Effects of low level lead exposure on associative learning and memory in the rat: Influences of sex and developmental timing of exposure.
Effects of low level lead exposure on associative learning and memory in the rat: Influences of sex and developmental timing of exposure.
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DOI：
10.1016/j.toxlet.2016.01.011
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发表时间：
2016-03-30
影响因子：
3.5
通讯作者：
Schneider JS
中科院分区：
文献类型：
--
作者：
Anderson DW;Mettil W;Schneider JS
发育过程中的铅暴露会损害各种认知、行为和神经化学过程，导致学习、记忆、注意力、冲动和执行功能的缺陷。许多研究试图模拟铅在啮齿动物中的这种作用，大多数研究集中在与空间学习和记忆过程相关的脑区。使用不同的范例，微量恐惧条件反射，一个过程，需要协调整合的内侧前额叶皮层和海马，我们已经评估了铅暴露对联想学习和记忆的影响。本研究探讨了女性和男性Long Evans大鼠暴露于三个环境相关水平的铅（150 ppm，375 ppm和750 ppm）在不同的发展时期：围产期（PERI;妊娠-出生后第21天），出生后早期（EPN;出生后第1-21天）和出生后晚期（LPN;出生后第1-55天）。测试在出生后第55天开始，包括一天的习得训练和三个训练后时间点（1、2和10天），以评估记忆巩固和回忆。所有的动物，无论性别，发展窗口或铅暴露水平，成功地收购条件-非条件刺激协会在训练过程中。然而，有显着的影响，铅暴露的巩固和记忆回忆在训练后1-10天。在女性中，EPN和LPN暴露于150 ppm铅（但不PERI暴露）显着受损的回忆。相比之下，只有PERI 150 ppm和750 ppm暴露的男性有显着的回忆缺陷。这些数据表明，性别之间的复杂的相互作用，发展窗口的曝光和铅暴露水平的巩固和回忆的联想记忆。
Lead (Pb) exposure during development impairs a variety of cognitive, behavioral and neurochemical processes resulting in deficits in learning, memory, attention, impulsivity and executive function. Numerous studies have attempted to model this effect of Pb in rodents, with the majority of studies focusing on hippocampus-associated spatial learning and memory processes. Using a different paradigm, trace fear conditioning, a process requiring coordinated integration of both the medial prefrontal cortex and the hippocampus, we have assessed the effects of Pb exposure on associative learning and memory. The present study examined both female and male Long Evans rats exposed to three environmentally relevant levels of Pb (150 ppm, 375 ppm and 750 ppm) during different developmental periods: perinatal (PERI; gestation – postnatal day 21), early postnatal (EPN; postnatal days 1–21) and late postnatal (LPN; postnatal days 1–55). Testing began at postnatal day 55 and consisted of a single day of acquisition training, and three post training time points (1, 2 and 10 days) to assess memory consolidation and recall. All animals, regardless of sex, developmental window or level of Pb-exposure, successfully acquired conditioned-unconditioned stimulus association during training. However, there were significant effects of Pb-exposure on consolidation and memory recall at days 1–10 post training. In females, EPN and LPN exposure to 150 ppm Pb (but not PERI exposure) significantly impaired recall. In contrast, only PERI 150 ppm and 750 ppm-exposed males had significant recall deficits. These data suggest a complex interaction between sex, developmental window of exposure and Pb-exposure level on consolidation and recall of associative memories.