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McCunn P, Chen X, Gimi B, Green AI, Khokhar JY. Glutamine and GABA alterations in cingulate cortex may underlie alcohol drinking in a rat model of co-occurring alcohol use disorder and schizophrenia: an 1H-MRS study. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2022; 8:67. [PMID: 35999232 PMCID: PMC9399110 DOI: 10.1038/s41537-022-00272-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Alcohol use disorder commonly occurs in patients with schizophrenia and significantly worsens the clinical course of the disorder. The neurobiological underpinnings of alcohol drinking are not well understood. Magnetic resonance spectroscopy (MRS) has been used to assess the neurochemical substrates that may be associated with alcohol drinking in patients; however, the causal impact of these findings remains elusive, highlighting the need for studies in animal models. This study performed MRS in the neonatal ventral hippocampal lesioned (NVHL) rat model, a model of co-occurring schizophrenia and substance use disorders. NVHL lesions (or sham surgeries) were performed on post-natal day 7 and animals were given brief exposure to alcohol during adolescence (10% v/v in a 2-bottle choice design). Animals were re-exposed to alcohol during adulthood (20% v/v) until a stable drinking baseline was established, and then forced into abstinence to control for the effects of differential alcohol drinking. Animals were scanned for MRS after one month of abstinence. NVHL rats consumed significantly more alcohol than sham rats and in the cingulate cortex showed significantly higher levels of GABA and glutamine. Significantly lower GABA levels were observed in the nucleus accumbens. No differences between the NVHL and sham animals were observed in the hippocampus. Correlation analysis revealed that GABA and glutamine concentrations in the cingulate cortex significantly correlated with the rats' alcohol drinking prior to 30 days of forced abstinence. These findings suggest that a potential dysfunction in the glutamate/GABA-glutamine cycle may contribute to alcohol drinking in a rat model of schizophrenia, and this dysfunction could be targeted in future treatment-focused studies.
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Affiliation(s)
- Patrick McCunn
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - Xi Chen
- Department of Radiology, Biomedical NMR Research Center, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
- Psychotic Disorders Division, McLean Hospital, Belmont, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Barjor Gimi
- Department of Radiology, Biomedical NMR Research Center, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
| | - Alan I Green
- Department of Psychiatry, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
| | - Jibran Y Khokhar
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.
- Department of Psychiatry, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
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Monroy-Jaramillo N, Martínez-Magaña JJ, Pérez-Aldana BE, Ortega-Vázquez A, Montalvo-Ortiz J, López-López M. The role of alcohol intake in the pharmacogenetics of treatment with clozapine. Pharmacogenomics 2022; 23:371-392. [PMID: 35311547 DOI: 10.2217/pgs-2022-0006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Clozapine (CLZ) is an atypical antipsychotic reserved for patients with refractory psychosis, but it is associated with a significant risk of severe adverse reactions (ADRs) that are potentiated with the concomitant use of alcohol. Additionally, pharmacogenetic studies have explored the influence of several genetic variants in CYP450, receptors and transporters involved in the interindividual response to CLZ. Herein, we systematically review the current multiomics knowledge behind the interaction between CLZ and alcohol intake, and how its concomitant use might modulate the pharmacogenetics. CYP1A2*1F, *1C and other alleles not yet discovered could support a precision medicine approach for better therapeutic effects and fewer CLZ ADRs. CLZ monitoring systems should be amended and include alcohol intake to protect patients from severe CLZ ADRs.
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Affiliation(s)
- Nancy Monroy-Jaramillo
- Department of Genetics, National Institute of Neurology & Neurosurgery, Manuel Velasco Suárez, La Fama, Tlalpan, Mexico City, 14269, Mexico
| | - José Jaime Martínez-Magaña
- Department of Psychiatry, Division of Human Genetics, Yale University School of Medicine, Orange, West Haven, CT 06477, USA
| | - Blanca Estela Pérez-Aldana
- Doctorado en Ciencias Biológicas y de la Salud, Metropolitan Autonomous University, Campus Xochimilco, Villa Quietud, Coyoacán, Mexico City, 04960, Mexico
| | - Alberto Ortega-Vázquez
- Metropolitan Autonomous University, Campus Xochimilco, Villa Quietud, Coyoacán, Mexico City, 04960, Mexico
| | - Janitza Montalvo-Ortiz
- Department of Psychiatry, Division of Human Genetics, Yale University School of Medicine, Orange, West Haven, CT 06477, USA
| | - Marisol López-López
- Metropolitan Autonomous University, Campus Xochimilco, Villa Quietud, Coyoacán, Mexico City, 04960, Mexico
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Idazoxan and Efaroxan Potentiate the Endurance Performances and the Antioxidant Activity of Ephedrine in Rats. ACTA ACUST UNITED AC 2021; 57:medicina57030194. [PMID: 33668888 PMCID: PMC7996498 DOI: 10.3390/medicina57030194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 12/19/2022]
Abstract
Background and objectives: The connections between the imidazoline system and multiple other neurotransmitter systems in the brain (adrenergic, dopaminergic, serotoninergic, glutamatergic, opioid) indicate the complexity of the mechanisms underlying motor activity and behavior. The aim of the present research was to investigate the effects of the combination of ephedrine (EPD) and imidazoline antagonists idazoxan (IDZ) and efaroxan (EFR) on the endurance performance in the treadmill test in rats. Materials and Methods: We used Wistar rats distributed as follows: Group 1 (Control) receiving distilled water 0.3 mL/100 g body weight; Group 2 (EPD) receiving 20 mg/kg ephedrine; Group 3 (EPD + IDZ) receiving 20 mg/kg ephedrine + 3 mg/kg idazoxan; Group 4 (EPD + EFR) receiving 20 mg/kg ephedrine + 1 mg/kg efaroxan. An additional group (C) of animals receiving 0.3 mL/100 g body weight distilled water (but not subjected to effort) was used. Endurance capacity was evaluated using a treadmill running PanLAB assay. The evaluation of the substances’ influence on oxidative stress was performed by spectrophotometric determination of superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity. Results: Treatment with EPD-IDZ and EPD-EFR were correlated with a longer distance traveled on the belt and with a decrease in the necessary electric shocks to motivate the animal to continue running in the forced locomotion test. Additionally, an increase in the activity of antioxidant enzymes was found. Conclusions: Idazoxan and efaroxan potentiated the physical effort-related effects of ephedrine with regard to endurance capacity and antioxidant activity in rats.
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Khokhar JY, Todd TP. Behavioral predictors of alcohol drinking in a neurodevelopmental rat model of schizophrenia and co-occurring alcohol use disorder. Schizophr Res 2018; 194:91-97. [PMID: 28285734 PMCID: PMC5591749 DOI: 10.1016/j.schres.2017.02.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/24/2017] [Accepted: 02/27/2017] [Indexed: 12/31/2022]
Abstract
Alcohol use disorder commonly occurs in patients with schizophrenia and contributes greatly to its morbidity. Unfortunately, the neural and behavioral underpinnings of alcohol drinking in these patients are not well understood. In order to begin to understand the cognitive and reward-related changes that may contribute to alcohol drinking, this study was designed to address: 1) latent inhibition; 2) conditioning; and 3) extinction of autoshaping in a neurodevelopmental rat model with relevance to co-occurring schizophrenia and alcohol use disorders, the neonatal ventral hippocampal lesioned (NVHL) rat. NVHL lesions (or sham surgeries) were performed on post-natal day 7 (PND7) and animals were given brief exposure to alcohol during adolescent (PND 28-42). Latent inhibition of autoshaping, conditioning and extinction were assessed between PND 72-90. On PND90 animals were given alcohol again and allowed to establish stable drinking. Latent inhibition of autoshaping was found to be prolonged in the NVHL rats; the NVHL rats pre-exposed to the lever stimulus were slower to acquire autoshaping than sham pre-exposed rats. NVHL rats that were not pre-exposed to the lever stimulus did not differ during conditioning, but were slower to extinguish conditioned responding compared to sham controls. Finally, the NVHL rats from both groups drank significantly more alcohol than sham rats, and the extent of latent inhibition predicted future alcohol intake in the pre-exposed animals. These findings suggest that the latent inhibition of autoshaping procedure can be used to model cognitive- and reward-related dysfunctions in schizophrenia, and these dysfunctions may contribute to the development of co-occurring alcohol use.
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Affiliation(s)
- Jibran Y Khokhar
- Department of Psychiatry, Geisel School of Medicine at Dartmouth, United States.
| | - Travis P Todd
- Department of Psychological and Brain Sciences, Dartmouth College, United States
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Khokhar JY, Henricks AM, Sullivan EDK, Green AI. Unique Effects of Clozapine: A Pharmacological Perspective. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2018; 82:137-162. [PMID: 29413518 DOI: 10.1016/bs.apha.2017.09.009] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Schizophrenia is a heterogenous and severe neuropsychiatric disorder that affects nearly 1% of the population worldwide. Antipsychotic drugs are the mainstay of treatment, but not all patients with schizophrenia respond to treatment with these agents. Clozapine, the first atypical antipsychotic, is a highly effective medication for patients with schizophrenia who do not respond to other antipsychotics. Although clozapine tends not to produce extrapyramidal symptoms, other side effects of the drug (e.g., agranulocytosis, myocarditis, seizures) limit its widespread use. This chapter reviews clozapine's unique clinical effects and unusual pharmacological profile. In addition to its effects in treatment-resistant schizophrenia, clozapine has been shown to decrease suicidality, which occurs at an increased rate in patients with schizophrenia. Still preliminary, but consistent data, also suggest that clozapine limits substance use in these patients, an important effect since substance use disorders are common in patients with schizophrenia and are associated with a poor outcome, including an increased risk for suicide and poor response to treatment. We have suggested, from animal studies, that clozapine's apparent ability to limit substance use may occur through its actions as a weak dopamine D2 receptor antagonist, a potent norepinephrine α-2 receptor antagonist and a norepinephrine reuptake inhibitor. Using animal models, we have built combinations of agents toward creation of safer clozapine-like drugs to reduce substance use in these patients. Future research into the mechanisms of action of clozapine toward the development of safe clozapine-like agents is of great public health importance.
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Affiliation(s)
- Jibran Y Khokhar
- Geisel School of Medicine at Dartmouth, Hanover, NH, United States; Dartmouth Clinical and Translational Science Institute, Dartmouth College, Hanover, NH, United States
| | - Angela M Henricks
- Geisel School of Medicine at Dartmouth, Hanover, NH, United States; Dartmouth Clinical and Translational Science Institute, Dartmouth College, Hanover, NH, United States
| | - Emily D K Sullivan
- Geisel School of Medicine at Dartmouth, Hanover, NH, United States; Dartmouth Clinical and Translational Science Institute, Dartmouth College, Hanover, NH, United States
| | - Alan I Green
- Geisel School of Medicine at Dartmouth, Hanover, NH, United States; Dartmouth Clinical and Translational Science Institute, Dartmouth College, Hanover, NH, United States.
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Brunette MF, Akerman SC, Dawson R, O'Keefe CD, Green AI. An open-label pilot study of quetiapine plus mirtazapine for heavy drinkers with alcohol use disorder. Alcohol 2016; 53:45-50. [PMID: 27256763 DOI: 10.1016/j.alcohol.2016.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 02/26/2016] [Accepted: 02/26/2016] [Indexed: 01/03/2023]
Abstract
Animal research suggests that medications that produce a weak dopamine D2 receptor blockade and potentiate noradrenergic activity may decrease alcohol drinking. In an open-label pilot study of subjects with alcohol dependence, we tested whether the combination of quetiapine, a weak dopamine D2 receptor antagonist, whose primary metabolite, desalkylquetiapine, is a norepinephrine reuptake inhibitor, and mirtazapine, a potent α2 norepinephrine receptor antagonist, would decrease alcohol drinking and craving. Twenty very heavy drinkers with alcohol dependence entered a trial of 8 weeks of treatment with quetiapine followed by 8 weeks of treatment with a combination of quetiapine plus mirtazapine. Alcohol use was assessed weekly with a Timeline Follow-Back interview and craving with the Penn Alcohol Craving Scale. Among the 11 completers, subjects reported improved outcomes in the quetiapine plus mirtazapine period compared to the quetiapine alone period: fewer very heavy drinking days per week (1.3 [SD = 2.4] vs. 2.1 [SD = 2.8]; t = 2.3, df = 10, p = 0.04); fewer total number of drinks per week (39.7 [SD = 61.6] vs. 53.4 [SD = 65.0]; t = 2.8, df = 10, p = 0.02); and lower craving scores (2.5 [SD = 1.4] vs. 3.2 [SD = 1.2]; t = 2.4, df = 10, p = 0.04). All subjects reported at least one adverse event; 72.7% reported somnolence. In this open-label pilot study, treatment with quetiapine plus mirtazapine was associated with a decrease in alcohol drinking and craving. These findings are consistent with our previous work in animal models of alcohol use disorders and suggest that further study of medications or combinations of medications with this pharmacologic profile is warranted.
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