Koprich James B, Campbell Nicholas G, Lipton Jack W
Department of Neurological Sciences, Rush University, Rush-Presbyterian-St. Luke's Medical Center, 1735 W. Harrison Street, Suite 265, Chicago, IL 60612, USA.
Brain Res Dev Brain Res. 2003 Dec 30;147(1-2):177-82. doi: 10.1016/s0165-3806(03)00219-0.
Growing concerns surround the risk of fetal exposure to 3,4-methylenedioxymethamphetamine (MDMA; ecstasy). Prior animal studies using neonatal rats administered MDMA from postnatal days (P) 11-20 (a period approximating third trimester brain development in humans) have demonstrated long-lasting decrements in serotonin (5-HT) and learning; however, no studies have examined the acute post-MDMA response of the brain at this early age. Specifically, it is of interest whether MDMA administration to neonatal rats produces the expected depletion of monoamines and whether the brain exhibits any ameliorative response to the pharmacologic insult. In the current study, this model was employed to determine whether forebrain and brainstem dopamine (DA) and 5-HT neurochemistry were altered 24 h after the last injection (P21), and whether brain-derived neurotrophic factor (BDNF) was upregulated in response to MDMA exposure. All forebrain structures examined (frontal cortex, hippocampus, and striatum) showed significant MDMA-induced reductions in 5-HT and its metabolite, 5-HIAA, and significant increases in the DA metabolite, HVA, as well as DA turnover (HVA/DA). In the brainstem, there were significant increases in 5-HIAA, HVA and DA turnover. BDNF was significantly increased (19-38%) in all forebrain structures and in the brainstem in MDMA-exposed neonates versus saline controls. These data suggest that MDMA exposure to the developing rat brain from P11-20 produces similar alterations in serotonin and dopamine neurochemistry to those observed from adult administrations. In addition, a compensatory increase in BDNF was observed and may be the brains ameliorative response to minimize MDMA effects. This is the first report demonstrating that MDMA exposure results in increased levels of BDNF and that such increases are correlated with changes in monoamine levels. Future research is needed to elucidate any deleterious effects MDMA-induced increases in trophic activity might have on the developing brain and to examine earlier gestational exposure periods in order to assess the risk throughout pregnancy.
人们越来越担心胎儿接触3,4-亚甲基二氧甲基苯丙胺(摇头丸)的风险。先前使用新生大鼠进行的动物研究,在出生后第11 - 20天(相当于人类妊娠晚期大脑发育阶段)给予摇头丸,结果显示血清素(5-羟色胺,5-HT)水平和学习能力出现长期下降;然而,尚无研究考察这一年龄段大鼠在接触摇头丸后的急性脑反应。具体而言,给新生大鼠服用摇头丸是否会导致预期的单胺耗竭,以及大脑是否会对这种药物损伤表现出任何改善反应,这一点很值得关注。在当前研究中,采用该模型来确定末次注射后24小时(出生后第21天,P21)前脑和脑干中的多巴胺(DA)和5-羟色胺神经化学是否发生改变,以及脑源性神经营养因子(BDNF)是否会因接触摇头丸而上调。所有检测的前脑结构(额叶皮质、海马体和纹状体)均显示,摇头丸导致5-羟色胺及其代谢物5-羟吲哚乙酸(5-HIAA)显著减少,多巴胺代谢物高香草酸(HVA)以及多巴胺周转率(HVA/DA)显著增加。在脑干中,5-HIAA、HVA和多巴胺周转率显著增加。与生理盐水对照组相比,接触摇头丸的新生大鼠前脑所有结构和脑干中的BDNF均显著增加(19% - 38%)。这些数据表明,出生后第11 - 20天接触摇头丸的发育中大鼠大脑,其血清素和多巴胺神经化学变化与成年给药后的变化相似。此外,还观察到BDNF出现代偿性增加,这可能是大脑为将摇头丸的影响降至最低而产生的改善反应。这是首份表明接触摇头丸会导致BDNF水平升高且这种升高与单胺水平变化相关的报告。未来需要开展研究,以阐明摇头丸诱导的营养活性增加可能对发育中大脑产生的任何有害影响,并研究更早的孕期接触期,以便评估整个孕期的风险。