Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, United States.
Behav Brain Res. 2011 Jan 1;216(1):396-401. doi: 10.1016/j.bbr.2010.08.022. Epub 2010 Aug 24.
Repeated administration of methamphetamine (mAMPH) to rodents in a single-day "binge" regimen damages forebrain monoaminergic nerve terminals and produces subsequent cognitive deficits. Here we investigate performance on a social odor-based task, demonstrating enduring mAMPH-induced deficits in recognition memory. Three weeks after a neurotoxic mAMPH regimen, singly-housed male Long-Evans rats had four wooden beads placed in their home cage: three beads containing odors from their home cage (HC beads) and one bead from a cage of a rat not present in the colony room (N1 bead). Exploration times for each bead were recorded during three 1-min habituation trials separated by 1-min intertrial intervals. Twenty-four hours later, a 1-min memory test was conducted, in which animals were presented with two HC beads, one N1 bead, and one bead from another novel animal (N2). Saline- and mAMPH-treated rats showed similar, progressive decreases in exploration time for the N1 bead during the habituation trials, indicating equivalent short-term olfactory habituation to the novel odor. By contrast, during the subsequent memory test, saline-treated rats showed a strong preference for the N2 bead over the N1 bead while mAMPH-treated rats showed no preference. The use of the rats' primary sensory modality (olfaction) coupled with the social significance (from conspecifics) of the odors produces strong, long-lasting memories. Our results show that prior treatment with a neurotoxic regimen of mAMPH impairs long-term memory for the previously experienced odors. As compared with previously employed object recognition tasks, this test may be advantageous for investigating mAMPH-induced memory impairments in rodents.
反复给予单日内“狂欢”方案的啮齿动物 methamphetamine（mAMPH）会损害前脑单胺能神经末梢，并导致随后的认知缺陷。在这里，我们研究了一项基于社会气味的任务的表现，证明了 mAMPH 诱导的识别记忆持久缺陷。在神经毒性 mAMPH 方案后 3 周，独居的雄性 Long-Evans 大鼠的家中笼子里放有四个木制珠子：三个珠子含有来自其家中笼子的气味（HC 珠子），一个珠子来自不在群体房间中的大鼠的笼子（N1 珠子）。在 1 分钟的间隔试验期间，记录每个珠子的探索时间。24 小时后，进行了 1 分钟的记忆测试，其中动物被呈现两个 HC 珠子、一个 N1 珠子和一个来自另一个新动物（N2）的珠子。盐水和 mAMPH 处理的大鼠在适应试验期间对 N1 珠子的探索时间表现出相似的、逐渐减少的趋势，表明对新气味的短期嗅觉适应相同。相比之下，在随后的记忆测试中，盐水处理的大鼠对 N2 珠子表现出强烈的偏好，而 mAMPH 处理的大鼠则没有偏好。利用大鼠的主要感觉方式（嗅觉）和气味的社交意义（来自同种动物）产生强烈而持久的记忆。我们的结果表明，先前用神经毒性 mAMPH 方案治疗会损害对先前经历过的气味的长期记忆。与以前使用的物体识别任务相比，该测试可能有利于研究啮齿动物中 mAMPH 诱导的记忆损伤。
