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Vlkolinsky R, Khom S, Vozella V, Bajo M, Roberto M. Withdrawal from chronic alcohol impairs the serotonin-mediated modulation of GABAergic transmission in the infralimbic cortex in male rats. Neurobiol Dis 2024; 199:106590. [PMID: 38996987 DOI: 10.1016/j.nbd.2024.106590] [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: 05/03/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/14/2024] Open
Abstract
The infralimbic cortex (IL) is part of the medial prefrontal cortex (mPFC), exerting top-down control over structures that are critically involved in the development of alcohol use disorder (AUD). Activity of the IL is tightly controlled by γ-aminobutyric acid (GABA) transmission, which is susceptible to chronic alcohol exposure and withdrawal. This inhibitory control is regulated by various neuromodulators, including 5-hydroxytryptamine (5-HT; serotonin). We used chronic intermittent ethanol vapor inhalation exposure, a model of AUD, in male Sprague-Dawley rats to induce alcohol dependence (Dep) followed by protracted withdrawal (WD; 2 weeks) and performed ex vivo electrophysiology using whole-cell patch clamp to study GABAergic transmission in layer V of IL pyramidal neurons. We found that WD increased frequencies of spontaneous inhibitory postsynaptic currents (sIPSCs), whereas miniature IPSCs (mIPSCs; recorded in the presence of tetrodotoxin) were unaffected by either Dep or WD. The application of 5-HT (50 μM) increased sIPSC frequencies and amplitudes in naive and Dep rats but reduced sIPSC frequencies in WD rats. Additionally, 5-HT2A receptor antagonist M100907 and 5-HT2C receptor antagonist SB242084 reduced basal GABA release in all groups to a similar extent. The blockage of either 5-HT2A or 5-HT2C receptors in WD rats restored the impaired response to 5-HT, which then resembled responses in naive rats. Our findings expand our understanding of synaptic inhibition in the IL in AUD, indicating that antagonism of 5-HT2A and 5-HT2C receptors may restore GABAergic control over IL pyramidal neurons. SIGNIFICANCE STATEMENT: Impairment in the serotonergic modulation of GABAergic inhibition in the medial prefrontal cortex contributes to alcohol use disorder (AUD). We used a well-established rat model of AUD and ex vivo whole-cell patch-clamp electrophysiology to characterize the serotonin modulation of GABAergic transmission in layer V infralimbic (IL) pyramidal neurons in ethanol-naive, ethanol-dependent (Dep), and ethanol-withdrawn (WD) male rats. We found increased basal inhibition following WD from chronic alcohol and altered serotonin modulation. Exogenous serotonin enhanced GABAergic transmission in naive and Dep rats but reduced it in WD rats. 5-HT2A and 5-HT2C receptor blockage in WD rats restored the typical serotonin-mediated enhancement of GABAergic inhibition. Our findings expand our understanding of synaptic inhibition in the infralimbic neurons in AUD.
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Affiliation(s)
- Roman Vlkolinsky
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Sophia Khom
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Pharmaceutical Sciences, University of Vienna, Vienna, 1090, Austria.
| | - Valentina Vozella
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Michal Bajo
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Marisa Roberto
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
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2
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Brockway DF, Crowley NA. Emerging pharmacological targets for alcohol use disorder. Alcohol 2024:S0741-8329(24)00101-0. [PMID: 39069210 DOI: 10.1016/j.alcohol.2024.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/27/2024] [Accepted: 07/24/2024] [Indexed: 07/30/2024]
Abstract
Alcohol Use Disorder (AUD) remains a challenging condition with limited effective treatment options; however new technology in drug delivery and advancements in pharmacology have paved the way for discovery of novel therapeutic targets. This review explores emerging pharmacological targets that offer new options for the management of AUD, focusing on the potential of somatostatin (SST), vasoactive intestinal peptide (VIP), glucagon-like peptide-1 (GLP-1), nociceptin (NOP), and neuropeptide S (NPS). These targets have been selected based on recent advancements in preclinical and clinical research, which suggest their significant roles in modulating alcohol consumption and related behaviors. SST dampens cortical circuits, and targeting both the SST neurons and the SST peptide itself presents promise for treating AUD and various related comorbidities. VIP neurons are modulated by alcohol and targeting the VIP system presents an unexplored avenue for addressing alcohol exposure at various stages of development. GLP-1 interacts with the dopaminergic reward system and reduces alcohol intake. Nociceptin modulates mesolimbic circuitry and agonism and antagonism of nociceptin receptor offers a complex but promising approach to reducing alcohol consumption. NPS stands out for its anxiolytic-like effects, particularly relevant for the anxiety associated with AUD. This review aims to synthesize the current understanding of these targets, highlighting their potential in developing more effective and personalized AUD therapies, and underscores the importance of continued research in identifying and validating novel targets for treatment of AUD and comorbid conditions.
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Affiliation(s)
- Dakota F Brockway
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Nicole A Crowley
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA; Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
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3
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Siddiqi MT, Podder D, Pahng AR, Athanason AC, Nadav T, Cates-Gatto C, Kreifeldt M, Contet C, Roberts AJ, Edwards S, Roberto M, Varodayan FP. Prefrontal cortex glutamatergic adaptations in a mouse model of alcohol use disorder. ADDICTION NEUROSCIENCE 2023; 9:100137. [PMID: 38152067 PMCID: PMC10752437 DOI: 10.1016/j.addicn.2023.100137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Alcohol use disorder (AUD) produces cognitive deficits, indicating a shift in prefrontal cortex (PFC) function. PFC glutamate neurotransmission is mostly mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type ionotropic receptors (AMPARs); however preclinical studies have mostly focused on other receptor subtypes. Here we examined the impact of early withdrawal from chronic ethanol on AMPAR function in the mouse medial PFC (mPFC). Dependent male C57BL/6J mice were generated using the chronic intermittent ethanol vapor-two bottle choice (CIE-2BC) paradigm. Non-dependent mice had access to water and ethanol bottles but did not receive ethanol vapor. Naïve mice had no ethanol exposure. We used patch-clamp electrophysiology to measure glutamate neurotransmission in layer 2/3 prelimbic mPFC pyramidal neurons. Since AMPAR function can be impacted by subunit composition or plasticity-related proteins, we probed their mPFC expression levels. Dependent mice had higher spontaneous excitatory postsynaptic current (sEPSC) amplitude and kinetics compared to the Naïve/Non-dependent mice. These effects were seen during intoxication and after 3-8 days withdrawal, and were action potential-independent, suggesting direct enhancement of AMPAR function. Surprisingly, 3 days withdrawal decreased expression of genes encoding AMPAR subunits (Gria1/2) and synaptic plasticity proteins (Dlg4 and Grip1) in Dependent mice. Further analysis within the Dependent group revealed a negative correlation between Gria1 mRNA levels and ethanol intake. Collectively, these data establish a role for mPFC AMPAR adaptations in the glutamatergic dysfunction associated with ethanol dependence. Future studies on the underlying AMPAR plasticity mechanisms that promote alcohol reinforcement, seeking, drinking and relapse behavior may help identify new targets for AUD treatment.
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Affiliation(s)
- Mahum T. Siddiqi
- Developmental Exposure Alcohol Research Center and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, NY, 13902, USA
| | - Dhruba Podder
- Developmental Exposure Alcohol Research Center and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, NY, 13902, USA
| | - Amanda R. Pahng
- Department of Physiology, Louisiana State University Health Sciences Center, 533 Bolivar Street, New Orleans, LA, 70112, USA
- Southeast Louisiana Veterans Health Care System, 2400 Canal Street, 11F, New Orleans, LA, 70119, USA
| | - Alexandria C. Athanason
- Developmental Exposure Alcohol Research Center and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, NY, 13902, USA
| | - Tali Nadav
- Animal Models Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Chelsea Cates-Gatto
- Animal Models Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Max Kreifeldt
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Candice Contet
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Amanda J. Roberts
- Animal Models Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Scott Edwards
- Department of Physiology, Louisiana State University Health Sciences Center, 533 Bolivar Street, New Orleans, LA, 70112, USA
| | - Marisa Roberto
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Florence P. Varodayan
- Developmental Exposure Alcohol Research Center and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, NY, 13902, USA
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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4
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Thompson SM, Fabian CB, Ferranti AS, Joffe ME. Acute alcohol and chronic drinking bidirectionally regulate the excitability of prefrontal cortex vasoactive intestinal peptide interneurons. Neuropharmacology 2023; 238:109638. [PMID: 37482180 PMCID: PMC10529784 DOI: 10.1016/j.neuropharm.2023.109638] [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: 03/10/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 07/25/2023]
Abstract
The prefrontal cortex (PFC) regulates drinking behaviors and affective changes following chronic alcohol use. PFC activity is dynamically modulated by local inhibitory interneurons (INs), which can be divided into non-overlapping groups with distinct functional roles. Within deeper layers of neocortex, INs that express either parvalbumin or somatostatin directly inhibit pyramidal cells. By contrast, the plurality of all remaining INs express vasoactive intestinal peptide (VIP), reside within superficial layers, and preferentially target other types of INs. While recent studies have described adaptations to PFC parvalbumin-INs and somatostatin-INs in alcohol use models, whether ethanol or drinking affect the physiology of PFC VIP-INs has not been reported. To address this gap, we used genetically engineered female and male mice to target VIP-INs in layers 1-3 of prelimbic PFC for whole-cell patch-clamp electrophysiology. We found that ethanol (20 mM, ∼0.09 BEC/90 mg/dL) application to PFC brain slices enhances VIP-IN excitability. We next examined effects following chronic drinking by providing mice with 4 weeks of intermittent access (IA) ethanol two-bottle choice in the home cage. In these studies, VIP-INs from female and male IA ethanol mice displayed reduced excitability relative to cells from water-only controls. Finally, we assessed whether these effects continue into abstinence. After 7-13 days without ethanol, the hypo-excitability of VIP-INs from male IA ethanol mice persisted, whereas cells from female IA ethanol mice were not different from their controls. Together, these findings illustrate that acute ethanol enhances VIP-IN excitability and suggest these cells undergo pronounced homeostatic changes following long-term drinking.
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Affiliation(s)
- Shannon M Thompson
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA; Translational Neuroscience Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carly B Fabian
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA; Translational Neuroscience Program, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neuroscience University of Pittsburgh, Pittsburgh, PA, USA
| | - Anthony S Ferranti
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Max E Joffe
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA; Translational Neuroscience Program, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neuroscience University of Pittsburgh, Pittsburgh, PA, USA.
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Tavares GEB, Bianchi PC, Yokoyama TS, Palombo P, Cruz FC. INVOLVEMENT OF CORTICAL PROJECTIONS TO BASOLATERAL AMYGDALA IN CONTEXT-INDUCED REINSTATEMENT OF ETHANOL-SEEKING IN RATS. Behav Brain Res 2023; 448:114435. [PMID: 37044222 DOI: 10.1016/j.bbr.2023.114435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/30/2023] [Accepted: 04/09/2023] [Indexed: 04/14/2023]
Abstract
Ethanol is the most consumed substance of abuse in the world, and its misuse may lead to the development of alcohol use disorder (AUD). High relapse rates remain a relevant problem in the treatment of AUD. Exposure to environmental cues previously associated with ethanol intake could trigger ethanol-seeking behavior. However, the neural mechanisms involved in this phenomenon are not entirely clear. In this context, cortical projections to the basolateral amygdala (BLA) play a role in appetitive and aversive learned behaviors. Therefore, we aimed to evaluate the activation of the cortical projections from the prelimbic (PL), orbitofrontal (OFC), and infralimbic (IL), to the BLA in the context-induced reinstatement of ethanol-seeking. Male Long-Evans rats were trained to self-administer 10% ethanol in Context A. Subsequently, lever pressing in the presence of the discrete cue was extinguished in Context B. After nine extinction sessions, rats underwent intracranial surgery for the unilateral injection of red fluorescent retrograde tracer into the BLA. The context-induced reinstatement of ethanol-seeking was assessed by re-exposing the rats to Context A or B under extinction conditions. Finally, we combined retrograde neuronal tracing with Fos to identify activated cortical inputs to BLA during the reinstatement of ethanol-seeking behavior. We found that PL, but not OFC or IL, retrogradely-labeled neurons from BLA presented increased Fos expression during the re-exposure to the ethanol-associated context, suggesting that PL projection to BLA is involved in the context-induced reinstatement of ethanol-seeking behavior.
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Affiliation(s)
| | - Paula Cristina Bianchi
- Molecular and Behavioral Neuroscience Laboratory, Department of Pharmacology, Federal University of São Paulo, São Paulo, SP, Brazil.
| | - Thais Suemi Yokoyama
- Molecular and Behavioral Neuroscience Laboratory, Department of Pharmacology, Federal University of São Paulo, São Paulo, SP, Brazil.
| | - Paola Palombo
- Molecular and Behavioral Neuroscience Laboratory, Department of Pharmacology, Federal University of São Paulo, São Paulo, SP, Brazil.
| | - Fábio Cardoso Cruz
- Molecular and Behavioral Neuroscience Laboratory, Department of Pharmacology, Federal University of São Paulo, São Paulo, SP, Brazil.
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6
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Mesa JR, Carter E, Padovan-Hernandez Y, Knackstedt LA. Alcohol consumption modulates prelimbic cortex response to cocaine following sequential cocaine and alcohol polysubstance use in the rat. Front Pharmacol 2023; 14:1132689. [PMID: 37007027 PMCID: PMC10060651 DOI: 10.3389/fphar.2023.1132689] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
Polysubstance use (PSU), involves the consumption of more than one drug within a period of time and is prevalent among cocaine users. Ceftriaxone, a beta-lactam antibiotic, reliably attenuates reinstatement of cocaine seeking in pre-clinical models by restoring glutamate homeostasis following cocaine self-administration but fails to do so when rats consume both cocaine and alcohol (cocaine + alcohol PSU). We previously found that cocaine + alcohol PSU rats reinstate cocaine seeking similarly to cocaine-only rats, but demonstrate differences in reinstatement-induced c-Fos expression throughout the reward system, including a lack of change upon ceftriaxone treatment. Here, we used this model to determine if previous findings were caused by tolerance or sensitization to the pharmacological effects of cocaine. Male rats underwent intravenous cocaine self-administration immediately followed by 6 h of home cage access to water or unsweetened alcohol for 12 days. Rats subsequently underwent 10 daily instrumental extinction sessions, during which time they were treated with either vehicle or ceftriaxone. Rats then received a non-contingent cocaine injection and were perfused for later immunohistochemical analysis of c-Fos expression in the reward neurocircuitry. c-Fos expression in the prelimbic cortex correlated with total alcohol intake in PSU rats. There were no effects of either ceftriaxone or PSU on c-Fos expression in the infralimbic cortex, nucleus accumbens core and shell, basolateral amygdala, or ventral tegmental area. These results support the idea that PSU and ceftriaxone alter the neurobiology underlying drug-seeking behavior in the absence of pharmacological tolerance or sensitization to cocaine.
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Affiliation(s)
- Javier R. Mesa
- Department of Psychology, University of Florida, Gainesville, FL, United States
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, United States
| | - Emily Carter
- Department of Psychology, Pennsylvania State University, University Park, PA, United States
| | - Yasmin Padovan-Hernandez
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Lori A. Knackstedt
- Department of Psychology, University of Florida, Gainesville, FL, United States
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, United States
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7
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Thompson SM, Ferranti AS, Joffe ME. Acute alcohol and chronic drinking bidirectionally regulate the excitability of prefrontal cortex vasoactive intestinal peptide interneurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.07.531614. [PMID: 36945582 PMCID: PMC10028880 DOI: 10.1101/2023.03.07.531614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
The prefrontal cortex (PFC) regulates drinking behaviors and affective changes following chronic alcohol use. PFC activity is dynamically modulated by local inhibitory interneurons (INs), which can be divided into non-overlapping groups with distinct functional roles. Within deeper layers of neocortex, INs that express either parvalbumin or somatostatin directly inhibit pyramidal cells. By contrast, the plurality of all remaining INs express vasoactive intestinal peptide (VIP), reside within superficial layers, and preferentially target other types of INs. While recent studies have described adaptations to PFC parvalbumin-INs and somatostatin-INs in alcohol use models, whether ethanol or drinking affect the physiology of PFC VIP-INs has not been reported. To address this gap, we used genetically engineered female and male mice to target VIP-INs in layers 1-3 of prelimbic PFC for whole-cell patch-clamp electrophysiology. We found that ethanol (20 mM, ∼0.09 BEC) application to PFC brain slices enhances VIP-IN excitability. We next examined effects following chronic drinking by providing mice with 4 weeks of intermittent access (IA) ethanol two-bottle choice in the home cage. In these studies, VIP-INs from female and male IA ethanol mice displayed reduced excitability relative to cells from water-only controls. Finally, we assessed whether these effects continue into abstinence. After 7-11 days without ethanol, the hypo-excitability of VIP-INs from male IA ethanol mice persisted, whereas cells from female IA ethanol mice were not different from their controls. Together, these findings illustrate that acute ethanol enhances VIP-IN excitability and suggest these cells undergo pronounced homeostatic changes following long-term drinking.
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8
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Asch RH, Hillmer AT, Baldassarri SR, Esterlis I. The metabotropic glutamate receptor 5 as a biomarker for psychiatric disorders. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 168:265-310. [PMID: 36868631 DOI: 10.1016/bs.irn.2022.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The role of glutamate system in the etiology and pathophysiology of psychiatric disorders has gained considerable attention in the past two decades, including dysregulation of the metabotropic glutamatergic receptor subtype 5 (mGlu5). Thus, mGlu5 may represent a promising therapeutic target for psychiatric conditions, particularly stress-related disorders. Here, we describe mGlu5 findings in mood disorders, anxiety, and trauma disorders, as well as substance use (specifically nicotine, cannabis, and alcohol use). We highlight insights gained from positron emission tomography (PET) studies, where possible, and discuss findings from treatment trials, when available, to explore the role of mGlu5 in these psychiatric disorders. Through the research evidence reviewed in this chapter, we make the argument that, not only is dysregulation of mGlu5 evident in numerous psychiatric disorders, potentially functioning as a disease "biomarker," the normalization of glutamate neurotransmission via changes in mGlu5 expression and/or modulation of mGlu5 signaling may be a needed component in treating some psychiatric disorders or symptoms. Finally, we hope to demonstrate the utility of PET as an important tool for investigating mGlu5 in disease mechanisms and treatment response.
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Affiliation(s)
- Ruth H Asch
- Department of Psychiatry, Yale University, New Haven, CT, United States.
| | - Ansel T Hillmer
- Department of Psychiatry, Yale University, New Haven, CT, United States; Department of Radiology and Biomedical Imaging, New Haven, CT, United States
| | - Stephen R Baldassarri
- Yale Program in Addiction Medicine, Yale University, New Haven, CT, United States; Department of Internal Medicine, Yale University, New Haven, CT, United States
| | - Irina Esterlis
- Department of Psychiatry, Yale University, New Haven, CT, United States; Department of Psychology, Yale University, New Haven, CT, United States; Clinical Neurosciences Division, U.S. Department of Veterans Affairs National Center for Posttraumatic Stress Disorder, Veterans Affairs Connecticut Healthcare System, West Haven, CT, United States
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Tyler RE, Besheer J, Joffe ME. Advances in translating mGlu 2 and mGlu 3 receptor selective allosteric modulators as breakthrough treatments for affective disorders and alcohol use disorder. Pharmacol Biochem Behav 2022; 219:173450. [PMID: 35988792 PMCID: PMC10405528 DOI: 10.1016/j.pbb.2022.173450] [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: 06/01/2022] [Revised: 07/26/2022] [Accepted: 08/13/2022] [Indexed: 11/16/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are promising targets for the treatment of affective disorders and alcohol use disorder (AUD). Nonspecific ligands for Group II (mGlu2 and mGlu3) mGlu receptors have demonstrated consistent therapeutic potential for affective disorders in preclinical models. Disentangling the specific roles of mGlu2 versus mGlu3 receptors in these effects has persisted as a major challenge, in part due to pharmacological limitations. However, the recent development of highly specific allosteric modulators for both mGlu2 and mGlu3 receptors have enabled straightforward and rigorous investigations into the specific function of each receptor. Here, we review recent experiments using these compounds that have demonstrated both similar and distinct receptor functions in behavioral, molecular, and electrophysiological measures associated with basal function and preclinical models of affective disorders. Studies using these selective drugs have demonstrated that mGlu2 is the predominant receptor subclass involved in presynaptic neurotransmitter release in prefrontal cortex. By contrast, the activation of postsynaptic mGlu3 receptors induces a cascade of cellular changes that results in AMPA receptor internalization, producing long-term depression and diminishing excitatory drive. Acute stress decreases the mGlu3 receptor function and dynamically alters transcript expression for both mGlu2 (Grm2) and mGlu3 (Grm3) receptors in brain areas involved in reward and stress. Accordingly, both mGlu2 and mGlu3 negative allosteric modulators show acute antidepressant-like effects and potential prophylactic effects against acute and traumatic stressors. The wide array of effects displayed by these new allosteric modulators of mGlu2 and mGlu3 receptors suggest that these drugs may act through improving endophenotypes of symptoms observed across several neuropsychiatric disorders. Therefore, recently developed allosteric modulators selective for mGlu2 or mGlu3 receptors show promise as potential therapeutics for affective disorders and AUD.
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Affiliation(s)
- Ryan E Tyler
- Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Neuroscience Curriculum, University of North Carolina at Chapel Hill, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, USA
| | - Joyce Besheer
- Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Neuroscience Curriculum, University of North Carolina at Chapel Hill, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, USA
| | - Max E Joffe
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15219, USA; Translational Neuroscience Program, University of Pittsburgh, USA.
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Fish KN, Joffe ME. Targeting prefrontal cortex GABAergic microcircuits for the treatment of alcohol use disorder. Front Synaptic Neurosci 2022; 14:936911. [PMID: 36105666 PMCID: PMC9465392 DOI: 10.3389/fnsyn.2022.936911] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
Developing novel treatments for alcohol use disorders (AUDs) is of paramount importance for improving patient outcomes and alleviating the suffering related to the disease. A better understanding of the molecular and neurocircuit mechanisms through which alcohol alters brain function will be instrumental in the rational development of new efficacious treatments. Clinical studies have consistently associated the prefrontal cortex (PFC) function with symptoms of AUDs. Population-level analyses have linked the PFC structure and function with heavy drinking and/or AUD diagnosis. Thus, targeting specific PFC cell types and neural circuits holds promise for the development of new treatments. Here, we overview the tremendous diversity in the form and function of inhibitory neuron subtypes within PFC and describe their therapeutic potential. We then summarize AUD population genetics studies, clinical neurophysiology findings, and translational neuroscience discoveries. This study collectively suggests that changes in fast transmission through PFC inhibitory microcircuits are a central component of the neurobiological effects of ethanol and the core symptoms of AUDs. Finally, we submit that there is a significant and timely need to examine sex as a biological variable and human postmortem brain tissue to maximize the efforts in translating findings to new clinical treatments.
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Affiliation(s)
| | - Max E. Joffe
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States
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11
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Elsilä LV, Harkki J, Enberg E, Martti A, Linden AM, Korpi ER. Effects of acute lysergic acid diethylamide on intermittent ethanol and sucrose drinking and intracranial self-stimulation in C57BL/6 mice. J Psychopharmacol 2022; 36:860-874. [PMID: 35695174 PMCID: PMC9247434 DOI: 10.1177/02698811221104641] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Psychedelics, like lysergic acid diethylamide (LSD), are again being studied as potential therapies for many neuropsychiatric disorders, including addictions. At the same time, the acute effects of psychedelics on rewarding behaviours have been scarcely studied. AIMS The current study aimed to clarify if LSD decreases binge-like ethanol drinking in mice, and whether the observed acute effects on ethanol consumption are generalizable to a natural reinforcer, sucrose, and if the effects resulted from aversive or reward-attenuating effects caused by LSD. METHODS The effects of acute LSD were examined using 2-bottle choice intermittent ethanol (20%) and sucrose drinking (10%), discrete-trial current-intensity threshold method of intracranial self-stimulation and short-term feeding behaviour assay in C57BL/6 male mice. RESULTS The results showed that acute 0.1 mg/kg, but not 0.05 mg/kg, dose (i.p.) of LSD reduced 2-h intermittent ethanol drinking transiently without any prolonged effects. No effects were seen in intermittent 2-h sucrose drinking. The tested LSD doses had neither effect on the intracranial self-stimulation current-intensity thresholds, nor did LSD affect the threshold-lowering, or rewarding, effects of simultaneous amphetamine treatment. Furthermore, LSD had small, acute diminishing effects on 2-h food and water intake. CONCLUSIONS Based on these results, LSD decreases binge-like ethanol drinking in mice, but only acutely. This effect is not likely to stem from reward-attenuating effects but could be in part due to reduced consummatory behaviour.
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Affiliation(s)
- Lauri V Elsilä
- Lauri V Elsilä, Department of
Pharmacology, Faculty of Medicine, University of Helsinki, P.O. Box 63
(Haartmaninkatu 8), Biomedicum Helsinki, Helsinki FI-00014, Finland.
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Smart K, Worhunsky PD, Scheinost D, Angarita GA, Esterlis I, Carson RE, Krystal JH, O'Malley SS, Cosgrove KP, Hillmer AT. Multimodal neuroimaging of metabotropic glutamate 5 receptors and functional connectivity in alcohol use disorder. Alcohol Clin Exp Res 2022; 46:770-782. [PMID: 35342968 PMCID: PMC9117461 DOI: 10.1111/acer.14816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/15/2022] [Accepted: 03/19/2022] [Indexed: 12/01/2022]
Abstract
BACKGROUND People recovering from alcohol use disorder (AUD) show altered resting brain connectivity. The metabotropic glutamate 5 (mGlu5) receptor is an important regulator of synaptic plasticity potentially linked with synchronized brain activity and a target of interest in treating AUD. The goal of this work was to assess potential relationships of brain connectivity at rest with mGlu5 receptor availability in people with AUD at two time points early in abstinence. METHODS Forty-eight image data sets were acquired with a multimodal neuroimaging battery that included resting-state functional magnetic resonance imaging (fMRI) and mGlu5 receptor positron emission tomography (PET) with the radiotracer [18 F]FPEB. Participants with AUD (n = 14) were scanned twice, at approximately 1 and 4 weeks after beginning supervised abstinence. [18 F]FPEB PET results were published previously. Primary comparisons of fMRI outcomes were performed between the AUD group and healthy controls (HCs; n = 23) and assessed changes over time within the AUD group. Relationships between resting-state connectivity measures and mGlu5 receptor availability were explored within groups. RESULTS Compared to HCs, global functional connectivity of the orbitofrontal cortex was higher in the AUD group at 4 weeks of abstinence (p = 0.003), while network-level functional connectivity within the default mode network (DMN) was lower (p < 0.04). Exploratory multimodal analyses showed that mGlu5 receptor availability was correlated with global connectivity across all brain regions (HCs, r = 0.41; AUD group at 1 week of abstinence, r = 0.50 and at 4 weeks, r = 0.46; all p < 0.0001). Furthermore, a component of cortical and striatal mGlu5 availability was correlated with connectivity between the DMN and salience networks in HCs (r = 0.60, p = 0.003) but not in the AUD group (p > 0.3). CONCLUSIONS These preliminary findings of altered global and network connectivity during the first month of abstinence from drinking may reflect the loss of efficient network function, while exploratory relationships with mGlu5 receptor availability suggest a potential glutamatergic relationship with network coherence.
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Affiliation(s)
- Kelly Smart
- Yale PET Center, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Patrick D Worhunsky
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Dustin Scheinost
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Biomedical Engineering, Yale School of Engineering & Applied Science, New Haven, Connecticut, USA
| | - Gustavo A Angarita
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Irina Esterlis
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Richard E Carson
- Yale PET Center, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Biomedical Engineering, Yale School of Engineering & Applied Science, New Haven, Connecticut, USA
| | - John H Krystal
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | | | - Kelly P Cosgrove
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Ansel T Hillmer
- Yale PET Center, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Biomedical Engineering, Yale School of Engineering & Applied Science, New Haven, Connecticut, USA
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13
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Yang W, Zhang M, Tang F, Du Y, Fan L, Luo J, Yan C, Wang S, Zhang J, Yuan K, Liu J. Recovery of superior frontal gyrus cortical thickness and resting-state functional connectivity in abstinent heroin users after 8 months of follow-up. Hum Brain Mapp 2022; 43:3164-3175. [PMID: 35324057 PMCID: PMC9188969 DOI: 10.1002/hbm.25841] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/11/2022] [Accepted: 03/06/2022] [Indexed: 12/28/2022] Open
Abstract
Compared with healthy controls, heroin users (HUs) show evidence of structural and functional brain alterations. However, little is known about the possibility of brain recovery after protracted heroin abstinence. The purpose of this study was to investigate whether brain recovery is possible after protracted abstinence in HUs. A total of 108 subjects with heroin addiction completed structural and functional scans, and 61 of those subjects completed 8-month follow-up scans. Resting-state data and 3D-T1 MR images were collected for all participants, first at baseline and again after 8 months. Cognitive function and craving were measured by the Trail Making Test-A (TMT-A) and Visual Analog Scale for Craving, respectively. The cortical thickness and resting-state functional connectivity (RSFC) differences were then analyzed and compared between baseline and follow-up, and correlations were obtained between neuroimaging and behavioral changes. HUs demonstrated improved cognition (shorter TMT-A time) and reduced craving at the follow-up (HU2) relative to baseline (HU1), and the cortical thickness in the bilateral superior frontal gyrus (SFG) was significantly greater at HU2 than at HU1. Additionally, the RSFC of the left SFG with the inferior frontal gyrus (IFG), insula, and nucleus accumbens and that of the right SFG with the IFG, insula and orbitofrontal cortex (OFC) were increased at HU2. The changes in TMT-A time were negatively correlated with the RSFC changes between the left SFG and the bilateral IFG, the bilateral caudate, and the right insula. The changes in craving were negatively correlated with the RSFC changes between the left OFC and the bilateral SFG. Our results demonstrated that impaired frontal-limbic neurocircuitry can be partially restored, which might enable improved cognition as well as reduced craving in substance-abusing individuals. We provided novel scientific evidence for the partial recovery of brain circuits implicated in cognition and craving after protracted abstinence.
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Affiliation(s)
- Wenhan Yang
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Min Zhang
- School of Life Science and Technology, Xidian University, Xi'an, China.,Engineering Research Center of Molecular and Neuroimaging, Ministry of Education, Xi'an, China
| | - Fei Tang
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Yanyao Du
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Li Fan
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Jing Luo
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Cui Yan
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Shicong Wang
- School of Life Science and Technology, Xidian University, Xi'an, China.,Engineering Research Center of Molecular and Neuroimaging, Ministry of Education, Xi'an, China
| | - Jun Zhang
- Hunan Judicial Police Academy, Changsha, China
| | - Kai Yuan
- School of Life Science and Technology, Xidian University, Xi'an, China.,Engineering Research Center of Molecular and Neuroimaging, Ministry of Education, Xi'an, China.,Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, China.,Inner Mongolia Key Laboratory of Pattern Recognition and Intelligent Image Processing, School of Information Engineering, Inner Mongolia University of Science and Technology, Baotou, China
| | - Jun Liu
- Department of Radiology, Second Xiangya Hospital of Central South University, Changsha, China
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14
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Dao NC, Brockway DF, Suresh Nair M, Sicher AR, Crowley NA. Somatostatin neurons control an alcohol binge drinking prelimbic microcircuit in mice. Neuropsychopharmacology 2021; 46:1906-1917. [PMID: 34112959 PMCID: PMC8429551 DOI: 10.1038/s41386-021-01050-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 02/08/2023]
Abstract
Somatostatin (SST) neurons have been implicated in a variety of neuropsychiatric disorders such as depression and anxiety, but their role in substance use disorders, including alcohol use disorder (AUD), is not fully characterized. Here, we found that repeated cycles of alcohol binge drinking via the Drinking-in-the-Dark (DID) model led to hypoactivity of SST neurons in the prelimbic (PL) cortex by diminishing their action potential firing capacity and excitatory/inhibitory transmission dynamic. We examined their role in regulating alcohol consumption via bidirectional chemogenetic manipulation. Both hM3Dq-induced excitation and KORD-induced silencing of PL SST neurons reduced alcohol binge drinking in males and females, with no effect on sucrose consumption. Alcohol binge drinking disinhibited pyramidal neurons by augmenting SST neurons-mediated GABA release and synaptic strength onto other GABAergic populations and reducing spontaneous inhibitory transmission onto pyramidal neurons. Pyramidal neurons additionally displayed increased intrinsic excitability. Direct inhibition of PL pyramidal neurons via hM4Di was sufficient to reduce alcohol binge drinking. Together these data revealed an SST-mediated microcircuit in the PL that modulates the inhibitory dynamics of pyramidal neurons, a major source of output to subcortical targets to drive reward-seeking behaviors and emotional response.
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Affiliation(s)
- Nigel C Dao
- Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - Dakota F Brockway
- Department of Biology, Pennsylvania State University, University Park, PA, USA
- Neuroscience Curriculum, Pennsylvania State University, University Park, PA, USA
| | - Malini Suresh Nair
- Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - Avery R Sicher
- Department of Biology, Pennsylvania State University, University Park, PA, USA
- Neuroscience Curriculum, Pennsylvania State University, University Park, PA, USA
| | - Nicole A Crowley
- Department of Biology, Pennsylvania State University, University Park, PA, USA.
- Neuroscience Curriculum, Pennsylvania State University, University Park, PA, USA.
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McCool BA. Ethanol modulation of cortico-basolateral amygdala circuits: Neurophysiology and behavior. Neuropharmacology 2021; 197:108750. [PMID: 34371080 DOI: 10.1016/j.neuropharm.2021.108750] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/22/2021] [Accepted: 08/05/2021] [Indexed: 12/19/2022]
Abstract
This review highlights literature relating the anatomy, physiology, and behavioral contributions by projections between rodent prefrontal cortical areas and the basolateral amygdala. These projections are robustly modulated by both environmental experience and exposure to drugs of abuse including ethanol. Recent literature relating optogenetic and chemogenetic dissection of these circuits within behavior both compliments and occasionally challenges roles defined by more traditional pharmacological or lesion-based approaches. In particular, cortico-amygdala circuits help control both aversive and reward-seeking. Exposure to pathology-producing environments or abused drugs dysregulates the relative 'balance' of these outcomes. Modern circuit-based approaches have also shown that overlapping populations of neurons within a given brain region frequently govern both aversion and reward-seeking. In addition, these circuits often dramatically influence 'local' cortical or basolateral amygdala excitatory or inhibitory circuits. Our understanding of these neurobiological processes, particularly in relation to ethanol research, has just begun and represents a significant opportunity.
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Affiliation(s)
- Brian A McCool
- Department of Physiology & Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA.
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