Alterations in diurnal and nocturnal locomotor activity in rats treated with a monoamine-depleting regimen of methamphetamine or 3,4-methylenedioxymethamphetamine

被引:24
作者
Wallace, TL
Gudelsky, GA
Vorhees, CV
机构
[1] Childrens Hosp Res Fdn, Div Dev Biol, Cincinnati, OH 45229 USA
[2] Univ Cincinnati, Grad Program Neurosci, Cincinnati, OH USA
[3] Univ Cincinnati, Coll Pharm, Cincinnati, OH USA
关键词
methamphetamine; MDMA; neurotoxicity; locomotor activity; diurnal cycle; nocturnal cycle;
D O I
10.1007/s002130000578
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
Rationale: The long-term neurochemical effects produced by the repeated administration of methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) are well documented; however, the functional consequences have not been clearly defined. Objective: The present study was designed to investigate whether rats treated with a monoamine-depleting regimen of MA or MDMA exhibit disturbances in locomotor activity during the diurnal and nocturnal cycles. Methods: Rats were treated with the vehicle or a monoamine-depleting regimen of MA or MDMA (10 mg/kg, IP, every 2 h for four injections on a single day). One week after drug treatment, the rats were placed in residential activity chambers and their locomotor activity was monitored for the next 7-day/night cycles. Results: MA-treated rats exhibited depletions of striatal dopamine and serotonin content of approximately 70%, whereas MDMA-treated rats showed depletions of striatal serotonin content of approximately 50%. Rats treated with MA demonstrated a significant reduction in diurnal, but not nocturnal, locomotor activity, whereas MDMA-treated rats exhibited significant reductions in both diurnal and nocturnal locomotor activity. Analysis of the difference in activity between the nocturnal and diurnal cycles revealed that MA-treated animals exhibited a significantly greater change in activity as compared to that observed in vehicle- and MDMA-treated rats. Conclusions: Although it is unknown whether the adaptations in locomotor activity observed in MA- and MDMA-treated rats are due to the loss of dopamine and/or serotonin, these data suggest that the administration of a monoamine-depleting regimen of MA or MDMA results in alterations in light-cycle-dependent locomotor activity.
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页码:321 / 326
页数:6
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