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Martínez-Clemente J, López-Arnau R, Abad S, Pubill D, Escubedo E, Camarasa J. Dose and time-dependent selective neurotoxicity induced by mephedrone in mice. PLoS One 2014; 9:e99002. [PMID: 24892744 PMCID: PMC4043985 DOI: 10.1371/journal.pone.0099002] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 05/08/2014] [Indexed: 11/18/2022] Open
Abstract
Mephedrone is a drug of abuse marketed as 'bath salts". There are discrepancies concerning its long-term effects. We have investigated the neurotoxicity of mephedrone in mice following different exposition schedules. Schedule 1: four doses of 50 mg/kg. Schedule 2: four doses of 25 mg/kg. Schedule 3: three daily doses of 25 mg/kg, for two consecutive days. All schedules induced, in some animals, an aggressive behavior and hyperthermia as well as a decrease in weight gain. Mephedrone (schedule 1) induced dopaminergic and serotoninergic neurotoxicity that persisted 7 days after exposition. At a lower dose (schedule 2) only a transient dopaminergic injury was found. In the weekend consumption pattern (schedule 3), mephedrone induced dopamine and serotonin transporter loss that was accompanied by a decrease in tyrosine hydroxylase and tryptophan hydroxylase 2 expression one week after exposition. Also, mephedrone induced a depressive-like behavior, as well as a reduction in striatal D2 density, suggesting higher susceptibility to addictive drugs. In cultured cortical neurons, mephedrone induced a concentration-dependent cytotoxic effect. Using repeated doses for 2 days in an elevated ambient temperature we evidenced a loss of frontal cortex dopaminergic and hippocampal serotoninergic neuronal markers that suggest injuries at nerve endings.
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Affiliation(s)
- José Martínez-Clemente
- Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section) and Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona, Barcelona, Spain
| | - Raúl López-Arnau
- Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section) and Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona, Barcelona, Spain
| | - Sonia Abad
- Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section) and Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona, Barcelona, Spain
| | - David Pubill
- Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section) and Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona, Barcelona, Spain
| | - Elena Escubedo
- Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section) and Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona, Barcelona, Spain
- * E-mail:
| | - Jorge Camarasa
- Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section) and Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona, Barcelona, Spain
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Scahill L, Aman MG, Lecavalier L, Halladay AK, Bishop SL, Bodfish JW, Grondhuis S, Jones N, Horrigan JP, Cook EH, Handen BL, King BH, Pearson DA, McCracken JT, Sullivan KA, Dawson G. Measuring repetitive behaviors as a treatment endpoint in youth with autism spectrum disorder. AUTISM : THE INTERNATIONAL JOURNAL OF RESEARCH AND PRACTICE 2013; 19:38-52. [DOI: 10.1177/1362361313510069] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Restricted interests and repetitive behaviors vary widely in type, frequency, and intensity among children and adolescents with autism spectrum disorder. They can be stigmatizing and interfere with more constructive activities. Accordingly, restricted interests and repetitive behaviors may be a target of intervention. Several standardized instruments have been developed to assess restricted interests and repetitive behaviors in the autism spectrum disorder population, but the rigor of psychometric assessment is variable. This article evaluated the readiness of available measures for use as outcome measures in clinical trials. The Autism Speaks Foundation assembled a panel of experts to examine available instruments used to measure restricted interests and repetitive behaviors in youth with autism spectrum disorder. The panel held monthly conference calls and two face-to-face meetings over 14 months to develop and apply evaluative criteria for available instruments. Twenty-four instruments were evaluated and five were considered “appropriate with conditions” for use as outcome measures in clinical trials. Ideally, primary outcome measures should be relevant to the clinical target, be reliable and valid, and cover the symptom domain without being burdensome to subjects. The goal of the report was to promote consensus across funding agencies, pharmaceutical companies, and clinical investigators about advantages and disadvantages of existing outcome measures.
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German CL, Fleckenstein AE, Hanson GR. Bath salts and synthetic cathinones: an emerging designer drug phenomenon. Life Sci 2013; 97:2-8. [PMID: 23911668 DOI: 10.1016/j.lfs.2013.07.023] [Citation(s) in RCA: 271] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/17/2013] [Accepted: 07/19/2013] [Indexed: 11/18/2022]
Abstract
Synthetic cathinones are an emerging class of designer drugs abused for psychostimulant and hallucinogenic effects similar to cocaine, methylenedioxymethamphetamine (MDMA), or other amphetamines. Abuse of synthetic cathinones, frequently included in products sold as 'bath salts', became prevalent in early 2009, leading to legislative classification throughout Europe in 2010 and schedule I classification within the United States in 2011. Recent pre-clinical and clinical studies indicate that dysregulation of central monoamine systems is a principal mechanism of synthetic cathinone action and presumably underlie the behavioral effects and abuse liability associated with these drugs. This review provides insight into the development of synthetic cathinones as substances of abuse, current patterns of their abuse, known mechanisms of their action and toxicology, and the benefits and drawbacks of their classification.
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Affiliation(s)
- Christopher L German
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT 84112, USA.
| | - Annette E Fleckenstein
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Glen R Hanson
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT 84112, USA
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Fantegrossi WE, Gannon BM, Zimmerman SM, Rice KC. In vivo effects of abused 'bath salt' constituent 3,4-methylenedioxypyrovalerone (MDPV) in mice: drug discrimination, thermoregulation, and locomotor activity. Neuropsychopharmacology 2013; 38:563-73. [PMID: 23212455 PMCID: PMC3572465 DOI: 10.1038/npp.2012.233] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In recent years, synthetic analogues of naturally occurring cathinone have emerged as psychostimulant-like drugs of abuse in commercial 'bath salt' preparations. 3,4-Methylenedioxypyrovalerone (MDPV) is a common constituent of these illicit products, and its structural similarities to the more well-known drugs of abuse 3,4-methylenedioxymethamphetamine (MDMA), and methamphetamine (METH) suggest that it may have similar in vivo effects to these substances. In these studies, adult male NIH Swiss mice were trained to discriminate 0.3 mg/kg MDPV from saline, and the interoceptive effects of a range of substitution doses of MDPV, MDMA, and METH were then assessed. In separate groups of mice, surgically implanted radiotelemetry probes simultaneously monitored thermoregulatory and locomotor responses to various doses of MDPV and MDMA, as a function of ambient temperature. We found that mice reliably discriminated the MDPV training dose from saline and that cumulative doses of MDPV, MDMA, and METH fully substituted for the MDPV training stimulus. All three drugs had similar ED(50) values in this procedure. Stimulation of motor activity was observed following administration of a wide range of MDPV doses (1-30 mg/kg), and the warm ambient temperature potentiated motor activity and elicited profound stereotypy and self-injurious behavior at 30 mg/kg. In contrast, MDPV-induced hyperthermic effects were observed in only the warm ambient environment. This pattern of effects is in sharp contrast to MDMA, where ambient temperature interacts with thermoregulation, but not locomotor activity. These studies suggest that although the interoceptive effects of MDPV are similar to those of MDMA and METH, direct effects on thermoregulatory processes and locomotor activity are likely mediated by different mechanisms than those of MDMA.
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Affiliation(s)
- William E Fantegrossi
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Brenda M Gannon
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Sarah M Zimmerman
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Kenner C Rice
- Drug Design and Synthesis Section, Chemical Biology Research Branch, NIDA and NIAAA, Bethesda, MD, USA
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5
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Silverman JL, Smith DG, Sukoff Rizzo SJ, Karras MN, Turner SM, Tolu SS, Bryce DK, Smith DL, Fonseca K, Ring RH, Crawley JN. Negative allosteric modulation of the mGluR5 receptor reduces repetitive behaviors and rescues social deficits in mouse models of autism. Sci Transl Med 2012; 4:131ra51. [PMID: 22539775 PMCID: PMC4904784 DOI: 10.1126/scitranslmed.3003501] [Citation(s) in RCA: 200] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neurodevelopmental disorders such as autism and fragile X syndrome were long thought to be medically untreatable, on the assumption that brain dysfunctions were immutably hardwired before diagnosis. Recent revelations that many cases of autism are caused by mutations in genes that control the ongoing formation and maturation of synapses have challenged this dogma. Antagonists of metabotropic glutamate receptor subtype 5 (mGluR5), which modulate excitatory neurotransmission, are in clinical trials for fragile X syndrome, a major genetic cause of intellectual disabilities. About 30% of patients with fragile X syndrome meet the diagnostic criteria for autism. Reasoning by analogy, we considered the mGluR5 receptor as a potential target for intervention in autism. We used BTBR T+tf/J (BTBR) mice, an established model with robust behavioral phenotypes relevant to the three diagnostic behavioral symptoms of autism--unusual social interactions, impaired communication, and repetitive behaviors--to probe the efficacy of a selective negative allosteric modulator of the mGluR5 receptor, GRN-529. GRN-529 reduced repetitive behaviors in three cohorts of BTBR mice at doses that did not induce sedation in control assays of open field locomotion. In addition, the same nonsedating doses reduced the spontaneous stereotyped jumping that characterizes a second inbred strain of mice, C58/J. Further, GRN-529 partially reversed the striking lack of sociability in BTBR mice on some parameters of social approach and reciprocal social interactions. These findings raise the possibility that a single targeted pharmacological intervention may alleviate multiple diagnostic behavioral symptoms of autism.
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MESH Headings
- Animals
- Behavior, Animal/drug effects
- Blood-Brain Barrier/metabolism
- Brain/drug effects
- Brain/metabolism
- Brain/physiopathology
- Capillary Permeability
- Child Development Disorders, Pervasive/drug therapy
- Child Development Disorders, Pervasive/metabolism
- Child Development Disorders, Pervasive/physiopathology
- Child Development Disorders, Pervasive/psychology
- Child, Preschool
- Disease Models, Animal
- Excitatory Amino Acid Antagonists/blood
- Excitatory Amino Acid Antagonists/pharmacology
- Female
- Humans
- Male
- Mice
- Mice, Inbred C57BL
- Motor Activity/drug effects
- Receptor, Metabotropic Glutamate 5
- Receptors, Metabotropic Glutamate/antagonists & inhibitors
- Receptors, Metabotropic Glutamate/metabolism
- Sleep/drug effects
- Social Behavior
- Stereotyped Behavior
- Time Factors
- Video Recording
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Affiliation(s)
- Jill L. Silverman
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892–3730, USA
| | - Daniel G. Smith
- Pfizer Worldwide Research and Development, Groton, CT 06340, USA
| | | | - Michael N. Karras
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892–3730, USA
| | - Sarah M. Turner
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892–3730, USA
| | - Seda S. Tolu
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892–3730, USA
| | - Dianne K. Bryce
- Pfizer Worldwide Research and Development, Groton, CT 06340, USA
| | - Deborah L. Smith
- Pfizer Worldwide Research and Development, Groton, CT 06340, USA
| | - Kari Fonseca
- Pfizer Worldwide Research and Development, Groton, CT 06340, USA
| | - Robert H. Ring
- Pfizer Worldwide Research and Development, Groton, CT 06340, USA
| | - Jacqueline N. Crawley
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD 20892–3730, USA
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6
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Silverman JL, Tolu SS, Barkan CL, Crawley JN. Repetitive self-grooming behavior in the BTBR mouse model of autism is blocked by the mGluR5 antagonist MPEP. Neuropsychopharmacology 2010; 35:976-89. [PMID: 20032969 PMCID: PMC2827881 DOI: 10.1038/npp.2009.201] [Citation(s) in RCA: 320] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Autism is a neurodevelopmental disorder characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. BTBR T+tf/J (BTBR) is an inbred mouse strain that shows robust behavioral phenotypes with analogies to all three of the diagnostic symptoms of autism, including well-replicated deficits in reciprocal social interactions and social approach, unusual patterns of ultrasonic vocalization, and high levels of repetitive self-grooming. These phenotypes offer straightforward behavioral assays for translational investigations of pharmacological compounds. Two suggested treatments for autism were evaluated in the BTBR mouse model. Methyl-6-phenylethynyl-pyridine (MPEP), an antagonist of the mGluR5 metabotropic glutamate receptor, blocks aberrant phenotypes in the Fmr1 mouse model of Fragile X, a comorbid neurodevelopmental disorder with autistic features. Risperidone has been approved by the United States Food and Drug Administration for the treatment of irritability, tantrums, and self-injurious behavior in autistic individuals. We evaluated the actions of MPEP and risperidone on two BTBR phenotypes, low sociability and high repetitive self-grooming. Open field activity served as an independent control for non-social exploratory activity and motor functions. C57BL/6J (B6), an inbred strain with high sociability and low self-grooming, served as the strain control. MPEP significantly reduced repetitive self-grooming in BTBR, at doses that had no sedating effects on open field activity. Risperidone reduced repetitive self-grooming in BTBR, but only at doses that induced sedation in both strains. No overall improvements in sociability were detected in BTBR after treatment with either MPEP or risperidone. Our findings suggest that antagonists of mGluR5 receptors may have selective therapeutic efficacy in treating repetitive behaviors in autism.
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Affiliation(s)
- Jill L Silverman
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Porter Neuroscience Research Center, Bethesda, MD 20892, USA.
| | - Seda S Tolu
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Porter Neuroscience Research Center, Bethesda, MD, USA
| | - Charlotte L Barkan
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Porter Neuroscience Research Center, Bethesda, MD, USA
| | - Jacqueline N Crawley
- Laboratory of Behavioral Neuroscience, National Institute of Mental Health, Porter Neuroscience Research Center, Bethesda, MD, USA
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7
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Kuroda KO, Ornthanalai VG, Kato T, Murphy NP. FosB null mutant mice show enhanced methamphetamine neurotoxicity: potential involvement of FosB in intracellular feedback signaling and astroglial function. Neuropsychopharmacology 2010; 35:641-55. [PMID: 19890265 PMCID: PMC3055620 DOI: 10.1038/npp.2009.169] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Previous studies show that (1) two members of fos family transcription factors, c-Fos and FosB, are induced in frontal brain regions by methamphetamine; (2) null mutation of c-Fos exacerbates methamphetamine-induced neurotoxicity; and (3) null mutation of FosB enhances behavioral responses to cocaine. Here we sought a role of FosB in responses to methamphetamine by studying FosB null mutant (-/-) mice. After a 10 mg/kg methamphetamine injection, FosB(-/-) mice were more prone to self-injury. Concomitantly, the intracellular feedback regulators of Sprouty and Rad-Gem-Kir (RGK) family transcripts had lower expression profiles in the frontoparietal cortex and striatum of the FosB(-/-) mice. Three days after administration of four 10 mg/kg methamphetamine injections, the frontoparietal cortex and striatum of FosB(-/-) mice contained more degenerated neurons as determined by Fluoro-Jade B staining. The abundance of the small neutral amino acids, serine, alanine, and glycine, was lower and/or was poorly induced after methamphetamine administration in the frontoparietal cortex and striatum of FosB(-/-) mice. In addition, methamphetamine-treated FosB(-/-) frontoparietal and piriform cortices showed more extravasation of immunoglobulin, which is indicative of blood-brain barrier dysfunction. Methamphetamine-induced hyperthermia, brain dopamine content, and loss of tyrosine hydroxylase immunoreactivity in the striatum, however, were not different between genotypes. These data indicate that FosB is involved in thermoregulation-independent protective functions against methamphetamine neurotoxicity in postsynaptic neurons. Our findings suggest two possible mechanisms of FosB-mediated neuroprotection: one is induction of negative feedback regulation within postsynaptic neurons through Sprouty and RGK. Another is supporting astroglial function such as maintenance of the blood-brain barrier, and metabolism of serine and glycine, which are important glial modulators of nerve cells.
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Affiliation(s)
- Kumi O Kuroda
- Unit for Affiliative Social Behavior, RIKEN Brain Science Institute, Saitama, Japan.
| | | | - Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorder, RIKEN Brain Science Institute, Saitama, Japan
| | - Niall P Murphy
- Neuropathology Research Group, RIKEN Brain Science Institute, Saitama, Japan
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8
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Kita T, Miyazaki I, Asanuma M, Takeshima M, Wagner GC. Dopamine-Induced Behavioral Changes and Oxidative Stress in Methamphetamine-Induced Neurotoxicity. NEW CONCEPTS OF PSYCHOSTIMULANT INDUCED NEUROTOXICITY 2009; 88:43-64. [DOI: 10.1016/s0074-7742(09)88003-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Cope MB, Li X, Jumbo-Lucioni P, DiCostanzo CA, Jamison WG, Kesterson RA, Allison DB, Nagy TR. Risperidone alters food intake, core body temperature, and locomotor activity in mice. Physiol Behav 2008; 96:457-63. [PMID: 19084548 DOI: 10.1016/j.physbeh.2008.11.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 11/06/2008] [Accepted: 11/21/2008] [Indexed: 11/17/2022]
Abstract
Risperidone induces significant weight gain in female mice; however, the underlying mechanisms related to this effect are unknown. We investigated the effects of risperidone on locomotor activity, core body temperature, and uncoupling protein (UCP) and hypothalamic orexin mRNA expression. Female C57BL/6J mice were acclimated to individual housing and randomly assigned to either risperidone (4 mg/kg BW day) or placebo (PLA). Activity and body temperature were measured over 48-hour periods twice a week for 3 weeks. Food intake and body weights were measured weekly. UCP1 (BAT), UCP3 (gastrocnemius), and orexin (hypothalamus) mRNA expressions were measured using RT-PCR. Risperidone-treated mice consumed more food (p=0.050) and gained more weight (p=0.0001) than PLA-treated mice after 3 weeks. During the initial 2 days of treatment, there was an acute effect of treatment on activity (p=0.046), but not body temperature (p=0.290). During 3 weeks of treatment, average core body temperatures were higher in risperidone-treated mice compared to controls during the light phase (p=0.0001), and tended to be higher during the dark phase (p=0.057). Risperidone-treated mice exhibited lower activity levels than controls during the dark phase (p=0.006); there were no differences in activity during the light phase (p=0.47). UCP1 (p<0.01) and UCP3 (p<0.05) mRNA expressions were greater in risperidone-treated mice compared to controls, whereas, orexin mRNA expression was lower in risperidone-treated mice (p<0.01). These results suggest that risperidone-induced weight gain in mice is a consequence of increased energy intake and reduced activity, while the elevation in body temperature may be a result of thermogenic effect of food intake and elevated UCP1, UCP3, and a reduced hypothalamic orexin expression.
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Affiliation(s)
- Mark B Cope
- Department of Nutrition Sciences, University of Alabama at Birmingham, United States
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10
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Chun S, McEvilly R, Foster JA, Sakic B. Proclivity to self-injurious behavior in MRL-lpr mice: implications for autoimmunity-induced damage in the dopaminergic system. Mol Psychiatry 2008; 13:1043-53. [PMID: 17768421 DOI: 10.1038/sj.mp.4002078] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Systemic lupus erythematosus is frequently accompanied by psychiatric manifestations of unknown origin. Although damage of central neurons had been documented, little is known about neurotransmitter systems affected by the autoimmune/inflammatory process. Recent studies on lupus-prone MRL-lpr mice point to imbalanced dopamine function and neurodegeneration in dopamine-rich brain regions. We follow up on anecdotal observations of singly housed mice developing chest wounds. Compulsive grooming and/or skin biting accounted for open lesions, lending itself to the operational term 'self-injurious behavior' (SIB). Low incidence of spontaneous SIB increased significantly after repeated injections of dopamine-2/3 receptor (D2/D3R) agonist quinpirole (QNP). To further probe the dopaminergic circuitry and examine whether SIB is associated with development of lupus-like disease, we compared behavioral responses among cohorts that differed in the immune status. Two-week treatment with QNP (intraperitoneal, 0.5 mg kg(-1) body weight per day) induced SIB in 60% of diseased MRL-lpr mice, and exacerbated their splenomegaly. Although increased grooming and stereotypy were observed in less symptomatic MRL+/+ controls, only one mouse (10%) developed SIB. Similarly, SIB was not seen in young, asymptomatic groups despite dissimilar ambulatory responses to QNP. In situ hybridization revealed treatment-independent upregulation of D2R mRNA in substantia nigra of diseased MRL-lpr mice. The above results suggest that development of systemic autoimmunity alters sensitivity of the dopaminergic system and renders MRL-lpr mice prone to SIB. Although pathogenic factors were not examined, we hypothesize that immune and endocrine mechanisms jointly contribute to early neuronal damage, which underlies behavioral deficiency in the adulthood.
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Affiliation(s)
- S Chun
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
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11
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Muehlmann AM, Brown BD, Devine DP. Pemoline (2-amino-5-phenyl-1,3-oxazol-4-one)-induced self-injurious behavior: a rodent model of pharmacotherapeutic efficacy. J Pharmacol Exp Ther 2007; 324:214-23. [PMID: 17925479 DOI: 10.1124/jpet.107.128207] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Self-injury is a devastating, maladaptive behavior disorder that is common in developmental disabilities and is comorbid with numerous psychiatric disorders. Examples of self-injurious behavior (SIB) include head-banging, self-biting, and self-punching. The neurochemical basis of SIB is unknown; however, many different classes of drugs are prescribed (e.g., neuroleptics, atypical neuroleptics, anti-epileptics, opioid antagonists) to reduce these behaviors. These drugs have all shown clinically significant but limited efficacy in patient populations, and no class of drug is effective for all patients. The development and characterization of a valid animal model could provide important information regarding the neurochemical basis of SIB and could be used to screen potential new pharmacotherapies. In one model of SIB, high doses of pemoline (2-amino-5-phenyl-1,3-oxazol-4-one) are administered to rats. Using this model, we evaluated the effectiveness of three drugs (risperidone, valproate, and topiramate) that reduce SIB in humans. We also screened the potential effectiveness of tramadol, a drug that decreases stereotyped and compulsive behaviors but has not been assessed in human self-injurers. We found that risperidone, valproate, and topiramate each significantly attenuate pemoline-induced SIB, whereas tramadol does not. These findings suggest that the pemoline model of SIB has predictive validity across a range of drug classes and implicate important potential neurochemical mechanisms that may contribute to the behavior disorder. The findings also indicate that tramadol may not be an effective pharmacotherapy for SIB.
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Affiliation(s)
- Amber M Muehlmann
- University of Florida, Department of Psychology, P.O. Box 112250, Gainesville, FL 32611-2250, USA.
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12
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Wagner GC, Reuhl KR, Ming X, Halladay AK. Behavioral and neurochemical sensitization to amphetamine following early postnatal administration of methylmercury (MeHg). Neurotoxicology 2007; 28:59-66. [PMID: 16942796 DOI: 10.1016/j.neuro.2006.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Revised: 06/21/2006] [Accepted: 07/16/2006] [Indexed: 11/19/2022]
Abstract
Perinatal exposure to methylmercury (MeHg) in rodents has been linked to changes in sensitivity to dopaminergic agents later in life. In an effort to determine the behavioral and neurochemical response to the indirect dopaminergic and serotonergic agonist amphetamine following neonatal exposure to MeHg, male BALB/c mice were administered MeHg during critical periods of neural development and challenged with amphetamine as adults. Mice were observed 15, 30 and 60 min after a single amphetamine injection (7.5 mg/kg i.p.) for presence of stereotypic and self-injurious behaviors, abnormal posture, and hyperthermia. Mice treated with 2 or 4 mg/kg MeHg on alternate days 3-15 of life demonstrated an increase in body temperature and the appearance of stereotypic and self-injurious behaviors not observed when amphetamine was administered to either vehicle-exposed mice or those treated with an equivalent total amount of MeHg administered on postnatal days 13 and 15. Neurochemical analysis of MeHg- and vehicle-exposed mice challenged with amphetamine or saline revealed alterations in dopaminergic and serotonergic activity which corresponded to the sensitized behavioral response to amphetamine. These observations demonstrate a critical window for MeHg exposure affecting the later appearance of amphetamine-induced self-injurious behavior and support the hypothesis that early exposure to environmental neurotoxicants may predispose individuals to engage in aberrant, intrusive behaviors later in life.
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Affiliation(s)
- George C Wagner
- Department of Pharmacology and Toxicology, Rutgers University, New Brunswick, NJ 08854, United States.
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13
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McKerchar TL, Zarcone TJ, Fowler SC. Use of a force-plate actometer for detecting and quantifying vertical leaping induced by amphetamine in BALB/cJ mice, but not in C57BL/6J, DBA/2J, 129X1/SvJ, C3H/HeJ, and CD-1 mice. J Neurosci Methods 2005; 153:48-54. [PMID: 16290200 DOI: 10.1016/j.jneumeth.2005.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Revised: 10/03/2005] [Accepted: 10/05/2005] [Indexed: 11/30/2022]
Abstract
The force-plate actometer is a relatively new computer-based instrument with high temporal and spatial resolution that has been used to measure the behavioral effects of genetic restriction (e.g., inbred mice) and drugs (e.g., dopaminergic agonists and antagonists) on a variety of behaviors in rodents, including locomotor activity, stereotypies, tremor, and wall rearing. In the present study, the force-plate actometer was used to measure the differential effects of amphetamine-induced (10.0mg/kg) vertical leaping in five inbred mouse strains (BALB/cJ, C57BL/6J, DBA/2J, 129X1/SvJ, and C3H/HeJ) and one outbred stock (CD-1). Across a 13-day, five-injection procedure, mice of the BALB/cJ strain leaped an average of 82 times per 60-min session; the C57BL/6J, DBA/2J, 129X1/SvJ, C3H/HeJ strains and CD-1 stock always showed zero or near zero levels of vertical leaping following amphetamine treatment. The quantitative precision afforded by the force-plate actometer revealed that the mean duration of the leaps by the BALB/cJ strain was 0.18 second, and the corresponding peak force averaged 87.4 gram per leap, which was more than 400% of the average body weight of this strain. Although no evidence of behavioral sensitization was indicated for amphetamine's effects on vertical leaping, sensitization to amphetamine's effects on spatial confinement (i.e., bouts of low mobility) was observed in all mouse types. Results indicate that the force-plate actometer is an instrument well suited for detecting and quantifying both vertical leaping and collateral behaviors induced by amphetamine in mice.
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Affiliation(s)
- Todd L McKerchar
- Department of Applied Behavioral Science, University of Kansas, Lawrence, KS 66045-2505, USA
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Mori T, Ito S, Kita T, Sawaguchi T. Effects of dopamine- and serotonin-related compounds on methamphetamine-induced self-injurious behavior in mice. J Pharmacol Sci 2004; 96:459-64. [PMID: 15599099 DOI: 10.1254/jphs.fpj04040x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Methamphetamine induces hyperlocomotion, and high doses of methamphetamine induce self-injurious behavior (SIB) in rodents. It is well known that the monoaminergic system is involved in methamphetamine-induced behavior. However, the effects of dopamine- and serotonin (5-HT)-related compounds on high-dose methamphetamine-induced behavior have not been sufficiently clarified. Therefore, the present study was designed to investigate the effects of dopamine receptor antagonists and indirect 5-HT receptor agonists on high-dose methamphetamine-induced behavior in mice. Methamphetamine (20 mg/kg) initially increased locomotor activity. As the dosage increased, continuous SIB accompanied by a reduction in locomotor activity was observed. The hyperlocomotion and SIB induced by 20 mg/kg of methamphetamine was abolished by high doses of SCH23390 and haloperidol, indicating that the hyperlocomotion and SIB induced by high doses of methamphetamine are mediated by the activation of D1- and D2-receptors. Furthermore, haloperidol (0.1 mg/kg) potently increased locomotor activity in combination with 20 mg/kg methamphetamine. These results suggest that excess dopaminergic activation, especially activation of dopamine D2-receptors, may be involved in the decrease in locomotor activity induced by a high dose of methamphetamine. On the other hand, indirect 5-HT receptor agonists attenuated methamphetamine-induced SIB, suggesting that the stimulation of 5-HT receptors plays an important role in high-dose methamphetamine-induced SIB in mice.
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Affiliation(s)
- Tomohisa Mori
- Department of Legal Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
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