1
|
Yeh SHH, Kuo YY, Huang WS, Chiu CH, Yu TH, II LGF, Tsai CJ, Cheng CY, Ma KH. Preliminary Results on the Long-Term Effects of Dextromethorphan on MDMA-Mediated Serotonergic Deficiency and Volumetric Changes in Primates Based on 4-[18F]-ADAM PET/MRI. Front Neurosci 2022; 16:837194. [PMID: 35692422 PMCID: PMC9175743 DOI: 10.3389/fnins.2022.837194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/26/2022] [Indexed: 11/13/2022] Open
Abstract
Alterations to the serotonergic system due to 3,4-methylenedioxymethamphetamine (MDMA) (ecstasy) consumption have been extensively documented. However, knowledge of the reversibility of these neurotoxic effects based on in vivo evaluations of serotonin transport (SERT) availability remains limited. This study aimed to evaluate the long-term neurotoxicity of MDMA after 66 months abstinence and explored whether Dextromethorphan, a non-competitive N-methyl-D-aspartate (NMDA) receptor, could attenuate MDMA-induced neurotoxicity using 4-[18F]-ADAM, an imaging ligand that selectively targets SERT, with positron emission tomography technology (PET). Nine monkeys (Macaca cyclopis) were used in this study: control, MDMA, and DM + MDMA. Static 4-[18F]-ADAM PET was performed at 60 and 66 months after drug treatment. Serotonin transport (SERT) availability was presented as the specific uptake ratios (SURs) of 4-[18F]-ADAM in brain regions. Voxel-based region-specific SERT availability was calculated to generate 3D PET/MR images. Structural Magnetic Resonance Imaging (MRI) volumetric analysis was also conducted at 60 months. Significantly decreased 4-[18F]-ADAM SURs were observed in the striatum and thalamus of the MDMA group at 60 and 66 months compared to controls; the midbrain and frontal cortex SURs were similar at 60 and 66 months in the MDMA and control groups. All eleven brain regions showed significantly lower (∼13%) self-recovery rates over time; the occipital cortex and cingulate recovered to baseline by 66 months. DM attenuated MDMA-induced SERT deficiency on average, by ∼8 and ∼1% at 60 and 66 months, respectively; whereas significant differences were observed between the thalamus and amygdala of the MDMA and DM + MDMA groups at 66 months. Compared to controls, the MDMA group exhibited significantly increased (∼6.6%) gray matter volumes in the frontal cortex, occipital cortex, caudate nucleus, hippocampus, midbrain, and amygdala. Moreover, the gray matter volumes of the occipital cortex, hippocampus and amygdala correlated negatively with the 4-[18F]-ADAM SURs of the same regions. DM (n = 2) did not appear to affect MDMA-induced volumetric changes. The 4-[18F]-ADAM SURs, lower self-recovery rate and increased volumetric values indicate the occipital cortex, hippocampus and amygdala still exhibit MDMA-induced neurotoxicity after 66 months’ abstinence. Moreover, DM may prevent MDMA-induced serotonergic deficiency, as indicated by increased 4-[18F]-ADAM SURs and SERT availability, but not volumetric changes.
Collapse
Affiliation(s)
- Skye Hsin-Hsien Yeh
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
- School of Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Yeh Kuo
- Department of Nursing, Hsin-Sheng College of Medical Care and Management, Taoyuan, Taiwan
| | - Wen-Sheng Huang
- Department of Nuclear Medicine, Cheng-Hsin General Hospital, Taipei, Taiwan
- Department of Nuclear Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Chuang-Hsin Chiu
- Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan
| | - Tsung-Hsun Yu
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | | | - Chi-Jung Tsai
- Department of Nuclear Medicine, Taipei Medical University Hospital, Taipei, Taiwan
- *Correspondence: Kuo-Hsing Ma,
| | - Cheng-Yi Cheng
- Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan
- *Correspondence: Kuo-Hsing Ma,
| | - Kuo-Hsing Ma
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
- *Correspondence: Kuo-Hsing Ma,
| |
Collapse
|
2
|
Sex and strain differences in dynamic and static properties of the mesolimbic dopamine system. Neuropsychopharmacology 2020; 45:2079-2086. [PMID: 32663840 PMCID: PMC7547712 DOI: 10.1038/s41386-020-0765-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 07/04/2020] [Accepted: 07/08/2020] [Indexed: 02/02/2023]
Abstract
Sex is a biological variable that contributes to the incidence, clinical course, and treatment outcome of brain disorders. Chief among these are disorders associated with the dopamine system. These include Parkinson's disease, ADHD, schizophrenia, and mood disorders, which show stark differences in prevalence and outcome between men and women. In order to reveal the influence of biological sex as a risk factor in these disorders, there is a critical need to collect fundamental information about basic properties of the dopamine system in males and females. In Long Evans rats, we measured dynamic and static properties related to the mesolimbic dopamine system. Static measures included assessing ventral tegmental area (VTA) dopamine cell number and volume and expression of tyrosine hydroxylase and dopamine transporter. Dynamic measures in behaving animals included assessing (1) VTA neuronal encoding during learning of a cue-action-reward instrumental task and (2) dopamine release in the nucleus accumbens in response to electrical stimulation of the VTA, vesicular depletion of dopamine, and amphetamine. We found little or no sex difference in these measures, suggesting sexual congruency in fundamental static and dynamic properties of dopamine neurons. Thus, dopamine related sex-differences are likely mediated by secondary mechanisms that flexibly influence the function of the dopamine cells and circuits. Finally, we noted that most behavioral sex differences had been reported in Sprague-Dawley rats and repeated some of the above measures in that strain. We found some sex differences in those animals highlighting the importance of considering strain differences in experimental design and result interpretation.
Collapse
|
3
|
Felmer AC, Janson MT, Summers KE, Wallace LJ. Extracellular dopamine kinetic parameters consistent with amphetamine effects. Synapse 2019; 73:e22129. [DOI: 10.1002/syn.22129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/20/2019] [Accepted: 08/22/2019] [Indexed: 02/03/2023]
Affiliation(s)
- Anna C. Felmer
- Division of Pharmacology College of Pharmacy The Ohio State University Columbus Ohio
| | - Marnie T. Janson
- Division of Pharmacology College of Pharmacy The Ohio State University Columbus Ohio
| | - Katherine E. Summers
- Division of Pharmacology College of Pharmacy The Ohio State University Columbus Ohio
| | - Lane J. Wallace
- Division of Pharmacology College of Pharmacy The Ohio State University Columbus Ohio
| |
Collapse
|
4
|
Musolino ST, Schartner EP, Hutchinson MR, Salem A. Minocycline attenuates 3,4-methylenedioxymethamphetamine-induced hyperthermia in the rat brain. Eur J Pharmacol 2019; 858:172495. [PMID: 31238065 DOI: 10.1016/j.ejphar.2019.172495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/21/2019] [Accepted: 06/21/2019] [Indexed: 10/26/2022]
Abstract
Hyperthermia is most dangerous clinical symptom of acute MDMA administration, and a key factor related to potentially life-threatening MDMA-induced complications. MDMA induces a consistently faster onset of brain hyperthermia when compared to a delayed and moderate hyperthermia in the body, and the most harmful effects of MDMA are related to its modulation of neural functions. The primary focus of this study was to investigate the effects of minocycline, a centrally acting tetracycline derivative on MDMA-induced brain hyperthermia at high ambient temperature. However, we also simultaneously recorded body temperature, heart rate, and locomotor activity changes, allowing us to gain a better understanding of the mechanisms underlying the MDMA-induced hyperthermic response. We also investigated the effects of MDMA at normal ambient temperature to provide further evidence as to the importance of environmental factors on the intensity of MDMA's temperature effects. At normal ambient temperature, MDMA (10 mg/kg, i.p.) induced a significant brain and body hypothermia for the first 90 min following drug administration, and significantly increased heart rate and locomotor activity compared to saline controls. At high ambient temperature however, MDMA (10 mg/kg, i.p.) induced a robust and extended brain and body hyperthermia, as well as significantly increased heart rate and locomotor activity. A 3-day minocycline (50 mg/kg, i.p.) pre-treatment significantly attenuated MDMA-induced increases in brain temperature, body temperature, heart rate, and locomotor activity. Our findings indicate that minocycline is more effective in attenuating the exacerbated MDMA-induced hyperthermic response in the brain compared to the body at high ambient temperature.
Collapse
Affiliation(s)
- Stefan T Musolino
- ARC Centre of Excellence for Nanoscale BioPhotonics and Institute for Photonics and Advanced Sensing, Adelaide, SA, 5005, Australia; Discipline of Pharmacology, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.
| | - Erik P Schartner
- ARC Centre of Excellence for Nanoscale BioPhotonics and Institute for Photonics and Advanced Sensing, Adelaide, SA, 5005, Australia; School of Physical Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Mark R Hutchinson
- ARC Centre of Excellence for Nanoscale BioPhotonics and Institute for Photonics and Advanced Sensing, Adelaide, SA, 5005, Australia; Discipline of Pharmacology, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Abdallah Salem
- Discipline of Pharmacology, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
| |
Collapse
|
5
|
Hake HS, Davis JKP, Wood RR, Tanner MK, Loetz EC, Sanchez A, Ostrovskyy M, Oleson EB, Grigsby J, Doblin R, Greenwood BN. 3,4-methylenedioxymethamphetamine (MDMA) impairs the extinction and reconsolidation of fear memory in rats. Physiol Behav 2019; 199:343-350. [PMID: 30529341 PMCID: PMC6557441 DOI: 10.1016/j.physbeh.2018.12.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 01/04/2023]
Abstract
Clinical trials have demonstrated that 3,4-methylenedioxymethamphetamine (MDMA) paired with psychotherapy is more effective at reducing symptoms of post-traumatic stress disorder (PTSD) than psychotherapy or pharmacotherapy, alone or in combination. The processes through which MDMA acts to enhance psychotherapy are not well understood. Given that fear memories contribute to PTSD symptomology, MDMA could augment psychotherapy by targeting fear memories. The current studies investigated the effects of a single administration of MDMA on extinction and reconsolidation of cued and contextual fear memory in adult, male Long-Evans rats. Rats were exposed to contextual or auditory fear conditioning followed by systemic administration of saline or varying doses of MDMA (between 1 and 10 mg/kg) either 30 min before fear extinction training or immediately after brief fear memory retrieval (i.e. during the reconsolidation phase). MDMA administered prior to fear extinction training failed to enhance fear extinction memory, and in fact impaired drug-free cued fear extinction recall without impacting later fear relapse. MDMA administered during the reconsolidation phase, but not outside of the reconsolidation phase, produced a delayed and persistent reduction in conditioned fear. These findings are consistent with a general memory-disrupting effect of MDMA and suggest that MDMA could augment psychotherapy by modifying fear memories during reconsolidation without necessarily enhancing their extinction.
Collapse
Affiliation(s)
- Holly S Hake
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| | - Jazmyne K P Davis
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| | - River R Wood
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| | - Margaret K Tanner
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| | - Esteban C Loetz
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| | - Anais Sanchez
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| | - Mykola Ostrovskyy
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| | - Erik B Oleson
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| | - Jim Grigsby
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA; Department of Medicine, University of Colorado Denver School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Rick Doblin
- Multidisciplinary Association for Psychedelic Studies, 1115 Mission Street, Santa Cruz, CA 95060-9989, USA
| | - Benjamin N Greenwood
- Department of Psychology, University of Colorado Denver, PO Box 173364, Denver, CO 80217-3364, USA.
| |
Collapse
|
6
|
Abstract
There is a plethora of amphetamine derivatives exerting stimulant, euphoric, anti-fatigue, and hallucinogenic effects; all structural properties allowing these effects are contained within the amphetamine structure. In the first part of this review, the interaction of amphetamine with the dopamine transporter (DAT), crucially involved in its behavioral effects, is covered, as well as the role of dopamine synthesis, the vesicular monoamine transporter VMAT2, and organic cation 3 transporter (OCT3). The second part deals with requirements in amphetamine's effect on the kinases PKC, CaMKII, and ERK, whereas the third part focuses on where we are in developing anti-amphetamine therapeutics. Thus, treatments are discussed that target DAT, VMAT2, PKC, CaMKII, and OCT3. As is generally true for the development of therapeutics for substance use disorder, there are multiple preclinically promising specific compounds against (meth)amphetamine, for which further development and clinical trials are badly needed.
Collapse
Affiliation(s)
- Maarten E A Reith
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA.
| | - Margaret E Gnegy
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, MI, USA
| |
Collapse
|
7
|
Contribution of dopamine to mitochondrial complex I inhibition and dopaminergic deficits caused by methylenedioxymethamphetamine in mice. Neuropharmacology 2015; 93:124-33. [DOI: 10.1016/j.neuropharm.2015.01.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 12/19/2014] [Accepted: 01/27/2015] [Indexed: 11/13/2022]
|
8
|
Rouine J, Kelly ME, Jennings-Murphy C, Duffy P, Gorman I, Gormley S, Kerskens CM, Harkin A. Investigation of the mechanisms mediating MDMA "Ecstasy"-induced increases in cerebro-cortical perfusion determined by btASL MRI. Psychopharmacology (Berl) 2015; 232:1501-13. [PMID: 25366875 DOI: 10.1007/s00213-014-3790-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 10/19/2014] [Indexed: 01/16/2023]
Abstract
RATIONALE Acute administration of the recreational drug of abuse 3,4-methylenedioxymethamphetamine (MDMA; Ecstasy) has previously been shown to increase cerebro-cortical perfusion as determined by bolus-tracking arterial spin labelling (btASL) MRI. OBJECTIVES The purpose of the current study was to assess the mechanisms mediating these changes following systemic administration of MDMA to rats. METHODS Pharmacological manipulation of serotonergic, dopaminergic and nitrergic transmission was carried out to determine the mechanism of action of MDMA-induced increases in cortical perfusion using btASL MRI. RESULTS Fenfluramine (10 mg/kg), like MDMA (20 mg/kg), increased cortical perfusion. Increased cortical perfusion was not obtained with the 5-HT2 receptor agonist 2,5-dimethoxy-4-iodophenyl-aminopropane hydrochloride (DOI) (1 mg/kg). Depletion of central 5-HT following systemic administration of the tryptophan hydroxylase inhibitor para-chlorophenylalanine (pCPA) produced effects similar to those observed with MDMA. Pre-treatment with the 5-HT receptor antagonist metergoline (4 mg/kg) or with the 5-HT reuptake inhibitor citalopram (30 mg/kg), however, failed to produce any effect alone or influence the response to MDMA. Pre-treatment with the dopamine D1 receptor antagonist SCH 23390 (1 mg/kg) failed to influence the changes in cortical perfusion obtained with MDMA. Treatment with the neuronal nitric oxide (NO) synthase inhibitor 7-nitroindazole (7-NI) (25 mg/kg) provoked no change in cerebral perfusion alone yet attenuated the MDMA-related increase in cortical perfusion. CONCLUSIONS Cortical 5-HT depletion is associated with increases in perfusion although this mechanism alone does not account for MDMA-related changes. A role for NO, a key regulator of cerebrovascular perfusion, is implicated in MDMA-induced increases in cortical perfusion.
Collapse
Affiliation(s)
- J Rouine
- Trinity College Institute of Neuroscience, Trinity College, Dublin, 2, Ireland
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Lizarraga LE, Cholanians AB, Phan AV, Herndon JM, Lau SS, Monks TJ. Vesicular monoamine transporter 2 and the acute and long-term response to 3,4-(±)-methylenedioxymethamphetamine. Toxicol Sci 2014; 143:209-19. [PMID: 25370842 DOI: 10.1093/toxsci/kfu222] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
3,4-(±)-Methylenedioxymethamphetamine (MDMA, Ecstasy) is a ring-substituted amphetamine derivative with potent psychostimulant properties. The neuropharmacological effects of MDMA are biphasic in nature, initially causing synaptic monoamine release, primarily of serotonin (5-HT). Conversely, the long-term effects of MDMA manifest as prolonged depletions in 5-HT, and reductions in 5-HT reuptake transporter (SERT), indicative of serotonergic neurotoxicity. MDMA-induced 5-HT efflux relies upon disruption of vesicular monoamine storage, which increases cytosolic 5-HT concentrations available for release via a carrier-mediated mechanism. The vesicular monoamine transporter 2 (VMAT2) is responsible for packaging monoamine neurotransmitters into cytosolic vesicles. Thus, VMAT2 is a molecular target for a number of psychostimulant drugs, including methamphetamine and MDMA. We investigated the effects of depressed VMAT2 activity on the adverse responses to MDMA, via reversible inhibition of the VMAT2 protein with Ro4-1284. A single dose of MDMA (20 mg/kg, subcutaneous) induced significant hyperthermia in rats. Ro4-1284 (10 mg/kg, intraperitoneal) pretreatment prevented the thermogenic effects of MDMA, instead causing a transient decrease in body temperature. MDMA-treated rats exhibited marked increases in horizontal velocity and rearing behavior. In the presence of Ro4-1284, MDMA-mediated horizontal hyperlocomotion was delayed and attenuated, whereas rearing activity was abolished. Finally, Ro4-1284 prevented deficits in 5-HT content in rat cortex and striatum, and reduced depletions in striatal SERT staining, 7 days after MDMA administration. In summary, acute inhibition of VMAT2 by Ro4-1284 protected against MDMA-mediated hyperthermia, hyperactivity, and serotonergic neurotoxicity. The data suggest the involvement of VMAT2 in the thermoregulatory, behavioral, and neurotoxic effects of MDMA.
Collapse
Affiliation(s)
- Lucina E Lizarraga
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721
| | - Aram B Cholanians
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721
| | - Andy V Phan
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721
| | - Joseph M Herndon
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721
| | - Serrine S Lau
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721
| | - Terrence J Monks
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721
| |
Collapse
|
10
|
The role of serotonin in drug use and addiction. Behav Brain Res 2014; 277:146-92. [PMID: 24769172 DOI: 10.1016/j.bbr.2014.04.007] [Citation(s) in RCA: 208] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/04/2014] [Accepted: 04/05/2014] [Indexed: 12/26/2022]
Abstract
The use of psychoactive drugs is a wide spread behaviour in human societies. The systematic use of a drug requires the establishment of different drug use-associated behaviours which need to be learned and controlled. However, controlled drug use may develop into compulsive drug use and addiction, a major psychiatric disorder with severe consequences for the individual and society. Here we review the role of the serotonergic (5-HT) system in the establishment of drug use-associated behaviours on the one hand and the transition and maintenance of addiction on the other hand for the drugs: cocaine, amphetamine, methamphetamine, MDMA (ecstasy), morphine/heroin, cannabis, alcohol, and nicotine. Results show a crucial, but distinct involvement of the 5-HT system in both processes with considerable overlap between psychostimulant and opioidergic drugs and alcohol. A new functional model suggests specific adaptations in the 5-HT system, which coincide with the establishment of controlled drug use-associated behaviours. These serotonergic adaptations render the nervous system susceptible to the transition to compulsive drug use behaviours and often overlap with genetic risk factors for addiction. Altogether we suggest a new trajectory by which serotonergic neuroadaptations induced by first drug exposure pave the way for the establishment of addiction.
Collapse
|
11
|
Kyzar E, Stewart AM, Landsman S, Collins C, Gebhardt M, Robinson K, Kalueff AV. Behavioral effects of bidirectional modulators of brain monoamines reserpine and d-amphetamine in zebrafish. Brain Res 2013; 1527:108-16. [PMID: 23827499 DOI: 10.1016/j.brainres.2013.06.033] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 05/11/2013] [Accepted: 06/25/2013] [Indexed: 02/06/2023]
Abstract
Brain monoamines play a key role in the regulation of behavior. Reserpine depletes monoamines, and causes depression and hypoactivity in humans and rodents. In contrast, d-amphetamine increases brain monoamines' levels, and evokes hyperactivity and anxiety. However, the effects of these agents on behavior and in relation to monoamine levels remain poorly understood, necessitating further experimental studies to understand their psychotropic action. Zebrafish (Danio rerio) are rapidly emerging as a promising model organism for drug screening and translational neuroscience research. Here, we have examined the acute and long-term effects of reserpine and d-amphetamine on zebrafish behavior in the novel tank test. Overall, d-amphetamine (5 and 10mg/L) evokes anxiogenic-like effects in zebrafish acutely, but not 7 days later. In contrast, reserpine (20 and 40 mg/L) did not evoke overt acute behavioral effects, but markedly reduced activity 7 days later, resembling motor retardation observed in depression and/or Parkinson's disease. Three-dimensional 'temporal' (X, Y, time) reconstructions of zebrafish locomotion further supports these findings, confirming the utility of 3D-based video-tracking analyses in zebrafish models of drug action. Our results show that zebrafish are highly sensitive to drugs bi-directionally modulating brain monoamines, generally paralleling rodent and clinical findings. Collectively, this emphasizes the potential of zebrafish tests to model complex brain disorders associated with monoamine dysregulation.
Collapse
Affiliation(s)
- Evan Kyzar
- Zebrafish Neuroscience Research Consortium (ZNRC) and ZENEREI Institute, 309 Palmer Court, Slidell, LA 70458, USA
| | | | | | | | | | | | | |
Collapse
|
12
|
Cognitive impairments from developmental exposure to serotonergic drugs: citalopram and MDMA. Int J Neuropsychopharmacol 2013; 16:1383-94. [PMID: 23308402 PMCID: PMC4594864 DOI: 10.1017/s1461145712001447] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously showed that developmental 3,4-methylenedioxymethamphetamine (MDMA) treatment induces long-term spatial and egocentric learning and memory deficits and serotonin (5-HT) reductions. During brain development, 5-HT is a neurotrophic factor influencing neurogenesis, synaptogenesis, migration, and target field organization. MDMA (10 mg/kg × 4/d at 2 h intervals) given on post-natal day (PD) 11-20 in rats (a period of limbic system development that approximates human third trimester brain development) induces 50% reductions in 5-HT during treatment and 20% reductions when assessed as adults. To determine whether the 5-HT reduction is responsible for the cognitive deficits, we used citalopram (Cit) pretreatment to inhibit the effects of MDMA on 5-HT reuptake in a companion study. Cit attenuated MDMA-induced 5-HT reductions by 50% (Schaefer et al., 2012). Here we tested whether Cit (5 or 7.5 mg/kg × 2/d) pretreatment attenuates the cognitive effects of MDMA. Within each litter, different offspring were treated on PD11-20 with saline (Sal) + MDMA, Cit + MDMA, Cit + Sal or Sal + Sal. Neither spatial nor egocentric learning/memory was improved by Cit pretreatment. Unexpectedly, Cit + Sal (at both doses) produced spatial and egocentric learning deficits as severe as those caused by Sal + MDMA. These are the first data showing cognitive deficits resulting from developmental exposure to a selective serotonin reuptake inhibitor. These data indicate the need for further research on the long-term safety of antidepressants during pregnancy.
Collapse
|
13
|
Ferris MJ, Calipari ES, Mateo Y, Melchior JR, Roberts DCS, Jones SR. Cocaine self-administration produces pharmacodynamic tolerance: differential effects on the potency of dopamine transporter blockers, releasers, and methylphenidate. Neuropsychopharmacology 2012; 37:1708-16. [PMID: 22395730 PMCID: PMC3358740 DOI: 10.1038/npp.2012.17] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The dopamine transporter (DAT) is the primary site of action for psychostimulant drugs such as cocaine, methylphenidate, and amphetamine. Our previous work demonstrated a reduced ability of cocaine to inhibit the DAT following high-dose cocaine self-administration (SA), corresponding to a reduced ability of cocaine to increase extracellular dopamine. However, this effect had only been demonstrated for cocaine. Thus, the current investigations sought to understand the extent to which cocaine SA (1.5 mg/kg/inf × 40 inf/day × 5 days) altered the ability of different dopamine uptake blockers and releasers to inhibit dopamine uptake, measured using fast-scan cyclic voltammetry in rat brain slices. We demonstrated that, similar to cocaine, the DAT blockers nomifensine and bupropion were less effective at inhibiting dopamine uptake following cocaine SA. The potencies of amphetamine-like dopamine releasers such as 3,4-methylenedioxymethamphetamine, methamphetamine, amphetamine, and phentermine, as well as a non-amphetamine releaser, 4-benzylpiperidine, were all unaffected. Finally, methylphenidate, which blocks dopamine uptake like cocaine while being structurally similar to amphetamine, shared characteristics of both, resembling an uptake blocker at low concentrations and a releaser at high concentrations. Combined, these experiments demonstrate that after high-dose cocaine SA, there is cross-tolerance of the DAT to other uptake blockers, but not releasers. The reduced ability of psychostimulants to inhibit dopamine uptake following cocaine SA appears to be contingent upon their functional interaction with the DAT as a pure blocker or releaser rather than their structural similarity to cocaine. Further, methylphenidate's interaction with the DAT is unique and concentration-dependent.
Collapse
Affiliation(s)
- Mark J Ferris
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
| | - Erin S Calipari
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Yolanda Mateo
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - James R Melchior
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - David CS Roberts
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Sara R Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| |
Collapse
|
14
|
Baladi MG, Daws LC, France CP. You are what you eat: influence of type and amount of food consumed on central dopamine systems and the behavioral effects of direct- and indirect-acting dopamine receptor agonists. Neuropharmacology 2012; 63:76-86. [PMID: 22710441 DOI: 10.1016/j.neuropharm.2012.02.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 12/21/2011] [Accepted: 02/07/2012] [Indexed: 12/27/2022]
Abstract
The important role of dopamine (DA) in mediating feeding behavior and the positive reinforcing effects of some drugs is well recognized. Less widely studied is how feeding conditions might impact the sensitivity of drugs acting on DA systems. Food restriction, for example, has often been the focus of aging and longevity studies; however, other studies have demonstrated that mild food restriction markedly increases sensitivity to direct- and indirect-acting DA receptor agonists. Moreover, it is becoming clear that not only the amount of food, but the type of food, is an important factor in modifying the effects of drugs. Given the increased consumption of high fat and sugary foods, studies are exploring how consumption of highly palatable food impacts DA neurochemistry and the effects of drugs acting on these systems. For example, eating high fat chow increases sensitivity to some behavioral effects of direct- as well as indirect-acting DA receptor agonists. A compelling mechanistic possibility is that central DA pathways that mediate the effects of some drugs are regulated by one or more of the endocrine hormones (e.g. insulin) that undergo marked changes during food restriction or after consuming high fat or sugary foods. Although traditionally recognized as an important signaling molecule in regulating energy homeostasis, insulin can also regulate DA neurochemistry. Because direct- and indirect-acting DA receptor drugs are used therapeutically and some are abused, a better understanding of how food intake impacts response to these drugs would likely facilitate improved treatment of clinical disorders and provide information that would be relevant to the causes of vulnerability to abuse drugs. This article is part of a Special Issue entitled 'Central Control of Food Intake'.
Collapse
Affiliation(s)
- Michelle G Baladi
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | | | | |
Collapse
|
15
|
Meng H, Cao J, Kang J, Ying X, Ji J, Reynolds W, Rampe D. Mephedrone, a new designer drug of abuse, produces acute hemodynamic effects in the rat. Toxicol Lett 2012; 208:62-8. [DOI: 10.1016/j.toxlet.2011.10.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 10/11/2011] [Accepted: 10/12/2011] [Indexed: 01/07/2023]
|
16
|
Contributions of serotonin in addiction vulnerability. Neuropharmacology 2011; 61:421-32. [PMID: 21466815 DOI: 10.1016/j.neuropharm.2011.03.022] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 03/24/2011] [Accepted: 03/25/2011] [Indexed: 12/29/2022]
Abstract
The serotonin (5-hydroxytryptamine; 5-HT) system has long been associated with mood and its dysregulation implicated in the pathophysiology of mood and anxiety disorders. While modulation of 5-HT neurotransmission by drugs of abuse is also recognized, its role in drug addiction and vulnerability to drug relapse is a more recent focus of investigation. First, we review preclinical data supporting the serotonergic raphe nuclei and their forebrain projections as targets of drugs of abuse, with emphasis on the effects of psychostimulants, opioids and ethanol. Next, we examine the role of 5-HT receptors in impulsivity, a core behavior that contributes to the vulnerability to addiction and relapse. Finally, we discuss evidence for serotonergic dysregulation in comorbid mood and addictive disorders and suggest novel serotonergic targets for the treatment of addiction and the prevention of drug relapse.
Collapse
|
17
|
A role for adenosine A(1) receptor blockade in the ability of caffeine to promote MDMA "Ecstasy"-induced striatal dopamine release. Eur J Pharmacol 2010; 650:220-8. [PMID: 20951694 DOI: 10.1016/j.ejphar.2010.10.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 09/10/2010] [Accepted: 10/03/2010] [Indexed: 11/23/2022]
Abstract
Co-administration of caffeine profoundly enhances the acute toxicity of 3,4 methylenedioxymethamphetamine (MDMA) in rats. The aim of this study was to determine the ability of caffeine to impact upon MDMA-induced dopamine release in superfused brain tissue slices as a contributing factor to this drug interaction. MDMA (100 and 300μM) induced a dose-dependent increase in dopamine release in striatal and hypothalamic tissue slices preloaded with [(3)H] dopamine (1μM). Caffeine (100μM) also induced dopamine release in the striatum and hypothalamus, albeit to a much lesser extent than MDMA. When striatal tissue slices were superfused with MDMA (30μM) in combination with caffeine (30μM), caffeine enhanced MDMA-induced dopamine release, provoking a greater response than that obtained following either caffeine or MDMA applications alone. The synergistic effects in the striatum were not observed in hypothalamic slices. As adenosine A(1) receptors are, one of the main pharmacological targets of caffeine, which are known to play an important role in the regulation of dopamine release, their role in the modulation of MDMA-induced dopamine release was investigated. 1μM 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a specific A(1) antagonist, like caffeine, enhanced MDMA-induced dopamine release from striatal slices while 1μM 2,chloro-N(6)-cyclopentyladenosine (CCPA), a selective adenosine A(1) receptor agonist, attenuated this. Treatment with either SCH 58261, a selective A(2A) receptor antagonist, or rolipram, a selective PDE-4 inhibitor, failed to reproduce a caffeine-like effect on MDMA-induced dopamine release. These results suggest that caffeine regulates MDMA-induced dopamine release in striatal tissue slices, via inhibition of adenosine A(1) receptors.
Collapse
|
18
|
Puerta E, Hervias I, Goñi-Allo B, Zhang SF, Jordán J, Starkov AA, Aguirre N. Methylenedioxymethamphetamine inhibits mitochondrial complex I activity in mice: a possible mechanism underlying neurotoxicity. Br J Pharmacol 2010; 160:233-45. [PMID: 20423338 DOI: 10.1111/j.1476-5381.2010.00663.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND AND PURPOSE 3,4-methylenedioxymethamphetamine (MDMA) causes a persistent loss of dopaminergic cell bodies in the substantia nigra of mice. Current evidence indicates that such neurotoxicity is due to oxidative stress but the source of free radicals remains unknown. Inhibition of mitochondrial electron transport chain complexes by MDMA was assessed as a possible source. EXPERIMENTAL APPROACH Activities of mitochondrial complexes after MDMA were evaluated spectrophotometrically. In situ visualization of superoxide production in the striatum was assessed by ethidium fluorescence and striatal dopamine levels were determined by HPLC as an index of dopaminergic toxicity. KEY RESULTS 3,4-methylenedioxymethamphetamine decreased mitochondrial complex I activity in the striatum of mice, an effect accompanied by an increased production of superoxide radicals and the inhibition of endogenous aconitase. alpha-Lipoic acid prevented superoxide generation and long-term toxicity independent of any effect on complex I inhibition. These effects of alpha-lipoic acid were also associated with a significant increase of striatal glutathione levels. The relevance of glutathione was supported by reducing striatal glutathione content with L-buthionine-(S,R)-sulfoximine, which exacerbated MDMA-induced dopamine deficits, effects suppressed by alpha-lipoic acid. The nitric oxide synthase inhibitor, N(G)-nitro-L-arginine, partially prevented MDMA-induced dopamine depletions, an effect reversed by L-arginine but not D-arginine. Finally, a direct relationship between mitochondrial complex I inhibition and long-term dopamine depletions was found in animals treated with MDMA in combination with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. CONCLUSIONS AND IMPLICATIONS Inhibition of mitochondrial complex I following MDMA could be the source of free radicals responsible for oxidative stress and the consequent neurotoxicity of this drug in mice.
Collapse
Affiliation(s)
- Elena Puerta
- Department of Pharmacology, University of Navarra, Spain
| | | | | | | | | | | | | |
Collapse
|
19
|
Müller CP, Pum ME, Schumann G, Huston JP. The Role of Serotonin in Drug Addiction. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2010. [DOI: 10.1016/s1569-7339(10)70099-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
20
|
Carhart-Harris RL, Nutt DJ, Munafò M, Wilson SJ. Current and former ecstasy users report different sleep to matched controls: a web-based questionnaire study. J Psychopharmacol 2009; 23:249-57. [PMID: 18562419 DOI: 10.1177/0269881108089599] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study sought to test the association between ecstasy-use and abnormal sleep. An anonymous web-based questionnaire containing questions on drug use and sleep was completed by 1035 individuals. From this large sample, a group of 89 ecstasy users were found who reported very little use of other drugs. This "ecstasy-only" group was further divided into two groups of 31 current users and 58 abstinent users. The subjective sleep of current and former ecstasy-only users was compared with that of matched controls. Patients were asked to rate their sleep according to: 1) sleep quality, 2) sleep latency, 3) night time awakenings and 4) total sleep time. Current ecstasy-only users reported significantly worse sleep quality (P < 0.05) and a greater total sleep time (P < 0.001) than controls. It was inferred that these differences might be due to recovery from the acute effects of the drug. Abstinent ecstasy-only users reported significantly more nighttime awakenings than controls (P < 0.01). These subjective findings are in agreement with the objective findings of previous studies showing persistent sleep abnormalities in ecstasy users.
Collapse
|
21
|
Doherty JM, Masten VL, Powell SB, Ralph RJ, Klamer D, Low MJ, Geyer MA. Contributions of dopamine D1, D2, and D3 receptor subtypes to the disruptive effects of cocaine on prepulse inhibition in mice. Neuropsychopharmacology 2008; 33:2648-56. [PMID: 18075489 DOI: 10.1038/sj.npp.1301657] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Deficits in prepulse inhibition (PPI) of startle, an operational measure of sensorimotor gating, are characteristics of schizophrenia and related neuropsychiatric disorders. Previous studies in mice demonstrate a contribution of dopamine (DA) D(1)-family receptors in modulating PPI and DA D(2) receptors (D2R) in mediating the PPI-disruptive effects of amphetamine. To examine further the contributions of DA receptor subtypes in PPI, we used a combined pharmacological and genetic approach. In congenic C57BL/6 J wild-type mice, we tested whether the D1R antagonist SCH23390 or the D2/3R antagonist raclopride would attenuate the effects of the indirect DA agonist cocaine (40 mg/kg). Both the D1R and D2/3R antagonists attenuated the cocaine-induced PPI deficit. We also tested the effect of cocaine on PPI in wild-type and DA D1R, D2R, or D3R knockout mice. The cocaine-induced PPI deficit was influenced differently by the three DA receptor subtypes, being absent in D1R knockout mice, partially attenuated in D2R knockout mice, and exaggerated in D3R knockout mice. Thus, the D1R is necessary for the PPI-disruptive effects of cocaine, while the D2R partially contributes to these effects. Conversely, the D3R appears to inhibit the PPI-disruptive effects of cocaine. Uncovering neural mechanisms involved in PPI will further our understanding of substrates of sensorimotor gating and could lead to better therapeutics to treat complex cognitive disorders such as schizophrenia.
Collapse
Affiliation(s)
- James M Doherty
- Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093-0804, USA
| | | | | | | | | | | | | |
Collapse
|
22
|
A new brain area affected by 3,4-methylenedioxymethamphetamine: A microdialysis–biotelemetry study. Eur J Pharmacol 2008; 596:84-8. [DOI: 10.1016/j.ejphar.2008.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 07/09/2008] [Accepted: 08/04/2008] [Indexed: 11/22/2022]
|
23
|
Effects of ethanol and 3,4-methylenedioxymethamphetamine (MDMA) alone or in combination on spontaneous and evoked overflow of dopamine, serotonin and acetylcholine in striatal slices of the rat brain. Int J Neuropsychopharmacol 2008; 11:743-63. [PMID: 18248690 DOI: 10.1017/s1461145708008481] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ethanol (EtOH) potentiates the locomotor effects of 3,4-methylenedioxymetamphetamine (MDMA) in rats. This potentiation might involve pharmacokinetic and/or pharmacodynamic mechanisms. We explored whether the latter could be local. Using a slice superfusion approach, we assessed the effects of MDMA (0.3, 3microm) and/or EtOH (2mm) on the spontaneous outflow and electrically evoked release of serotonin (5-HT), dopamine (DA) and acetylcholine (ACh) in the striatum, and for comparison, on 5-HT release in hippocampal and neocortical tissue. MDMA and less effectively EtOH, augmented the outflow of 5-HT in all regions. The electrically evoked 5-HT release was increased by MDMA at 3microm in striatal slices only. With nomifensine throughout, EtOH significantly potentiated the 0.3microm MDMA-induced outflow of 5-HT, but only in striatal slices. EtOH or MDMA also enhanced the spontaneous outflow of DA, but MDMA reduced the electrically evoked DA release. With fluvoxamine throughout superfusion, EtOH potentiated the effect of MDMA on the spontaneous outflow of DA. Finally, 3microm MDMA diminished the electrically evoked release of ACh, an effect involving several receptors (D2, 5-HT2, NMDA, nicotinic, NK1), with some interactions with EtOH. Among other results, we show for the first time a local synergistic interaction of EtOH and MDMA on the spontaneous outflow of striatal DA and 5-HT, which could be relevant to the EtOH-induced potentiation of hyperlocomotion in MDMA-treated rats. These data do not preclude the contribution of other pharmacodynamic and/or pharmacokinetic mechanisms in vivo but support the hypothesis that EtOH may affect the abuse liability of MDMA.
Collapse
|
24
|
Abstract
+/-3,4-Methylenedioxymethamphetamine (MDMA) is a chemical derivative of amphetamine that has become a popular drug of abuse and has been shown to deplete serotonin in the brains of users and animals exposed to it. To date, most studies have investigated the effects of MDMA on adult animals. With a majority of users of MDMA being young adults, the chances of the users becoming pregnant and exposing the fetuses to MDMA are also a concern. Evidence to date has shown that developmental exposure to MDMA results in learning and memory impairments in the Morris water maze, a task known to be sensitive to hippocampal disruption, when the animals are tested as adults. Developmental MDMA exposure leads to hypoactivity in the offspring as adults but does not affect outcome on tests of anxiety. MDMA administration decreases pup weight, increases corticosterone and brain-derived neurotrophic factor levels during treatment while decreasing brain levels of serotonin; a decrease that initially dissipates and then reappears in adulthood. Neonatal MDMA exposure increases the sensitivity of the serotonin 1A receptor, a possible mechanism underlying the learning and memory deficits seen. Taken together, the evidence shows that MDMA exposure has adverse effects on the developing brain and behavior. The animal and human data on developmental MDMA exposure are reviewed and their public health implications discussed.
Collapse
|
25
|
Verheij MMM, Cools AR. Twenty years of dopamine research: individual differences in the response of accumbal dopamine to environmental and pharmacological challenges. Eur J Pharmacol 2008; 585:228-44. [PMID: 18423601 DOI: 10.1016/j.ejphar.2008.02.084] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 02/07/2008] [Accepted: 02/13/2008] [Indexed: 11/30/2022]
Abstract
Individual differences in the dopaminergic system of the nucleus accumbens of rats have extensively been reported. These individual differences have frequently been used to explain individual differences in response to environmental and pharmacological challenges. Remarkably, only little attention is paid to the factors that underlie these individual differences. This review gives an overview of the studies that have been performed in our institute during the last 20 years to investigate individual differences in accumbal dopamine release. Data are summarised demonstrating that individual differences in accumbal dopamine release are due to individual differences in: the functional reactivity of the noradrenergic system, the accumbal concentration of vesicular monoamine transporters and tyrosine hydroxylase as well as in the quantal size of the presynaptic pools of dopamine. Our data are embedded in the available literature to create a model that illustrates the putative hardware giving rise to the individual-specific release of accumbal dopamine. An important role is contributed to individual differences in the reactivity of the: hypothalamic-pituitary-adrenal axes, the reactivity of second messenger systems as well in the aminergic reactivity of the accumbens shell and core. The consequences of the individual-specific make-up and reactivity of the nucleus accumbens on the regulation of behaviour and the response to drugs of abuse will also be discussed. Apart from agents that interact with dopaminergic receptors, re-uptake or breakdown, noradrenergic agents as well as agents that interact with vesicular monoamine transporters or tyrosine hydroxylase are suggested to have therapeutic effects in subjects that are suffering from diseases in which the dopaminergic system is disturbed.
Collapse
Affiliation(s)
- Michel M M Verheij
- Department of Cognitive Neuroscience (CNS), Division of Psychoneuropharmacology (PNF), Radboud University Nijmegen Medical Centre, 6525 EZ, Nijmegen, The Netherlands.
| | | |
Collapse
|
26
|
Chakrabarty R, Rao J, Anand A, Roy AD, Roy R, Shankar G, Dua PR, Saxena AK. Rational design, synthesis and evaluation of (6aR∗,11bS∗)-1-(4-fluorophenyl)-4-{7-[4-(4-fluorophenyl)-4-oxobutyl]1,2,3,4,6,6a,7,11b,12,12a(RS)-decahydropyrazino[2′,1′:6,1]pyrido[3,4-b]indol-2-yl}-butan-1-one as a potential neuroleptic agent. Bioorg Med Chem 2007; 15:7361-7. [PMID: 17869521 DOI: 10.1016/j.bmc.2007.07.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2007] [Revised: 07/28/2007] [Accepted: 07/31/2007] [Indexed: 11/25/2022]
Abstract
In our pursuit to prepare a potent antipsychotic compound, a novel 1,2,3,4,6,6a,7,11b,12,12a-decahydropyrazino[2',1':6,1]pyrido[3,4-b]indole derivative was synthesized which incorporates the butyrophenone substructure twice. This molecule has shown D(1), D(2) and 5-HT(2A) receptor blocking activity where the ratio pK(i) (5-HT(2A)) to pK(i) (D(2)) is 1.42 better than risperidone (1.15). It blocks amphetamine induced hyperactivity/stereotypy and secondary conditioned avoidance responses in rodents at lower doses than those required for the neuroleptic drugs haloperidol and centbutindole (biriperone).
Collapse
Affiliation(s)
- Ruchika Chakrabarty
- Medicinal and Process Chemistry Division, Central Drug Research Institute, Lucknow-226001, India
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Gudelsky GA, Yamamoto BK. Actions of 3,4-methylenedioxymethamphetamine (MDMA) on cerebral dopaminergic, serotonergic and cholinergic neurons. Pharmacol Biochem Behav 2007; 90:198-207. [PMID: 18035407 DOI: 10.1016/j.pbb.2007.10.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 09/22/2007] [Accepted: 10/03/2007] [Indexed: 10/22/2022]
Abstract
3,4-Methylenedioxymethamphetamine (MDMA) is an amphetamine derivative and a popular drug of abuse that exhibits mild hallucinogenic and rewarding properties and engenders feelings of connectedness and openness. The unique psychopharmacological profile of this drug of abuse most likely is derived from the property of MDMA to promote the release of dopamine and serotonin (5-HT) in multiple brain regions. The present review highlights primarily data from studies employing in vivo microdialysis that detail the actions of MDMA on the release of these neurotransmitters. Data from in vivo microdialysis experiments indicate that MDMA, like most amphetamine derivatives, increases the release of dopamine in the striatum, n. accumbens and prefrontal cortex. However, the release of dopamine evoked by MDMA in each of these brain regions appears to be modulated by concomitantly released 5-HT and the subsequent activation of 5-HT2A/C or 5-HT2B/C receptors. In addition to its stimulatory effect on the release of monoamines, MDMA also enhances the release of acetylcholine in the striatum, hippocampus and prefrontal cortex, and this cholinergic response appears to be secondary to the activation of histaminergic, dopaminergic and/or serotonergic receptors. Beyond the acute stimulatory effect of MDMA on neurotransmitter release, MDMA also increases the extracellular concentration of energy substrates, e.g., glucose and lactate in the brain. In contrast to the acute stimulatory actions of MDMA on the release of monoamines and acetylcholine, the repeated administration of high doses of MDMA is thought to result in a selective neurotoxicity to 5-HT axon terminals in the rat. Additional studies are reviewed that focus on the alterations in neurotransmitter responses to pharmacological and physiological stimuli that accompany MDMA-induced 5-HT neurotoxicity.
Collapse
Affiliation(s)
- Gary A Gudelsky
- University of Cincinnati, James L. Winkle College of Pharmacy, 3225 Eden Ave., Cincinnati, OH 45267, United States.
| | | |
Collapse
|
28
|
Acquas E, Pisanu A, Spiga S, Plumitallo A, Zernig G, Di Chiara G. Differential effects of intravenous R,S-(�)-3,4-methylenedioxymethamphetamine (MDMA, Ecstasy) and its S(+)- and R(?)-enantiomers on dopamine transmission and extracellular signal regulated kinase phosphorylation (pERK) in the rat nucleus accumbens shell and core. J Neurochem 2007; 102:121-32. [PMID: 17564678 DOI: 10.1111/j.1471-4159.2007.04451.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
R,S(+/-)-3,4-methylenedioxymethamphetamine (R,S(+/-)-MDMA, 'Ecstasy') is known to stimulate dopamine (DA) transmission in the nucleus accumbens (NAc). In order to investigate the post-synaptic correlates of pre-synaptic changes in DA transmission and their relationship with MDMA enantiomers, we studied the effects of R,S(+/-)-MDMA, S(+)-MDMA, and R(-)-MDMA on extracellular DA and phosphorylated extracellular signal regulated kinase (pERK) in the NAc shell and core. Male Sprague-Dawley rats, implanted with a catheter in the femoral vein and vertical concentric dialysis probes in the NAc shell and core, were administered i.v. saline, R,S(+/-)-MDMA, S(+)-MDMA, or R(-)-MDMA. Extracellular DA was monitored by in vivo microdialysis with HPLC. Intravenous R,S(+/-)-MDMA (0.64, 1, and 2 mg/kg) increased dialysate DA, preferentially in the shell, in a dose-related manner. S(+)-MDMA exerted similar effects but at lower doses than R,S(+/-)-MDMA, while R(-)-MDMA (1 and 2 mg/kg) failed to affect dialysate DA. R,S(+/-)- and S(+)-MDMA but not R(-)-MDMA increased ERK phosphorylation (expressed as density/neuron and number of pERK-positive neurons/area) in both subdivisions of the NAc. The administration of the D1 receptor antagonist, SCH 39166, prevented the increase in pERK elicited by R,S(+/-)-MDMA and S(+)-MDMA, while the D2/3 receptor antagonist, raclopride, increased pERK in the NAc core per se but failed to affect the R,S(+/-)-MDMA-elicited stimulation of pERK. The present results provide evidence that the DA stimulant effects of racemic MDMA are accounted for by the S(+)-enantiomer and that pERK may represent a post-synaptic correlate of the stimulant effect of R,S(+/-)-MDMA on D1-dependent DA transmission.
Collapse
Affiliation(s)
- Elio Acquas
- Department of Toxicology, University of Cagliari, Cagliari, Italy
| | | | | | | | | | | |
Collapse
|
29
|
Fleckenstein AE, Volz TJ, Riddle EL, Gibb JW, Hanson GR. New insights into the mechanism of action of amphetamines. Annu Rev Pharmacol Toxicol 2007; 47:681-98. [PMID: 17209801 DOI: 10.1146/annurev.pharmtox.47.120505.105140] [Citation(s) in RCA: 479] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Amphetamine is a psychostimulant commonly used to treat several disorders, including attention deficit, narcolepsy, and obesity. Plasmalemmal and vesicular monoamine transporters, such as the neuronal dopamine transporter and the vesicular monoamine transporter-2, are two of its principal targets. This review focuses on new insights, obtained from both in vivo and in vitro studies, into the molecular mechanisms whereby amphetamine, and the closely related compounds methamphetamine and methylenedioxymethamphetamine, cause monoamine, and particularly dopamine, release. These mechanisms include amphetamine-induced exchange diffusion, reverse transport, and channel-like transport phenomena as well as the weak base properties of amphetamine. Additionally, amphetamine analogs may affect monoamine transporters through phosphorylation, transporter trafficking, and the production of reactive oxygen and nitrogen species. All of these mechanisms have potential implications for both amphetamine- and methamphetamine-induced neurotoxicity, as well as dopaminergic neurodegenerative diseases.
Collapse
Affiliation(s)
- Annette E Fleckenstein
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA.
| | | | | | | | | |
Collapse
|
30
|
Müller CP, Carey RJ, Huston JP, De Souza Silva MA. Serotonin and psychostimulant addiction: Focus on 5-HT1A-receptors. Prog Neurobiol 2007; 81:133-78. [PMID: 17316955 DOI: 10.1016/j.pneurobio.2007.01.001] [Citation(s) in RCA: 232] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 12/04/2006] [Accepted: 01/03/2007] [Indexed: 01/03/2023]
Abstract
Serotonin(1A)-receptors (5-HT(1A)-Rs) are important components of the 5-HT system in the brain. As somatodendritic autoreceptors they control the activity of 5-HT neurons, and, as postsynaptic receptors, the activity in terminal areas. Cocaine (COC), amphetamine (AMPH), methamphetamine (METH) and 3,4-methylenedioxymethamphetamine ("Ecstasy", MDMA) are psychostimulant drugs that can lead to addiction-related behavior in humans and in animals. At the neurochemical level, these psychostimulant drugs interact with monoamine transporters and increase extracellular 5-HT, dopamine and noradrenalin activity in the brain. The increase in 5-HT, which, in addition to dopamine, is a core mechanism of action for drug addiction, hyperactivates 5-HT(1A)-Rs. Here, we first review the role of the various 5-HT(1A)-R populations in spontaneous behavior to provide a background to elucidate the contribution of the 5-HT(1A)-Rs to the organization of psychostimulant-induced addiction behavior. The progress achieved in this field shows the fundamental contribution of brain 5-HT(1A)-Rs to virtually all behaviors associated with psychostimulant addiction. Importantly, the contribution of pre- and postsynaptic 5-HT(1A)-Rs can be dissociated and frequently act in opposite directions. We conclude that 5-HT(1A)-autoreceptors mainly facilitate psychostimulant addiction-related behaviors by a limitation of the 5-HT response in terminal areas. Postsynaptic 5-HT(1A)-Rs, in contrast, predominantly inhibit the expression of various addiction-related behaviors directly. In addition, they may also influence the local 5-HT response by feedback mechanisms. The reviewed findings do not only show a crucial role of 5-HT(1A)-Rs in the control of brain 5-HT activity and spontaneous behavior, but also their complex role in the regulation of the psychostimulant-induced 5-HT response and subsequent addiction-related behaviors.
Collapse
Affiliation(s)
- Christian P Müller
- Institute of Physiological Psychology I, University of Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
| | | | | | | |
Collapse
|
31
|
Verheij MMM, Cools AR. Differential contribution of storage pools to the extracellular amount of accumbal dopamine in high and low responders to novelty: effects of reserpine. J Neurochem 2007; 100:810-21. [PMID: 17144901 DOI: 10.1111/j.1471-4159.2006.04259.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present study examined the effects of reserpine on the extracellular concentration of accumbal dopamine in high responders (HR) and low responders (LR) to novelty rats. Reserpine reduced the baseline concentration of extracellular accumbal dopamine more in HR than in LR, indicating that the dopamine release is more dependent on reserpine-sensitive storage vesicles in non-challenged HR than in non-challenged LR. In addition, reserpine reduced the novelty-induced increase of the extracellular concentration of accumbal dopamine in LR, but not in HR, indicating that the dopamine release in response to novelty depends on reserpine-sensitive storage vesicles only in LR, not in HR. Our data clearly demonstrate that HR and LR differ in the characteristics of those monoaminergic storage vesicles that mediate accumbal dopamine release.
Collapse
Affiliation(s)
- M M M Verheij
- Department of Psychoneuropharmacology, Nijmegen Institute for Neurosciences, Faculty of Medicine, Radboud University of Nijmegen, Nijmegen, The Netherlands.
| | | |
Collapse
|
32
|
Liles JT, Baber SR, Deng W, Porter JR, Corll C, Murthy SN, Thomas SA, Kadowitz PJ. Pressor responses to ephedrine are not impaired in dopamine beta-hydroxylase knockout mice. Br J Pharmacol 2006; 150:29-36. [PMID: 17099719 PMCID: PMC2013852 DOI: 10.1038/sj.bjp.0706942] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Ephedrine and amphetamine can cause substantial increases in systemic arterial pressure. However, the role of endogenous noradrenaline release in mediating the pressor response to ephedrine is controversial. Studies using pharmacologic agents to decrease the synthesis, storage, and release of catecholamines have supported both a direct and an indirect mechanism of action for ephedrine. The purpose of the present study was to determine if endogenous noradrenaline release is required for cardiovascular responses to ephedrine and amphetamine using a genetic mouse model. EXPERIMENTAL APPROACH Increases in systemic arterial pressure and heart rate in response to ephedrine and amphetamine were investigated and compared in dopamine beta-hydroxylase knockout (Dbh -/-) mice that cannot synthesize noradrenaline. Dbh +/- littermates have normal noradrenaline and adrenaline tissue levels, and served as controls in all experiments. KEY RESULTS In Dbh -/- mice the increases in systemic arterial pressure and heart rate in response to i.v. injections of ephedrine were not impaired whereas responses to amphetamine were markedly reduced, when compared with responses in Dbh +/- mice. The pressor response to tyramine was abolished whereas pressor responses to noradrenaline, phenylephrine, dopamine, and angiotensin II were similar in Dbh -/- and Dbh +/- mice. CONCLUSIONS AND IMPLICATIONS The present results in Dbh -/- mice provide support for the hypothesis that pressor responses to ephedrine are directly mediated whereas responses to amphetamine are dependent on the release of noradrenaline and suggest that Dbh +/- and Dbh -/- mice are useful for the study of direct and indirect mechanisms.
Collapse
Affiliation(s)
- J T Liles
- Department of Pharmacology, Tulane University Health Sciences Center, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Easton N, Marsden CA. Ecstasy: are animal data consistent between species and can they translate to humans? J Psychopharmacol 2006; 20:194-210. [PMID: 16510478 DOI: 10.1177/0269881106061153] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The number of 3,4-methylenedioxymethamphetamine (ecstasy or MDMA) animal research articles is rapidly increasing and yet studies which place emphasis on the clinical significance are limited due to a lack of reliable human data. MDMA produces an acute, rapid release of brain serotonin and dopamine in experimental animals and in the rat this is associated with increased locomotor activity and the serotonin behavioural syndrome in rats. MDMA causes dose-dependent hyperthermia, which is potentially fatal, in humans, primates and rodents. Subsequent serotonergic neurotoxicity has been demonstrated by biochemical and histological studies and is reported to last for months in rats and years in non-human primates. Relating human data to findings in animals is complicated by reports that MDMA exposure in mice produces selective long-term dopaminergic impairment with no effect on serotonin. This review compares data obtained from animal and human studies and examines the acute physiological, behavioural and biochemical effects of MDMA as well as the long-term behavioural effects together with serotonergic and dopaminergic impairments. Consideration is also given to the role of neurotoxic metabolites and the influence of age, sex and user groups on the long-term actions of MDMA.
Collapse
Affiliation(s)
- Neil Easton
- School of Biomedical Science, University of Nottingham, Queen's Medical Centre, UK.
| | | |
Collapse
|
34
|
Liles JT, Dabisch PA, Hude KE, Pradhan L, Varner KJ, Porter JR, Hicks AR, Corll C, Baber SR, Kadowitz PJ. Pressor Responses to Ephedrine Are Mediated by a Direct Mechanism in the Rat. J Pharmacol Exp Ther 2005; 316:95-105. [PMID: 16002460 DOI: 10.1124/jpet.105.090035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanism of the pressor response to ephedrine is controversial. In the present study. i.v. injections of ephedrine increased systemic and pulmonary arterial pressure, and i.a. injections decreased hindlimb blood flow in a dose-related manner. Responses to ephedrine were inhibited by alpha-receptor blocking agents and were not attenuated by blockade of the norepinephrine reuptake transporter (NET) or by catecholamine depletion using reserpine or a combination of reserpine and alpha-methyl-p-tyrosine, whereas responses to tyramine and amphetamine were inhibited by these treatments. The magnitude of the pressor response to ephedrine was similar in anesthetized and conscious rats. Tachyphylaxis developed to pressor responses to ephedrine and amphetamine with sequential injections; however, ephedrine tachyphylaxis differed in that subsequent responses to alpha-receptor agonists were attenuated. These results suggest that the systemic and pulmonary pressor and hindlimb vasoconstrictor responses to ephedrine are mediated by direct action on alpha-adrenergic receptors and that the release of norepinephrine from adrenergic terminals plays no significant role. These results provide support for the hypothesis that responses to ephedrine are directly mediated in the intact rat, whereas responses to amphetamine are mediated in a large part by the release of norepinephrine from adrenergic terminals.
Collapse
Affiliation(s)
- John T Liles
- Department of Pharmacology SL83, School of Medicine, Tulane University Health Sciences Center, 1430 Tulane Ave., New Orleans, LA 70112, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Lebsanft HB, Kohles T, Kovar KA, Schmidt WJ. 3,4-Methylenedioxymethamphetamine counteracts akinesia enantioselectively in rat rotational behavior and catalepsy. Synapse 2005; 55:148-55. [PMID: 15602749 DOI: 10.1002/syn.20102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have shown recently that 3,4-methylenedioxymethamphetamine (MDMA) has symptomatic antiparkinsonian activity in rodent models of Parkinson's disease. In search of its mechanism of action, we further investigated the enantiomers of MDMA in the rotational behavioral model and catalepsy test. Catalepsy testing was done in drug-naive unlesioned animals. The parkinsonian symptoms rigor and akinesia (i.e., catalepsy) were induced by intraperitoneal administration of haloperidol 0.5 mg/kg and measured repeatedly as descent latency from a horizontal bar and a vertical grid. MDMA and both its enantiomers were effective in counteracting haloperidol-induced catalepsy, but if given as racemic, the effects were more pronounced than with the enantiomers. For testing of rotational behavior, male Sprague Dawley rats were lesioned unilaterally with 6-hydroxydopamine (6-OHDA) at the medial forebrain bundle. Administration of S-MDMA (5 mg/kg) produced ipsilateral rotations. R-MDMA was far less effective in inducing ipsilateral rotations in 6-OHDA unilaterally lesioned rats, but when S-MDMA was given additionally rotations immediately increased. Regarding their overall antiparkinsonian effects, the S-enantiomer of MDMA was more effective than its R-congener. R-MDMA was able to increase the actions of S-MDMA.
Collapse
MESH Headings
- Adrenergic Uptake Inhibitors/chemistry
- Adrenergic Uptake Inhibitors/pharmacology
- Adrenergic Uptake Inhibitors/therapeutic use
- Animals
- Antiparkinson Agents/chemistry
- Antiparkinson Agents/pharmacology
- Antiparkinson Agents/therapeutic use
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Catalepsy/chemically induced
- Catalepsy/drug therapy
- Catalepsy/physiopathology
- Denervation
- Disease Models, Animal
- Gait Disorders, Neurologic/chemically induced
- Gait Disorders, Neurologic/drug therapy
- Gait Disorders, Neurologic/physiopathology
- Haloperidol
- Male
- N-Methyl-3,4-methylenedioxyamphetamine/chemistry
- N-Methyl-3,4-methylenedioxyamphetamine/pharmacology
- N-Methyl-3,4-methylenedioxyamphetamine/therapeutic use
- Oxidopamine
- Parkinsonian Disorders/drug therapy
- Parkinsonian Disorders/physiopathology
- Rats
- Rats, Sprague-Dawley
- Rotation
- Stereoisomerism
Collapse
Affiliation(s)
- Heike B Lebsanft
- Neuropharmacology, Zoological Institute, Faculty of Biology, University of Tuebingen, 72076 Tuebingen, Germany.
| | | | | | | |
Collapse
|
36
|
Adams DH, Hanson GR, Keefe KA. 3,4-Methylenedioxymethamphetamine increases neuropeptide messenger RNA expression in rat striatum. ACTA ACUST UNITED AC 2005; 133:131-42. [PMID: 15661373 DOI: 10.1016/j.molbrainres.2004.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2004] [Indexed: 11/25/2022]
Abstract
The amphetamine analog 3,4-methylenedioxymethamphetamine (MDMA) is also known as the recreational drug of abuse, Ecstasy. Several neuropeptides are found in striatal neurons postsynaptic to dopamine and serotonin nerve terminals, and changes in neuropeptide neurotransmission may be important for behavioral effects of 3,4-methylenedioxymethamphetamine. This study used in situ hybridization to characterize the effects of 3,4-methylenedioxymethamphetamine on four neuropeptide mRNAs: preprodynorphin, preprotachykinin, neurotensin/neuromedin N, and preproenkephalin. Male, Sprague-Dawley rats received a single administration of 10 mg/kg 3,4-methylenedioxymethamphetamine and were sacrificed 30 min or 3 h later. Three hours after administration, 3,4-methylenedioxymethamphetamine increased preprodynorphin, preprotachykinin, and neurotensin/neuromedin N mRNAs. These increases were most prominent in ventral and medial aspects of the rostral-middle striatum, and then became more dorsally restricted in the caudal striatum. At the 30-minute time point, MDMA significantly decreased the signal for preproenkephalin mRNA in a general manner but did not affect the signal for the other neuropeptide precursors. These data suggest that 3,4-methylenedioxymethamphetamine has a generalized, transient, inhibitory effect on striatopallidal neuron gene expression, and then preferentially influences striatonigral neuropeptide systems at the later time point in a regionally selective manner.
Collapse
Affiliation(s)
- David H Adams
- Department of Pharmacology and Toxicology, University of Utah, 30 South 2000 East, Rm. 201, Salt Lake City, UT 84112-5820, USA
| | | | | |
Collapse
|
37
|
Nair SG, Gudelsky GA. Protein kinase C inhibition differentially affects 3,4-methylenedioxymethamphetamine-induced dopamine release in the striatum and prefrontal cortex of the rat. Brain Res 2004; 1013:168-73. [PMID: 15193525 DOI: 10.1016/j.brainres.2004.04.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2004] [Indexed: 11/22/2022]
Abstract
The acute administration of 3,4-methylenedioxymethamphetamine (MDMA) elevates extracellular concentrations of dopamine (DA) and serotonin (5-HT) in the rat striatum and medial prefrontal cortex (mPFC). The release of DA induced by MDMA is thought to involve both transporter and impulse-mediated processes. Furthermore, the impulse-dependent release of DA in the striatum elicited by MDMA appears to involve 5-HT2 receptor activation. Since 5-HT2 receptors are known to utilize protein kinase C (PKC) for intracellular signaling, we examined the effects of modulators of PKC activity on DA release stimulated by MDMA. Reverse dialysis of the PKC inhibitors bisindolylmaleimide I (BIM; 30 microM) or chelerythrine chloride (100 microM) through a microdialysis probe significantly attenuated the MDMA (10 mg/kg, i.p.)-induced increase in the extracellular concentration of DA in the striatum. In contrast, BIM did not significantly alter the increase in the extracellular concentration of DA in the striatum elicited by amphetamine (5 mg/kg, i.p.). Reverse dialysis of a PKC activator, phorbol 12,13-dibutyrate (PDBu) (0.5 microM), through the microdialysis probe into the striatum, significantly increased MDMA-induced DA release. In contrast to the inhibitory effects of the PKC inhibitors on MDMA-induced DA release in the striatum, intracortical infusion of BIM enhanced MDMA-induced release of DA in the mPFC. These data suggest that PKC-mediated signaling pathways differentially modulate MDMA-induced DA release from mesocorticolimbic and nigrostriatal neurons.
Collapse
Affiliation(s)
- Sunila G Nair
- College of Pharmacy, University of Cincinnati, 3223 Eden Avenue, Cincinnati, OH 45267, USA
| | | |
Collapse
|
38
|
Sieber BA, Kuzmin A, Canals JM, Danielsson A, Paratcha G, Arenas E, Alberch J, Ogren SO, Ibáñez CF. Disruption of EphA/ephrin-A signaling in the nigrostriatal system reduces dopaminergic innervation and dissociates behavioral responses to amphetamine and cocaine. Mol Cell Neurosci 2004; 26:418-28. [PMID: 15234346 DOI: 10.1016/j.mcn.2004.03.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2004] [Accepted: 03/25/2004] [Indexed: 01/28/2023] Open
Abstract
We have investigated functional roles of EphA/ephrin-A signaling in the development and function of the nigrostriatal system by overexpressing a soluble, broad-range EphA receptor antagonist in the central nervous system of transgenic mice. Adult transgenic mice showed a 30-40% reduction in the total volume of the substantia nigra (SN) without detectable differences in the number of dopaminergic neurons. Using fluorogold retrograde tracing from the striatum, we detected a 40-50% reduction in the number of dopaminergic neurons that could be traced from this structure in transgenic mice, suggesting that, a lower proportion of these cells were able to reach the striatum after disruption of EphA/ephrin-A signaling. In spite of this, total dopamine content in the striatum of transgenic mice was comparable to wild type. Analysis of locomotor activity and its regulation by pharmacological treatments that stimulate dopaminergic transmission revealed an unexpected dissociation of the behavioral responses to amphetamine and cocaine. In particular, transgenic mice were relatively insensitive to amphetamine while retaining normal responsiveness to cocaine, which, to the best of our knowledge, represents the first report of a dissociation of the behavioral responses to these two psychostimulants. Together, these results reveal an unexpected role for EphA/ephrin-A signaling in the normal connectivity and function of midbrain dopaminergic neurons.
Collapse
Affiliation(s)
- Beth-Anne Sieber
- Division of Molecular Neurobiology, Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Colado MI, O'Shea E, Green AR. Acute and long-term effects of MDMA on cerebral dopamine biochemistry and function. Psychopharmacology (Berl) 2004; 173:249-63. [PMID: 15083264 DOI: 10.1007/s00213-004-1788-8] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2003] [Accepted: 12/22/2003] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES The majority of experimental and clinical studies on the pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) tend to focus on its action on 5-HT biochemistry and function. However, there is considerable evidence for MDMA having marked acute effects on dopamine release. Furthermore, while MDMA produces long-term effects on 5-HT neurones in most species examined, in mice its long-term effects appear to be restricted to the dopamine system. The objective of this review is to examine the actions of MDMA on dopamine biochemistry and function in mice, rats, guinea pigs, monkeys and humans. RESULTS AND DISCUSSION MDMA appears to produce a major release of dopamine from its nerve endings in all species investigated. This release plays a significant role in the expression of many of the behaviours that occur, including behavioural changes, alterations of the mental state in humans and the potentially life-threatening hyperthermia that can occur. While MDMA appears to be a selective 5-HT neurotoxin in most species examined (rats, guinea pigs and primates), it is a selective dopamine neurotoxin in mice. Selectivity may be a consequence of what neurotoxic metabolites are produced (which may depend on dosing schedules), their selectivity for monoamine nerve endings, or the endogenous free radical trapping ability of specific nerve endings, or both. We suggest more focus be made on the actions of MDMA on dopamine neurochemistry and function to provide a better understanding of the acute and long-term consequences of using this popular recreational drug.
Collapse
Affiliation(s)
- M Isabel Colado
- Departamento de Farmacologia, Facultad de Medicina, Universidad Complutense, 28040 Madrid, Spain.
| | | | | |
Collapse
|
40
|
Wilhelm CJ, Johnson RA, Lysko PG, Eshleman AJ, Janowsky A. Effects of methamphetamine and lobeline on vesicular monoamine and dopamine transporter-mediated dopamine release in a cotransfected model system. J Pharmacol Exp Ther 2004; 310:1142-51. [PMID: 15102929 DOI: 10.1124/jpet.104.067314] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Dopamine (DA) retention and drug-induced release kinetics were characterized in human embryonic kidney (HEK)-293 cells stably coexpressing the human DA transporter (hDAT) and human vesicular monoamine transporter (hVMAT2). Cofunction of hDAT and hVMAT2 caused greater retention of [3H]DA at 20 min (37 degrees C), or 45 min (22 degrees C) compared with cells that were treated with dihydrotetrabenazene (DHTB) to block the hVMAT2. In hDAT- and hVMAT2-coexpressing cells treated with DHTB during [3H]DA loading, methamphetamine (METH)-induced efflux was only 20% of preloaded [3H]DA, compared with 50 to 60% efflux in the absence of DHTB. Interestingly, the presence of DHTB (during release only) increased the potency and efficacy of METH at inducing [3H]DA release (without DHTB: EC50=33.8 microM, maximal release 51%; release with DHTB: EC50=3.2 microM, maximal release 61%), suggesting that the effects of METH and DHTB on vesicular storage are additive. High concentrations of lobeline induced a statistically significant release of [3H]DA from HEK-hDAT-hVMAT2 cells, but only in the absence of DHTB, suggesting an hVMAT2-mediated effect. Likewise, lobeline did not induce a significant release of [3H]DA from HEK-hDAT cells. The substrates DA and p-tyramine induced robust release of preloaded [3H]DA from cotransfected cells. Cocaine was somewhat effective at blocking substrate-induced [3H]DA efflux. These results suggest that coexpression of the hDAT and hVMAT2 can be used as a model system to distinguish functional pools of DA and to quantify differences in drug effects on DA disposition. In addition, cotransfected cells can be used to determine mechanisms of simultaneous drug interactions at multiple sites.
Collapse
Affiliation(s)
- Clare J Wilhelm
- Research Service 22), Veterans Affairs Medical Center, 3710 S.W. U.S. Veterans Hospital Portland, OR 97239, USA
| | | | | | | | | |
Collapse
|
41
|
O'Neill MF, Heron-Maxwell C, Conway MW, Monn JA, Ornstein P. Group II metabotropic glutamate receptor antagonists LY341495 and LY366457 increase locomotor activity in mice. Neuropharmacology 2003; 45:565-74. [PMID: 12941370 DOI: 10.1016/s0028-3908(03)00232-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The group II metabotropic glutamate receptor (mGluR) antagonists LY341495 and LY366457 were profiled for their effects on locomotor activity in mice. Both compounds significantly increased locomotor activity. Observational studies showed that rearing was also selectively increased. LY366457-induced hyperactivity was significantly attenuated by the selective D1 dopamine receptor antagonist SCH23390 and also by the D2 dopamine receptor antagonist haloperidol but only at doses that significantly suppressed spontaneous locomotion. The selective 5-HT(2A) antagonist MDL100907 had no effect on LY366457-induced hyperactivity, while the less selective 5-HT(2A-C) antagonist ritanserin had only a modest effect. In all cases, the doses of antagonists that reduced the locomotor response to LY366457 were greater than those previously shown to reduce the locomotor response to the psychostimulants amphetamine and cocaine and MK-801. Pretreatment with reserpine also significantly attenuated the response to LY366457, possibly implicating a monoaminergic substrate in the mediation of this effect. The phenomenonology and pharmacology of the locomotor activation induced by the mGluR antagonists differs markedly from that induced by locomotor stimulants such as amphetamine, cocaine or MK-801. These results suggest that group II mGluRs may be involved in the tonic suppression of locomotor and exploratory activity, and this suppression can be disinhibited in the presence of a group II mGluR antagonist.
Collapse
Affiliation(s)
- Michael F O'Neill
- Eli Lilly and Company Ltd, Behavioural Pharmacology, Lilly Research Centre, Erl Wood Manor, Sunninghill Rd., Windlesham, Surrey GU20 6PH, UK.
| | | | | | | | | |
Collapse
|
42
|
Green AR, Mechan AO, Elliott JM, O'Shea E, Colado MI. The pharmacology and clinical pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy"). Pharmacol Rev 2003; 55:463-508. [PMID: 12869661 DOI: 10.1124/pr.55.3.3] [Citation(s) in RCA: 783] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The amphetamine derivative (+/-)-3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is a popular recreational drug among young people, particularly those involved in the dance culture. MDMA produces an acute, rapid enhancement in the release of both serotonin (5-HT) and dopamine from nerve endings in the brains of experimental animals. It produces increased locomotor activity and the serotonin behavioral syndrome in rats. Crucially, it produces dose-dependent hyperthermia that is potentially fatal in rodents, primates, and humans. Some recovery of 5-HT stores can be seen within 24 h of MDMA administration. However, cerebral 5-HT concentrations then decline due to specific neurotoxic damage to 5-HT nerve endings in the forebrain. This neurodegeneration, which has been demonstrated both biochemically and histologically, lasts for months in rats and years in primates. In general, other neurotransmitters appear unaffected. In contrast, MDMA produces a selective long-term loss of dopamine nerve endings in mice. Studies on the mechanisms involved in the neurotoxicity in both rats and mice implicate the formation of tissue-damaging free radicals. Increased free radical formation may result from the further breakdown of MDMA metabolic products. Evidence for the occurrence of MDMA-induced neurotoxic damage in human users remains equivocal, although some biochemical and functional data suggest that damage may occur in the brains of heavy users. There is also some evidence for long-term physiological and psychological changes occurring in human recreational users. However, such evidence is complicated by the lack of knowledge of doses ingested and the fact that many subjects studied are or have been poly-drug users.
Collapse
|
43
|
Shimosato K, Nagao N, Watanabe S, Kitayama S. Suppressive effects of trihexyphenidyl on methamphetamine-induced dopamine release as measured by in vivo microdialysis. Synapse 2003; 49:47-54. [PMID: 12710014 DOI: 10.1002/syn.10191] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abuse of methamphetamine (MAP) and cocaine causes severe medical and social problems throughout the world. Our previous study found that trihexyphenidyl (THP), a muscarinic cholinergic receptor antagonist, specifically suppressed the rewarding properties of MAP but not of cocaine, as measured by conditioned place preference in mice. The present study examined using in vivo microdialysis whether THP differentially affects the extracellular dopamine (DA) levels in the nucleus accumbens and striatum of mice injected with MAP and cocaine in comparison with another antimuscarinic agent, scopolamine (SCP). In addition, locomotor activity was simultaneously measured during microdialysis. In vivo microdialysis experiments revealed that during the initial hour after injection of MAP (1 mg/kg) DA levels increased up to 698% in the nucleus accumbens and 367% in the striatum as compared to the basal level. These increases were reduced to 293% in the nucleus accumbens and 207% in the striatum by treatment with 5 mg/kg THP. However, SCP (3 mg/kg) had no effect on the increases in extracellular DA levels in both regions after MAP injection. Cocaine (10 mg/kg) increased DA levels during the initial hour to 254% in the nucleus accumbens and 220% in the striatum as compared to the basal level. These increases were unaffected by treatment with either THP or SCP. On the contrary, both THP and SCP enhanced the locomotor-stimulant action of MAP and cocaine. These results, together with our previous finding, suggest that THP may specifically antagonize the rewarding properties of MAP through suppression of DA release in the mesolimbic area without retarding locomotor activity.
Collapse
Affiliation(s)
- Kazuaki Shimosato
- Department of Pharmacology, Kawasaki Medical School, Kurashiki, Okayama 701-0192, Japan.
| | | | | | | |
Collapse
|
44
|
Cole JC, Sumnall HR. The pre-clinical behavioural pharmacology of 3,4-methylenedioxymethamphetamine (MDMA). Neurosci Biobehav Rev 2003; 27:199-217. [PMID: 12788333 DOI: 10.1016/s0149-7634(03)00031-9] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
3,4-Methylenedioxymethamphetamine (MDMA) is a relatively novel drug of abuse and as such little is currently known of its behavioural pharmacology. This review aims to examine whether MDMA represents a novel class of abused drug. MDMA is known as a selective serotonergic neurotoxin in a variety of animal species but acutely it is a potent releaser and/or reuptake inhibitor of presynaptic serotonin, dopamine, noradrenaline, and acetylcholine. Interaction of these effects contributes to its behavioural pharmacology, in particular its effects on body temperature. Drug discrimination studies indicate that MDMA and related drugs produce unique interoceptive effects which have led to their classification as entactogens. This is supported by results from other behavioural paradigms although there is evidence for dose dependency of MDMA-specific effects. MDMA also produces conditioned place preference but is not a potent reinforcer in self-administration studies. These unique behavioural effects probably underlie its current popularity. MDMA is found in the street drug ecstasy but it may not be appropriate to equate the two as other drugs are routinely found in ecstasy tablets
Collapse
Affiliation(s)
- Jon C Cole
- Department of Psychology, University of Liverpool, L69 7ZA, Liverpool, UK.
| | | |
Collapse
|
45
|
Falk EM, Cook VJ, Nichols DE, Sprague JE. An antisense oligonucleotide targeted at MAO-B attenuates rat striatal serotonergic neurotoxicity induced by MDMA. Pharmacol Biochem Behav 2002; 72:617-22. [PMID: 12175458 DOI: 10.1016/s0091-3057(02)00728-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The present study was designed to elucidate the role of dopamine (DA) metabolism in the serotonergic neurotoxicity induced by 3,4-methylenedioxymethamphetamine (MDMA). An antisense (AS) oligonucleotide (ODN) sequence targeted at monoamine oxidase-B (MAO-B) was utilized to attenuate MAO-B activity prior to MDMA administration. Sprague-Dawley rats were surgically implanted with intracerebroventricular (icv) cannulae and received a continuous infusion of MAO-B AS-ODN via an osmotic minipump. Constant AS ODN infusion for 7 days at a rate of 0.5 microl/h (total daily dose 600 pmol) resulted in a 63% knockdown of MAO-B activity. MDMA (40 mg/kg, sc) produced a rise in body temperature within 1 h of MDMA administration and a reduction in striatal serotonin (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) levels 7 days later. Pretreatment with the MAO-B AS ODN prior to MDMA attenuated this reduction in serotonergic markers, yet had no effect on MDMA-induced hyperthermia. Furthermore, in vivo microdialysis revealed that previous AS ODN treatment failed to alter the acute DA release induced by MDMA (10 mg/kg, sc) within the striatum. These results indicate that MAO-B plays an integral role in the development of MDMA-induced neurotoxicity while not affecting MDMA-induced hyperthermia or acute DA release.
Collapse
Affiliation(s)
- Erin M Falk
- The Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, Ada 45810, USA
| | | | | | | |
Collapse
|
46
|
Camarero J, Sanchez V, O'Shea E, Green AR, Colado MI. Studies, using in vivo microdialysis, on the effect of the dopamine uptake inhibitor GBR 12909 on 3,4-methylenedioxymethamphetamine ('ecstasy')-induced dopamine release and free radical formation in the mouse striatum. J Neurochem 2002; 81:961-72. [PMID: 12065608 DOI: 10.1046/j.1471-4159.2002.00879.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The present study examined the mechanisms by which 3,4-methylenedioxymethamphetamine (MDMA) produces long-term neurotoxicity of striatal dopamine neurones in mice and the protective action of the dopamine uptake inhibitor GBR 12909. MDMA (30 mg/kg, i.p.), given three times at 3-h intervals, produced a rapid increase in striatal dopamine release measured by in vivo microdialysis (maximum increase to 380 +/- 64% of baseline). This increase was enhanced to 576 +/- 109% of baseline by GBR 12909 (10 mg/kg, i.p.) administered 30 min before each dose of MDMA, supporting the contention that MDMA enters the terminal by diffusion and not via the dopamine uptake site. This, in addition to the fact that perfusion of the probe with a low Ca(2+) medium inhibited the MDMA-induced increase in extracellular dopamine, indicates that the neurotransmitter may be released by a Ca(2+) -dependent mechanism not related to the dopamine transporter. MDMA (30 mg/kg x 3) increased the formation of 2,3-dihydroxybenzoic acid (2,3-DHBA) from salicylic acid perfused through a probe implanted in the striatum, indicating that MDMA increased free radical formation. GBR 12909 pre-treatment attenuated the MDMA-induced increase in 2,3-DHBA formation by approximately 50%, but had no significant intrinsic radical trapping activity. MDMA administration increased lipid peroxidation in striatal synaptosomes, an effect reduced by approximately 60% by GBR 12909 pre-treatment. GBR 12909 did not modify the MDMA-induced changes in body temperature. These data suggest that MDMA-induced toxicity of dopamine neurones in mice results from free radical formation which in turn induces an oxidative stress process. The data also indicate that the free radical formation is probably not associated with the MDMA-induced dopamine release and that MDMA does not induce dopamine release via an action at the dopamine transporter.
Collapse
Affiliation(s)
- Jorge Camarero
- Departamento de Farmacologia, Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | | | | | | | | |
Collapse
|
47
|
Zimmer L, Vancassel S, Cantagrel S, Breton P, Delamanche S, Guilloteau D, Durand G, Chalon S. The dopamine mesocorticolimbic pathway is affected by deficiency in n-3 polyunsaturated fatty acids. Am J Clin Nutr 2002; 75:662-7. [PMID: 11916751 DOI: 10.1093/ajcn/75.4.662] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Several findings in humans support the hypothesis of links between n-3 polyunsaturated fatty acid (PUFA) status and psychiatric diseases. OBJECTIVE The involvement of PUFAs in central nervous system function can be assessed with the use of dietary manipulation in animal models. We studied the effects of chronic dietary n-3 PUFA deficiency on mesocorticolimbic dopamine neurotransmission in rats. DESIGN Using dual-probe microdialysis, we analyzed dopamine release under amphetamine stimulation simultaneously in the frontal cortex and the nucleus accumbens. The messenger RNA (mRNA) expression of vesicular monoamine transporter(2) and dopamine D(2) receptor was studied with the use of in situ hybridization. The protein expression of the synthesis-limiting enzyme tyrosine 3-monooxygenase (tyrosine 3-hydroxylase) was studied with the use of immunocytochemistry. RESULTS Dopamine release was significantly lower in both cerebral areas in n-3 PUFA-deficient rats than in control rats, but this effect was abolished in the frontal cortex and reversed in the nucleus accumbens by reserpine pretreatment, which depletes the dopamine vesicular storage pool. The mRNA expression of vesicular monoamine transporter(2) was lower in both cerebral areas in n-3 PUFA-deficient rats than in control rats, whereas the mRNA expression of D(2) receptor was lower in the frontal cortex and higher in the nucleus accumbens in n-3 PUFA-deficient rats than in control rats. Finally, tyrosine 3-monooxygenase immunoreactivity was higher in the ventral tegmental area in n-3 PUFA-deficient rats than in control rats. CONCLUSIONS Our results suggest that the mesolimbic dopamine pathway is more active whereas the mesocortical pathway is less active in n-3 PUFA-deficient rats than in control rats. This provides new neurochemical evidence supporting the effects of n-3 PUFA deficiency on behavior.
Collapse
Affiliation(s)
- Luc Zimmer
- INSERM U316, Laboratoire de Biophysique Médicale et Pharmaceutique, Université François Rabelais, Tours, France
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Mechan AO, Esteban B, O'Shea E, Elliott JM, Colado MI, Green AR. The pharmacology of the acute hyperthermic response that follows administration of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') to rats. Br J Pharmacol 2002; 135:170-80. [PMID: 11786492 PMCID: PMC1573106 DOI: 10.1038/sj.bjp.0704442] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The pharmacology of the acute hyperthermia that follows 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') administration to rats has been investigated. 2. MDMA (12.5 mg kg(-1) i.p.) produced acute hyperthermia (measured rectally). The tail skin temperature did not increase, suggesting that MDMA may impair heat dissipation. 3. Pretreatment with the 5-HT(1/2) antagonist methysergide (10 mg kg(-1)), the 5-HT(2A) antagonist MDL 100,907 (0.1 mg kg(-1)) or the 5-HT(2C) antagonist SB 242084 (3 mg kg(-1)) failed to alter the hyperthermia. The 5-HT(2) antagonist ritanserin (1 mg kg(-1)) was without effect, but MDL 11,939 (5 mg kg(-1)) blocked the hyperthermia, possibly because of activity at non-serotonergic receptors. 4. The 5-HT uptake inhibitor zimeldine (10 mg kg(-1)) had no effect on MDMA-induced hyperthermia. The uptake inhibitor fluoxetine (10 mg kg(-1)) markedly attenuated the MDMA-induced increase in hippocampal extracellular 5-HT, also without altering hyperthermia. 5. The dopamine D(2) antagonist remoxipride (10 mg kg(-1)) did not alter MDMA-induced hyperthermia, but the D(1) antagonist SCH 23390 (0.3 - 2.0 mg kg(-1)) dose-dependently antagonized it. 6. The dopamine uptake inhibitor GBR 12909 (10 mg kg(-1)) did not alter the hyperthermic response and microdialysis demonstrated that it did not inhibit MDMA-induced striatal dopamine release. 7. These results demonstrate that in vivo MDMA-induced 5-HT release is inhibited by 5-HT uptake inhibitors, but MDMA-induced dopamine release may not be altered by a dopamine uptake inhibitor. 8. It is suggested that MDMA-induced hyperthermia results not from MDMA-induced 5-HT release, but rather from the increased release of dopamine that acts at D(1) receptors. This has implications for the clinical treatment of MDMA-induced hyperthermia.
Collapse
MESH Headings
- 3,4-Methylenedioxyamphetamine/analogs & derivatives
- 3,4-Methylenedioxyamphetamine/toxicity
- Acute Disease
- Animals
- Benzazepines/pharmacology
- Body Temperature/drug effects
- Corpus Striatum/drug effects
- Corpus Striatum/metabolism
- Dopamine/metabolism
- Dopamine Antagonists/pharmacology
- Dopamine Uptake Inhibitors/pharmacology
- Fever/chemically induced
- Hallucinogens/toxicity
- Hippocampus/drug effects
- Hippocampus/metabolism
- Male
- Methysergide/pharmacology
- N-Methyl-3,4-methylenedioxyamphetamine/toxicity
- Neuroprotective Agents/pharmacology
- Piperazines/pharmacology
- Piperidines/pharmacology
- Rats
- Rats, Inbred Strains
- Receptor, Serotonin, 5-HT2A
- Receptor, Serotonin, 5-HT2C
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/metabolism
- Remoxipride/pharmacology
- Ritanserin/pharmacology
- Serotonin Antagonists/pharmacology
- Selective Serotonin Reuptake Inhibitors/pharmacology
Collapse
Affiliation(s)
- Annis O Mechan
- Pharmacology Research Group, School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9RH
| | - Blanca Esteban
- Pharmacology Research Group, School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9RH
- Departamento de Farmacologia, Facultad de Medicina, Universidad Complutense, Madrid 28040, Spain
| | - Esther O'Shea
- Departamento de Farmacologia, Facultad de Medicina, Universidad Complutense, Madrid 28040, Spain
| | - J Martin Elliott
- Pharmacology Research Group, School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9RH
| | - M Isabel Colado
- Departamento de Farmacologia, Facultad de Medicina, Universidad Complutense, Madrid 28040, Spain
| | - A Richard Green
- Pharmacology Research Group, School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9RH
- AstraZeneca R&D Charnwood, Bakewell Road, Loughborough LE11 5RH
- Author for correspondence:
| |
Collapse
|
49
|
Colado MI, Camarero J, Mechan AO, Sanchez V, Esteban B, Elliott JM, Green AR. A study of the mechanisms involved in the neurotoxic action of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') on dopamine neurones in mouse brain. Br J Pharmacol 2001; 134:1711-23. [PMID: 11739248 PMCID: PMC1572911 DOI: 10.1038/sj.bjp.0704435] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. Administration of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') to mice produces acute hyperthermia and long-term degeneration of striatal dopamine nerve terminals. Attenuation of the hyperthermia decreases the neurodegeneration. We have investigated the mechanisms involved in producing the neurotoxic loss of striatal dopamine. 2. MDMA produced a dose-dependent loss in striatal dopamine concentration 7 days later with 3 doses of 25 mg kg(-1) (3 h apart) producing a 70% loss. 3. Pretreatment 30 min before each MDMA dose with either of the N-methyl-D-aspartate antagonists AR-R15896AR (20, 5, 5 mg kg(-1)) or MK-801 (0.5 mg kg(-1)x3) failed to provide neuroprotection. 4. Pretreatment with clomethiazole (50 mg kg(-1)x3) was similarly ineffective in protecting against MDMA-induced dopamine loss. 5. The free radical trapping compound PBN (150 mg kg(-1)x3) was neuroprotective, but it proved impossible to separate neuroprotection from a hypothermic effect on body temperature. 6. Pretreatment with the nitric oxide synthase (NOS) inhibitor 7-NI (50 mg kg(-1)x3) produced neuroprotection, but also significant hypothermia. Two other NOS inhibitors, S-methyl-L-thiocitrulline (10 mg kg(-1)x3) and AR-R17477AR (5 mg kg(-1)x3), provided significant neuroprotection and had little effect on MDMA-induced hyperthermia. 7. MDMA (20 mg kg(-1)) increased 2,3-dihydroxybenzoic acid formation from salicylic acid perfused through a microdialysis tube implanted in the striatum, indicating increased free radical formation. This increase was prevented by AR-R17477AR administration. Since AR-R17477AR was also found to have no radical trapping activity this result suggests that MDMA-induced neurotoxicity results from MDMA or dopamine metabolites producing radicals that combine with NO to form tissue-damaging peroxynitrites.
Collapse
Affiliation(s)
- M Isabel Colado
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid 28040, Spain
| | - Jorge Camarero
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid 28040, Spain
| | - Annis O Mechan
- Pharmacology Research Group, School of Pharmacy, De Montfort University, Leicester LE1 9RH
| | - Veronica Sanchez
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid 28040, Spain
| | - Blanca Esteban
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid 28040, Spain
- Pharmacology Research Group, School of Pharmacy, De Montfort University, Leicester LE1 9RH
| | - J Martin Elliott
- Pharmacology Research Group, School of Pharmacy, De Montfort University, Leicester LE1 9RH
| | - A Richard Green
- Pharmacology Research Group, School of Pharmacy, De Montfort University, Leicester LE1 9RH
- AstraZeneca R&D Charnwood, Bakewell Road, Loughborough LE11 5RH
- Author for correspondence:
| |
Collapse
|
50
|
O'Shea E, Esteban B, Camarero J, Green AR, Colado MI. Effect of GBR 12909 and fluoxetine on the acute and long term changes induced by MDMA ('ecstasy') on the 5-HT and dopamine concentrations in mouse brain. Neuropharmacology 2001; 40:65-74. [PMID: 11077072 DOI: 10.1016/s0028-3908(00)00106-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We examined the long term effect of 3,4 methylenedioxymethamphetamine (MDMA, 10, 20 and 30 mg/kg, i.p.) on the cerebral 5-hydroxytryptamine (5-HT) and dopamine content in Swiss Webster mice. Three injections of MDMA (20 or 30 mg/kg, i.p.) given 3 h apart produced a marked depletion in the striatal content of dopamine and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) 7 days later. None of the doses administered altered the concentration of 5-HT or its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in several brain areas. Pre-treatment with the dopamine uptake inhibitor GBR 12909 (10 mg/kg, i.p.), 30 min before each of the three MDMA (30 mg/kg, i.p.) injections, completely prevented the long term loss in the striatal catechol concentrations. However, GBR 12909 (10 mg/kg, i.p.) not only failed to prevent the acute effects induced by MDMA (30 mg/kg x 3, i.p.) on dopamine metabolism 30 min later, but in fact potentiated them. The 5-HT uptake inhibitor, fluoxetine (10 mg/kg, i. p.) failed to prevent both the acute and long term dopaminergic deficits. MDMA (30 mg/kg x 3) altered the body temperature of the mice biphasically, producing a rapid hyperthermia followed by prolonged hypothermia. In contrast, MDMA (20 mg/kg x 3) produced an initial hypothermia followed by hyperthermia. The present experiments therefore appear to rule out any direct relationship between the neurotoxic effects of MDMA and its acute effects on body temperature in mice. Fluoxetine administered 30 min before each MDMA (30 mg/kg) injection prevented these temperature changes, while GBR 12909 was without effect. This suggests that the neuroprotective effect of GBR 12909 against MDMA-induced neurotoxicity is not directly related to its ability to inhibit the MDMA-induced acute effects on dopamine metabolism or alter the MDMA-induced temperature change. The data illustrate major differences in the neurotoxic profile of MDMA in mice and rats.
Collapse
Affiliation(s)
- E O'Shea
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, 28040, Madrid, Spain
| | | | | | | | | |
Collapse
|