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El Nahla S, Abdul-Mughni A, Dessouki A, Hassan S. Effect of the Prenatal Exposure of Khat on the Skeleton of Developing Rabbit Embryo: Morphometric and Gross Anatomical Study. Fetal Pediatr Pathol 2022; 41:381-395. [PMID: 33026921 DOI: 10.1080/15513815.2020.1827319] [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: 10/23/2022]
Abstract
Background: Khat leaves are chewed by many people worldwide, mainly in Africa and the southwest Arabian peninsula. Materials and methods: 27 apparently healthy adult New Zealand rabbits (3 males & 24 females) of 2.5 ± 0.5 kg body weight were used in this work. The animals were divided into 4 groups (control, low, medium and high doses groups). The khat extract was administered orally during (8th -18th) day of gestation. The mothers were sacrificed on the 29th day of gestation. The skeletons of the fetuses were stained with Alizarin Red S and Alcian Blue. Results: Skeletal examination of the fetuses of treated dams showed several types of malformations and variations in all treated groups such as unossified phalanges, deformed sternum, completely unossified vertebral lamina and opened anterior and posterior fontanelles, and reduced length of limb long bones. Conclusion: These findings support the teratogenic effect of the khat on the developing rabbit fetus.
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Affiliation(s)
- Sanaa El Nahla
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia Egypt
| | - Aref Abdul-Mughni
- Department of Anatomy and Embryology, Faculty of Agriculture and Veterinary Medicine, Dhamar University, Dhamar Yemen
| | - Amina Dessouki
- Department of Pathology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia Egypt
| | - Said Hassan
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia Egypt
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Liao YH, Su YC, Huang YH, Chen H, Chan YH, Sun LH, Cherng CG, Kuo ITB, Yu L. Social disruption-induced stress pre-exposure aggravates, while the presence of conspecifics diminishes, acetic acid-induced writhing. Psychopharmacology (Berl) 2021; 238:2851-2865. [PMID: 34181036 DOI: 10.1007/s00213-021-05901-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 06/08/2021] [Indexed: 10/21/2022]
Abstract
RATIONALE AND OBJECTIVE This study was undertaken to assess the modulating effects of (1) pre-exposure to repeated social disruption and (2) group testing on writhing associated with visceral pain induced by intraperitoneal administration of acetic acid. MATERIALS AND METHODS Six consecutive days of social disruption were used to prime for stress, while group testing referred to 3 mouse cage-mates receiving the acetic acid-induced writhing test as a group. RESULTS Social disruption-induced stress-pre-exposed mice displayed a greater number acid-induced writhes compared to mice not receiving the pre-exposure. However, mice displayed fewer acid-induced writhes in a triad group vs. individually, suggesting group-mediated writhing-reducing effects. Likewise, group testing prevented the stress pre-exposure escalation in acid-induced writhes. Additional studies revealed that the stress-pre-exposed mice had increased expression in accumbal TRPV1 receptors. Systemic (0.25 mg/kg) and bilateral intra-accumbal (0.2 ng/0.2 µl/side) administration of SB366791, a TRPV1 receptor antagonist, reliably prevented the stress pre-exposure escalation in acid-induced writhing; SB366791 treatment alone did not affect acid-induced writhing, stress pre-exposure anxiety-like behavior, or the group testing effects. Furthermore, lower neuronal activation was found in the medial septal nucleus in group vs. individual tested mice. Intra-medial septum (0.2 µg/0.5 µl) infusion with bicuculline, a GABAA receptor antagonist, effectively prevented group-mediated writhing-reducing effects, but not individual acid-induced writhing effects. CONCLUSIONS These findings suggest that social disruption-induced stress pre-exposure may upregulate accumbal TRPV1 receptor expression and consequently aggravate acid-induced writhing. Group testing prevents such stress pre-exposure escalation of acid-induced writhing most likely by strengthening the GABAergic inhibition on local neural activity in the medial septum.
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Affiliation(s)
- Yi-Han Liao
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China
| | - Yi-Chi Su
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China
| | - Yu-Han Huang
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China
| | - Hao Chen
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China
| | - Ya-Hsuan Chan
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China
| | - Li-Han Sun
- Institute of Basic Medical Sciences, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China
| | - Chianfang G Cherng
- Education Center of Humanities and Social Sciences, National Yang Ming Chiao Tung University, Taipei, 112, Taiwan, Republic of China
| | - Ing-Tiau B Kuo
- Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, 600 Taiwan, Republic of China.
| | - Lung Yu
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China. .,Institute of Basic Medical Sciences, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China. .,Institute of Behavioral Medicine, National Cheng Kung University College of Medicine, Tainan, 701, Taiwan, Republic of China.
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3
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Takeichi T, Hori O, Hattori T, Kiryu K, Zuka M, Kitamura O. Pre-administration of low-dose methamphetamine enhances movement and neural activity after high-dose methamphetamine administration in the striatum. Neurosci Lett 2019; 703:119-124. [DOI: 10.1016/j.neulet.2019.03.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 11/24/2022]
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Bisagno V, Cadet JL. Expression of immediate early genes in brain reward circuitries: Differential regulation by psychostimulant and opioid drugs. Neurochem Int 2018; 124:10-18. [PMID: 30557593 DOI: 10.1016/j.neuint.2018.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/27/2018] [Accepted: 12/13/2018] [Indexed: 12/22/2022]
Abstract
Although some of the clinical manifestations of substance use disorders might be superficially similar, it is highly likely that different classes of abused drugs including opioids (heroin, morphine, and oxycodone, other opioids) and psychostimulants (cocaine and amphetamines) cause different neuroadaptations in various brain regions dependent in the distribution and concentration of their biochemical sites of actions. In fact, different molecular networks are indeed impacted by acute and chronic administration of addictive substances. Some of the genes whose expression is influenced by the administration of these substances are immediate-early genes (IEGs). IEGs include classes of low expression genes that can become very highly induced within seconds or minutes of activation by endogenous or exogenous stimuli. These IEGs might play important roles in activating target genes that regulate adaptations implicated in the behavioral manifestations diagnosed as addiction. Therefore, the purpose of this review is to provide an overview of recent data on the effects of psychostimulants and opioids on IEG expression in the brain. The review documents some contrasting effects of these classes of drugs on gene expression and indicates that further studies are necessary to identify the specific effects of each drug class when trying to predict clinical responses to therapeutic agents.
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Affiliation(s)
- Veronica Bisagno
- Instituto de Investigaciones Farmacológicas (ININFA-UBA-CONICET), Junín 956, piso 5, C1113, Buenos Aires, Argentina
| | - Jean Lud Cadet
- NIDA Intramural Program, Molecular Neuropsychiatry Research Branch, 251 Bayview Boulevard, Baltimore, MD, 21224, USA.
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Jacobskind JS, Rosinger ZJ, Gonzalez T, Zuloaga KL, Zuloaga DG. Chronic Methamphetamine Exposure Attenuates Neural Activation in Hypothalamic-Pituitary-Adrenal Axis-Associated Brain Regions in a Sex-specific Manner. Neuroscience 2018; 380:132-145. [PMID: 29679646 DOI: 10.1016/j.neuroscience.2018.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/16/2018] [Accepted: 04/09/2018] [Indexed: 12/15/2022]
Abstract
Sex differences in methamphetamine (MA) abuse and consequences of MA have been reported with females showing an increased addiction phenotype and withdrawal symptoms. One mechanism through which these effects might occur is via sex-specific alterations in the hypothalamic-pituitary-adrenal (HPA) axis and its associated brain regions. In this study, mice were administered MA (5 mg/kg) or saline for 10 consecutive days. During early withdrawal, anxiety-like behaviors were assessed in the open field, light/dark box, and elevated plus maze. At ten days of withdrawal, mice were injected with a final dose of MA (5 mg/kg) or saline. Chronic MA did not alter anxiety-like behaviors or corticosterone responses to a final dose of MA, although females showed elevated corticosterone responses compared to males. Chronic MA attenuated final MA-induced c-Fos in both sexes in the paraventricular hypothalamus (PVH), bed nucleus of the stria terminalis (BNST), cingulate cortex, central and basolateral amygdala. In CA1 and CA3 hippocampal areas, c-Fos attenuation by chronic MA occurred only in females. Within the PVH, final MA injection increased c-Fos to a greater extent in females compared to males regardless of prior MA exposure. Dual-labeling of c-Fos with glucocorticoid receptor revealed a specific attenuation of neural activation within this cell type in the PVH, central and basolateral amygdala, and BNST. Together these findings demonstrate that chronic MA can suppress subsequent activation of HPA axis-associated brain regions and cell phenotypes. Further, in select regions this reduction is sex-specific. These changes may contribute to reported sex differences in MA abuse patterns.
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Affiliation(s)
- Jason S Jacobskind
- University at Albany, Department of Psychology, Albany, NY 12222, United States
| | - Zachary J Rosinger
- University at Albany, Department of Psychology, Albany, NY 12222, United States
| | - Tiffany Gonzalez
- University at Albany, Department of Psychology, Albany, NY 12222, United States
| | - Kristen L Zuloaga
- Albany Medical College, Department of Neuroscience & Experimental Therapeutics, Albany, NY 12208, United States
| | - Damian G Zuloaga
- University at Albany, Department of Psychology, Albany, NY 12222, United States.
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Exposure to Far Infrared Ray Protects Methamphetamine-Induced Behavioral Sensitization in Glutathione Peroxidase-1 Knockout Mice via Attenuating Mitochondrial Burdens and Dopamine D1 Receptor Activation. Neurochem Res 2018; 43:1118-1135. [DOI: 10.1007/s11064-018-2528-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 04/06/2018] [Accepted: 04/12/2018] [Indexed: 01/09/2023]
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Abstract
Phenethylamine-induced hyperthermia can occur following exposure to several different types of illicit stimulants, such as amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine ("Molly"), synthetic cathinones ("bath salts"), and N-methoxybenyl ("NBOMe"), to name a few. Peripheral norepinephrine release mediated by these sympathomimetic agents induces a double-edged sword of heat accumulation through β-adrenoreceptor-dependent activation of uncoupling protein (UCP1 and 3)-regulated thermogenesis and loss of heat dissipation through α1-adrenoreceptor-mediated vasoconstriction. Additionally, thyroid hormones are important determinants of the capacity of thermogenesis induced by phenethylamines through the regulation of free fatty acid release and the transcriptional activation of a host of metabolic genes, including adrenergic receptors and mitochondrial uncoupling proteins. Here, we review the central and peripheral mechanistic "triggers" of phenethylamine-induced hyperthermia and outline potential pharmacologic interventions for managing phenethylamine-induced hyperthermia based on these recently discovered hyperthermia mediators.
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Baracz SJ, Parker LM, Suraev AS, Everett NA, Goodchild AK, McGregor IS, Cornish JL. Chronic Methamphetamine Self-Administration Dysregulates Oxytocin Plasma Levels and Oxytocin Receptor Fibre Density in the Nucleus Accumbens Core and Subthalamic Nucleus of the Rat. J Neuroendocrinol 2016; 28. [PMID: 26563756 DOI: 10.1111/jne.12337] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 10/14/2015] [Accepted: 11/07/2015] [Indexed: 01/18/2023]
Abstract
The neuropeptide oxytocin attenuates reward and abuse for the psychostimulant methamphetamine (METH). Recent findings have implicated the nucleus accumbens (NAc) core and subthalamic nucleus (STh) in oxytocin modulation of acute METH reward and relapse to METH-seeking behaviour. Surprisingly, the oxytocin receptor (OTR) is only modestly involved in both regions in oxytocin attenuation of METH-primed reinstatement. Coupled with the limited investigation of the role of the OTR in psychostimulant-induced behaviours, we primarily investigated whether there are cellular changes to the OTR in the NAc core and STh, as well as changes to oxytocin plasma levels, after chronic METH i.v. self-administration (IVSA) and after extinction of drug-taking. An additional aim was to examine whether changes to central corticotrophin-releasing factor (CRF) and plasma corticosterone levels were also apparent because of the interaction of oxytocin with stress-regulatory mechanisms. Male Sprague-Dawley rats were trained to lever press for i.v. METH (0.1 mg/kg/infusion) under a fixed-ratio 1 schedule or received yoked saline infusions during 2-h sessions for 20 days. An additional cohort of rats underwent behavioural extinction for 15 days after METH IVSA. Subsequent to the last day of IVSA or extinction, blood plasma was collected for enzyme immunoassay, and immunofluorescence was conducted on NAc core and STh coronal sections. Rats that self-administered METH had higher oxytocin plasma levels, and decreased OTR-immunoreactive (-IR) fibres in the NAc core than yoked controls. In animals that self-administered METH and underwent extinction, oxytocin plasma levels remained elevated, OTR-IR fibre density increased in the STh, and a trend towards normalisation of OTR-IR fibre density was evident in the NAc core. CRF-IR fibre density in both brain regions and corticosterone plasma levels did not change across treatment groups. These findings demonstrate that oxytocin systems, both centrally within the NAc core and STh, as well as peripherally through plasma measures, are dysregulated after METH abuse.
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Affiliation(s)
- S J Baracz
- Department of Psychology, Macquarie University, North Ryde, NSW, Australia
- School of Psychology, University of Sydney, Sydney, NSW, Australia
| | - L M Parker
- Australian School of Advanced Medicine, Macquarie University, North Ryde, NSW, Australia
- ARC Center of Excellence for Nanoscale BioPhotonics, Macquarie University, North Ryde, NSW, Australia
| | - A S Suraev
- School of Psychology, University of Sydney, Sydney, NSW, Australia
| | - N A Everett
- Department of Psychology, Macquarie University, North Ryde, NSW, Australia
| | - A K Goodchild
- Australian School of Advanced Medicine, Macquarie University, North Ryde, NSW, Australia
| | - I S McGregor
- School of Psychology, University of Sydney, Sydney, NSW, Australia
| | - J L Cornish
- Department of Psychology, Macquarie University, North Ryde, NSW, Australia
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Moratalla R, Khairnar A, Simola N, Granado N, García-Montes JR, Porceddu PF, Tizabi Y, Costa G, Morelli M. Amphetamine-related drugs neurotoxicity in humans and in experimental animals: Main mechanisms. Prog Neurobiol 2015; 155:149-170. [PMID: 26455459 DOI: 10.1016/j.pneurobio.2015.09.011] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 09/04/2015] [Accepted: 09/15/2015] [Indexed: 12/13/2022]
Abstract
Amphetamine-related drugs, such as 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine (METH), are popular recreational psychostimulants. Several preclinical studies have demonstrated that, besides having the potential for abuse, amphetamine-related drugs may also elicit neurotoxic and neuroinflammatory effects. The neurotoxic potentials of MDMA and METH to dopaminergic and serotonergic neurons have been clearly demonstrated in both rodents and non-human primates. This review summarizes the species-specific cellular and molecular mechanisms involved in MDMA and METH-mediated neurotoxic and neuroinflammatory effects, along with the most important behavioral changes elicited by these substances in experimental animals and humans. Emphasis is placed on the neuropsychological and neurological consequences associated with the neuronal damage. Moreover, we point out the gap in our knowledge and the need for developing appropriate therapeutic strategies to manage the neurological problems associated with amphetamine-related drug abuse.
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Affiliation(s)
- Rosario Moratalla
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, CSIC, Madrid, Spain; CIBERNED, ISCIII, Madrid, Spain.
| | - Amit Khairnar
- Applied Neuroscience Research Group, CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Nicola Simola
- Department of Biomedical Sciences, Section of Neuropsychopharmacology, University of Cagliari, Via Ospedale 72, 09124 Cagliari, Italy
| | - Noelia Granado
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, CSIC, Madrid, Spain; CIBERNED, ISCIII, Madrid, Spain
| | - Jose Ruben García-Montes
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, CSIC, Madrid, Spain; CIBERNED, ISCIII, Madrid, Spain
| | - Pier Francesca Porceddu
- Department of Biomedical Sciences, Section of Neuropsychopharmacology, University of Cagliari, Via Ospedale 72, 09124 Cagliari, Italy
| | - Yousef Tizabi
- Department of Pharmacology, Howard University College of Medicine, Washington, DC, USA
| | - Giulia Costa
- Department of Biomedical Sciences, Section of Neuropsychopharmacology, University of Cagliari, Via Ospedale 72, 09124 Cagliari, Italy
| | - Micaela Morelli
- Department of Biomedical Sciences, Section of Neuropsychopharmacology, University of Cagliari, Via Ospedale 72, 09124 Cagliari, Italy; Centre of Excellence for Neurobiology of Dependence, University of Cagliari, Cagliari, Italy; National Research Council (CNR), Institute of Neuroscience, Cagliari, Italy
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Phillips TJ, Shabani S. An animal model of differential genetic risk for methamphetamine intake. Front Neurosci 2015; 9:327. [PMID: 26441502 PMCID: PMC4585292 DOI: 10.3389/fnins.2015.00327] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/31/2015] [Indexed: 11/13/2022] Open
Abstract
The question of whether genetic factors contribute to risk for methamphetamine (MA) use and dependence has not been intensively investigated. Compared to human populations, genetic animal models offer the advantages of control over genetic family history and drug exposure. Using selective breeding, we created lines of mice that differ in genetic risk for voluntary MA intake and identified the chromosomal addresses of contributory genes. A quantitative trait locus was identified on chromosome 10 that accounts for more than 50% of the genetic variance in MA intake in the selected mouse lines. In addition, behavioral and physiological screening identified differences corresponding with risk for MA intake that have generated hypotheses that are testable in humans. Heightened sensitivity to aversive and certain physiological effects of MA, such as MA-induced reduction in body temperature, are hallmarks of mice bred for low MA intake. Furthermore, unlike MA-avoiding mice, MA-preferring mice are sensitive to rewarding and reinforcing MA effects, and to MA-induced increases in brain extracellular dopamine levels. Gene expression analyses implicate the importance of a network enriched in transcription factor genes, some of which regulate the mu opioid receptor gene, Oprm1, in risk for MA use. Neuroimmune factors appear to play a role in differential response to MA between the mice bred for high and low intake. In addition, chromosome 10 candidate gene studies provide strong support for a trace amine-associated receptor 1 gene, Taar1, polymorphism in risk for MA intake. MA is a trace amine-associated receptor 1 (TAAR1) agonist, and a non-functional Taar1 allele segregates with high MA consumption. Thus, reduced TAAR1 function has the potential to increase risk for MA use. Overall, existing findings support the MA drinking lines as a powerful model for identifying genetic factors involved in determining risk for harmful MA use. Future directions include the development of a binge model of MA intake, examining the effect of withdrawal from chronic MA on MA intake, and studying potential Taar1 gene × gene and gene × environment interactions. These and other studies are intended to improve our genetic model with regard to its translational value to human addiction.
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Affiliation(s)
- Tamara J Phillips
- VA Portland Health Care System Portland, OR, USA ; Department of Behavioral Neuroscience and Methamphetamine Abuse Research Center, Oregon Health & Science University Portland, OR, USA
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Zuloaga DG, Jacobskind JS, Jacosbskind JS, Raber J. Methamphetamine and the hypothalamic-pituitary-adrenal axis. Front Neurosci 2015; 9:178. [PMID: 26074755 PMCID: PMC4444766 DOI: 10.3389/fnins.2015.00178] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 05/03/2015] [Indexed: 01/22/2023] Open
Abstract
Psychostimulants such as methamphetamine (MA) induce significant alterations in the function of the hypothalamic-pituitary-adrenal (HPA) axis. These changes in HPA axis function are associated with altered stress-related behaviors and might contribute to addictive processes such as relapse. In this mini-review we discuss acute and chronic effects of MA (adult and developmental exposure) on the HPA axis, including effects on HPA axis associated genes/proteins, brain regions, and behaviors such as anxiety and depression. A better understanding of the mechanisms through which MA affects the HPA axis may lead to more effective treatment strategies for MA addiction.
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Affiliation(s)
| | | | | | - Jacob Raber
- Departments of Behavioral Neuroscience, Neurology, and Radiation Medicine, Oregon Health and Science University Portland Portland, OR, USA ; Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University Portland Portland, OR, USA
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Stress hormone exposure reduces mGluR5 expression in the nucleus accumbens: functional implications for interoceptive sensitivity to alcohol. Neuropsychopharmacology 2014; 39:2376-86. [PMID: 24713611 PMCID: PMC4138747 DOI: 10.1038/npp.2014.85] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 03/11/2014] [Accepted: 04/02/2014] [Indexed: 12/19/2022]
Abstract
Escalations in alcohol drinking associated with experiencing stressful life events and chronic life stressors may be related to altered sensitivity to the interoceptive/subjective effects of alcohol. Indeed, through the use of drug discrimination methods, rats show decreased sensitivity to the discriminative stimulus (interoceptive) effects of alcohol following exposure to the stress hormone corticosterone (CORT). This exposure produces heightened elevations in plasma CORT levels (eg, as may be experienced by an individual during stressful episodes). We hypothesized that decreased sensitivity to alcohol may be related, in part, to changes in metabotropic glutamate receptors-subtype 5 (mGluR5) in the nucleus accumbens, as these receptors in this brain region are known to regulate the discriminative stimulus effects of alcohol. In the accumbens, we found reduced mGluR5 expression (immunohistochemistry and Western blot) and decreased neural activation (as measured by c-Fos immunohistochemistry) in response to a moderate alcohol dose (1 g/kg) following CORT exposure (7 days). The functional role of these CORT-induced adaptations in relation to the discriminative stimulus effects of alcohol was confirmed, as both the systemic administration of 3-Cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB) an mGluR5 positive allosteric modulator and the intra-accumbens administration of (R,S)-2-Amino-2-(2-chloro-5-hydroxyphenyl)acetic acid sodium salt (CHPG) an mGluR5 agonist restored sensitivity to alcohol in discrimination-trained rats. These results suggest that activation of mGluR5 may alleviate the functional impact of the CORT-induced downregulation of mGluR5 in relation to sensitivity to alcohol. Understanding the contribution of such neuroadaptations to the interoceptive effects of alcohol may enrich our understanding of potential changes in subjective sensitivity to alcohol during stressful episodes.
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Tomita M, Katsuyama H, Watanabe Y, Okuyama T, Fushimi S, Ishikawa T, Nata M, Miyamoto O. Does methamphetamine affect bone metabolism? Toxicology 2014; 319:63-8. [DOI: 10.1016/j.tox.2014.01.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 12/26/2013] [Accepted: 01/26/2014] [Indexed: 01/27/2023]
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