Charles University in Prague, Third Faculty of Medicine, Department of Normal, Pathological and Clinical Physiology, Ke Karlovu 4, Prague, Czech Republic.
Behav Brain Res. 2010 Mar 17;208(1):63-71. doi: 10.1016/j.bbr.2009.11.001. Epub 2009 Nov 10.
The aim of our study was to examine the effect of prenatal methamphetamine (MA) exposure and cross-fostering on cognitive functions of adult male rats tested in Morris water maze (MWM). Rat mothers were exposed daily to injection of MA (5mg/kg) or saline for 9 weeks: prior to impregnation, throughout gestation and lactation periods. Females without any injections were used as an absolute control. On postnatal day 1, pups were cross-fostered so that each mother raised 4 pups of her own and 8 pups from the mothers with the other two treatments. Four types of tests were used: (1) Place navigation test (Learning), (2) Probe test (Probe), (3) Retention memory test (Memory) and (4) Visible platform task. Our results demonstrate that the prenatal exposure to MA does not impact learning and memory, while postnatal exposure to MA shows impairments in cognition. In the test of learning, all animals fostered to MA-treated dams had longer latencies, bigger search error and used lower spatial strategies than the animals fostered to control or saline-treated mother, regardless of prenatal exposure. Regardless of postnatal exposure, the animals prenatally exposed to saline swam faster in all the tests than the animals prenatally exposed to MA and controls, respectively. This study indicates that postnatal but not prenatal exposure to MA affects learning in adult male rats. However, it is still not clear whether these impairments are due to a direct effect of MA on neuronal structure or due to an indirect effect of MA mediated by impaired maternal care.
我们的研究目的是检验产前甲基苯丙胺（MA）暴露和交叉寄养对雄性成年大鼠在 Morris 水迷宫（MWM）中认知功能的影响。鼠母每日接受 MA（5mg/kg）或生理盐水注射，共 9 周：在受孕前、整个妊娠期和哺乳期。未接受任何注射的雌性作为绝对对照。在产后第 1 天，幼崽被交叉寄养，这样每个母亲就可以抚养 4 只自己的幼崽和 8 只来自接受其他两种处理的母亲的幼崽。使用了四种测试：（1）位置导航测试（学习），（2）探测测试（探测），（3）保留记忆测试（记忆）和（4）可见平台任务。我们的结果表明，产前暴露于 MA 不会影响学习和记忆，而产后暴露于 MA 则显示出认知障碍。在学习测试中，所有寄养在 MA 处理过的母鼠的幼崽的潜伏期更长，搜索错误更大，并且使用的空间策略更低，而与寄养在对照或生理盐水处理的母鼠的幼崽相比，无论产前暴露如何。无论产后暴露如何，在所有测试中，产前暴露于生理盐水的动物比产前暴露于 MA 和对照的动物游泳速度都更快。这项研究表明，产后而不是产前暴露于 MA 会影响成年雄性大鼠的学习能力。然而，目前尚不清楚这些损伤是由于 MA 对神经元结构的直接影响，还是由于 MA 通过受损的母婴照顾而产生的间接影响。
