Drugs online research references
Synapse. 1991 Aug;8(4):249-60.
Neuroanatomic specificity and time course of alterations in rat brain serotonergic pathways induced by MDMA (3,4-methylenedioxymethamphetamine): assessment using quantitative autoradiography.
Battaglia G, Sharkey J, Kuhar MJ, de Souza EB.
Neuroscience Branch, National Institute on Drug Abuse, Baltimore, Maryland 21224.
The widely abused "designer" drug MDMA (3,4-methylenedioxymethamphetamine) has been shown to cause marked and long-lasting changes in brain serotonergic systems. The present study uses quantitative in vitro autoradiography of 3H-paroxetine labeled 5-HT uptake sites to assess the time-dependent effects of MDMA on 5-HT neurons in specific neuroanatomic loci. Following treatment with MDMA (20 mg/kg, b.i.d. for 4 days), marked decreases in 5-HT uptake sites were observed in a number of brain regions known to receive projections of 5-HT neurons. These regions included cerebral cortex, caudate nucleus, hippocampus, nucleus accumbens, olfactory tubercle, superior and inferior colliculi, geniculate nuclei, and most thalamic nuclei. In contrast, other areas such as the septal nuclei and some thalamic nuclei which also receive 5-HT projections were not substantially affected by this drug. In most regions, decreases in 5-HT uptake sites occurred within 24 hours of the last dose of MDMA and persisted at the 2 week time point. Some regions such as dorsal striatum exhibited a time-dependent reduction with greater reductions occurring at 2 weeks rather than immediately following the MDMA treatment regimen. The density of 5-HT uptake sites in other regions such as endopiriform nucleus and substantia nigra at the 2 week versus 18 hour time point indicated some degree of region-specific recovery. Regions which demonstrated no significant reduction in 5-HT uptake sites included the dorsal and median raphe nuclei, ventral tegmental area, central grey, interpeduncular nucleus, locus coerulus, pontine reticular formation and cerebellum. Likewise, regions containing 5-HT axons of passage (e.g., indusium griseum and lateral hypothalamus) appeared to be insensitive to the neurotoxic effects of MDMA on 5-HT neurons. Furthermore, the neurotoxic effects of MDMA showed specificity in that the catecholamine neurons labeled by 3H-mazindol were unaffected by the treatment regimen. These data indicate that the preferential degeneration of serotonergic neurons by MDMA is mediated primarily at 5-HT terminal regions, whereas regions containing 5-HT perikarya and axons of passage remain relatively unaffected. In addition, the observed time-dependent reductions and recovery of 5-HT uptake sites which were detected within 2 weeks of the treatment regimen in certain brain regions suggest region-specific differences in recovery of 5-HT systems from MDMA-induced lesion.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1681594&dopt=Abstract
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Psychopharmacology (Berl). 1991;105(1):113-8.
Alterations in hippocampal function following repeated exposure to the amphetamine derivative methylenedioxymethamphetamine ("Ecstasy").
Sharkey J, McBean DE, Kelly PA.
University of Edinburgh, Department of Clinical Neurosciences, Western General Hospital, UK.
The effect of the psychomotor stimulant, 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"), upon integrated cerebral function was measured in rats using the quantitative [14C]deoxyglucose autoradiographic technique. Animals were injected with MDMA (20 mg/kg sc) twice daily for 4 days. Fourteen days after the final administration, [3H]-paroxetine binding to 5HT uptake sites was reduced by 89% in membranes prepared from tissue samples of frontal cortex. In the same rats [3H]-paroxetine binding autoradiography revealed heterogeneity in the regional distribution of 5-HT uptake site depletion within neocortex (0-92%) and hippocampus (30-95%). Despite these profound reductions in 5-HT uptake sites no significant alterations were found in glucose utilisation in any area of neocortex examined. However, significant increases in glucose use were found in subregions of the hippocampus, most notably within the pyramidal cell layer of CA2 and CA3 (25-35%). This study provides direct evidence that the loss of 5-HT innervation caused by exposure to MDMA results in lasting functional changes in hippocampus.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1684057&dopt=Abstract
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Neuropharmacology. 1990 Jul;29(7):633-9.
Reduction of in vivo binding of [3H]paroxetine in mouse brain by 3,4-methylenedioxymethamphetamine.
Hashimoto K, Goromaru T.
Department of Radiopharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, University of Fukuyama, Japan.
The effects of 3,4-methylenedioxymethamphetamine (MDMA) on the in vivo binding of [3H]paroxetine, a potent and selective 5-hydroxytryptamine (5-HT; serotonin) uptake inhibitor, in the brain of the mouse were studied. The distribution of radioactivity in the brain of the mouse, after intravenous administration of [3H]paroxetine, was significantly altered by pretreatment with MDMA (15 mg/kg, i.p., 3 hr before). The hypothalamus/cerebellum and cerebral cortex/cerebellum ratios, as a function of time, were significantly decreased after the pretreatment with MDMA, indicating that the in vivo binding of [3H]paroxetine to uptake sites for 5-HT in the brain of the mouse was significantly decreased by MDMA. These ratios could reflect those of the total binding, to the non-specific binding and free ligand, since the cerebellum has very low levels of binding for [3H]paroxetine. Furthermore, these ratios decreased after pretreatment with MDMA, in a dose-dependent manner. However, the binding of [3H]paroxetine to membranes from the brain of the mouse in vitro was not altered by treatment with MDMA. The discrepancy between the in vivo binding and in vitro binding of [3H]paroxetine in the brain of the mouse is discussed.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1696701&dopt=Abstract
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