novel relationship between activity of CaMKII and GluN receptors in the mPFC and DG, and neuronal excitability in these brain regions in the context of moderate to severe AUD.
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Affiliation(s)
| | | | - Wulfran Trenet
- VA San Diego Healthcare System, San Diego, CA, 92161, USA
| | | | | | | | - Candice Contet
- Departments of Molecular Medicine and Neuroscience, Scripps Research, La Jolla, CA, 92037, USA
| | - Marisa Roberto
- Departments of Molecular Medicine and Neuroscience, Scripps Research, La Jolla, CA, 92037, USA
| | - John J Woodward
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Chitra D Mandyam
- VA San Diego Healthcare System, San Diego, CA, 92161, USA; Departments of Molecular Medicine and Neuroscience, Scripps Research, La Jolla, CA, 92037, USA; Department of Anesthesiology, University of California San Diego, San Diego, CA, 92161, USA.
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17
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Sun J, Liu Y, Baudry M, Bi X. SK2 channel regulation of neuronal excitability, synaptic transmission, and brain rhythmic activity in health and diseases. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2020; 1867:118834. [PMID: 32860835 PMCID: PMC7541745 DOI: 10.1016/j.bbamcr.2020.118834] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/13/2020] [Accepted: 08/19/2020] [Indexed: 11/20/2022]
Abstract
Small conductance calcium-activated potassium channels (SKs) are solely activated by intracellular Ca2+ and their activation leads to potassium efflux, thereby repolarizing/hyperpolarizing membrane potential. Thus, these channels play a critical role in synaptic transmission, and consequently in information transmission along the neuronal circuits expressing them. SKs are widely but not homogeneously distributed in the central nervous system (CNS). Activation of SKs requires submicromolar cytoplasmic Ca2+ concentrations, which are reached following either Ca2+ release from intracellular Ca2+ stores or influx through Ca2+ permeable membrane channels. Both Ca2+ sensitivity and synaptic levels of SKs are regulated by protein kinases and phosphatases, and degradation pathways. SKs in turn control the activity of multiple Ca2+ channels. They are therefore critically involved in coordinating diverse Ca2+ signaling pathways and controlling Ca2+ signal amplitude and duration. This review highlights recent advances in our understanding of the regulation of SK2 channels and of their roles in normal brain functions, including synaptic plasticity, learning and memory, and rhythmic activities. It will also discuss how alterations in their expression and regulation might contribute to various brain disorders such as Angelman Syndrome, Alzheimer's disease and Parkinson's disease.
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Affiliation(s)
- Jiandong Sun
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Yan Liu
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Michel Baudry
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America.
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18
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Padula AE, Rinker JA, Lopez MF, Mulligan MK, Williams RW, Becker HC, Mulholland PJ. Bioinformatics identification and pharmacological validation of Kcnn3/K Ca2 channels as a mediator of negative affective behaviors and excessive alcohol drinking in mice. Transl Psychiatry 2020; 10:414. [PMID: 33247097 PMCID: PMC7699620 DOI: 10.1038/s41398-020-01099-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/16/2020] [Accepted: 11/06/2020] [Indexed: 12/12/2022] Open
Abstract
Mood disorders are often comorbid with alcohol use disorder (AUD) and play a considerable role in the development and maintenance of alcohol dependence and relapse. Because of this high comorbidity, it is necessary to determine shared and unique genetic factors driving heavy drinking and negative affective behaviors. In order to identify novel pharmacogenetic targets, a bioinformatics analysis was used to quantify the expression of amygdala K+ channel genes that covary with anxiety-related phenotypes in the well-phenotyped and fully sequenced family of BXD strains. We used a model of stress-induced escalation of drinking in alcohol-dependent mice to measure negative affective behaviors during abstinence. A pharmacological approach was used to validate the key bioinformatics findings in alcohol-dependent, stressed mice. Amygdalar expression of Kcnn3 correlated significantly with 40 anxiety-associated phenotypes. Further examination of Kcnn3 expression revealed a strong eigentrait for anxiety-like behaviors and negative correlations with binge-like and voluntary alcohol drinking. Mice treated with chronic intermittent alcohol exposure and repeated swim stress consumed more alcohol in their home cages and showed hypophagia on the novelty-suppressed feeding test during abstinence. Pharmacologically targeting Kcnn gene products with the KCa2 (SK) channel-positive modulator 1-EBIO decreased drinking and reduced feeding latency in alcohol-dependent, stressed mice. Collectively, these validation studies provide central nervous system links into the covariance of stress, negative affective behaviors, and AUD in the BXD strains. Further, the bioinformatics discovery tool is effective in identifying promising targets (i.e., KCa2 channels) for treating alcohol dependence exacerbated by comorbid mood disorders.
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Affiliation(s)
- Audrey E Padula
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Jennifer A Rinker
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Marcelo F Lopez
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, 29425, USA
- Department of Psychiatry & Behavioral Sciences, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Megan K Mulligan
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, Tennessee, 38163, USA
| | - Robert W Williams
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, Tennessee, 38163, USA
| | - Howard C Becker
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, 29425, USA
- Department of Psychiatry & Behavioral Sciences, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Patrick J Mulholland
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA.
- Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, 29425, USA.
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19
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Maldonado O, Jenkins A, Belalcazar HM, Hernandez-Cuervo H, Hyman KM, Ladaga G, Padilla L, de Erausquin GA. Age-dependent neuroprotective effect of an SK3 channel agonist on excitotoxity to dopaminergic neurons in organotypic culture. PLoS One 2020; 15:e0223633. [PMID: 32701951 PMCID: PMC7377472 DOI: 10.1371/journal.pone.0223633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 07/06/2020] [Indexed: 11/19/2022] Open
Abstract
Background Small conductance, calcium-activated (SK3) potassium channels control the intrinsic excitability of dopaminergic neurons (DN) in the midbrain and modulate their susceptibility to toxic insults during development. Methods We evaluated the age-dependency of the neuroprotective effect of an SK3 agonist, 1-Ethyl-1,3-dihydro-2H-benzimidazol-2-one (1-EBIO), on Amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) excitotoxicity to DN in ventral mesencephalon (VM) organotypic cultures. Results Most tyrosine hydroxylase (TH)+ neurons were also SK3+; SK3+/TH- cells (DN+) were common at each developmental stage but more prominently at day in vitro (DIV) 8. Young DN+ neurons were small bipolar and fusiform, whereas mature ones were large and multipolar. Exposure of organotypic cultures to AMPA (100 μm, 16 h) had no effect on the survival of DN+ at DIV 8, but caused significant toxicity at DIV 15 (n = 15, p = 0.005) and DIV 22 (n = 15, p<0.001). These results indicate that susceptibility of DN to AMPA excitotoxicity is developmental stage-dependent in embryonic VM organotypic cultures. Immature DN+ (small, bipolar) were increased after AMPA (100 μm, 16 h) at DIV 8, at the expense of the number of differentiated (large, multipolar) DN+ (p = 0.039). This effect was larger at DIV 15 (p<<<0.0001) and at DIV 22 (p<<<0.0001). At DIV 8, 30 μM 1-EBIO resulted in a large increase in DN+. At DIV 15, AMPA toxicity was prevented by exposure to 30 μM, but not 100 μM 1-EBIO. At DIV 22, excitotoxicity was unaffected by 30 μM 1-EBIO, and partially reduced by 100 μM 1-EBIO. Conclusion The effects of the SK3 channel agonist 1-EBIO on the survival of SK3-expressing dopaminergic neurons were concentration-dependent and influenced by neuronal developmental stage.
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Affiliation(s)
- Oscar Maldonado
- Laboratory of Brain Development, and Repair, Biggs Institute for Alzheimer and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas, United States of America
| | - Alexandra Jenkins
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Helen M. Belalcazar
- Department of Genetics, Albert Einstein College of Medicine, New York City, New York, United States of America
| | - Helena Hernandez-Cuervo
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Katelynn M. Hyman
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Giannina Ladaga
- Laboratory of Brain Development, and Repair, Biggs Institute for Alzheimer and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas, United States of America
| | - Lucia Padilla
- Laboratory of Brain Development, and Repair, Biggs Institute for Alzheimer and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas, United States of America
| | - Gabriel A. de Erausquin
- Laboratory of Brain Development, and Repair, Biggs Institute for Alzheimer and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas, United States of America
- * E-mail:
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20
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Cannady R, Nimitvilai-Roberts S, Jennings SD, Woodward JJ, Mulholland PJ. Distinct Region- and Time-Dependent Functional Cortical Adaptations in C57BL/6J Mice after Short and Prolonged Alcohol Drinking. eNeuro 2020; 7:ENEURO.0077-20.2020. [PMID: 32439714 PMCID: PMC7307629 DOI: 10.1523/eneuro.0077-20.2020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/03/2020] [Accepted: 05/15/2020] [Indexed: 12/27/2022] Open
Abstract
Alcohol (ethanol) use disorder is associated with changes in frontal cortical areas including the anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC) that contribute to cognitive deficits, uncontrolled drinking, and relapse. Acute ethanol exposure reduces intrinsic excitability of lateral OFC (lOFC) neurons, while chronic exposure and long-term drinking influence plasticity of intrinsic excitability and function of glutamatergic synapses. However, the time course that these adaptations occur across a history of ethanol drinking is unknown. The current study examined whether short-term and long-term voluntary ethanol consumption using an intermittent access paradigm would alter the biophysical properties of deep-layer pyramidal neurons in the ACC and lOFC. Neuronal spiking varied in the ACC with an initial increase in evoked firing after 1 d of drinking followed by a decrease in firing in mice that consumed ethanol for one week. No difference in lOFC spike number was observed between water controls and 1-d ethanol drinking mice, but mice that consumed ethanol for one week or more showed a significant increase in evoked firing. Voluntary ethanol drinking for 4 weeks also produced a total loss of ethanol inhibition of lOFC neurons. There was no effect of drinking on excitatory or inhibitory synaptic events in ACC or lOFC neurons across all time points in this model. Overall, these results demonstrate that voluntary drinking alters neuronal excitability in the ACC and lOFC in distinct ways and on a different time scale that may contribute to the impairment of prefrontal cortex-dependent behaviors observed in individuals with alcohol use disorder (AUD).
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Affiliation(s)
| | | | - Sarah D Jennings
- Department of Neuroscience, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC 29425
| | - John J Woodward
- Department of Neuroscience, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC 29425
| | - Patrick J Mulholland
- Department of Neuroscience, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC 29425
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21
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Halladay LR, Kocharian A, Piantadosi PT, Authement ME, Lieberman AG, Spitz NA, Coden K, Glover LR, Costa VD, Alvarez VA, Holmes A. Prefrontal Regulation of Punished Ethanol Self-administration. Biol Psychiatry 2020; 87:967-978. [PMID: 31937415 PMCID: PMC7217757 DOI: 10.1016/j.biopsych.2019.10.030] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 10/08/2019] [Accepted: 10/25/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND A clinical hallmark of alcohol use disorder is persistent drinking despite potential adverse consequences. The ventromedial prefrontal cortex (vmPFC) and dorsomedial prefrontal cortex (dmPFC) are positioned to exert top-down control over subcortical regions, such as the nucleus accumbens shell (NAcS) and basolateral amygdala, which encode positive and negative valence of ethanol (EtOH)-related stimuli. Prior rodent studies have implicated these regions in regulation of punished EtOH self-administration (EtOH-SA). METHODS We conducted in vivo electrophysiological recordings in mouse vmPFC and dmPFC to obtain neuronal correlates of footshock-punished EtOH-SA. Ex vivo recordings were performed in NAcS D1 receptor-expressing medium spiny neurons receiving vmPFC input to examine punishment-related plasticity in this pathway. Optogenetic photosilencing was employed to assess the functional contribution of the vmPFC, dmPFC, vmPFC projections to NAcS, or vmPFC projections to basolateral amygdala, to punished EtOH-SA. RESULTS Punishment reduced EtOH lever pressing and elicited aborted presses (lever approach followed by rapid retraction). Neurons in the vmPFC and dmPFC exhibited phasic firing to EtOH lever presses and aborts, but only in the vmPFC was there a population-level shift in coding from lever presses to aborts with punishment. Closed-loop vmPFC, but not dmPFC, photosilencing on a postpunishment probe test negated the reduction in EtOH lever presses but not in aborts. Punishment was associated with altered plasticity at vmPFC inputs to D1 receptor-expressing medium spiny neurons in the NAcS. Photosilencing vmPFC projections to the NAcS, but not to the basolateral amygdala, partially reversed suppression of EtOH lever presses on probe testing. CONCLUSIONS These findings demonstrate a key role for the vmPFC in regulating EtOH-SA after punishment, with implications for understanding the neural basis of compulsive drinking in alcohol use disorder.
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Affiliation(s)
- Lindsay R Halladay
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland; Department of Psychology, Santa Clara University, Santa Clara, California.
| | - Adrina Kocharian
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
| | - Patrick T Piantadosi
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland; Center on Compulsive Behaviors, Intramural Research Program, National Institutes of Health, Bethesda, Maryland
| | - Michael E Authement
- Laboratory on Neurobiology of Compulsive Behaviors, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland; Center on Compulsive Behaviors, Intramural Research Program, National Institutes of Health, Bethesda, Maryland
| | - Abby G Lieberman
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
| | - Nathen A Spitz
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
| | - Kendall Coden
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
| | - Lucas R Glover
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
| | - Vincent D Costa
- Department of Behavioral Neuroscience, Oregon Health Sciences University, Portland, Oregon
| | - Veronica A Alvarez
- Laboratory on Neurobiology of Compulsive Behaviors, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland; Center on Compulsive Behaviors, Intramural Research Program, National Institutes of Health, Bethesda, Maryland
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
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22
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Nucleus accumbens shell small conductance potassium channels underlie adolescent ethanol exposure-induced anxiety. Neuropsychopharmacology 2019; 44:1886-1895. [PMID: 31096263 PMCID: PMC6784903 DOI: 10.1038/s41386-019-0415-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 04/14/2019] [Accepted: 05/07/2019] [Indexed: 12/24/2022]
Abstract
Alcohol use typically begins in adolescence, increasing the likelihood of adult mental disorders such as anxiety. However, the cellular mechanisms underlying the consequences of adolescent alcohol exposure as well as the behavioral consequences remain poorly understood. We examined the effects of adolescent or adult chronic intermittent ethanol (CIE) exposure on intrinsic excitability of striatal medium-sized spiny neurons (MSNs) and anxiety levels. Rats underwent one of the following procedures: (1) light-dark transition (LDT) and open-field (OF) tests to evaluate anxiety levels and general locomotion; (2) whole-cell patch clamp recordings and biocytin labeling to assess excitability of striatal MSNs, as well as morphological properties; and (3) western blot immunostaining to determine small conductance (SK) calcium-activated potassium channel protein levels. Three weeks, but not 2 days, after CIE treatment, adolescent CIE-treated rats showed shorter crossover latency from the light to dark side in the LDT test and higher MSN excitability in the nucleus accumbens shell (NAcS). Furthermore, the amplitude of the medium afterhyperpolarization (mAHP), mediated by SK channels, and SK3 protein levels in the NAcS decreased concomitantly. Finally, increased anxiety levels, increased excitability, and decreased amplitude of mAHP of NAcS MSNs were reversed by SK channel activator 1-EBIO and mimicked by the SK channel blocker apamin. Thus, adolescent ethanol exposure increases adult anxiety-like behavior by downregulating SK channel function and protein expression, which leads to an increase of intrinsic excitability in NAcS MSNs. SK channels in the NAcS may serve as a target to treat adolescent alcohol binge exposure-induced mental disorders, such as anxiety in adulthood.
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Kim KW, Kim K, Lee H, Suh BC. Ethanol Elevates Excitability of Superior Cervical Ganglion Neurons by Inhibiting Kv7 Channels in a Cell Type-Specific and PI(4,5)P 2-Dependent Manner. Int J Mol Sci 2019; 20:E4419. [PMID: 31500374 PMCID: PMC6770022 DOI: 10.3390/ijms20184419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 12/13/2022] Open
Abstract
Alcohol causes diverse acute and chronic symptoms that often lead to critical health problems. Exposure to ethanol alters the activities of sympathetic neurons that control the muscles, eyes, and blood vessels in the brain. Although recent studies have revealed the cellular targets of ethanol, such as ion channels, the molecular mechanism by which alcohol modulates the excitability of sympathetic neurons has not been determined. Here, we demonstrated that ethanol increased the discharge of membrane potentials in sympathetic neurons by inhibiting the M-type or Kv7 channel consisting of the Kv7.2/7.3 subunits, which were involved in determining the membrane potential and excitability of neurons. Three types of sympathetic neurons, classified by their threshold of activation and firing patterns, displayed distinct sensitivities to ethanol, which were negatively correlated with the size of the Kv7 current that differs depending on the type of neuron. Using a heterologous expression system, we further revealed that the inhibitory effects of ethanol on Kv7.2/7.3 currents were facilitated or diminished by adjusting the amount of plasma membrane phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). These results suggested that ethanol and PI(4,5)P2 modulated gating of the Kv7 channel in superior cervical ganglion neurons in an antagonistic manner, leading to regulation of the membrane potential and neuronal excitability, as well as the physiological functions mediated by sympathetic neurons.
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Affiliation(s)
- Kwon-Woo Kim
- Department of Brain and cognitive sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.
| | - Keetae Kim
- Department of New biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.
| | - Hyosang Lee
- Department of Brain and cognitive sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.
| | - Byung-Chang Suh
- Department of Brain and cognitive sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.
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24
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O'Donovan B, Adeluyi A, Anderson EL, Cole RD, Turner JR, Ortinski PI. Altered gating of K v1.4 in the nucleus accumbens suppresses motivation for reward. eLife 2019; 8:e47870. [PMID: 31487241 PMCID: PMC6728144 DOI: 10.7554/elife.47870] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 08/22/2019] [Indexed: 12/13/2022] Open
Abstract
Deficient motivation contributes to numerous psychiatric disorders, including withdrawal from drug use, depression, schizophrenia, and others. Nucleus accumbens (NAc) has been implicated in motivated behavior, but it remains unclear whether motivational drive is linked to discrete neurobiological mechanisms within the NAc. To examine this, we profiled cohorts of Sprague-Dawley rats in a test of motivation to consume sucrose. We found that substantial variability in willingness to exert effort for reward was not associated with operant responding under low-effort conditions or stress levels. Instead, effort-based motivation was mirrored by a divergent NAc shell transcriptome with differential regulation at potassium and dopamine signaling genes. Functionally, motivation was inversely related to excitability of NAc principal neurons. Furthermore, neuronal and behavioral outputs associated with low motivation were linked to faster inactivation of a voltage-gated potassium channel, Kv1.4. These results raise the prospect of targeting Kv1.4 gating in psychiatric conditions associated with motivational dysfunction.
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Affiliation(s)
| | - Adewale Adeluyi
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of PharmacyUniversity of South CarolinaColumbiaUnited States
| | - Erin L Anderson
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of PharmacyUniversity of South CarolinaColumbiaUnited States
| | - Robert D Cole
- Department of NeuroscienceUniversity of KentuckyLexingtonUnited States
| | - Jill R Turner
- College of PharmacyUniversity of KentuckyLexingtonUnited States
| | - Pavel I Ortinski
- Department of NeuroscienceUniversity of KentuckyLexingtonUnited States
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25
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Brown BM, Shim H, Christophersen P, Wulff H. Pharmacology of Small- and Intermediate-Conductance Calcium-Activated Potassium Channels. Annu Rev Pharmacol Toxicol 2019; 60:219-240. [PMID: 31337271 DOI: 10.1146/annurev-pharmtox-010919-023420] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The three small-conductance calcium-activated potassium (KCa2) channels and the related intermediate-conductance KCa3.1 channel are voltage-independent K+ channels that mediate calcium-induced membrane hyperpolarization. When intracellular calcium increases in the channel vicinity, it calcifies the flexible N lobe of the channel-bound calmodulin, which then swings over to the S4-S5 linker and opens the channel. KCa2 and KCa3.1 channels are highly druggable and offer multiple binding sites for venom peptides and small-molecule blockers as well as for positive- and negative-gating modulators. In this review, we briefly summarize the physiological role of KCa channels and then discuss the pharmacophores and the mechanism of action of the most commonly used peptidic and small-molecule KCa2 and KCa3.1 modulators. Finally, we describe the progress that has been made in advancing KCa3.1 blockers and KCa2.2 negative- and positive-gating modulators toward the clinic for neurological and cardiovascular diseases and discuss the remaining challenges.
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Affiliation(s)
- Brandon M Brown
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | - Heesung Shim
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | | | - Heike Wulff
- Department of Pharmacology, University of California, Davis, California 95616, USA;
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26
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Qu L, Wang Y, Ge SN, Li N, Fu J, Zhang Y, Wang X, Jing JP, Li Y, Wang Q, Gao GD, He SM, Wang XL. Altered Activity of SK Channel Underpins Morphine Withdrawal Relevant Psychiatric Deficiency in Infralimbic to Accumbens Shell Pathway. Front Psychiatry 2019; 10:240. [PMID: 31031665 PMCID: PMC6470400 DOI: 10.3389/fpsyt.2019.00240] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/29/2019] [Indexed: 12/17/2022] Open
Abstract
Drug addiction can be viewed as a chronic psychiatric disorder that is related to dysfunction of neural circuits, including reward deficits, stress surfeits, craving changes, and compromised executive function. The nucleus accumbens (NAc) plays a crucial role in regulating craving and relapse, while the medial prefrontal cortex (mPFC) represents a higher cortex projecting into the NAc that is active in the management of executive function. In this study, we investigated the role of the small conductance calcium-activated potassium channels (SK channels) in NAc and mPFC after morphine withdrawal. Action potential (AP) firing of neurons in the NAc shell was enhanced via the downregulations of the SK channels after morphine withdrawal. Furthermore, the expression of SK2 and SK3 subunits in the NAc was significantly reduced after 3 weeks of morphine withdrawal, but was not altered in the dorsal striatum. In mPFC, the SK channel subunits were differentially expressed. To be specific, the expression of SK3 was upregulated, while the expression of SK2 was unchanged. Furthermore, the AP firing in layer 5 pyramidal neurons of the infralimbic (IL) cortex was decreased via the upregulations of the SK channel-related tail current after 3 weeks of morphine withdrawal. These results suggest that the SK channel plays a specific role in reward circuits following morphine exposure and a period of drug withdrawal, making it a potential target for the prevention of relapse.
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Affiliation(s)
- Liang Qu
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Yuan Wang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Shun-Nan Ge
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Nan Li
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Jian Fu
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Yue Zhang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Xin Wang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Jiang-Peng Jing
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Yang Li
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Qiang Wang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Guo-Dong Gao
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Shi-Ming He
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Xue-Lian Wang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
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27
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Ewin SE, Morgan JW, Niere F, McMullen NP, Barth SH, Almonte AG, Raab-Graham KF, Weiner JL. Chronic Intermittent Ethanol Exposure Selectively Increases Synaptic Excitability in the Ventral Domain of the Rat Hippocampus. Neuroscience 2018; 398:144-157. [PMID: 30481568 DOI: 10.1016/j.neuroscience.2018.11.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/15/2018] [Accepted: 11/17/2018] [Indexed: 12/17/2022]
Abstract
Many studies have implicated hippocampal dysregulation in the pathophysiology of alcohol use disorder (AUD). However, over the past twenty years, a growing body of evidence has revealed distinct functional roles of the dorsal (dHC) and ventral (vHC) hippocampal subregions, with the dHC being primarily involved in spatial learning and memory and the vHC regulating anxiety- and depressive-like behaviors. Notably, to our knowledge, no rodent studies have examined the effects of chronic ethanol exposure on synaptic transmission along the dorsal/ventral axis. To that end, we examined the effects of the chronic intermittent ethanol vapor exposure (CIE) model of AUD on dHC and vHC synaptic excitability. Adult male Long-Evans rats were exposed to CIE or AIR for 10 days (12 h/day; targeting blood ethanol levels of 175-225 mg%) and recordings were made 24 h into withdrawal. As expected, this protocol increased anxiety-like behaviors on the elevated plus-maze and successive alleys test. Extracellular recordings revealed marked CIE-associated increases in synaptic excitation in the CA1 region that were exclusively restricted to the ventral domain of the hippocampus. Western blot analysis of synaptoneurosomal fractions revealed that the expression of two proteins that regulate synaptic strength, GluA2 and SK2, were dysregulated in the vHC, but not the dHC, following CIE. Together, these findings suggest that the ventral CA1 region may be particularly sensitive to the maladaptive effects of chronic ethanol exposure and provide new insight into some of the neural substrates that may contribute to the negative affective state that develops during withdrawal.
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Affiliation(s)
- Sarah E Ewin
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - James W Morgan
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Farr Niere
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Nate P McMullen
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Samuel H Barth
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Antoine G Almonte
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Kimberly F Raab-Graham
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Jeffrey L Weiner
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
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28
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Farris SP, Riley BP, Williams RW, Mulligan MK, Miles MF, Lopez MF, Hitzemann R, Iancu OD, Colville A, Walter NAR, Darakjian P, Oberbeck DL, Daunais JB, Zheng CL, Searles RP, McWeeney SK, Grant KA, Mayfield RD. Cross-species molecular dissection across alcohol behavioral domains. Alcohol 2018; 72:19-31. [PMID: 30213503 PMCID: PMC6309876 DOI: 10.1016/j.alcohol.2017.11.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 11/17/2017] [Accepted: 11/28/2017] [Indexed: 12/14/2022]
Abstract
This review summarizes the proceedings of a symposium presented at the "Alcoholism and Stress: A Framework for Future Treatment Strategies" conference held in Volterra, Italy on May 9-12, 2017. Psychiatric diseases, including alcohol-use disorders (AUDs), are influenced through complex interactions of genes, neurobiological pathways, and environmental influences. A better understanding of the common neurobiological mechanisms underlying an AUD necessitates an integrative approach, involving a systematic assessment of diverse species and phenotype measures. As part of the World Congress on Stress and Alcoholism, this symposium provided a detailed account of current strategies to identify mechanisms underlying the development and progression of AUDs. Dr. Sean Farris discussed the integration and organization of transcriptome and postmortem human brain data to identify brain regional- and cell type-specific differences related to excessive alcohol consumption that are conserved across species. Dr. Brien Riley presented the results of a genome-wide association study of DSM-IV alcohol dependence; although replication of genetic associations with alcohol phenotypes in humans remains challenging, model organism studies show that COL6A3, KLF12, and RYR3 affect behavioral responses to ethanol, and provide substantial evidence for their role in human alcohol-related traits. Dr. Rob Williams expanded upon the systematic characterization of extensive genetic-genomic resources for quantifying and clarifying phenotypes across species that are relevant to precision medicine in human disease. The symposium concluded with Dr. Robert Hitzemann's description of transcriptome studies in a mouse model selectively bred for high alcohol ("binge-like") consumption and a non-human primate model of long-term alcohol consumption. Together, the different components of this session provided an overview of systems-based approaches that are pioneering the experimental prioritization and validation of novel genes and gene networks linked with a range of behavioral phenotypes associated with stress and AUDs.
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Affiliation(s)
- Sean P Farris
- University of Texas at Austin, Austin, TX, United States
| | - Brien P Riley
- Virginia Commonwealth University, Richmond, VA, United States
| | - Robert W Williams
- University of Tennessee Health Science Center, Memphis, TN, United States
| | - Megan K Mulligan
- University of Tennessee Health Science Center, Memphis, TN, United States
| | - Michael F Miles
- University of Tennessee Health Science Center, Memphis, TN, United States
| | - Marcelo F Lopez
- University of Tennessee Health Science Center, Memphis, TN, United States
| | - Robert Hitzemann
- Oregon Health and Science University, Portland, OR, United States
| | - Ovidiu D Iancu
- Oregon Health and Science University, Portland, OR, United States
| | | | | | | | | | - James B Daunais
- Wake Forest School of Medicine, Winston-Salem, NC, United States
| | | | - Robert P Searles
- Oregon Health and Science University, Portland, OR, United States
| | | | - Kathleen A Grant
- Oregon Health and Science University, Portland, OR, United States
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29
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Whitaker LR, Hope BT. Chasing the addicted engram: identifying functional alterations in Fos-expressing neuronal ensembles that mediate drug-related learned behavior. ACTA ACUST UNITED AC 2018; 25:455-460. [PMID: 30115767 PMCID: PMC6097770 DOI: 10.1101/lm.046698.117] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 07/09/2018] [Indexed: 01/13/2023]
Abstract
Given that addiction has been characterized as a disorder of maladaptive learning and memory, one critical question is whether there are unique physical adaptations within neuronal ensembles that support addiction-related learned behavior. The search for the physical mechanisms of encoding these and other memories in the brain, often called the engram as a whole, continues despite decades of research. As we develop new technologies and tools that allow us to study cue- and behavior-activated Fos-expressing neuronal ensembles, the possibility of identifying the engrams of learning and memory is moving into the realm of reality rather than speculation. It has become clear from recent studies that there are specific functional, electrophysiological alterations unique to Fos-expressing ensemble neurons that may participate in encoding memories. The ultimate goal is to identify the addicted engram and reverse the physical changes that support this maladaptive form of learning.
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Affiliation(s)
- Leslie R Whitaker
- Office of the Scientific Director; Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Bruce T Hope
- Neuronal Ensembles in Addiction Section; Behavioral Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland 21224, USA
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30
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Effects of monoamines on the intrinsic excitability of lateral orbitofrontal cortex neurons in alcohol-dependent and non-dependent female mice. Neuropharmacology 2018; 137:1-12. [PMID: 29689260 DOI: 10.1016/j.neuropharm.2018.04.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/10/2018] [Accepted: 04/19/2018] [Indexed: 11/20/2022]
Abstract
Changes in brain reward and control systems of frontal cortical areas including the orbitofrontal cortex (OFC) are associated with alcohol use disorders (AUD). The OFC is extensively innervated by monoamines, and drugs that target monoamine receptors have been used to treat a number of neuropsychiatric diseases, including AUDs. Recent findings from this laboratory demonstrate that D2, α2-adrenergic and 5HT1A receptors all decrease the intrinsic excitability of lateral OFC (lOFC) neurons in naïve male mice and that this effect is lost in mice exposed to repeated cycles of chronic intermittent ethanol (CIE) vapor. As biological sex differences may influence an individual's response to alcohol and contribute to the propensity to engage in addictive behaviors, we examined whether monoamines have similar effects on lOFC neurons in control and CIE exposed female mice. Dopamine, norepinephrine and serotonin all decreased spiking of lOFC neurons in naïve females via activation of Giα-coupled D2, α2-adrenergic and 5HT1A receptors, respectively. Firing was also inhibited by the direct GIRK channel activator ML297, while blocking these channels with barium eliminated the inhibitory actions of monoamines. Following CIE treatment, evoked spiking of lOFC neurons from female mice was significantly enhanced and monoamines and ML297 no longer inhibited firing. Unlike in male mice, the enhanced firing of neurons from CIE exposed female mice was not associated with changes in the after-hyperpolarization and the small-conductance potassium channel blocker apamin had no effect on current-evoked tail currents from either control or CIE exposed female mice. These results suggest that while CIE exposure alters monoamine regulation of OFC neuron firing similarly in males and female mice, there are sex-dependent differences in processes that regulate the intrinsic excitability of these neurons.
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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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32
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Cannady R, Rinker JA, Nimitvilai S, Woodward JJ, Mulholland PJ. Chronic Alcohol, Intrinsic Excitability, and Potassium Channels: Neuroadaptations and Drinking Behavior. Handb Exp Pharmacol 2018; 248:311-343. [PMID: 29374839 DOI: 10.1007/164_2017_90] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neural mechanisms underlying alcohol use disorder remain elusive, and this lack of understanding has slowed the development of efficacious treatment strategies for reducing relapse rates and prolonging abstinence. While synaptic adaptations produced by chronic alcohol exposure have been extensively characterized in a variety of brain regions, changes in intrinsic excitability of critical projection neurons are understudied. Accumulating evidence suggests that prolonged alcohol drinking and alcohol dependence produce plasticity of intrinsic excitability as measured by changes in evoked action potential firing and after-hyperpolarization amplitude. In this chapter, we describe functional changes in cell firing of projection neurons after long-term alcohol exposure that occur across species and in multiple brain regions. Adaptations in calcium-activated (KCa2), voltage-dependent (KV7), and G protein-coupled inwardly rectifying (Kir3 or GIRK) potassium channels that regulate the evoked firing and after-hyperpolarization parallel functional changes in intrinsic excitability induced by chronic alcohol. Moreover, there are strong genetic links between alcohol-related behaviors and genes encoding KCa2, KV7, and GIRK channels, and pharmacologically targeting these channels reduces alcohol consumption and alcohol-related behaviors. Together, these studies demonstrate that chronic alcohol drinking produces adaptations in KCa2, KV7, and GIRK channels leading to impaired regulation of the after-hyperpolarization and aberrant cell firing. Correcting the deficit in the after-hyperpolarization with positive modulators of KCa2 and KV7 channels and altering the GIRK channel binding pocket to block the access of alcohol represent a potentially highly effective pharmacological approach that can restore changes in intrinsic excitability and reduce alcohol consumption in affected individuals.
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Affiliation(s)
- Reginald Cannady
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Jennifer A Rinker
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Sudarat Nimitvilai
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - John J Woodward
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Patrick J Mulholland
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA.
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33
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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: 259] [Impact Index Per Article: 37.0] [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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Bidirectional Modulation of Intrinsic Excitability in Rat Prelimbic Cortex Neuronal Ensembles and Non-Ensembles after Operant Learning. J Neurosci 2017; 37:8845-8856. [PMID: 28779019 DOI: 10.1523/jneurosci.3761-16.2017] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 07/10/2017] [Accepted: 07/18/2017] [Indexed: 11/21/2022] Open
Abstract
Learned associations between environmental stimuli and rewards drive goal-directed learning and motivated behavior. These memories are thought to be encoded by alterations within specific patterns of sparsely distributed neurons called neuronal ensembles that are activated selectively by reward-predictive stimuli. Here, we use the Fos promoter to identify strongly activated neuronal ensembles in rat prelimbic cortex (PLC) and assess altered intrinsic excitability after 10 d of operant food self-administration training (1 h/d). First, we used the Daun02 inactivation procedure in male FosLacZ-transgenic rats to ablate selectively Fos-expressing PLC neurons that were active during operant food self-administration. Selective ablation of these neurons decreased food seeking. We then used male FosGFP-transgenic rats to assess selective alterations of intrinsic excitability in Fos-expressing neuronal ensembles (FosGFP+) that were activated during food self-administration and compared these with alterations in less activated non-ensemble neurons (FosGFP-). Using whole-cell recordings of layer V pyramidal neurons in an ex vivo brain slice preparation, we found that operant self-administration increased excitability of FosGFP+ neurons and decreased excitability of FosGFP- neurons. Increased excitability of FosGFP+ neurons was driven by increased steady-state input resistance. Decreased excitability of FosGFP- neurons was driven by increased contribution of small-conductance calcium-activated potassium (SK) channels. Injections of the specific SK channel antagonist apamin into PLC increased Fos expression but had no effect on food seeking. Overall, operant learning increased intrinsic excitability of PLC Fos-expressing neuronal ensembles that play a role in food seeking but decreased intrinsic excitability of Fos- non-ensembles.SIGNIFICANCE STATEMENT Prefrontal cortex activity plays a critical role in operant learning, but the underlying cellular mechanisms are unknown. Using the chemogenetic Daun02 inactivation procedure, we found that a small number of strongly activated Fos-expressing neuronal ensembles in rat PLC play an important role in learned operant food seeking. Using GFP expression to identify Fos-expressing layer V pyramidal neurons in prelimbic cortex (PLC) of FosGFP-transgenic rats, we found that operant food self-administration led to increased intrinsic excitability in the behaviorally relevant Fos-expressing neuronal ensembles, but decreased intrinsic excitability in Fos- neurons using distinct cellular mechanisms.
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Cadet JL, Brannock C, Krasnova IN, Jayanthi S, Ladenheim B, McCoy MT, Walther D, Godino A, Pirooznia M, Lee RS. Genome-wide DNA hydroxymethylation identifies potassium channels in the nucleus accumbens as discriminators of methamphetamine addiction and abstinence. Mol Psychiatry 2017; 22:1196-1204. [PMID: 27046646 PMCID: PMC7405865 DOI: 10.1038/mp.2016.48] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/28/2016] [Accepted: 02/18/2016] [Indexed: 12/17/2022]
Abstract
Epigenetic consequences of exposure to psychostimulants are substantial but the relationship of these changes to compulsive drug taking and abstinence is not clear. Here, we used a paradigm that helped to segregate rats that reduce or stop their methamphetamine (METH) intake (nonaddicted) from those that continue to take the drug compulsively (addicted) in the presence of footshocks. We used that model to investigate potential alterations in global DNA hydroxymethylation in the nucleus accumbens (NAc) because neuroplastic changes in the NAc may participate in the development and maintenance of drug-taking behaviors. We found that METH-addicted rats did indeed show differential DNA hydroxymethylation in comparison with both control and nonaddicted rats. Nonaddicted rats also showed differences from control rats. Differential DNA hydroxymethylation observed in addicted rats occurred mostly at intergenic sites located on long and short interspersed elements. Interestingly, differentially hydroxymethylated regions in genes encoding voltage (Kv1.1, Kv1.2, Kvb1 and Kv2.2)- and calcium (Kcnma1, Kcnn1 and Kcnn2)-gated potassium channels observed in the NAc of nonaddicted rats were accompanied by increased mRNA levels of these potassium channels when compared with mRNA expression in METH-addicted rats. These observations indicate that changes in differentially hydroxymethylated regions and increased expression of specific potassium channels in the NAc may promote abstinence from drug-taking behaviors. Thus, activation of specific subclasses of voltage- and/or calcium-gated potassium channels may provide an important approach to the beneficial treatment for METH addiction.
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Affiliation(s)
- Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program Baltimore, MD, USA
| | - Christie Brannock
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program Baltimore, MD, USA
| | - Irina N. Krasnova
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program Baltimore, MD, USA
| | - Subramaniam Jayanthi
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program Baltimore, MD, USA
| | - Bruce Ladenheim
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program Baltimore, MD, USA
| | - Michael T. McCoy
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program Baltimore, MD, USA
| | - Donna Walther
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program Baltimore, MD, USA
| | - Arthur Godino
- Département de Biologie, École Normale Supérieure de Lyon, Lyon, France
| | - Mehdi Pirooznia
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Richard S. Lee
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
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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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Cannady R, McGonigal JT, Newsom RJ, Woodward JJ, Mulholland PJ, Gass JT. Prefrontal Cortex K Ca2 Channels Regulate mGlu 5-Dependent Plasticity and Extinction of Alcohol-Seeking Behavior. J Neurosci 2017; 37:4359-4369. [PMID: 28320841 PMCID: PMC5413180 DOI: 10.1523/jneurosci.2873-16.2017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 03/10/2017] [Accepted: 03/15/2017] [Indexed: 12/17/2022] Open
Abstract
Identifying novel treatments that facilitate extinction learning could enhance cue-exposure therapy and reduce high relapse rates in alcoholics. Activation of mGlu5 receptors in the infralimbic prefrontal cortex (IL-PFC) facilitates learning during extinction of cue-conditioned alcohol-seeking behavior. Small-conductance calcium-activated potassium (KCa2) channels have also been implicated in extinction learning of fear memories, and mGlu5 receptor activation can reduce KCa2 channel function. Using a combination of electrophysiological, pharmacological, and behavioral approaches, this study examined KCa2 channels as a novel target to facilitate extinction of alcohol-seeking behavior in rats. This study also explored related neuronal and synaptic mechanisms within the IL-PFC that underlie mGlu5-dependent enhancement of extinction learning. Using whole-cell patch-clamp electrophysiology, activation of mGlu5 in ex vivo slices significantly reduced KCa2 channel currents in layer V IL-PFC pyramidal neurons, confirming functional downregulation of KCa2 channel activity by mGlu5 receptors. Additionally, positive modulation of KCa2 channels prevented mGlu5 receptor-dependent facilitation of long-term potentiation in the IL-PFC. Systemic and intra-IL-PFC treatment with apamin (KCa2 channel allosteric inhibitor) significantly enhanced extinction of alcohol-seeking behavior across multiple extinction sessions, an effect that persisted for 3 weeks, but was not observed after apamin microinfusions into the prelimbic PFC. Positive modulation of IL-PFC KCa2 channels significantly attenuated mGlu5-dependent facilitation of alcohol cue-conditioned extinction learning. These data suggest that mGlu5-dependent facilitation of extinction learning and synaptic plasticity in the IL-PFC involves functional inhibition of KCa2 channels. Moreover, these findings demonstrate that KCa2 channels are a novel target to facilitate long-lasting extinction of alcohol-seeking behavior.SIGNIFICANCE STATEMENT Alcohol use disorder is a chronic relapsing disorder that is associated with compulsive alcohol-seeking behavior. One of the main causes of alcohol relapse is the craving caused by environmental cues that are associated with alcohol. These cues are formed by normal learning and memory principles, and the understanding of the brain mechanisms that help form these associations can lead to the development of drugs and/or behavior therapies that reduce the impact that these cues have on relapse in alcoholics.
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Affiliation(s)
- Reginald Cannady
- Department of Neuroscience
- Department of Psychiatry & Behavioral Sciences, and
| | | | | | - John J Woodward
- Department of Neuroscience
- Department of Psychiatry & Behavioral Sciences, and
| | | | - Justin T Gass
- Department of Neuroscience,
- Department of Psychiatry & Behavioral Sciences, and
- Charleston Alcohol Research Center, Addiction Sciences Division, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina 29425
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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: 38] [Impact Index Per Article: 5.4] [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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Huang CG, Chacron MJ. SK channel subtypes enable parallel optimized coding of behaviorally relevant stimulus attributes: A review. Channels (Austin) 2017; 11:281-304. [PMID: 28277938 DOI: 10.1080/19336950.2017.1299835] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Ion channels play essential roles toward determining how neurons respond to sensory input to mediate perception and behavior. Small conductance calcium-activated potassium (SK) channels are found ubiquitously throughout the brain and have been extensively characterized both molecularly and physiologically in terms of structure and function. It is clear that SK channels are key determinants of neural excitability as they mediate important neuronal response properties such as spike frequency adaptation. However, the functional roles of the different known SK channel subtypes are not well understood. Here we review recent evidence from the electrosensory system of weakly electric fish suggesting that the function of different SK channel subtypes is to optimize the processing of independent but behaviorally relevant stimulus attributes. Indeed, natural sensory stimuli frequently consist of a fast time-varying waveform (i.e., the carrier) whose amplitude (i.e., the envelope) varies slowly and independently. We first review evidence showing how somatic SK2 channels mediate tuning and responses to carrier waveforms. We then review evidence showing how dendritic SK1 channels instead determine tuning and optimize responses to envelope waveforms based on their statistics as found in the organism's natural environment in an independent fashion. The high degree of functional homology between SK channels in electric fish and their mammalian orthologs, as well as the many important parallels between the electrosensory system and the mammalian visual, auditory, and vestibular systems, suggest that these functional roles are conserved across systems and species.
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Affiliation(s)
- Chengjie G Huang
- a Department of Physiology , McGill University , Montreal , QC , Canada
| | - Maurice J Chacron
- a Department of Physiology , McGill University , Montreal , QC , Canada
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40
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Rinker JA, Fulmer DB, Trantham-Davidson H, Smith ML, Williams RW, Lopez MF, Randall PK, Chandler LJ, Miles MF, Becker HC, Mulholland PJ. Differential potassium channel gene regulation in BXD mice reveals novel targets for pharmacogenetic therapies to reduce heavy alcohol drinking. Alcohol 2017; 58:33-45. [PMID: 27432260 DOI: 10.1016/j.alcohol.2016.05.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 04/12/2016] [Accepted: 05/03/2016] [Indexed: 12/22/2022]
Abstract
Alcohol (ethanol) dependence is a chronic relapsing brain disorder partially influenced by genetics and characterized by an inability to regulate harmful levels of drinking. Emerging evidence has linked genes that encode KV7, KIR, and KCa2 K+ channels with variation in alcohol-related behaviors in rodents and humans. This led us to experimentally test relations between K+ channel genes and escalation of drinking in a chronic-intermittent ethanol (CIE) exposure model of dependence in BXD recombinant inbred strains of mice. Transcript levels for K+ channel genes in the prefrontal cortex (PFC) and nucleus accumbens (NAc) covary with voluntary ethanol drinking in a non-dependent cohort. Transcripts that encode KV7 channels covary negatively with drinking in non-dependent BXD strains. Using a pharmacological approach to validate the genetic findings, C57BL/6J mice were allowed intermittent access to ethanol to establish baseline consumption before they were treated with retigabine, an FDA-approved KV7 channel positive modulator. Systemic administration significantly reduced drinking, and consistent with previous evidence, retigabine was more effective at reducing voluntary consumption in high-drinking than low-drinking subjects. We evaluated the specific K+ channel genes that were most sensitive to CIE exposure and identified a gene subset in the NAc and PFC that were dysregulated in the alcohol-dependent BXD cohort. CIE-induced modulation of nine genes in the NAc and six genes in the PFC covaried well with the changes in drinking induced by ethanol dependence. Here we identified novel candidate genes in the NAc and PFC that are regulated by ethanol dependence and correlate with voluntary drinking in non-dependent and dependent BXD mice. The findings that Kcnq expression correlates with drinking and that retigabine reduces consumption suggest that KV7 channels could be pharmacogenetic targets to treat individuals with alcohol addiction.
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41
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McGuier NS, Griffin WC, Gass JT, Padula AE, Chesler EJ, Mulholland PJ. Kv7 channels in the nucleus accumbens are altered by chronic drinking and are targets for reducing alcohol consumption. Addict Biol 2016; 21:1097-1112. [PMID: 26104325 DOI: 10.1111/adb.12279] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Alcohol use disorders (AUDs) are a major public health issue and produce enormous societal and economic burdens. Current Food and Drug Administration (FDA)-approved pharmacotherapies for treating AUDs suffer from deleterious side effects and are only effective in a subset of individuals. It is therefore essential to find improved medications for the management of AUDs. Emerging evidence suggests that anticonvulsants are a promising class of drugs for treating individuals with AUDs. In these studies, we used integrative functional genomics to demonstrate that genes that encode Kv7 channels (i.e. Kcnq2/3) are related to alcohol (ethanol) consumption, preference and acceptance in rodents. We then tested the ability of the FDA-approved anticonvulsant retigabine, a Kv7 channel opener, to reduce voluntary ethanol consumption of Wistar rats in a two-bottle choice intermittent alcohol access paradigm. Systemic administration and microinjections of retigabine into the nucleus accumbens significantly reduced alcohol drinking, and retigabine was more effective at reducing intake in high- versus low-drinking populations of Wistar rats. Prolonged voluntary drinking increased the sensitivity to the proconvulsant effects of pharmacological blockade of Kv7 channels and altered surface trafficking and SUMOylation patterns of Kv7.2 channels in the nucleus accumbens. These data implicate Kcnq2/3 in the regulation of ethanol drinking and demonstrate that long-term drinking produces neuroadaptations in Kv7 channels. In addition, these results have identified retigabine as a potential pharmacotherapy for treating AUDs and Kv7 channels as a novel therapeutic target for reducing heavy drinking.
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Affiliation(s)
- Natalie S. McGuier
- 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
| | - Justin T. Gass
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | - Audrey E. Padula
- Department of Neuroscience; 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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Lei K, Wegner SA, Yu JH, Mototake A, Hu B, Hopf FW. Nucleus Accumbens Shell and mPFC but Not Insula Orexin-1 Receptors Promote Excessive Alcohol Drinking. Front Neurosci 2016; 10:400. [PMID: 27625592 PMCID: PMC5004043 DOI: 10.3389/fnins.2016.00400] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/15/2016] [Indexed: 12/22/2022] Open
Abstract
Addiction to alcohol remains a major social and economic problem, in part because of the high motivation for alcohol that humans exhibit and the hazardous binge intake this promotes. Orexin-1-type receptors (OX1Rs) promote reward intake under conditions of strong drives for reward, including excessive alcohol intake. While systemic modulation of OX1Rs can alter alcohol drinking, the brain regions that mediate this OX1R enhancement of excessive drinking remain unknown. Given the importance of the nucleus accumbens (NAc) and anterior insular cortex (aINS) in driving many addictive behaviors, including OX1Rs within these regions, we examined the importance of OX1Rs in these regions on excessive alcohol drinking in C57BL/6 mice during limited-access alcohol drinking in the dark cycle. Inhibition of OX1Rs with the widely used SB-334867 within the medial NAc Shell (mNAsh) significantly reduced drinking of alcohol, with no effect on saccharin intake, and no effect on alcohol consumption when infused above the mNAsh. In contrast, intra-mNAsh infusion of the orexin-2 receptor TCS-OX2-29 had no impact on alcohol drinking. In addition, OX1R inhibition within the aINS had no effect on excessive drinking, which was surprising given the importance of aINS-NAc circuits in promoting alcohol consumption and the role for aINS OX1Rs in driving nicotine intake. However, OX1R inhibition within the mPFC did reduce alcohol drinking, indicating cortical OXR involvement in promoting intake. Also, in support of the critical role for mNAsh OX1Rs, SB within the mNAsh also significantly reduced operant alcohol self-administration in rats. Finally, orexin ex vivo enhanced firing in mNAsh neurons from alcohol-drinking mice, with no effect on evoked EPSCs or input resistance; a similar orexin increase in firing without a change in input resistance was observed in alcohol-naïve mice. Taken together, our results suggest that OX1Rs within the mNAsh and mPFC, but not the aINS, play a central role in driving excessive alcohol drinking.
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Affiliation(s)
- Kelly Lei
- Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco San Francisco, CA, USA
| | - Scott A Wegner
- Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco San Francisco, CA, USA
| | - Ji Hwan Yu
- Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco San Francisco, CA, USA
| | - Arisa Mototake
- Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco San Francisco, CA, USA
| | - Bing Hu
- Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco San Francisco, CA, USA
| | - Frederic W Hopf
- Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco San Francisco, CA, USA
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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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44
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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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45
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Nimitvilai S, Lopez MF, Mulholland PJ, Woodward JJ. Chronic Intermittent Ethanol Exposure Enhances the Excitability and Synaptic Plasticity of Lateral Orbitofrontal Cortex Neurons and Induces a Tolerance to the Acute Inhibitory Actions of Ethanol. Neuropsychopharmacology 2016; 41:1112-27. [PMID: 26286839 PMCID: PMC4748436 DOI: 10.1038/npp.2015.250] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 08/14/2015] [Accepted: 08/15/2015] [Indexed: 02/07/2023]
Abstract
Alcoholism is associated with changes in brain reward and control systems, including the prefrontal cortex. In prefrontal areas, the orbitofrontal cortex (OFC) has been suggested to have an important role in the development of alcohol-abuse disorders and studies from this laboratory demonstrate that OFC-mediated behaviors are impaired in alcohol-dependent animals. However, it is not known whether chronic alcohol (ethanol) exposure alters the fundamental properties of OFC neurons. In this study, mice were exposed to repeated cycles of chronic intermittent ethanol (CIE) exposure to induce dependence and whole-cell patch-clamp electrophysiology was used to examine the effects of CIE treatment on lateral OFC (lOFC) neuron excitability, synaptic transmission, and plasticity. Repeated cycles of CIE exposure and withdrawal enhanced current-evoked action potential (AP) spiking and this was accompanied by a reduction in the after-hyperpolarization and a decrease in the functional activity of SK channels. CIE mice also showed an increase in the AMPA/NMDA ratio, and this was associated with an increase in GluA1/GluA2 AMPA receptor expression and a decrease in GluN2B NMDA receptor subunits. Following CIE treatment, lOFC neurons displayed a persistent long-term potentiation of glutamatergic synaptic transmission following a spike-timing-dependent protocol. Lastly, CIE treatment diminished the inhibitory effect of acute ethanol on AP spiking of lOFC neurons and reduced expression of the GlyT1 transporter. Taken together, these results suggest that chronic exposure to ethanol leads to enhanced intrinsic excitability and glutamatergic synaptic signaling of lOFC neurons. These alterations may contribute to the impairment of OFC-dependent behaviors in alcohol-dependent individuals.
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Affiliation(s)
- Sudarat Nimitvilai
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Marcelo F Lopez
- Addiction Sciences Division, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Patrick J Mulholland
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
- Addiction Sciences Division, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - John J Woodward
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
- Addiction Sciences Division, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
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46
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Poland RS, Bull C, Syed WA, Bowers MS. Rodent Brain Microinjection to Study Molecular Substrates of Motivated Behavior. J Vis Exp 2015. [PMID: 26437131 PMCID: PMC4692606 DOI: 10.3791/53018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Brain microinjection can aid elucidation of the molecular substrates of complex behaviors, such as motivation. For this purpose rodents can serve as appropriate models, partly because the response to behaviorally relevant stimuli and the circuitry parsing stimulus-action outcomes is astonishingly similar between humans and rodents. In studying molecular substrates of complex behaviors, the microinjection of reagents that modify, augment, or silence specific systems is an invaluable technique. However, it is crucial that the microinjection site is precisely targeted in order to aid interpretation of the results. We present a method for the manufacture of surgical implements and microinjection needles that enables accurate microinjection and unlimited customizability with minimal cost. Importantly, this technique can be successfully completed in awake rodents if conducted in conjunction with other JoVE articles that covered requisite surgical procedures. Additionally, there are many behavioral paradigms that are well suited for measuring motivation. The progressive ratio is a commonly used method that quantifies the efficacy of a reinforcer to maintain responding despite an (often exponentially) increasing work requirement. This assay is sensitive to reinforcer magnitude and pharmacological manipulations, which allows reinforcing efficacy and/ or motivation to be determined. We also present a straightforward approach to program operant software to accommodate a progressive ratio reinforcement schedule.
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Affiliation(s)
- Ryan S Poland
- Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University School of Medicine
| | - Cecilia Bull
- Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University School of Medicine
| | - Wahab A Syed
- Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University School of Medicine
| | - M Scott Bowers
- Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University School of Medicine; Institute for Drug and Alcohol Studies, Departments of Psychiatry, Pharmacology, and Neuroscience, Virginia Commonwealth University School of Medicine;
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47
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Increased Basolateral Amygdala Pyramidal Cell Excitability May Contribute to the Anxiogenic Phenotype Induced by Chronic Early-Life Stress. J Neurosci 2015; 35:9730-40. [PMID: 26134655 DOI: 10.1523/jneurosci.0384-15.2015] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
UNLABELLED Adolescence represents a particularly vulnerable period during which exposure to stressors can precipitate the onset of psychiatric disorders and addiction. The basolateral amygdala (BLA) plays an integral role in the pathophysiology of anxiety and addiction. Acute and chronic stress promote increases in BLA pyramidal cell firing, and decreasing BLA excitability alleviates anxiety measures in humans and rodents. Notably, the impact of early-life stress on the mechanisms that govern BLA excitability is unknown. To address this gap in our knowledge, we used a rodent model of chronic early-life stress that engenders robust and enduring increases in anxiety-like behaviors and ethanol intake and examined the impact of this model on the intrinsic excitability of BLA pyramidal cells. Adolescent social isolation was associated with a significant increase in the intrinsic excitability of BLA pyramidal cells and a blunting of the medium component of the afterhyperpolarization potential, a voltage signature of calcium-activated potassium (Kca) channel activity. Western blot analysis revealed reduced expression of small-conductance Kca (SK) channel protein in the BLA of socially isolated (SI) rats. Bath application of a positive SK channel modulator (1-EBIO) normalized firing in ex vivo recordings from SI rats, and in vivo intra-BLA 1-EBIO infusion reduced anxiety-like behaviors. These findings reveal that chronic adolescent stress impairs SK channel function, which contributes to an increase in BLA pyramidal cell excitability and highlights BLA SK channels as promising targets for the treatment of anxiety disorders and comorbid addiction. SIGNIFICANCE STATEMENT Although anxiety disorders and alcohol addiction frequently co-occur, the mechanisms that contribute to this comorbidity are poorly understood. Here, we used a rodent early-life stress model that leads to robust and longlasting increases in behaviors associated with elevated risk of anxiety disorders and addiction to identify novel neurobiological substrates that may underlie these behaviors. Our studies focused on the primary output neurons of the basolateral amygdala, a brain region that plays a key role in anxiety and addiction. We discovered that early-life stress decreases the activity of a specific class of potassium channels and increases the intrinsic excitability of BLA neurons and present evidence that enhancing the function of these channels normalizes BLA excitability and attenuates anxiety-like behaviors.
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48
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KCNN Genes that Encode Small-Conductance Ca2+-Activated K+ Channels Influence Alcohol and Drug Addiction. Neuropsychopharmacology 2015; 40:1928-39. [PMID: 25662840 PMCID: PMC4839516 DOI: 10.1038/npp.2015.42] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 01/17/2015] [Accepted: 01/26/2015] [Indexed: 02/02/2023]
Abstract
Small-conductance Ca(2+)-activated K(+) (KCa2) channels control neuronal excitability and synaptic plasticity, and have been implicated in substance abuse. However, it is unknown if genes that encode KCa2 channels (KCNN1-3) influence alcohol and drug addiction. In the present study, an integrative functional genomics approach shows that genetic datasets for alcohol, nicotine, and illicit drugs contain the family of KCNN genes. Alcohol preference and dependence QTLs contain KCNN2 and KCNN3, and Kcnn3 transcript levels in the nucleus accumbens (NAc) of genetically diverse BXD strains of mice predicted voluntary alcohol consumption. Transcript levels of Kcnn3 in the NAc negatively correlated with alcohol intake levels in BXD strains, and alcohol dependence enhanced the strength of this association. Microinjections of the KCa2 channel inhibitor apamin into the NAc increased alcohol intake in control C57BL/6J mice, while spontaneous seizures developed in alcohol-dependent mice following apamin injection. Consistent with this finding, alcohol dependence enhanced the intrinsic excitability of medium spiny neurons in the NAc core and reduced the function and protein expression of KCa2 channels in the NAc. Altogether, these data implicate the family of KCNN genes in alcohol, nicotine, and drug addiction, and identify KCNN3 as a mediator of voluntary and excessive alcohol consumption. KCa2.3 channels represent a promising novel target in the pharmacogenetic treatment of alcohol and drug addiction.
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49
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Zhang M, Meng XY, Zhang JF, Cui M, Logothetis DE. Molecular overlap in the regulation of SK channels by small molecules and phosphoinositides. SCIENCE ADVANCES 2015; 1:e1500008. [PMID: 26366439 PMCID: PMC4563807 DOI: 10.1126/sciadv.1500008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 05/29/2015] [Indexed: 06/05/2023]
Abstract
Phosphatidylinositol 4,5-bisphosphate (PIP2) directly interacts with the small-conductance Ca2+-activated K+ 2-a (SK2-a) channel/calmodulin complex, serving as a critical element in the regulation of channel activity. We report that changes of protein conformation in close proximity to the PIP2 binding site induced by a small-molecule SK channel modulator, NS309, can effectively enhance the interaction between the protein and PIP2 to potentiate channel activity. This novel modulation of PIP2 sensitivity by small-molecule drugs is likely not to be limited in its application to SK channels, representing an intriguing strategy to develop drugs controlling the activity of the large number of PIP2-dependent proteins.
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Affiliation(s)
- Miao Zhang
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, 1101 East Marshall Street, Richmond, VA 23298, USA
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, 9401 Jeronimo Road, Irvine, CA 92618, USA
| | - Xuan-Yu Meng
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, 1101 East Marshall Street, Richmond, VA 23298, USA
| | - Ji-fang Zhang
- Department of Molecular Physiology and Biophysics, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
- Farber Institute for Neurosciences and Graduate Program in Neuroscience, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Meng Cui
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, 1101 East Marshall Street, Richmond, VA 23298, USA
| | - Diomedes E. Logothetis
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, 1101 East Marshall Street, Richmond, VA 23298, USA
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50
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Rau AR, Ariwodola OJ, Weiner JL. Postsynaptic adenosine A2A receptors modulate intrinsic excitability of pyramidal cells in the rat basolateral amygdala. Int J Neuropsychopharmacol 2015; 18:pyv017. [PMID: 25716780 PMCID: PMC4438553 DOI: 10.1093/ijnp/pyv017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The basolateral amygdala plays a critical role in the etiology of anxiety disorders and addiction. Pyramidal neurons, the primary output cells of this region, display increased firing following exposure to stressors, and it is thought that this increase in excitability contributes to stress responsivity and the expression of anxiety-like behaviors. However, much remains unknown about the underlying mechanisms that regulate the intrinsic excitability of basolateral amygdala pyramidal neurons. METHODS Ex vivo gramicidin perforated patch recordings were conducted in current clamp mode where hyper- and depolarizing current steps were applied to basolateral amygdala pyramidal neurons to assess the effects of adenosine A(2A) receptor modulation on intrinsic excitability. RESULTS Activation of adenosine A(2A) receptors with the selective A(2A) receptor agonist CGS-21680 significantly increased the firing rate of basolateral amygdala pyramidal neurons in rat amygdala brain slices, likely via inhibition of the slow afterhyperpolarization potential. Both of these A(2A) receptor-mediated effects were blocked by preapplication of a selective A(2A) receptor antagonist (ZM-241385) or by intra-pipette infusion of a protein kinase A inhibitor, suggesting a postsynaptic locus of A(2A) receptors on basolateral amygdala pyramidal neurons. Interestingly, bath application of the A(2A) receptor antagonist alone significantly attenuated basolateral amygdala pyramidal cell firing, consistent with a role for tonic adenosine in the regulation of the intrinsic excitability of these neurons. CONCLUSIONS Collectively, these data suggest that adenosine, via activation of A(2A) receptors, may directly facilitate basolateral amygdala pyramidal cell output, providing a possible balance for the recently described inhibitory effects of adenosine A1 receptor activation on glutamatergic excitation of basolateral amygdala pyramidal cells.
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Affiliation(s)
- Andrew R Rau
- Department of Physiology and Pharmacology, School of Medicine (Mr Rau, Mr Ariwodola, and Dr Weiner), Neuroscience Graduate Program, Graduate School of Arts and Sciences (Mr Rau), Wake Forest University, Winston-Salem, North Carolina
| | - Olusegun J Ariwodola
- Department of Physiology and Pharmacology, School of Medicine (Mr Rau, Mr Ariwodola, and Dr Weiner), Neuroscience Graduate Program, Graduate School of Arts and Sciences (Mr Rau), Wake Forest University, Winston-Salem, North Carolina
| | - Jeff L Weiner
- Department of Physiology and Pharmacology, School of Medicine (Mr Rau, Mr Ariwodola, and Dr Weiner), Neuroscience Graduate Program, Graduate School of Arts and Sciences (Mr Rau), Wake Forest University, Winston-Salem, North Carolina.
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