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Khayat A, Yaka R. Activation of nucleus accumbens projections to the ventral tegmental area alters molecular signaling and neurotransmission in the reward system. Front Mol Neurosci 2024; 17:1271654. [PMID: 38528956 PMCID: PMC10962329 DOI: 10.3389/fnmol.2024.1271654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 02/12/2024] [Indexed: 03/27/2024] Open
Abstract
The nucleus accumbens (NAc) and the ventral tegmental area (VTA) are integral brain regions involved in reward processing and motivation, including responses to drugs of abuse. Previously, we have demonstrated that activation of NAc-VTA afferents during the acquisition of cocaine conditioned place preference (CPP) reduces the rewarding properties of cocaine and diminished the activity of VTA dopamine neurons. In the current study, we examined the impact of enhancing these inhibitory inputs on molecular changes and neurotransmission associated with cocaine exposure. Our results unveiled significant reductions in extracellular signal-regulated kinase (ERK) levels in the VTA and medial prefrontal cortex (mPFC) of both cocaine-treated groups compared with the saline control group. Furthermore, optic stimulation of NAc-VTA inputs during cocaine exposure decreased the expression of GluA1 subunit of AMPA receptor in the VTA and mPFC. Notably, in the NAc, cocaine exposure paired with optic stimulation increased ERK levels and reduced GluA1 phosphorylation at Ser845 as compared with all other groups. Additionally, both cocaine-treated groups exhibited decreased levels of GluA1 phosphorylation at Ser831 in the NAc compared with the saline control group. Moreover, cocaine exposure led to reduced ERK, GluA1, and GluA1 phosphorylation at Ser845 and Ser831 in the mPFC. Augmentation of GABAergic tone from the NAc during cocaine conditioning mitigated changes in GluA1 phosphorylation at Ser845 in the mPFC but reduced ERK, GluA1, and GluA1 phosphorylation at Ser831 compared with the saline control group. Interestingly, enhancing GABAergic tone during saline conditioning decreased GluA1 phosphorylation at Ser831 compared with the saline control group in the mPFC. Our findings highlight the influence of modulating inhibitory inputs from the NAc to the VTA on molecular signaling and glutamatergic neurotransmission in cocaine-exposed animals. Activation of these inhibitory inputs during cocaine conditioning induced alterations in key signaling molecules and AMPA receptor, providing valuable insights into the neurobiological mechanisms underlying cocaine reward and cocaine use disorder. Further exploration of these pathways may offer potential therapeutic targets for the treatment of substance use disorder.
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Affiliation(s)
| | - Rami Yaka
- Faculty of Medicine, School of Pharmacy, Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
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2
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Wronikowska-Denysiuk O, Michalak A, Pankowska A, Kurach Ł, Kozioł P, Łazorczyk A, Kochalska K, Targowska-Duda K, Boguszewska-Czubara A, Budzyńska B. Relationship between GABA-Ergic System and the Expression of Mephedrone-Induced Reward in Rats-Behavioral, Chromatographic and In Vivo Imaging Study. Int J Mol Sci 2023; 24:9958. [PMID: 37373105 DOI: 10.3390/ijms24129958] [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: 05/10/2023] [Revised: 05/31/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Mephedrone is a psychoactive drug that increases dopamine, serotonin and noradrenaline levels in the central nervous system via interaction with transporters or monoamines. The aim of the presented study was to assess the role of the GABA-ergic system in the expression of mephedrone-induced reward. For this purpose, we conducted (a) a behavioral evaluation of the impact of baclofen (a GABAB receptors agonist) and GS39783 (a positive allosteric modulator of GABAB receptors) on the expression of mephedrone-induced conditioned place preference (CPP) in rats, (b) an ex vivo chromatographic determination of the GABA level in the hippocampi of rats subchronically treated with mephedrone and (c) an in vivo evaluation of GABA hippocampal concentration in rats subchronically administered with mephedrone using magnetic resonance spectroscopy (MRS). The results show that GS39783 (but not baclofen) blocked the expression of CPP induced by (20 mg/kg of) mephedrone. The behavioral effect was consistent with chromatographic analysis, which showed that mephedrone (5 and 20 mg/kg) led to a decrease in GABA hippocampal concentration. Altogether, the presented study provides a new insight into the involvement of the GABA-ergic system in the rewarding effects of mephedrone, implying that those effects are at least partially mediated through GABAB receptors, which suggests their potential role as new targets for the pharmacological management of mephedrone use disorder.
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Affiliation(s)
- Olga Wronikowska-Denysiuk
- Independent Laboratory of Behavioral Studies, Chair of Biomedical Sciences, Medical University of Lublin, Chodzki 4a Street, 20-093 Lublin, Poland
| | - Agnieszka Michalak
- Independent Laboratory of Behavioral Studies, Chair of Biomedical Sciences, Medical University of Lublin, Chodzki 4a Street, 20-093 Lublin, Poland
| | - Anna Pankowska
- Department of Radiography, Medical University of Lublin, Staszica 16 Street, 20-081 Lublin, Poland
| | - Łukasz Kurach
- Independent Laboratory of Behavioral Studies, Chair of Biomedical Sciences, Medical University of Lublin, Chodzki 4a Street, 20-093 Lublin, Poland
| | - Paulina Kozioł
- Department of Radiography, Medical University of Lublin, Staszica 16 Street, 20-081 Lublin, Poland
| | - Artur Łazorczyk
- Department of Radiography, Medical University of Lublin, Staszica 16 Street, 20-081 Lublin, Poland
| | - Katarzyna Kochalska
- Department of Radiography, Medical University of Lublin, Staszica 16 Street, 20-081 Lublin, Poland
| | - Katarzyna Targowska-Duda
- Department of Biopharmacy, Medical University of Lublin, Chodzki 4a Street, 20-093 Lublin, Poland
| | - Anna Boguszewska-Czubara
- Department of Medical Chemistry, Medical University of Lublin, Chodzki 4a Street, 20-093 Lublin, Poland
| | - Barbara Budzyńska
- Independent Laboratory of Behavioral Studies, Chair of Biomedical Sciences, Medical University of Lublin, Chodzki 4a Street, 20-093 Lublin, Poland
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Ito M, Walzer M, Blauwet MB, Spence A, Heo N, Kelsh D, Blahunka P, Erdman J, Alsharif MN, Marek GJ. A phase 1 randomized, placebo-controlled study to investigate potential interactions between ASP8062, a positive allosteric modulator of the GABA B receptor, and morphine in recreational opioid users. J Psychopharmacol 2023; 37:449-461. [PMID: 37125424 DOI: 10.1177/02698811231167852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND Recent increases in opioid use and subsequent opioid use disorder are a major public health crisis in the United States. AIMS This phase 1 randomized, placebo-controlled study investigated the safety, tolerability, and pharmacokinetics (PKs) of ASP8062, a γ-aminobutyric acid B receptor-positive allosteric modulator, with and without administration of morphine in participants who used opioids recreationally. METHODS Participants were randomly assigned (2:1) to daily dosing with ASP8062 25 mg or placebo on days 1-10. On day 10, all participants received morphine as a single oral dose of 45 mg; assessments were performed on days 11-16. The primary end point was safety, evaluated as the nature, frequency, and severity of adverse events, and end-tidal CO2 levels. PK end points were a secondary outcome measure. RESULTS A total of 24 participants (aged 21-54 years) received ASP8062 (n = 16) or placebo (n = 8). There were no deaths or serious adverse events leading to treatment discontinuation during the study. Most adverse events were mild, with numerically lower absolute number of adverse events reported with ASP8062 plus morphine versus placebo plus morphine. ASP8062 plus morphine did not increase respiratory depression, potential drug abuse- or withdrawal-related adverse events. There were no significant PK interactions. CONCLUSIONS In this phase 1 study, we did not observe any unexpected safety signals or notable PK interactions with concomitant morphine administration. These data suggest a potentially low risk for an increase in drug abuse- or withdrawal-related adverse events or respiratory distress in participants exposed to ASP8062 and morphine.
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Affiliation(s)
- Mototsugu Ito
- Development Project Management, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mark Walzer
- Clinical Pharmacology & Exploratory Development, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mary Beth Blauwet
- Biostatistics Department, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Anna Spence
- Biostatistics Department, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Nakyo Heo
- Clinical Pharmacology & Exploratory Development, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Debra Kelsh
- Altasciences, Clinical Kansas, Inc., Overland Park, KS, USA
| | - Paul Blahunka
- Employee of Astellas, Northbrook, IL, USA, at the time of the study
| | - Jay Erdman
- Development Project Management, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mohamad Nour Alsharif
- Development Project Management, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Gerard J Marek
- Employee of Astellas, Northbrook, IL, USA, at the time of the study
- Gilgamesh Pharmaceuticals Inc., New York, NY, USA
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4
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Ito M, Walzer M, Beth Blauwet M, Spence A, Heo N, Kelsh D, Blahunka P, Erdman J, Nour Alsharif M, Marek GJ. A phase 1b study to investigate the potential interactions between ASP8062 and buprenorphine/naloxone in patients with opioid use disorder. J Psychopharmacol 2023; 37:144-154. [PMID: 36738100 DOI: 10.1177/02698811221149657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND There is an unmet need for therapeutics with greater efficacy and tolerability for the treatment of opioid use disorder (OUD). ASP8062 is a novel compound with positive allosteric modulator activity on the γ-aminobutyric acid type B receptor under development for use with standard-of-care treatment for patients with OUD. AIMS To investigate the safety, tolerability, interaction potential, and pharmacokinetics (PK) of ASP8062 in combination with buprenorphine/naloxone (B/N; Suboxone®). METHODS In this phase 1, randomized, double-masked, placebo-controlled study, patients with OUD began B/N (titrated to 16/4 mg/day) treatment upon enrollment (induction, Days 1-4; maintenance, Days 5-18; downward titration, Days 19-26; and discharge, Day 27). On Day 12, patients received a single dose of ASP8062 60 mg or placebo with B/N and underwent safety and PK assessments. Primary endpoints included frequency and severity of treatment-emergent adverse events (TEAEs), clinical laboratory tests, respiratory depression, and suicidal ideation. Secondary endpoints investigated the impact of ASP8062 on B/N PK. RESULTS Eighteen patients were randomized and completed the study (ASP8062, n = 12; placebo, n = 6). With this sample size typical for phase 1 drug-drug interaction studies, ASP8062 was well tolerated; most TEAEs were mild in severity, and none led to treatment withdrawal. ASP8062 did not enhance substance use-related TEAEs, respiratory depression, or suicidal ideation and did not have a clinically significant impact on the PK of B/N. CONCLUSIONS In this phase 1 study, ASP8062 was safe, well tolerated, and did not enhance respiratory suppression induced by buprenorphine. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT04447287.
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Affiliation(s)
- Mototsugu Ito
- Development Project Management, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mark Walzer
- Clinical Pharmacology and Exploratory Development, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mary Beth Blauwet
- Biostatistics Department, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Anna Spence
- Biostatistics Department, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Nakyo Heo
- Clinical Pharmacology and Exploratory Development, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Debra Kelsh
- Altasciences Clinical Kansas, Inc., Overland Park, KS, USA
| | | | - Jay Erdman
- Medical Specialties, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | | | - Gerard J Marek
- Employee of Astellas at the time of the study.,Gilgamesh Pharmaceuticals, Inc., New York, NY, USA
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5
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Shyu C, Chavez S, Boileau I, Foll BL. Quantifying GABA in Addiction: A Review of Proton Magnetic Resonance Spectroscopy Studies. Brain Sci 2022; 12:brainsci12070918. [PMID: 35884725 PMCID: PMC9316447 DOI: 10.3390/brainsci12070918] [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: 05/31/2022] [Revised: 07/07/2022] [Accepted: 07/09/2022] [Indexed: 02/04/2023] Open
Abstract
Gamma-aminobutyric acid (GABA) signaling plays a crucial role in drug reward and the development of addiction. Historically, GABA neurochemistry in humans has been difficult to study due to methodological limitations. In recent years, proton magnetic resonance spectroscopy (1H-MRS, MRS) has emerged as a non-invasive imaging technique that can detect and quantify human brain metabolites in vivo. Novel sequencing and spectral editing methods have since been developed to allow for quantification of GABA. This review outlines the clinical research utilization of 1H-MRS in understanding GABA neurochemistry in addiction and summarizes current literature that reports GABA measurements by MRS in addiction. Research on alcohol, nicotine, cocaine, and cannabis addiction all suggest medications that modulate GABA signaling may be effective in reducing withdrawal, craving, and other addictive behaviors. Thus, we discuss how improvements in current MRS techniques and design can optimize GABA quantification in future studies and explore how monitoring changes to brain GABA could help identify risk factors, improve treatment efficacy, further characterize the nature of addiction, and provide crucial insights for future pharmacological development.
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Affiliation(s)
- Claire Shyu
- Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, Toronto, ON M5S 2S1, Canada;
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (S.C.); (I.B.)
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Sofia Chavez
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (S.C.); (I.B.)
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, Division of Brain and Therapeutics, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Isabelle Boileau
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (S.C.); (I.B.)
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, Division of Brain and Therapeutics, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Bernard Le Foll
- Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, Toronto, ON M5S 2S1, Canada;
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada; (S.C.); (I.B.)
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, Division of Brain and Therapeutics, University of Toronto, Toronto, ON M5T 1R8, Canada
- Centre for Addiction and Mental Health, Concurrent Outpatient Medical & Psychosocial Addiction Support Services, Toronto, ON M6J 1H4, Canada
- Centre for Addiction and Mental Health, Acute Care Program, Toronto, ON M6J 1H3, Canada
- Department of Family and Community Medicine, University of Toronto, Toronto, ON M5G 1V7, Canada
- Waypoint Centre for Mental Health Care, Waypoint Research Institute, 500 Church Street, Penetanguishene, ON L9M 1G3, Canada
- Correspondence: ; Tel.: +1-416-535-8501
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Maccioni P, Kaczanowska K, Lawrence H, Yun S, Bratzu J, Gessa GL, McDonald P, Colombo G. The Novel Positive Allosteric Modulator of the GABA B Receptor, KK-92A, Suppresses Alcohol Self-Administration and Cue-Induced Reinstatement of Alcohol Seeking in Rats. Front Cell Dev Biol 2021; 9:727576. [PMID: 34778249 PMCID: PMC8585307 DOI: 10.3389/fcell.2021.727576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Abstract
Positive allosteric modulators (PAMs) of the GABAB receptor (GABAB PAMs) are of interest in the addiction field due to their ability to suppress several behaviors motivated by drugs of abuse. KK-92A is a novel GABAB PAM found to attenuate intravenous self-administration of nicotine and reinstatement of nicotine seeking in rats. This present study was aimed at extending to alcohol the anti-addictive properties of KK-92A. To this end, Sardinian alcohol-preferring rats were trained to lever-respond for oral alcohol (15% v/v) or sucrose (0.7% w/v) under the fixed ratio (FR) 5 (FR5) schedule of reinforcement. Once lever-responding behavior had stabilized, rats were exposed to tests with acutely administered KK-92A under FR5 and progressive ratio schedules of reinforcement and cue-induced reinstatement of previously extinguished alcohol seeking. KK-92A effect on spontaneous locomotor activity was also evaluated. Treatment with 10 and 20 mg/kg KK-92A suppressed lever-responding for alcohol, amount of self-administered alcohol, and breakpoint for alcohol. Treatment with 20 mg/kg KK-92A reduced sucrose self-administration. Combination of per se ineffective doses of KK-92A (2.5 mg/kg) and the GABAB receptor agonist, baclofen (1 mg/kg), reduced alcohol self-administration. Treatment with 5, 10, and 20 mg/kg KK-92A suppressed reinstatement of alcohol seeking. Only treatment with 80 mg/kg KK-92A affected spontaneous locomotor activity. These results demonstrate the ability of KK-92A to inhibit alcohol-motivated behaviors in rodents and confirm that these effects are common to the entire class of GABAB PAMs. The remarkable efficacy of KK-92A is discussed in terms of its ago-allosteric properties.
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Affiliation(s)
- Paola Maccioni
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Katarzyna Kaczanowska
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, United States
| | - Harshani Lawrence
- Chemical Biology Core, Moffitt Cancer Center, Tampa, FL, United States
| | - Sang Yun
- Chemical Biology Core, Moffitt Cancer Center, Tampa, FL, United States
| | - Jessica Bratzu
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Gian Luigi Gessa
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Patricia McDonald
- Department of Cancer Physiology, Moffitt Cancer Center, Tampa, FL, United States
| | - Giancarlo Colombo
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
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7
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Cheron J, Kerchove d'Exaerde AD. Drug addiction: from bench to bedside. Transl Psychiatry 2021; 11:424. [PMID: 34385417 PMCID: PMC8361217 DOI: 10.1038/s41398-021-01542-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/14/2021] [Accepted: 07/23/2021] [Indexed: 02/06/2023] Open
Abstract
Drug addiction is responsible for millions of deaths per year around the world. Still, its management as a chronic disease is shadowed by misconceptions from the general public. Indeed, drug consumers are often labelled as "weak", "immoral" or "depraved". Consequently, drug addiction is often perceived as an individual problem and not societal. In technical terms, drug addiction is defined as a chronic, relapsing disease resulting from sustained effects of drugs on the brain. Through a better characterisation of the cerebral circuits involved, and the long-term modifications of the brain induced by addictive drugs administrations, first, we might be able to change the way the general public see the patient who is suffering from drug addiction, and second, we might be able to find new treatments to normalise the altered brain homeostasis. In this review, we synthetise the contribution of fundamental research to the understanding drug addiction and its contribution to potential novel therapeutics. Mostly based on drug-induced modifications of synaptic plasticity and epigenetic mechanisms (and their behavioural correlates) and after demonstration of their reversibility, we tried to highlight promising therapeutics. We also underline the specific temporal dynamics and psychosocial aspects of this complex psychiatric disease adding parameters to be considered in clinical trials and paving the way to test new therapeutic venues.
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Affiliation(s)
- Julian Cheron
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, B-1070, Belgium
| | - Alban de Kerchove d'Exaerde
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, B-1070, Belgium.
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8
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Acupuncture Modulates Intracranial Self-Stimulation of the Medial Forebrain Bundle in Rats. Int J Mol Sci 2021; 22:ijms22147519. [PMID: 34299139 PMCID: PMC8304740 DOI: 10.3390/ijms22147519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/12/2021] [Accepted: 07/12/2021] [Indexed: 11/24/2022] Open
Abstract
Acupuncture affects the central nervous system via the regulation of neurotransmitter transmission. We previously showed that Shemen (HT7) acupoint stimulation decreased cocaine-induced dopamine release in the nucleus accumbens. Here, we used the intracranial self-stimulation (ICSS) paradigm to evaluate whether HT stimulation regulates the brain reward function of rats. We found that HT stimulation triggered a rightward shift of the frequency–rate curve and elevated the ICSS thresholds. However, HT7 stimulation did not affect the threshold-lowering effects produced by cocaine. These results indicate that HT7 points only effectively regulates the ICSS thresholds of the medial forebrain bundle in drug-naïve rats.
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9
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Lobina C, Maccioni P, Lorrai I, Zaru A, Collu M, Carai MAM, Brizzi A, Mugnaini C, Gessa GL, Corelli F, Colombo G. Suppressing effect of the novel positive allosteric modulator of the GABA B receptor, COR659, on locomotor hyperactivity induced by different drugs of abuse. Behav Brain Res 2020; 400:113045. [PMID: 33309750 DOI: 10.1016/j.bbr.2020.113045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/10/2020] [Accepted: 11/23/2020] [Indexed: 01/08/2023]
Abstract
COR659 is a recently synthesized positive allosteric modulator (PAM) of the GABAB receptor. Similarly to all GABAB PAMs tested to date, COR659 has been reported to suppress different alcohol-related behaviors in rodents. The present study was designed to assess whether the anti-addictive properties of COR659 extend to drugs of abuse other than alcohol. Specifically, it investigated the effect of COR659 on cocaine-, amphetamine-, nicotine-, and morphine-induced locomotor hyperactivity in mice. To this aim, independent groups of CD1 mice were acutely pretreated with COR659 (0, 10, and 20 mg/kg; i.p.), then acutely treated with cocaine (0 and 10 mg/kg, s.c.), amphetamine (0 and 5 mg/kg; s.c.), nicotine (0 and 0.05 mg/kg; s.c.), or morphine (0 and 20 mg/kg; s.c.), and finally exposed for 60 min to a photocell-equipped motility cage. When given alone, both doses of COR659 were ineffective on spontaneous locomotor activity. Pretreatment with COR659 reduced, or even suppressed, the increase in motility counts induced by cocaine, amphetamine, nicotine, and morphine. Since locomotor hyperactivity is an attribute common to drugs of abuse, the results of the present study constitute the first line of evidence on the extension of the preclinical, anti-addictive profile of COR659 to cocaine, amphetamine, nicotine, and morphine.
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Affiliation(s)
- Carla Lobina
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA, I-09042, Italy
| | - Paola Maccioni
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA, I-09042, Italy
| | - Irene Lorrai
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA, I-09042, Italy; Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, I-09042, Italy
| | - Alessandro Zaru
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA, I-09042, Italy; Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, I-09042, Italy
| | - Maria Collu
- Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, I-09042, Italy
| | - Mauro A M Carai
- Cagliari Pharmacological Research, Cagliari, CA, I-09127, Italy
| | - Antonella Brizzi
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, Siena, SI, I-53100, Italy
| | - Claudia Mugnaini
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, Siena, SI, I-53100, Italy
| | - Gian Luigi Gessa
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA, I-09042, Italy; Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, I-09042, Italy
| | - Federico Corelli
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, Siena, SI, I-53100, Italy
| | - Giancarlo Colombo
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, CA, I-09042, Italy.
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10
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Gawlińska K, Jastrzębska J, Gamberini S, Gawliński D, Pieniążek R, Suder A, Wydra K, Frankowska M. The impact of GABA B receptors and their pharmacological stimulation on cocaine reinforcement and drug-seeking behaviors in a rat model of depression. Eur J Pharmacol 2020; 883:173324. [PMID: 32621910 DOI: 10.1016/j.ejphar.2020.173324] [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: 04/17/2020] [Revised: 06/24/2020] [Accepted: 06/26/2020] [Indexed: 11/24/2022]
Abstract
Depression and cocaine use disorder represent frequent co-current diagnoses and the GABAB receptors are involved in both conditions. This research involved the application of the animal model of depression (bulbectomy, OBX) and cocaine use disorder (self-administration) to assess the efficiency of GABAB receptor agonists, baclofen and SKF-97541, on cocaine rewarding property and reinforcement of seeking-behaviors in rats with depressive phenotype. Additionally, we applied immunoreactive techniques to determine changes in the expression of GABAB receptor subunit 1 and 2 in rats with depression and cocaine addiction. The results obtained the study illustrate that the GABAB receptor agonists reduced the rewarding property of cocaine in both OBX and control (SHAM) rats. Both agonists significantly reduced cue- and cocaine-induced reinstatement in both groups. This is the first report demonstrating a different impact of cocaine abuse on GABAB receptor levels in depressed animals. It was documented that the expression of GABAB1 subunit in the infralimbic cortex increased during self-administration and extinction training in OBX animals. The lower level of expression for this subunit in addictive SHAM rats during self-administration, and increased in extinguished addictive OBX rats was found in the ventrolateral striatum. The expression of GABAB2 subunit changed only in the case of cocaine self-administration paradigm, as a decline of the subunit level in the nucleus accumbens and ventral hippocampus was observed only in OBX rats. The relevance of GABAB receptors in depression and addiction comorbidity is clearly implicated and can open a new era of drug discovery for individuals with dual diagnosis.
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Affiliation(s)
- Kinga Gawlińska
- Maj Institute of Pharmacology, Polish Academy of Sciences, Department of Drug Addiction Pharmacology, Ul. 12 Smętna Street, 31-343, Kraków, Poland
| | - Joanna Jastrzębska
- Maj Institute of Pharmacology, Polish Academy of Sciences, Department of Drug Addiction Pharmacology, Ul. 12 Smętna Street, 31-343, Kraków, Poland
| | - Sara Gamberini
- Department of Life Sciences and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Dawid Gawliński
- Maj Institute of Pharmacology, Polish Academy of Sciences, Department of Drug Addiction Pharmacology, Ul. 12 Smętna Street, 31-343, Kraków, Poland
| | - Renata Pieniążek
- Maj Institute of Pharmacology, Polish Academy of Sciences, Department of Drug Addiction Pharmacology, Ul. 12 Smętna Street, 31-343, Kraków, Poland
| | - Agata Suder
- Maj Institute of Pharmacology, Polish Academy of Sciences, Department of Drug Addiction Pharmacology, Ul. 12 Smętna Street, 31-343, Kraków, Poland
| | - Karolina Wydra
- Maj Institute of Pharmacology, Polish Academy of Sciences, Department of Drug Addiction Pharmacology, Ul. 12 Smętna Street, 31-343, Kraków, Poland
| | - Małgorzata Frankowska
- Maj Institute of Pharmacology, Polish Academy of Sciences, Department of Drug Addiction Pharmacology, Ul. 12 Smętna Street, 31-343, Kraków, Poland.
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Abstract
Baclofen, β-(4-chlorophenyl)-γ-aminobutyric acid, holds a unique position in neuroscience, remaining the only U.S. Food and Drug Administration (FDA) approved GABAB agonist. While intended to be a more brain penetrant, i.e, ability to cross the blood-brain barrier (BBB), version of GABA (γ-aminobutyric acid) for the potential treatment of epilepsy, baclofen's highly efficacious muscle relaxant properties led to its approval, as a racemate, for the treatment of spasticity. Interestingly, baclofen received FDA approval before its receptor, GABAB, was discovered and its exact mechanism of action was known. In recent times, baclofen has a myriad of off-label uses, with the treatment for alcohol abuse and drug addiction garnering a great deal of attention. This Review aims to capture the >60 year legacy of baclofen by walking through the history, pharmacology, synthesis, drug metabolism, routes of administration, and societal impact of this Classic in chemical neuroscience.
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Affiliation(s)
- Caitlin N. Kent
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Charlotte Park
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Craig W. Lindsley
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
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Li X, Slesinger PA. GABA B Receptors and Drug Addiction: Psychostimulants and Other Drugs of Abuse. Curr Top Behav Neurosci 2020; 52:119-155. [PMID: 33442842 DOI: 10.1007/7854_2020_187] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Metabotropic GABAB receptors (GABABRs) mediate slow inhibition and modulate synaptic plasticity throughout the brain. Dysfunction of GABABRs has been associated with psychiatric illnesses and addiction. Drugs of abuse alter GABAB receptor (GABABR) signaling in multiple brain regions, which partly contributes to the development of drug addiction. Recently, GABABR ligands and positive allosteric modulators (PAMs) have been shown to attenuate the initial rewarding effect of addictive substances, inhibit seeking and taking of these drugs, and in some cases, ameliorate drug withdrawal symptoms. The majority of the anti-addiction effects seen with GABABR modulation can be localized to ventral tegmental area (VTA) dopamine neurons, which receive complex inhibitory and excitatory inputs that are modified by drugs of abuse. Preclinical research suggests that GABABR PAMs are emerging as promising candidates for the treatment of drug addiction. Clinical studies on drug dependence have shown positive results with GABABR ligands but more are needed, and compounds with better pharmacokinetics and fewer side effects are critically needed.
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Affiliation(s)
- Xiaofan Li
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Paul A Slesinger
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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Sampaio TB, Soares de Souza B, Roversi K, Schuh T, Poli A, Takahashi RN, Prediger RD. Temporal development of behavioral impairments in rats following locus coeruleus lesion induced by 6-hydroxydopamine: Involvement of β 3-adrenergic receptors. Neuropharmacology 2019; 151:98-111. [PMID: 30959019 DOI: 10.1016/j.neuropharm.2019.04.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 03/29/2019] [Accepted: 04/04/2019] [Indexed: 01/17/2023]
Abstract
Noradrenergic degeneration in the locus coeruleus (LC) seems a convergent neuropathological marker of different neurodegenerative diseases. Herein, we investigated the temporal development of apoptotic signaling activation in the LC, noradrenergic dysfunction and behavioral impairments in rats following the noradrenergic lesion of the LC. For this purpose, the dopamine reuptake inhibitor nomifensine was administered 1 h before the stereotaxic bilateral injections of 6-hydroxydopamine (6-OHDA; 5, 10 or 20 μg/hem) into the LC. The behavioral and neurochemical analyses were performed at 7, 21 and 42 days after 6-OHDA injections. All doses of 6-OHDA induced neuronal death in LC, but only the highest dose (20 μg/hem) disrupted the motor function. 6-OHDA (5 μg/hem) injection induced short-term memory deficits in all periods, olfactory discrimination and long-term memory impairments at 7 days, and depressive-like behaviors at 21 and 42 days after injection. Moreover, 6-OHDA infusion increased Bax/Bcl2 ratio and caspase 3 levels, and decreased the dopamine β-hydroxylase immunocontent in the LC. Noradrenergic neurotransmission dysfunction was observed in the LC, olfactory bulb, prefrontal cortex, hippocampus and striatum. The intranasal (i.n.) noradrenaline (NA) infusion restored the impairments in the olfactory discrimination, short-term memory and depressive-like behavior of 6-OHDA-lesioned rats. In addition, these effects were blocked by the prior i.n. infusion of the β3-adrenergic receptor antagonist SR59230A. These findings indicate that the 6-OHDA injection into the LC induced the apoptosis signaling activation, noradrenergic neurotransmission dysfunction and behavioral impairments that were restored via β3-adrenergic receptors activation mediated by the i.n. NA administration.
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Affiliation(s)
- Tuane Bazanella Sampaio
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Bruna Soares de Souza
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Katiane Roversi
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Tayná Schuh
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Anicleto Poli
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Reinaldo Naoto Takahashi
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil
| | - Rui Daniel Prediger
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, Florianópolis, SC, Brazil.
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Efficacy and side effects of baclofen and the novel GABA B receptor positive allosteric modulator CMPPE in animal models for alcohol and cocaine addiction. Psychopharmacology (Berl) 2018; 235:1955-1965. [PMID: 29651507 DOI: 10.1007/s00213-018-4893-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/28/2018] [Indexed: 12/15/2022]
Abstract
RATIONALE Preclinical studies suggest that the GABAB receptor is a potential target for treatment of substance use disorders. However, recent clinical trials report adverse effects in patients treated with the GABAB receptor agonist baclofen and even question efficacy. How can the discrepancy between preclinical and clinical findings be explained? OBJECTIVE To test efficacy and adverse effects of baclofen and the novel GABAB positive allosteric modulator (PAM) CMPPE in rat addiction models, which were developed in accordance with DSM. METHODS We used a well-characterized rat model of long-term alcohol consumption with repeated deprivation phases that result in compulsive alcohol drinking in a relapse situation, and a rat model of long-term intravenous cocaine self-administration resulting in key symptoms of addictive behavior. We tested repeated baclofen (0, 1, and 3 mg/kg; i.p.) and CMPPE doses (0, 10, and 30 mg/kg; i.p.) in relapse-like situations, in either alcohol or cocaine addicted-like rats. RESULTS Baclofen produced a weak anti-relapse effect at the highest dose in alcohol addicted-like rats, and this effect was mainly due to the treatment-induced sedation. CMPPE had a better profile, with a dose-dependent reduction of relapse-like alcohol drinking and without any signs of sedation. The cue-induced cocaine-seeking response was completely abolished by both compounds. CONCLUSION Positive allosteric modulation of the GABAB receptor provides efficacy, and no observable side effects in relapse behavior whereas baclofen may cause, not only sedation, but also considerable impairment of food intake or metabolism. However, targeting GABAB receptors may be effective in reducing certain aspects of addictive-like behavior, such as cue-reactivity.
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15
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Frangaj A, Fan QR. Structural biology of GABA B receptor. Neuropharmacology 2018; 136:68-79. [PMID: 29031577 PMCID: PMC5897222 DOI: 10.1016/j.neuropharm.2017.10.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 11/17/2022]
Abstract
Metabotropic GABAB receptor is a G protein-coupled receptor (GPCR) that mediates slow and prolonged inhibitory neurotransmission in the brain. It functions as a constitutive heterodimer composed of the GABAB1 and GABAB2 subunits. Each subunit contains three domains; the extracellular Venus flytrap module, seven-helix transmembrane region and cytoplasmic tail. In recent years, the three-dimensional structures of GABAB receptor extracellular and intracellular domains have been elucidated. These structures reveal the molecular basis of ligand recognition, receptor heterodimerization and receptor activation. Here we provide a brief review of the GABAB receptor structures, with an emphasis on describing the different ligand-bound states of the receptor. We will also compare these with the known structures of related GPCRs to shed light on the molecular mechanisms of activation and regulation in the GABAB system, as well as GPCR dimers in general. This article is part of the "Special Issue Dedicated to Norman G. Bowery".
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Affiliation(s)
- Aurel Frangaj
- Department of Pharmacology, Columbia University, New York, NY 10032, USA
| | - Qing R Fan
- Department of Pharmacology, Columbia University, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University, New York, NY 10032, USA.
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16
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Kenny PJ, Hoyer D, Koob GF. Animal Models of Addiction and Neuropsychiatric Disorders and Their Role in Drug Discovery: Honoring the Legacy of Athina Markou. Biol Psychiatry 2018; 83:940-946. [PMID: 29602521 DOI: 10.1016/j.biopsych.2018.02.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/14/2018] [Accepted: 02/14/2018] [Indexed: 12/28/2022]
Abstract
Each of the co-authors worked with Athina Markou, at different stages of our careers and in different capacities, to develop, optimize, and use animal models of drug addiction and, more generally, mental health disorders such as anxiety, depression, and schizophrenia. Here, we briefly summarize some of our work with Athina, primarily involving the use of the intracranial self-stimulation and intravenous drug self-administration procedures. This work established that excessive consumption of addictive drugs can induce profound dysfunction in brain reward circuits. Such drug-induced reward deficits are likely to play a key role in precipitating the emergence of compulsive drug-seeking behaviors. We also summarize findings suggesting that perturbations in glutamatergic transmission contribute to brain reward deficits in drug-dependent animals and that metabotropic glutamate receptors are potential targets for the development of novel medications to facilitate long-term drug abstinence and prevention of relapse.
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Affiliation(s)
- Paul J Kenny
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York.
| | - Daniel Hoyer
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia; The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia; Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California; and the National Institute on Alcohol Abuse and Alcoholism, Rockville, Maryland
| | - George F Koob
- National Institute on Alcohol Abuse and Alcoholism, Rockville, Maryland
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17
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Jacobson LH, Vlachou S, Slattery DA, Li X, Cryan JF. The Gamma-Aminobutyric Acid B Receptor in Depression and Reward. Biol Psychiatry 2018; 83:963-976. [PMID: 29759132 DOI: 10.1016/j.biopsych.2018.02.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 01/14/2018] [Accepted: 02/06/2018] [Indexed: 12/31/2022]
Abstract
The metabotropic gamma-aminobutyric acid B (GABAB) receptor was the first described obligate G protein-coupled receptor heterodimer and continues to set the stage for discoveries in G protein-coupled receptor signaling complexity. In this review, dedicated to the life and work of Athina Markou, we explore the role of GABAB receptors in depression, reward, and the convergence of these domains in anhedonia, a shared symptom of major depressive disorder and withdrawal from drugs of abuse. GABAB receptor expression and function are enhanced by antidepressants and reduced in animal models of depression. Generally, GABAB receptor antagonists are antidepressant-like and agonists are pro-depressive. Exceptions to this rule likely reflect the differential influence of GABAB1 isoforms in depression-related behavior and neurobiology, including the anhedonic effects of social stress. A wealth of data implicate GABAB receptors in the rewarding effects of drugs of abuse. We focus on nicotine as an example. GABAB receptor activation attenuates, and deactivation enhances, nicotine reward and associated neurobiological changes. In nicotine withdrawal, however, GABAB receptor agonists, antagonists, and positive allosteric modulators enhance anhedonia, perhaps owing to differential effects of GABAB1 isoforms on the dopaminergic system. Nicotine cue-induced reinstatement is more reliably attenuated by GABAB receptor activation. Separation of desirable and undesirable side effects of agonists is achievable with positive allosteric modulators, which are poised to enter clinical studies for drug abuse. GABAB1 isoforms are key to understanding the neurobiology of anhedonia, whereas allosteric modulators may offer a mechanism for targeting specific brain regions and processes associated with reward and depression.
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Affiliation(s)
- Laura H Jacobson
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia; Department of Pharmacology and Therapeutics, University of Melbourne, Victoria, Australia.
| | - Styliani Vlachou
- School of Nursing and Human Sciences, Faculty of Science and Health, Dublin City University, Glasnevin, Dublin
| | - David A Slattery
- Klinik für Psychiatrie, Psychosomatik und Psychotherapie, Universitätsklinikum Frankfurt, Frankfurt am Main, Germany
| | - Xia Li
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, California
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
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18
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Cryan JF, de Wit H. Special issue: recognizing the lifetime scientific contributions of Athina Markou. Psychopharmacology (Berl) 2017; 234:1311-1313. [PMID: 28421256 PMCID: PMC5473252 DOI: 10.1007/s00213-017-4624-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
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19
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Winsky L, Brady LS. Athina Markou's contributions to treatment development for mental illnesses: a perspective. Psychopharmacology (Berl) 2017; 234:1645-1647. [PMID: 27882396 DOI: 10.1007/s00213-016-4485-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 11/08/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Lois Winsky
- Division of Neuroscience and Basic Behavioral Neuroscience, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Linda S Brady
- Division of Neuroscience and Basic Behavioral Neuroscience, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, USA.
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20
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Obituary: Athina Markou PhD (1961–2016). Neuropharmacology 2017; 113:591-593. [DOI: 10.1016/j.neuropharm.2016.10.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 10/23/2016] [Indexed: 11/19/2022]
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21
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Edwards NJ, Tejeda HA, Pignatelli M, Zhang S, McDevitt RA, Wu J, Bass CE, Bettler B, Morales M, Bonci A. Circuit specificity in the inhibitory architecture of the VTA regulates cocaine-induced behavior. Nat Neurosci 2017; 20:438-448. [DOI: 10.1038/nn.4482] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 12/20/2016] [Indexed: 12/17/2022]
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22
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Xin W, Edwards N, Bonci A. VTA dopamine neuron plasticity - the unusual suspects. Eur J Neurosci 2016; 44:2975-2983. [PMID: 27711998 DOI: 10.1111/ejn.13425] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/26/2016] [Accepted: 10/03/2016] [Indexed: 12/25/2022]
Abstract
Dopamine neurons in the ventral tegmental area (VTA) are involved in a variety of physiological and pathological conditions, ranging from motivated behaviours to substance use disorders. While many studies have shown that these neurons can express plasticity at excitatory and inhibitory synapses, little is known about how inhibitory inputs and glial activity shape the output of DA neurons and therefore, merit greater discussion. In this review, we will attempt to fill in a bit more of the puzzle, with a focus on inhibitory transmission and astrocyte function. We summarize the findings within the VTA as well as observations made in other brain regions that have important implications for plasticity in general and should be considered in the context of DA neuron plasticity.
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Affiliation(s)
- Wendy Xin
- Synaptic Plasticity Section, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA.,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - Nicholas Edwards
- Synaptic Plasticity Section, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Antonello Bonci
- Synaptic Plasticity Section, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA.,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
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23
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Brown JW, Moeller A, Schmidt M, Turner SC, Nimmrich V, Ma J, Rueter LE, van der Kam E, Zhang M. Anticonvulsant effects of structurally diverse GABA(B) positive allosteric modulators in the DBA/2J audiogenic seizure test: Comparison to baclofen and utility as a pharmacodynamic screening model. Neuropharmacology 2015; 101:358-69. [PMID: 26471422 DOI: 10.1016/j.neuropharm.2015.10.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 07/31/2015] [Accepted: 10/04/2015] [Indexed: 02/02/2023]
Abstract
The GABA(B) receptor has been indicated as a promising target for multiple CNS-related disorders. Baclofen, a prototypical orthosteric agonist, is used clinically for the treatment of spastic movement disorders, but is associated with unwanted side-effects, such as sedation and motor impairment. Positive allosteric modulators (PAM), which bind to a topographically-distinct site apart from the orthosteric binding pocket, may provide an improved side-effect profile while maintaining baclofen-like efficacy. GABA, the major inhibitory neurotransmitter in the CNS, plays an important role in the etiology and treatment of seizure disorders. Baclofen is known to produce anticonvulsant effects in the DBA/2J mouse audiogenic seizure test (AGS), suggesting it may be a suitable assay for assessing pharmacodynamic effects. Little is known about the effects of GABA(B) PAMs, however. The studies presented here sought to investigate the AGS test as a pharmacodynamic (PD) screening model for GABA(B) PAMs by comparing the profile of structurally diverse PAMs to baclofen. GS39783, rac-BHFF, CMPPE, A-1295120 (N-(3-(4-(4-chloro-3-fluorobenzyl)-6-methoxy-3,5-dioxo-4,5-dihydro-1,2,4-triazin-2(3H)-yl)phenyl)acetamide), and A-1474713 (N-(3-(4-(4-chlorobenzyl)-3,5-dioxo-4,5-dihydro-1,2,4-triazin-2(3H)-yl)phenyl)acetamide) all produced robust, dose-dependent anticonvulsant effects; a similar profile was observed with baclofen. Pre-treatment with the GABA(B) antagonist SCH50911 completely blocked the anticonvulsant effects of baclofen and CMPPE in the AGS test, indicating such effects are likely mediated by the GABA(B) receptor. In addition to the standard anticonvulsant endpoint of the AGS test, video tracking software was employed to assess potential drug-induced motor side-effects during the acclimation period of the test. This analysis was sensitive to detecting drug-induced changes in total distance traveled, which was used to establish a therapeutic index (TI = hypoactivity/anticonvulsant effects). Calculated TIs for A-1295120, CMPPE, rac-BHFF, GS39783, and A-1474713 were 5.31x, 5.00x, 4.74x, 3.41x, and 1.83x, respectively, whereas baclofen was <1. The results presented here suggest the DBA/2J mouse AGS test is a potentially useful screening model for detecting PD effects of GABA(B) PAMs and can provide an initial read-out on target-related motor side-effects. Furthermore, an improved TI was observed for PAMs compared to baclofen, indicating the PAM approach may be a viable therapeutic alternative to baclofen.
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Affiliation(s)
- Jordan W Brown
- Neuroscience Discovery, AbbVie, Inc., 1 North Waukegan Rd., North Chicago, IL 60064, United States.
| | - Achim Moeller
- Neuroscience Discovery, AbbVie Deutschland GmbH & Co KG, Knollstrasse, Ludwigshafen 67061, Germany
| | - Martin Schmidt
- Neuroscience Discovery, AbbVie Deutschland GmbH & Co KG, Knollstrasse, Ludwigshafen 67061, Germany
| | - Sean C Turner
- Neuroscience Discovery, AbbVie Deutschland GmbH & Co KG, Knollstrasse, Ludwigshafen 67061, Germany
| | - Volker Nimmrich
- Neuroscience Discovery, AbbVie Deutschland GmbH & Co KG, Knollstrasse, Ludwigshafen 67061, Germany
| | - Junli Ma
- Drug Metabolism and Pharmacokinetics, AbbVie, Inc., North Chicago, IL 60064, United States
| | - Lynne E Rueter
- Neuroscience Discovery, AbbVie, Inc., 1 North Waukegan Rd., North Chicago, IL 60064, United States
| | - Elizabeth van der Kam
- Neuroscience Discovery, AbbVie Deutschland GmbH & Co KG, Knollstrasse, Ludwigshafen 67061, Germany
| | - Min Zhang
- Neuroscience Discovery, AbbVie, Inc., 1 North Waukegan Rd., North Chicago, IL 60064, United States
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mGlu5-GABAB interplay in animal models of positive, negative and cognitive symptoms of schizophrenia. Neurochem Int 2015; 88:97-109. [DOI: 10.1016/j.neuint.2015.03.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 03/17/2015] [Accepted: 03/23/2015] [Indexed: 11/19/2022]
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25
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Filip M, Frankowska M, Sadakierska-Chudy A, Suder A, Szumiec Ł, Mierzejewski P, Bienkowski P, Przegaliński E, Cryan JF. GABAB receptors as a therapeutic strategy in substance use disorders: Focus on positive allosteric modulators. Neuropharmacology 2015; 88:36-47. [DOI: 10.1016/j.neuropharm.2014.06.016] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/10/2014] [Accepted: 06/15/2014] [Indexed: 12/16/2022]
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26
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Pitman KA, Puil E, Borgland SL. GABA(B) modulation of dopamine release in the nucleus accumbens core. Eur J Neurosci 2014; 40:3472-80. [PMID: 25229321 DOI: 10.1111/ejn.12733] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 08/20/2014] [Indexed: 11/27/2022]
Abstract
Modulation of the concentration of dopamine (DA) released from dopaminergic terminals in the nucleus accumbens (NAc) influences behaviours such as the motivation to obtain drugs of abuse. γ-Aminobutyric acid type B (GABAB ) receptors are expressed throughout the mesolimbic circuit, including in the NAc, and baclofen, an agonist of GABAB receptors, can decrease drug-seeking behaviours. However, the mechanism by which GABAB receptors modulate terminal DA release has not been well studied. We explored how baclofen modulates the concentration of DA released from terminals in the NAc core using fast-scan cyclic voltammetry in brain slices from adult male C57BL/6J mice. We found that baclofen concentration-dependently decreased single pulse-evoked DA release. This effect was blocked by the GABAB antagonist, CGP 52432, but not by a nicotinic acetylcholine receptor antagonist. Suppression of DA release by a saturating concentration of baclofen was sustained for up to 1 h. The effect of baclofen was reduced with electrical stimulations mimicking burst firing of DA neurons. Similar to the D2 receptor agonist, quinpirole, baclofen reduced the probability of DA release, supporting a mechanistic overlap with D2 receptors. Baclofen-mediated suppression of DA release persisted after a locomotor-sensitizing cocaine treatment, indicating that GABAB receptors on DA terminals were not altered by cocaine exposure. These data suggest that baclofen-mediated suppression of terminal DA release is due to GABAB activation on DA terminals to reduce the probability of DA release. This effect does not readily desensitize, and persists regardless of chronic cocaine treatment.
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Affiliation(s)
- Kimberley A Pitman
- Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia, Vancouver, BC, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
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Abstract
Intracranial self-stimulation (ICSS) is a behavioral procedure in which operant responding is maintained by pulses of electrical brain stimulation. In research to study abuse-related drug effects, ICSS relies on electrode placements that target the medial forebrain bundle at the level of the lateral hypothalamus, and experimental sessions manipulate frequency or amplitude of stimulation to engender a wide range of baseline response rates or response probabilities. Under these conditions, drug-induced increases in low rates/probabilities of responding maintained by low frequencies/amplitudes of stimulation are interpreted as an abuse-related effect. Conversely, drug-induced decreases in high rates/probabilities of responding maintained by high frequencies/amplitudes of stimulation can be interpreted as an abuse-limiting effect. Overall abuse potential can be inferred from the relative expression of abuse-related and abuse-limiting effects. The sensitivity and selectivity of ICSS to detect abuse potential of many classes of abused drugs is similar to the sensitivity and selectivity of drug self-administration procedures. Moreover, similar to progressive-ratio drug self-administration procedures, ICSS data can be used to rank the relative abuse potential of different drugs. Strengths of ICSS in comparison with drug self-administration include 1) potential for simultaneous evaluation of both abuse-related and abuse-limiting effects, 2) flexibility for use with various routes of drug administration or drug vehicles, 3) utility for studies in drug-naive subjects as well as in subjects with controlled levels of prior drug exposure, and 4) utility for studies of drug time course. Taken together, these considerations suggest that ICSS can make significant contributions to the practice of abuse potential testing.
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Affiliation(s)
- S Stevens Negus
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Laurence L Miller
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
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The effects of N-acetylcysteine on cocaine reward and seeking behaviors in a rat model of depression. Behav Brain Res 2014; 266:108-18. [DOI: 10.1016/j.bbr.2014.02.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 02/19/2014] [Accepted: 02/23/2014] [Indexed: 12/20/2022]
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McCarson KE, Enna SJ. GABA pharmacology: the search for analgesics. Neurochem Res 2014; 39:1948-63. [PMID: 24532294 DOI: 10.1007/s11064-014-1254-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 01/28/2014] [Accepted: 01/31/2014] [Indexed: 12/28/2022]
Abstract
Decades of research have been devoted to defining the role of GABAergic transmission in nociceptive processing. Much of this work was performed using rigid, orthosteric GABA analogs created by Povl Krogsgaard-Larsen and his associates. A relationship between GABA and pain is suggested by the anatomical distribution of GABA receptors and the ability of some GABA agonists to alter nociceptive responsiveness. Outlined in this report are data supporting this proposition, with particular emphasis on the anatomical localization and function of GABA-containing neurons and the molecular and pharmacological properties of GABAA and GABAB receptor subtypes. Reference is made to changes in overall GABAergic tone, GABA receptor expression and activity as a function of the duration and intensity of a painful stimulus or exposure to GABAergic agents. Evidence is presented that the plasticity of this receptor system may be responsible for the variability in the antinociceptive effectiveness of compounds that influence GABA transmission. These findings demonstrate that at least some types of persistent pain are associated with a regionally selective decline in GABAergic tone, highlighting the need for agents that enhance GABA activity in the affected regions without compromising GABA function over the long-term. As subtype selective positive allosteric modulators may accomplish these goals, such compounds might represent a new class of analgesic drugs.
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Affiliation(s)
- Kenneth E McCarson
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 1018, Kansas City, KS, 66160, USA
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Leading compounds for the validation of animal models of psychopathology. Cell Tissue Res 2013; 354:309-30. [DOI: 10.1007/s00441-013-1692-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 07/01/2013] [Indexed: 12/18/2022]
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Choi SH, Chung S, Cho JH, Cho YH, Kim JW, Kim JM, Kim HJ, Kim HJ, Shin KH. Changes in c-Fos Expression in the Forced Swimming Test: Common and Distinct Modulation in Rat Brain by Desipramine and Citalopram. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2013; 17:321-9. [PMID: 23946692 PMCID: PMC3741489 DOI: 10.4196/kjpp.2013.17.4.321] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 05/23/2013] [Accepted: 06/05/2013] [Indexed: 12/05/2022]
Abstract
Rodents exposed to a 15-min pretest swim in the forced swimming test (FST) exhibit prolonged immobility in a subsequent 5-min test swim, and antidepressant treatment before the test swim reduces immobility. At present, neuronal circuits recruited by antidepressant before the test swim remain unclear, and also less is known about whether antidepressants with different mechanisms of action could influence neural circuits differentially. To reveal the neural circuits associated with antidepressant effect in the FST, we injected desipramine or citalopram 0.5 h, 19 h, and 23 h after the pretest swim and observed changes in c-Fos expression in rats before the test swim, namely 24 h after the pretest swim. Desipramine treatment alone in the absence of pretest swim was without effect, whereas citalopram treatment alone significantly increased the number of c-Fos-like immunoreactive cells in the central nucleus of the amygdala and bed nucleus of the stria terminalis, where this pattern of increase appears to be maintained after the pretest swim. Both desipramine and citalopram treatment after the pretest swim significantly increased the number of c-Fos-like immunoreactive cells in the ventral lateral septum and ventrolateral periaqueductal gray before the test swim. These results suggest that citalopram may affect c-Fos expression in the central nucleus of the amygdala and bed nucleus of the stria terminalis distinctively and raise the possibility that upregulation of c-Fos in the ventral lateral septum and ventrolateral periaqueductal gray before the test swim may be one of the probable common mechanisms underlying antidepressant effect in the FST.
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Affiliation(s)
- Sun Hye Choi
- Department of Pharmacology, Korea University College of Medicine, Seoul 136-705, Korea
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Therapeutic potential of GABA(B) receptor ligands in drug addiction, anxiety, depression and other CNS disorders. Pharmacol Biochem Behav 2013; 110:174-84. [PMID: 23872369 DOI: 10.1016/j.pbb.2013.07.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 06/27/2013] [Accepted: 07/05/2013] [Indexed: 01/06/2023]
Abstract
Glutamate and γ-aminobutyric acid (GABA) are the major excitatory and inhibitory neurotransmitter systems, respectively in the central nervous system (CNS). Dysregulation, in any of these or both, has been implicated in various CNS disorders. GABA acts via ionotropic (GABA(A) and GABA(C) receptor) and metabotropic (GABA(B)) receptor. Dysregulation of GABAergic signaling and alteration in GABA(B) receptor expression has been implicated in various CNS disorders. Clinically, baclofen-a GABA(B) receptor agonist is available for the treatment of spasticity, dystonia etc., associated with various neurological disorders. Moreover, GABAB receptor ligands has also been suggested to be beneficial in various neuropsychiatric and neurodegenerative disorders. The present review is aimed to discuss the role of GABA(B) receptors and the possible outcomes of GABA(B) receptor modulation in CNS disorders.
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Li X, Risbrough VB, Cates-Gatto C, Kaczanowska K, Finn MG, Roberts AJ, Markou A. Comparison of the effects of the GABAB receptor positive modulator BHF177 and the GABAB receptor agonist baclofen on anxiety-like behavior, learning, and memory in mice. Neuropharmacology 2013; 70:156-67. [PMID: 23376712 PMCID: PMC3644349 DOI: 10.1016/j.neuropharm.2013.01.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 01/02/2013] [Accepted: 01/12/2013] [Indexed: 12/14/2022]
Abstract
γ-Aminobutyric acid B (GABAB) receptor activation is a potential therapeutic approach for the treatment of drug addiction, pain, anxiety, and depression. However, full agonists of this receptor induce side-effects, such as sedation, muscle relaxation, tolerance, and cognitive disruption. Positive allosteric modulators (PAMs) of the GABAB receptor may have similar therapeutic effects as agonists with superior side-effect profiles. The present study behaviorally characterized N-([1R,2R,4S]-bicyclo[2.2.1]hept-2-yl)-2-methyl-5-(4-[trifluoromethyl]phenyl)-4-pyrimidinamine (BHF177), a GABAB receptor PAM, in mouse models of anxiety-like behavior, learning and memory. In addition, the effects of BHF177 were compared with the agonist baclofen. Unlike the anxiolytic chlordiazepoxide, baclofen (0.5, 1.5, and 2.5 mg/kg, intraperitoneally) and BHF177 (10, 20, and 40 mg/kg, orally) had no effect on anxiety-like behavior in the elevated plus maze, light/dark box, or Vogel conflict test. Baclofen increased punished drinking in the Vogel conflict test, but this effect may be attributable to the analgesic actions of baclofen. At the highest dose tested (2.5 mg/kg), baclofen-treated mice exhibited sedation-like effects (i.e., reduced locomotor activity) across many of the tests, whereas BHF177-treated mice exhibited no sedation-like effects. BHF177 exhibited pro-convulsion properties only in mice, but not in rats, indicating that this effect may be species-specific. At doses that were not sedative or pro-convulsant, baclofen and BHF177 had no selective effects on fear memory retrieval in contextual and cued fear conditioning or spatial learning and memory in the Barnes maze. These data suggest that BHF177 has little sedative activity, no anxiolytic-like profile, and minimal impairment of learning and memory in mice.
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Affiliation(s)
- Xia Li
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Victoria B. Risbrough
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Veterans Affairs Center of Excellence for Stress and Mental Health, La Jolla, CA, USA
| | - Chelsea Cates-Gatto
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, CA, USA
| | | | - M. G. Finn
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Amanda J Roberts
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, CA, USA
| | - Athina Markou
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
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Abstract
The neurosurgical treatment of treatment-resistant depression (TRD) has entered a new era with more and more patients being treated with deep brain stimulation (DBS) via surgically implanted intracerebral electrodes. Although the mechanisms of action of DBS are still not fully understood, preclinical studies are being conducted to elucidate how the treatment might work. DBS in its present form can be considered as a relatively new neurosurgical treatment for TRD. However, the use of neurosurgery in the management of depression has a much longer history particularly with ablative procedures but also vagal nerve stimulation. Here, we provide a review of the clinical neurosurgical treatments for TRD, with a main emphasis on DBS. In addition, we discuss relevant preclinical data that are revealing new information about DBS mechanisms.
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Affiliation(s)
- Yasin Temel
- Department of Neurosurgery and Neuroscience, Maastricht University Medical Center, The Netherlands.
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Agabio R, Preti A, Gessa GL. Efficacy and tolerability of baclofen in substance use disorders: a systematic review. Eur Addict Res 2013; 19:325-45. [PMID: 23775042 DOI: 10.1159/000347055] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND It has been reported that baclofen, a drug used in the treatment of spasticity, reduces the severity of withdrawal symptoms and substance use disorders (SUDs) for some psychoactive drugs. AIMS AND METHODS To evaluate the effectiveness and safety of baclofen in the treatment of withdrawal syndrome and/or SUDs, providing (1) an outline of its pharmacological features; (2) a summary of studies that have suggested its possible effectiveness in the treatment of SUDs, and (3) a review of randomized, controlled trials (RCTs) on baclofen and SUDs. RESULTS Baclofen tolerability is generally considered to be good. Eleven RCTs investigated its effectiveness in the treatment of SUDs. Of these, 5 RCTs found that baclofen is effective, 5 RCTs found that it is ineffective and the results of 1 RCT were not appreciable because it did not achieve the preplanned level of participation. CONCLUSIONS The number of RCTs on baclofen and SUDs is still low, and their results are divergent. Further RCTs should be undertaken, particularly with higher doses of baclofen. Its administration may be suggested in patients who fail to respond to other approved drugs or who are affected by liver disease that prevents their administration, or in patients affected by SUDs for which no approved drugs are available. Treatment should be conducted under strict medical supervision.
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Affiliation(s)
- Roberta Agabio
- Department of Biomedical Sciences, Section of Neuroscience, Clinical Pharmacology, University of Cagliari, Cagliari, Italy
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Gąska M, Kuśmider M, Solich J, Faron-Górecka A, Krawczyk MJ, Kułakowski K, Dziedzicka-Wasylewska M. Analysis of region-specific changes in gene expression upon treatment with citalopram and desipramine reveals temporal dynamics in response to antidepressant drugs at the transcriptome level. Psychopharmacology (Berl) 2012; 223:281-97. [PMID: 22547330 PMCID: PMC3438400 DOI: 10.1007/s00213-012-2714-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 03/30/2012] [Indexed: 12/20/2022]
Abstract
RATIONALE The notion that the onset of action of antidepressant drugs (ADs) takes weeks is widely accepted; however, the sequence of events necessary for therapeutic effects still remains obscure. OBJECTIVE We aimed to evaluate a time-course of ADs-induced alterations in the expression of 95 selected genes in 4 regions of the rat brain: the prefrontal and cingulate cortices, the dentate gyrus of the hippocampus, and the amygdala. METHODS We employed RT-PCR array to evaluate changes during a time-course (1, 3, 7, 14, and 21 days) of treatments with desipramine (DMI) and citalopram (CIT). In addition to repeated treatment, we also conducted acute treatment (a single dose of drug followed by the same time intervals as the repeated doses). RESULTS Time-dependent and structure-specific changes in gene expression patterns allowed us to identify spatiotemporal differences in the molecular action of two ADs. Singular value decomposition analysis revealed differences in the global gene expression profiles between treatment types. The numbers of characteristic modes were generally smaller after CIT treatment than after DMI treatment. Analysis of the dynamics of gene expression revealed that the most significant changes concerned immediate early genes, whose expression was also visualized by in situ hybridization. Transcription factor binding site analysis revealed an over-representation of serum response factor binding sites in the promoters of genes that changed upon treatment with both ADs. CONCLUSIONS The observed gene expression patterns were highly dynamic, with oscillations and peaks at various time points of treatment. Our study also revealed novel potential targets of antidepressant action, i.e., Dbp and Id1 genes.
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Affiliation(s)
- Magdalena Gąska
- Department of Pharmacology, Institute of Pharmacology Polish Academy of Sciences, Smętna 12 Street, 31-343 Krakow, Poland.
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Orrù A, Fujani D, Cassina C, Conti M, Di Clemente A, Cervo L. Operant, oral alcoholic beer self-administration by C57BL/6J mice: effect of BHF177, a positive allosteric modulator of GABA(B) receptors. Psychopharmacology (Berl) 2012; 222:685-700. [PMID: 22411427 DOI: 10.1007/s00213-012-2672-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 02/14/2012] [Indexed: 12/30/2022]
Abstract
RATIONALE With its high palatability, near-beer has been successfully used in rats as a vehicle to induce ethanol oral self-administration. OBJECTIVES The study aimed to develop an operant model of oral alcoholic beer self-administration promoting a stable intake of pharmacologically relevant amounts of ethanol in free-feeding C57BL/6J mice. It also aimed to assess the model's predictive validity by evaluating the influence of baclofen, a GABA(B) agonist, and BHF177, a GABA(B) positive allosteric modulator, on alcoholic beer self-administration. METHODS Mice were trained to self-administer, under a fixed ratio three schedule of reinforcement, 10 μl of beer containing increasing ethanol concentrations (0-18% v/v) in daily 30-min sessions. The effects on motor coordination (rotarod), locomotor activity (open field, automated cages) and anxiety-like behavior (elevated plus maze, EPM) were examined. Baclofen (1.25-5 mg/kg, intraperitoneal, i.p.) and BHF177 (3.75-30 mg/kg, i.p.) were used to see the effects on 9% alcoholic beer and near-beer self-administration. RESULTS Near-beer stably maintained operant oral self-administration in mice. Adding ethanol to near-beer reduced the number of active lever presses, while the corresponding amount of ethanol self-administration increased (0.8-1.0 g/kg/session). Motor impairment was observed when more than 1.3 g/kg/session of ethanol was self-administered with beer and slight but consistent hyperlocomotion with more than 0.9-1.0 g/kg/session. BHF177 (15 mg/kg) preferentially reduced 9% alcoholic beer self-administration, while the higher dose (30 mg/kg)-like baclofen 5 mg/kg-also reduced near-beer self-administration. CONCLUSIONS The operant model of oral alcoholic beer self-administration in C57BL/6J mice should prove useful for studying ethanol-reinforced behaviors and to identify candidate compounds for the pharmacological management of alcohol addiction.
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Affiliation(s)
- Alessandro Orrù
- Experimental Psychopharmacology, Department of Neuroscience, "Mario Negri" Institute for Pharmacological Research, Via La Masa 19, 20156 Milan, Italy.
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Moran MD, Wilson AA, Elmore CS, Parkes J, Ng A, Sadovski O, Graff A, Daskalakis ZJ, Houle S, Chapdelaine MJ, Vasdev N. Development of new carbon-11 labelled radiotracers for imaging GABAA- and GABAB-benzodiazepine receptors. Bioorg Med Chem 2012; 20:4482-8. [PMID: 22717238 DOI: 10.1016/j.bmc.2012.05.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 05/05/2012] [Accepted: 05/12/2012] [Indexed: 11/16/2022]
Abstract
Two quinolines identified as positive allosteric modulators of γ-aminobutyric acid (GABA)(A) receptors containing the α(2) subunit, 9-amino-2-cyclobutyl-5-(6-methoxy-2-methylpyridin-3-yl)-2,3-dihydro-1H-pyrrolo[3,4-b]quinolin-1-one (4) and 9-amino-2-cyclobutyl-5-(2-methoxypyridin-3-yl)-2,3-dihydro-1H-pyrrolo[3,4-b]quinolin-1-one (5), were radiolabelled at the methoxy position with carbon-11 (half-life=20.4 min). These quinolines represent a new class of potential radiotracers for imaging the benzodiazepine site of GABA(A) receptors with positron emission tomography (PET). Both radiotracers were reliably isolated following reaction of their respective pyridinone/pyridinol tautomeric precursors with [(11)C]CH(3)I in clinically useful, formulated quantities (2.9% and 2.7% uncorrected radiochemical yield, respectively, relative to [(11)C]CO(2)) with high specific activities (>70 GBq μ mol(-1); >2 Ci μ mol(-1)) and high radiochemical purities (>95%). The radiosyntheses reported herein represent rare examples of selectively isolating radiolabelled compounds bearing [(11)C]2-methoxypyridine moieties. Although both radiotracers demonstrated promising imaging characteristics based on preliminary ex vivo biodistribution studies in conscious rodents, higher brain uptake was observed with [(11)C]5 and therefore this radiotracer was further evaluated. Carbon-11 labelled 5 readily penetrated the brain (>1 standard uptake value in cortical regions at 15 min post-injection of the radiotracer), had an appropriate regional brain distribution for GABA(A) receptors that appeared to be reversible, and did not show any appreciable radiometabolites in rat brain homogenates up to 15 min post-injection. Preadministration of flumazenil (1, 10 mg kg(-1)) or 5 (5 mg kg(-1)) effectively blocked >50% of [(11)C]5 binding to the GABA(A) receptor-rich regions, thereby suggesting that this radiotracer is worthy of further evaluation for imaging GABA(A) receptors. Additionally (R,S)-N-(1-(3-chloro-4-methoxyphenyl)ethyl)-3,3-diphenylpropan-1-amine, 6, an allosteric modulator of GABA(B) receptors, was efficiently labelled in one step using [(11)C]methyl iodide. Ex vivo biodistribution studies in conscious rats showed low brain uptake, therefore, efforts are underway to discover alternative radiotracers to image GABA(B). In conclusion, [(11)C]5 is worthy of further evaluation in higher species for imaging GABA(A) receptors in the central nervous system.
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Affiliation(s)
- Matthew D Moran
- Centre for Addiction and Mental Health and University of Toronto, 250 College St., Toronto, ON, Canada M5T 1R8
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Maccioni P, Zaru A, Loi B, Lobina C, Carai MAM, Gessa GL, Capra A, Mugnaini C, Pasquini S, Corelli F, Hyytiä P, Lumeng L, Colombo G. Comparison of the effect of the GABAΒ receptor agonist, baclofen, and the positive allosteric modulator of the GABAB receptor, GS39783, on alcohol self-administration in 3 different lines of alcohol-preferring rats. Alcohol Clin Exp Res 2012; 36:1748-66. [PMID: 22486245 DOI: 10.1111/j.1530-0277.2012.01782.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 02/02/2012] [Indexed: 12/20/2022]
Abstract
BACKGROUND Administration of the GABA(B) receptor agonist, baclofen, and positive allosteric modulator, GS39783, has been repeatedly reported to suppress multiple alcohol-related behaviors, including operant oral alcohol self-administration, in rats. This study was designed to compare the effect of baclofen and GS39783 on alcohol self-administration in 3 lines of selectively bred, alcohol-preferring rats: Indiana alcohol-preferring (P), Sardinian alcohol-preferring (sP), and Alko Alcohol (AA). METHODS Rats of each line were initially trained to respond on a lever, on a fixed ratio (FR) 4 (FR4) schedule of reinforcement, to orally self-administer alcohol (15%, v/v) in daily 30-minute sessions. Once responding reached stable levels, rats were exposed to a sequence of experiments testing baclofen (0, 1, 1.7, and 3 mg/kg; i.p.) and GS39783 (0, 25, 50, and 100 mg/kg; i.g.) on FR4 and progressive ratio (PR) schedules of reinforcement. Finally, to assess the specificity of baclofen and GS39783 action, rats were slightly food-deprived and trained to lever-respond for food pellets. RESULTS The rank of order of the reinforcing and motivational properties of alcohol was P>sP>AA rats. Under both FR and PR schedules of reinforcement, the rank of order of potency and efficacy of baclofen and GS39783 in suppressing alcohol self-administration was P>sP>AA rats. Only the highest dose of baclofen reduced lever-responding for food pellets; this effect was common to all 3 rat lines. Conversely, no dose of GS39783 altered lever-responding for food in any rat line. CONCLUSIONS These results suggest that: (i) the strength of the reinforcing and motivational properties of alcohol differ among P, sP, and AA rats; (ii) the reinforcing and motivational properties of alcohol in P, sP, and AA rats are differentially sensitive to treatment with baclofen and GS39783; (iii) the heterogeneity in sensitivity to baclofen and GS39783 of alcohol self-administration in P, sP, and AA rats may resemble the differential effectiveness of pharmacotherapies among the different typologies of human alcoholics; and (iv) the GABA(B) receptor is part of the neural substrate mediating the reinforcing and motivational properties of alcohol.
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Affiliation(s)
- Paola Maccioni
- Section of Cagliari, Neuroscience Institute, National Research Council of Italy, Monserrato, Italy
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Hayes DJ, Hoang J, Greenshaw AJ. The role of nucleus accumbens shell GABA receptors on ventral tegmental area intracranial self-stimulation and a potential role for the 5-HT(2C) receptor. J Psychopharmacol 2011; 25:1661-75. [PMID: 21169393 DOI: 10.1177/0269881110389212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Brain γ-aminobutyric acid (GABA) and 5-hydroxytryptamine (5-HT)(2C) receptors are implicated in the neuronal regulation of reward- and aversion-related behaviour. Within the mesocorticolimbic pathways of the brain, relationships between GABA containing neurons and 5-HT(2C) receptor activity may be important in this context. The primary aim of this study was to investigate the role of NAc shell GABA receptors on ventral tegmental area intracranial self-stimulation (ICSS) and to examine the systemic effects of GABAergic ligands in this context. The second aim was to investigate the relationship between GABA receptor- and 5-HT(2C) receptor-related ICSS behaviour, using systemic administration of the selective agonist WAY 161503. Locomotor activity was assessed to compare the potential motor effects of drugs; feeding behaviour and intra-NAc injections of amphetamine (1.0 µg/side) were used as positive controls. When administered systemically the GABA(A) receptor agonist muscimol and antagonist picrotoxin did not selectively change ICSS reward thresholds, although the 5-HT(2C) receptor agonist WAY 161503 (1.0 mg/kg) decreased reward measures. Intra-NAc shell administration of muscimol (225 ng/side) and picrotoxin (125 ng/side), respectively, decreased and increased measures of reward. Intra-NAc shell baclofen (0-225 ng/side; GABA(B) receptor agonist) did not affect any ICSS measures although it increased feeding. Combining picrotoxin and WAY 161503 attenuated the effects of each. These results suggest that a 5-HT(2C) and GABA(A) receptor-mediated neuronal relationship in the NAc shell may be relevant for the regulation of brain reward pathways.
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Affiliation(s)
- Dave J Hayes
- Centre for Neuroscience, University of Alberta, Edmonton, AB, Canada.
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Silva M, Aguiar DC, Diniz CRA, Guimarães FS, Joca SRL. Neuronal NOS Inhibitor and Conventional Antidepressant Drugs Attenuate Stress-induced Fos Expression in Overlapping Brain Regions. Cell Mol Neurobiol 2011; 32:443-53. [DOI: 10.1007/s10571-011-9775-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 11/15/2011] [Indexed: 01/22/2023]
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Slattery DA, Neumann ID, Cryan JF. Transient inactivation of the infralimbic cortex induces antidepressant-like effects in the rat. J Psychopharmacol 2011; 25:1295-303. [PMID: 20530589 DOI: 10.1177/0269881110368873] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Affective disorders are among the main causes of disability worldwide, yet the underlying pathophysiology remains poorly understood. Recently, landmark neuroimaging studies have shown increased metabolic activity in Brodmann Area 25 (BA25) in depressed patients. Moreover, functional inactivation of this region using deep brain stimulation alleviated depressive symptoms in severely depressed patients. Thus, we examined the effect of a similar manipulation, pharmacological inactivation of the infralimbic cortex, the rodent correlate of BA25, in an animal model of antidepressant activity: the modified rat forced swim test. Transient inactivation of the infralimbic cortex using muscimol reduced immobility, an antidepressant-like effect in the test. Importantly, this activity was not the result of a general increase in locomotor activity. Activation of the infralimbic cortex using bicuculline did not alter behaviour. Finally, we examined the effect of muscimol in animals bred for high anxiety-related behaviour, which also display elevated depression-related behaviour. Transient inactivation of the infralimbic cortex decreased the high inborn depression-like behaviour of these rats. These results show that it is possible to replicate findings from a clinical trial in a rodent model. Further, they support the use of the forced swim test to gain greater understanding of the neurocircuitry involved in depression and antidepressant-action.
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Affiliation(s)
- David A Slattery
- Neuroscience Research, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland.
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Halbout B, Quarta D, Valerio E, Heidbreder CA, Hutcheson DM. The GABA-B positive modulator GS39783 decreases psychostimulant conditioned-reinforcement and conditioned-reward. Addict Biol 2011; 16:416-27. [PMID: 21309927 DOI: 10.1111/j.1369-1600.2010.00278.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Baclofen, a γ-amino-butyric-acid (GABA)(B) receptor agonist, can reduce cue-enhanced cocaine-seeking in rats and attenuate cue-evoked craving in cocaine addicts. However, baclofen also has sedative effects that might interfere with its efficacy in reducing cocaine's rewarding effects. The present study aimed at comparing the effects of baclofen with the GABA(B) -receptor positive allosteric modulator GS39783 on psychostimulant conditioned cues. Two identically trained groups of male Lister-Hooded rats were baselined on a new responding for a light stimulus previously paired with cocaine self-administration. One group was treated with the GABA(B) -receptor positive allosteric modulator GS39783 (0, 10, 30, 100 mg/kg, i.p.), the other with baclofen (0, 0.6, 1.25, 1.9, 2.5 mg/kg, i.p.). In another series of experiments, male Wistar rats received GS39783 (0, 10, 30, 100 mg/kg, i.p.) or baclofen (1.25 mg/kg) prior to the expression of a conditioned place preference (CPP) to amphetamine (2 mg/kg i.p.). Both GS39783 (30 and 100 mg/kg) and baclofen (2.5 mg/kg) significantly decreased responding for the cocaine cue; however, only GS39783 (30 mg/kg) reduced lever pressing responding without interfering with locomotor activity. Both GS39783 (30 and 100 mg/kg) and baclofen (1.25 mg/kg), significantly blocked the expression of amphetamine CPP without affecting locomotor activity. These findings suggest that GABA(B) positive allosteric modulators can modulate discrete and contextual psychostimulant conditioned stimuli in a manner dissociable from unwanted sedative effects and may offer a novel therapeutic approach to treat cravings and relapse to drug-taking triggered by stimuli associated with psychostimulant use.
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Urwyler S. Allosteric modulation of family C G-protein-coupled receptors: from molecular insights to therapeutic perspectives. Pharmacol Rev 2011; 63:59-126. [PMID: 21228259 DOI: 10.1124/pr.109.002501] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Allosteric receptor modulation is an attractive concept in drug targeting because it offers important potential advantages over conventional orthosteric agonism or antagonism. Allosteric ligands modulate receptor function by binding to a site distinct from the recognition site for the endogenous agonist. They often have no effect on their own and therefore act only in conjunction with physiological receptor activation. This article reviews the current status of allosteric modulation at family C G-protein coupled receptors in the light of their specific structural features on the one hand and current concepts in receptor theory on the other hand. Family C G-protein-coupled receptors are characterized by a large extracellular domain containing the orthosteric agonist binding site known as the "venus flytrap module" because of its bilobal structure and the dynamics of its activation mechanism. Mutational analysis and chimeric constructs have revealed that allosteric modulators of the calcium-sensing, metabotropic glutamate and GABA(B) receptors bind to the seven transmembrane domain, through which they modify signal transduction after receptor activation. This is in contrast to taste-enhancing molecules, which bind to different parts of sweet and umami receptors. The complexity of interactions between orthosteric and allosteric ligands is revealed by a number of adequate biochemical and electrophysiological assay systems. Many allosteric family C GPCR modulators show in vivo efficacy in behavioral models for a variety of clinical indications. The positive allosteric calcium sensing receptor modulator cinacalcet is the first drug of this type to enter the market and therefore provides proof of principle in humans.
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Affiliation(s)
- Stephan Urwyler
- Department of Chemistry and Biochemistry, University of Berne, P/A Weissensteinweg 3, CH-3303 Jegenstorf, Berne, Switzerland.
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Abstract
gamma-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the brain which acts through different receptor subtypes. Metabotropic GABA(B) receptors are widely distributed throughout the brain. Alterations in GABA signaling through pharmacological activation or deactivation of the GABA(B) receptor regulate behavior and brain reward processes. GABA(B) receptor agonists and, most recently, positive modulators have been found to inhibit the reinforcing effects of drugs of abuse, such as cocaine, amphetamine, nicotine, ethanol, and opiates. This converging evidence of the effects of GABA(B) compounds on the reinforcing properties of addictive drugs is based on behavioral studies that used a variety of procedures with relevance to reward processes and drug abuse liability, including intracranial self-stimulation, intravenous self-administration under both fixed- and progressive-ratio schedules of reinforcement, reinstatement, and conditioned place preference. GABA(B) receptor agonists and positive modulators block the reinforcing effects of drugs of abuse in these animal models. However, GABA(B) receptor agonists also have undesirable side-effects. GABA(B) receptor modulators have potential advantages as medications for drug addiction. These compounds have a better side-effect profile than GABA(B) agonists because they are devoid of intrinsic agonistic activity in the absence of GABA. They only exert their modulatory actions in concert with endogenous GABAergic activity. Thus, GABA(B) receptor positive modulators are promising therapeutics for the treatment of various aspects of dependence (e.g., initiation, maintenance, and relapse) on various drugs of abuse, such as cocaine, nicotine, heroin, and alcohol.
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Affiliation(s)
- Styliani Vlachou
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, California, USA
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Philip NS, Carpenter LL, Tyrka AR, Price LH. Nicotinic acetylcholine receptors and depression: a review of the preclinical and clinical literature. Psychopharmacology (Berl) 2010; 212:1-12. [PMID: 20614106 PMCID: PMC5316481 DOI: 10.1007/s00213-010-1932-6] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 06/21/2010] [Indexed: 12/11/2022]
Abstract
Many patients with depression fail to derive sufficient benefit from available treatment options, with up to a third never reaching remission despite multiple trials of appropriate treatment. Novel antidepressant agents are needed, and drugs targeting nicotinic acetylcholine receptors (nAChRs) appear to hold promise in this regard. nAChRs are involved in a variety of neurobiological systems implicated in the pathophysiology of depression. In addition to their role in cholinergic neurotransmission, they modulate dopamine function and influence inflammation and hypothalamic-pituitary-adrenal axis activity. Preclinical studies have suggested antidepressant-like effects of drugs targeting nAChRs, with the most consistent results observed with alpha4beta2 nAChR modulators such as varenicline and nonspecific nAChR antagonists such as mecamylamine. These agents appear to offer the most potential antidepressant-like efficacy when used in conjunction with other established antidepressant treatments. nAChR modulators also influence neural processes that appear to mediate the behavioral effects of antidepressants, such as hippocampal cell proliferation. Clinical evidence, while limited, shows preliminary efficacy for mecamylamine and varenicline. Taken together, the preclinical and clinical evidence suggests that drugs targeting nAChRs may represent an important new approach to the treatment of depression.
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Affiliation(s)
- Noah S Philip
- Butler Hospital, Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Providence, RI 02906, USA.
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Pin JP, Prézeau L. Allosteric modulators of GABA(B) receptors: mechanism of action and therapeutic perspective. Curr Neuropharmacol 2010; 5:195-201. [PMID: 19305802 PMCID: PMC2656813 DOI: 10.2174/157015907781695919] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Accepted: 04/05/2007] [Indexed: 12/19/2022] Open
Abstract
γ-aminobutyric acid (GABA) plays important roles in the central nervous system, acting as a neurotransmitter on both ionotropic ligand-gated Cl--channels, and metabotropic G-protein coupled receptors (GPCRs). These two types of receptors called GABAA (and C) and GABAB are the targets of major therapeutic drugs such as the anxiolytic benzodiazepines, and antispastic drug baclofen (lioresal®), respectively. Although the multiplicity of GABAA receptors offer a number of possibilities to discover new and more selective drugs, the molecular characterization of the GABAB receptor revealed a unique, though complex, heterodimeric GPCR. High throughput screening strategies carried out in pharmaceutical industries, helped identifying new compounds positively modulating the activity of the GABAB receptor. These molecules, almost devoid of apparent activity when applied alone, greatly enhance both the potency and efficacy of GABAB agonists. As such, in contrast to baclofen that constantly activates the receptor everywhere in the brain, these positive allosteric modulators induce a large increase in GABAB-mediated responses only WHERE and WHEN physiologically needed. Such compounds are then well adapted to help GABA to activate its GABAB receptors, like benzodiazepines favor GABAA receptor activation. In this review, the way of action of these molecules will be presented in light of our actual knowledge of the activation mechanism of the GABAB receptor. We will then show that, as expected, these molecules have more pronounced in vivo responses and less side effects than pure agonists, offering new potential therapeutic applications for this new class of GABAB ligands.
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Slattery DA, Neumann ID. Oxytocin and Major Depressive Disorder: Experimental and Clinical Evidence for Links to Aetiology and Possible Treatment. Pharmaceuticals (Basel) 2010; 3:702-724. [PMID: 27713275 PMCID: PMC4033976 DOI: 10.3390/ph3030702] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Revised: 02/24/2010] [Accepted: 03/05/2010] [Indexed: 11/16/2022] Open
Abstract
Affective disorders represent the most common psychiatric diseases, with substantial co-morbidity existing between major depressive disorders (MDD) and anxiety disorders. The lack of truly novel acting compounds has led to non-monoaminergic based research and hypotheses in recent years. The large number of brain neuropeptides, characterized by discrete synthesis sites and multiple receptors, represent likely research candidates for novel therapeutic targets. The present review summarises the available preclinical and human evidence regarding the neuropeptide, oxytocin, and its implications in the aetiology and treatment of MDD. While the evidence is not conclusive at present additional studies are warranted to determine whether OXT may be of therapeutic benefit in subsets of MDD patients such as those with comorbid anxiety symptoms and low levels of social attachment.
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Affiliation(s)
- David A Slattery
- Department of Behavioural and Molecular Neuroendocrinology, University of Regensburg, Universitätsstr 31, Regensburg D-93053, Germany.
| | - Inga D Neumann
- Department of Behavioural and Molecular Neuroendocrinology, University of Regensburg, Universitätsstr 31, Regensburg D-93053, Germany
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