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Beane CR, Lewis DG, Bruns Vi N, Pikus KL, Durfee MH, Zegarelli RA, Perry TW, Sandoval O, Radke AK. Cholinergic mu-opioid receptor deletion alters reward preference and aversion-resistance. Neuropharmacology 2024; 255:110019. [PMID: 38810926 DOI: 10.1016/j.neuropharm.2024.110019] [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: 12/15/2023] [Revised: 05/26/2024] [Accepted: 05/26/2024] [Indexed: 05/31/2024]
Abstract
The endogenous opioid system has been implicated in alcohol consumption and preference in both humans and animals. The mu opioid receptor (MOR) is expressed on multiple cells in the striatum, however little is known about the contributions of specific MOR populations to alcohol drinking behaviors. The current study used mice with a genetic deletion of MOR in cholinergic cells (ChAT-Cre/Oprm1fl/fl) to examine the role of MORs expressed in cholinergic interneurons (CINs) in home cage self-administration paradigms. Male and female ChAT-Cre/Oprm1fl/fl mice were generated and heterozygous Cre+ (knockout) and Cre- (control) mice were tested for alcohol consumption in two drinking paradigms: limited access "Drinking in the Dark" and intermittent access. Quinine was added to the drinking bottles in the DID experiment to test aversion-resistant, "compulsive" drinking. Nicotine and sucrose drinking were also assessed so comparisons could be made with other rewarding substances. Cholinergic MOR deletion did not influence consumption or preference for ethanol (EtOH) in either drinking task. Differences were observed in aversion-resistance in males with Cre + mice tolerating lower concentrations of quinine than Cre-. In contrast to EtOH, preference for nicotine was reduced following cholinergic MOR deletion while sucrose consumption and preference was increased in Cre+ (vs. Cre-) females. Locomotor activity was also greater in females following the deletion. These results suggest that cholinergic MORs participate in preference for rewarding substances. Further, while they are not required for consumption of alcohol alone, cholinergic MORs may influence the tendency to drink despite negative consequences.
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Affiliation(s)
- Cambria R Beane
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA
| | - Delainey G Lewis
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA
| | - Nicolaus Bruns Vi
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA
| | - Kat L Pikus
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA
| | - Mary H Durfee
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA
| | - Roman A Zegarelli
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA
| | - Thomas W Perry
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA
| | - Oscar Sandoval
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA
| | - Anna K Radke
- Department of Psychology and Center for Neuroscience and Behavior, Miami University, Oxford, OH, USA.
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2
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Islam S, Gleber-Netto FO, Mulcahy CF, Glaun MDE, Srivastava S, Hunt PJ, Williams MD, Barbon CE, Spiotto M, Zhao W, Adebayo A, Akhter S, Xie T, Debnath KC, Sathishkumar HN, Myers B, Lothumalla S, Yaman I, Burks JK, Gomez J, Rao X, Wang J, Woodman K, Mansour J, Arenkiel B, Osman KL, Haxton C, Lever TE, Hutcheson KA, Amit M. Neural landscape is associated with functional outcomes in irradiated patients with oropharyngeal squamous cell carcinoma. Sci Transl Med 2024; 16:eabq5585. [PMID: 39083586 DOI: 10.1126/scitranslmed.abq5585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 01/02/2024] [Accepted: 07/03/2024] [Indexed: 08/02/2024]
Abstract
The incidence of human papilloma virus-mediated oropharyngeal squamous cell carcinoma (OPSCC) has increased over the past 40 years, particularly among young individuals with a favorable prognosis; however, current therapy often leads to unfortunate side effects, such as dysphagia. Despite the emphasis on dysphagia in previous studies, there is an important research gap in understanding the correlation between neuronal changes and patient-reported and functional outcomes in patients with OPSCC. To address this issue, we examined pathologic tissue samples from patients with OPSCC using multiplex immunofluorescence staining and machine learning to correlate tumor-associated neuronal changes with prospectively collected patient-reported and functional outcomes. We found that tumor enrichment of adrenergic (TH+) and CGRP+ sensory-afferent nerves correlated with poorer swallowing outcomes. Functional electromyography recordings showed correlations between growing (GAP43+) and immature cholinergic (ChAT+DCX+) nerves and denervation patterns in survivors of OPSCC. A murine model of radiation-induced dysphagia further confirmed that immature cholinergic and CGRP+ nerves were correlated with impaired swallowing. Preclinical interventional studies also supported the independent contributions of CGRP+ and cholinergic (ChAT+) nerves to dysphagia in treated mouse models of OPSCC. Our results suggest that CGRP+ and ChAT+ neuronal signaling play distinct roles in tumor- and radiation-induced dysphagia in OPSCC and offer a comprehensive dataset on the neural landscape of OPSCC. These insights may guide early interventions for swallow preservation and the repurposing of neurology-related drugs, such as CGRP blockers, in clinical oncology and survivorship.
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Affiliation(s)
- Shajedul Islam
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Frederico O Gleber-Netto
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Collin F Mulcahy
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Mica D E Glaun
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Snigdha Srivastava
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Patrick J Hunt
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michelle D Williams
- Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Carly E Barbon
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Michael Spiotto
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Weilu Zhao
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Biostatistics and Data Science, University of Texas Health Science Center at Houston (UTHealth Houston) School of Public Health, Houston, TX 77030, USA
| | - Adewale Adebayo
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Shamima Akhter
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Tongxin Xie
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Kala Chand Debnath
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Hinduja Naidu Sathishkumar
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Blake Myers
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Sahana Lothumalla
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ismail Yaman
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jared K Burks
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Leukemia and Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Javier Gomez
- Department of Leukemia and Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xiayu Rao
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jing Wang
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Karin Woodman
- Department of Neuro-Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jobran Mansour
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Otolaryngology-Head and Neck Surgery, Louisiana State University Shreveport Medical Center, Shreveport, LA 71103, USA
| | - Benjamin Arenkiel
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kate L Osman
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Chandler Haxton
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Teresa E Lever
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Katherine A Hutcheson
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Moran Amit
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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3
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Beane CR, Lewis DG, Bruns NK, Pikus KL, Durfee MH, Zegarelli RA, Perry TW, Sandoval O, Radke AK. Cholinergic mu-opioid receptor deletion alters reward preference and aversion-resistance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.13.566881. [PMID: 38014065 PMCID: PMC10680803 DOI: 10.1101/2023.11.13.566881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Heavy alcohol use and binge drinking are important contributors to alcohol use disorder (AUD). The endogenous opioid system has been implicated in alcohol consumption and preference in both humans and animals. The mu opioid receptor (MOR) is expressed on multiple cells in the striatum, however little is known about the contributions of specific MOR populations to alcohol drinking behaviors. The current study used mice with a genetic deletion of MOR in cholinergic cells (ChAT-Cre/Oprm1fl/fl) to examine the role of MORs expressed in cholinergic interneurons (CINs) in home cage self-administration paradigms. Male and female ChAT-Cre/Oprm1fl/fl mice were generated and heterozygous Cre+ (knockout) and Cre- (control) mice were tested for alcohol and nicotine consumption. In Experiment 1, binge-like and quinine-resistant drinking was tested using 15% ethanol (EtOH) in a two-bottle, limited-access Drinking in the Dark paradigm. Experiment 2 involved a six-week intermittent access paradigm in which mice received 20% EtOH, nicotine, and then a combination of the two drugs. Experiment 3 assessed locomotor activity, sucrose preference, and quinine sensitivity. Deleting MORs in cholinergic cells did not alter consumption of EtOH in Experiment 1 or 2. In Experiment 1, the MOR deletion resulted in greater consumption of quinine-adulterated EtOH in male Cre+ mice (vs. Cre-). In Experiment 2, Cre+ mice demonstrated a significantly lower preference for nicotine but did not differ from Cre- mice in nicotine or nicotine + EtOH consumption. Overall fluid consumption was also heightened in the Cre+ mice. In Experiment 3, Cre+ females were found to have greater locomotor activity and preference for sucrose vs. Cre- mice. These data suggest that cholinergic MORs are not required for EtOH, drinking behaviors but may contribute to aversion resistant EtOH drinking in a sex-dependent manner.
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Söderpalm B, Ericson M. Alcohol and the dopamine system. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2024; 175:21-73. [PMID: 38555117 DOI: 10.1016/bs.irn.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
The mesolimbic dopamine pathway plays a major role in drug reinforcement and is likely involved also in the development of drug addiction. Ethanol, like most addictive drugs, acutely activates the mesolimbic dopamine system and releases dopamine, and ethanol-associated stimuli also appear to trigger dopamine release. In addition, chronic exposure to ethanol reduces the baseline function of the mesolimbic dopamine system. The molecular mechanisms underlying ethanol´s interaction with this system remain, however, to be unveiled. Here research on the actions of ethanol in the mesolimbic dopamine system, focusing on the involvement of cystein-loop ligand-gated ion channels, opiate receptors, gastric peptides and acetaldehyde is briefly reviewed. In summary, a great complexity as regards ethanol´s mechanism(s) of action along the mesolimbic dopamine system has been revealed. Consequently, several new targets and possibilities for pharmacotherapies for alcohol use disorder have emerged.
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Affiliation(s)
- Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Addiction and Dependency, Sahlgrenska University Hospital, Gothenburg, Sweden.
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Olsson Y, Lidö H, Ademar K, Cadeddu D, Ericson M, Söderpalm B. The GlyT1-inhibitor Org 24598 facilitates the alcohol deprivation abolishing and dopamine elevating effects of bupropion + varenicline in rats. J Neural Transm (Vienna) 2024; 131:95-106. [PMID: 37773223 PMCID: PMC10769923 DOI: 10.1007/s00702-023-02701-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/18/2023] [Indexed: 10/01/2023]
Abstract
Alcohol Use Disorder (AUD) is a relapsing brain disorder that involves perturbations of brain dopamine (DA) systems, and combined treatment with varenicline + bupropion produces additive effects on accumbal DA output and abolishes the alcohol deprivation effect (ADE) in rats. Also, direct and indirect glycine receptor (GlyR) agonists raise basal DA, attenuate alcohol-induced DA release in the nucleus Accumbens (nAc) and reduce alcohol consumption in rats. This study in rats examines whether the GlyT1-inhibitor Org 24598, an indirect GlyR agonist, enhances the ADE-reducing and DA elevating action of the combined administration of varenicline + bupropion in lower doses than previously applied. Effects on voluntary alcohol consumption, the ADE and extracellular levels of glycine and DA in nAc were examined following treatment with Org 24598 6 and 9 mg/kg i.p., bupropion 3.75 mg/kg i.p. and varenicline 1.5 mg/kg s.c., in monotherapy or combined, using a two-bottle, free-choice alcohol consumption paradigm with an ADE paradigm, and in vivo microdialysis in male Wistar rats. Notably, all treatment regimens appeared to abolish the ADE but only the effect produced by the triple combination (Org24598 + varenicline + bupropion) was significant compared to vehicle. Hence, addition of Org 24598 may enhance the ADE-reducing action of varenicline + bupropion and appears to allow for a dose reduction of bupropion. Treatment with Org 24598 raised accumbal glycine levels but did not significantly alter DA output in monotherapy. Varenicline + bupropion produced a substantial elevation in accumbal DA output that was slightly enhanced following addition of Org 24598. Conceivably, the blockade of the ADE is achieved by the triple combination enhancing accumbal DA transmission in complementary ways, thereby alleviating a hypothesized hypodopaminergia and negative reinforcement to drink. Ultimately, combining an indirect or direct GlyR agonist with varenicline + bupropion may constitute a new pharmacological treatment principle for AUD, although further refinement in dosing and evaluation of other glycinergic compounds are warranted.
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Affiliation(s)
- Yasmin Olsson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, PO Box 410, 405 30, Gothenburg, SE, Sweden.
- Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden.
- Department of Neurology, Sahlgrenska University Hospital, Gothenburg, Sweden.
| | - Helga Lidö
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, PO Box 410, 405 30, Gothenburg, SE, Sweden
- Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Karin Ademar
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, PO Box 410, 405 30, Gothenburg, SE, Sweden
| | - Davide Cadeddu
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, PO Box 410, 405 30, Gothenburg, SE, Sweden
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, PO Box 410, 405 30, Gothenburg, SE, Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, PO Box 410, 405 30, Gothenburg, SE, Sweden
- Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
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6
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Loftén A, Adermark L, Ericson M, Söderpalm B. Regulation of ethanol-mediated dopamine elevation by glycine receptors located on cholinergic interneurons in the nucleus accumbens. Addict Biol 2023; 28:e13349. [PMID: 38017639 DOI: 10.1111/adb.13349] [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: 07/04/2023] [Revised: 09/08/2023] [Accepted: 09/26/2023] [Indexed: 11/30/2023]
Abstract
Alcohol use disorder is one of the major psychiatric disorders worldwide, and there are many factors and effects contributing to the disorder, for example, the experience of ethanol reward. The rewarding and reinforcing properties of ethanol have been linked to activation of the mesolimbic dopamine system, an effect that appears to involve glycine receptors (GlyRs) in the nucleus accumbens. On which neuronal subtypes these receptors are located is, however, not known. The aim of this study was to explore the role of GlyRs on cholinergic interneurons (CIN) in sustaining extracellular dopamine levels and in ethanol-induced dopamine release. To this end, CIN were ablated by anti-choline acetyltransferase-saporin administered locally in the nucleus accumbens of male Wistar rats. Changes in dopamine levels induced by ablation, ethanol and/or a GlyR antagonist were monitored using in vivo microdialysis. The GlyRs antagonist strychnine depressed extracellular dopamine in a similar manner independent on local ablation, suggesting that GlyRs on CIN are not important for sustaining the extracellular dopamine tone. However, a low concentration of strychnine hampered ethanol-induced dopamine release in sham-treated animals, whilst no reduction was seen in ablated animals, suggesting that GlyRs located on CIN are involved in ethanol-induced dopamine release. Further, in ablated rats, ethanol-induced increases of the extracellular levels of the GlyR agonists glycine and taurine were attenuated. In conclusion, this study suggests that CIN are not important for GlyR-mediated regulation of basal dopamine output, but that CIN ablation blunts the ethanol-induced dopamine release, putatively by reducing the release of GlyR agonists.
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Affiliation(s)
- Anna Loftén
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Louise Adermark
- Department of Pharmacology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
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7
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Wadsworth HA, Anderson EQ, Williams BM, Ronström JW, Moen JK, Lee AM, McIntosh JM, Wu J, Yorgason JT, Steffensen SC. Role of α6-Nicotinic Receptors in Alcohol-Induced GABAergic Synaptic Transmission and Plasticity to Cholinergic Interneurons in the Nucleus Accumbens. Mol Neurobiol 2023; 60:3113-3129. [PMID: 36802012 PMCID: PMC10690621 DOI: 10.1007/s12035-023-03263-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 02/03/2023] [Indexed: 02/21/2023]
Abstract
The prevailing view is that enhancement of dopamine (DA) transmission in the mesolimbic system, consisting of DA neurons in the ventral tegmental area (VTA) that project to the nucleus accumbens (NAc), underlies the reward properties of ethanol (EtOH) and nicotine (NIC). We have shown previously that EtOH and NIC modulation of DA release in the NAc is mediated by α6-containing nicotinic acetylcholine receptors (α6*-nAChRs), that α6*-nAChRs mediate low-dose EtOH effects on VTA GABA neurons and EtOH preference, and that α6*-nAChRs may be a molecular target for low-dose EtOH. However, the most sensitive target for reward-relevant EtOH modulation of mesolimbic DA transmission and the involvement of α6*-nAChRs in the mesolimbic DA reward system remains to be elucidated. The aim of this study was to evaluate EtOH effects on GABAergic modulation of VTA GABA neurons and VTA GABAergic input to cholinergic interneurons (CINs) in the NAc. Low-dose EtOH enhanced GABAergic input to VTA GABA neurons that was blocked by knockdown of α6*-nAChRs. Knockdown was achieved either by α6-miRNA injected into the VTA of VGAT-Cre/GAD67-GFP mice or by superfusion of the α-conotoxin MII[H9A;L15A] (MII). Superfusion of MII blocked EtOH inhibition of mIPSCs in NAc CINs. Concomitantly, EtOH enhanced CIN firing rate, which was blocked by knockdown of α6*-nAChRs with α6-miRNA injected into the VTA of VGAT-Cre/GAD67-GFP mice. The firing rate of CINs was not enhanced by EtOH in EtOH-dependent mice, and low-frequency stimulation (LFS; 1 Hz, 240 pulses) caused inhibitory long-term depression at this synapse (VTA-NAc CIN-iLTD) which was blocked by knockdown of α6*-nAChR and MII. Ethanol inhibition of CIN-mediated evoked DA release in the NAc was blocked by MII. Taken together, these findings suggest that α6*-nAChRs in the VTA-NAc pathway are sensitive to low-dose EtOH and play a role in plasticity associated with chronic EtOH.
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Affiliation(s)
- Hillary A Wadsworth
- Department of Psychology and Neuroscience, Brigham Young University, 1050 KMBL, Provo, UT, 84602, USA
| | - Elizabeth Q Anderson
- Department of Psychology and Neuroscience, Brigham Young University, 1050 KMBL, Provo, UT, 84602, USA
| | - Benjamin M Williams
- Department of Psychology and Neuroscience, Brigham Young University, 1050 KMBL, Provo, UT, 84602, USA
| | - Joakim W Ronström
- Department of Psychology and Neuroscience, Brigham Young University, 1050 KMBL, Provo, UT, 84602, USA
| | - Janna K Moen
- Department of Pharmacology, Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Anna M Lee
- Department of Pharmacology, Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA
| | - J Michael McIntosh
- School of Biological Sciences and Department of Psychiatry, University of Utah, Salt Lake City, UT, 84108, USA
- George E. Whalen Veterans Affairs Medical Center, Salt Lake City, UT, 84148, USA
| | - Jie Wu
- Brain Function and Disease Laboratory, Shantou University Medical College, Shantou, 515041, Guangdong, China
| | - Jordan T Yorgason
- Department of Psychology and Neuroscience, Brigham Young University, 1050 KMBL, Provo, UT, 84602, USA
| | - Scott C Steffensen
- Department of Psychology and Neuroscience, Brigham Young University, 1050 KMBL, Provo, UT, 84602, USA.
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8
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Loftén A, Adermark L, Ericson M, Söderpalm B. An acetylcholine-dopamine interaction in the nucleus accumbens and its involvement in ethanol's dopamine-releasing effect. Addict Biol 2021; 26:e12959. [PMID: 32789970 PMCID: PMC8244087 DOI: 10.1111/adb.12959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 07/02/2020] [Accepted: 07/29/2020] [Indexed: 11/28/2022]
Abstract
Alcohol use disorder is a chronic, relapsing brain disorder causing substantial morbidity and mortality. Cholinergic interneurons (CIN) within the nucleus accumbens (nAc) have been suggested to exert a regulatory impact on dopamine (DA) neurotransmission locally, and defects in CIN have been implied in several psychiatric disorders. The aim of this study was to investigate the role of CIN in regulation of basal extracellular levels of DA and in modulation of nAc DA release following ethanol administration locally within the nAc of male Wistar rats. Using reversed in vivo microdialysis, the acetylcholinesterase inhibitor physostigmine was administered locally in the nAc followed by addition of either the muscarinic acetylcholine (ACh) receptor antagonist scopolamine or the nicotinic ACh receptor antagonist mecamylamine. Further, ethanol was locally perfused in the nAc following pretreatment with scopolamine and/or mecamylamine. Lastly, ethanol was administered locally into the nAc of animals with accumbal CIN‐ablation induced by anticholine acetyl transferase‐saporin. Physostigmine increased accumbal DA levels via activation of muscarinic ACh receptors. Neither scopolamine and/or mecamylamine nor CIN‐ablation altered basal DA levels, suggesting that extracellular DA levels are not tonically controlled by ACh in the nAc. In contrast, ethanol‐induced DA elevation was prevented following coadministration of scopolamine and mecamylamine and blunted in CIN‐ablated animals, suggesting involvement of CIN‐ACh in ethanol‐mediated DA signaling. The data presented in this study suggest that basal extracellular levels of DA within the nAc are not sustained by ACh, whereas accumbal CIN‐ACh is involved in mediating ethanol‐induced DA release.
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Affiliation(s)
- Anna Loftén
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology The Sahlgrenska Academy at University of Gothenburg Gothenburg Sweden
- Beroendekliniken Sahlgrenska University Hospital Gothenburg Sweden
| | - Louise Adermark
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology The Sahlgrenska Academy at University of Gothenburg Gothenburg Sweden
- Department of Pharmacology, Institute of Neuroscience and Physiology The Sahlgrenska Academy at University of Gothenburg Gothenburg Sweden
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology The Sahlgrenska Academy at University of Gothenburg Gothenburg Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology The Sahlgrenska Academy at University of Gothenburg Gothenburg Sweden
- Beroendekliniken Sahlgrenska University Hospital Gothenburg Sweden
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