Da Cunha Claudio, Wietzikoski Samantha, Wietzikoski Evellyn C, Silva Marcio H C, Chandler Jeff, Ferro Marcelo M, Andreatini Roberto, Canteras Newton S
Laboratório de Fisiologia e Farmacologia do Sistema Nervoso Central, Departamentos de Farmacologia, Bioquímica e Biologia Molecular, UFPR, Curitiba, Brazil.
Neurobiol Learn Mem. 2007 May;87(4):451-63. doi: 10.1016/j.nlm.2006.12.004. Epub 2007 Jan 16.
The bilateral intranigral infusion of 1 micromol 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in adult male Wistar rats caused a specific and partial loss of substantia nigra pars compacta (SNc) dopamine neurons, a partial depletion of striatal dopamine, and a deficit to learn the intra-maze cued version of the Morris water maze. Pre-training the SNc rats in the spatial version of the water maze or simply maintaining the animals on the water maze platform reversed this deficit. This improvement was even observed when the order of the extra-maze cues presented to the rats during pre-training of the spatial version was changed during training of the intra-maze cued version. However, this deficit was not reversed either by maintaining the animals on the platform if the spatial cues were surrounded and covered with a curtain or by swimming sessions in the maze without the escape platform and the curtain. These findings suggest that none of the following elements alone, learned during the spatial task pre-training, could help SNc rats learn the intra-maze cued task: improvement of swimming skills or knowledge of the existence of the escape platform; distance between the platform and the border of the pool; location of a particular extra-maze cue; relations among extra-maze cues. However, the simultaneous presence of the escape platform and extra-maze cues (irrespective of their relational configuration) during the pre-training sessions proved to be necessary for this improving effect to occur.
在成年雄性Wistar大鼠双侧黑质内注入1微摩尔1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP），导致黑质致密部（SNc）多巴胺能神经元出现特异性部分缺失、纹状体多巴胺部分耗竭，以及在学习莫里斯水迷宫的迷宫内线索版本时出现缺陷。在水迷宫空间版本中对SNc大鼠进行预训练，或者仅仅将动物维持在水迷宫平台上，均可逆转这一缺陷。当在迷宫内线索版本训练期间改变在空间版本预训练期间呈现给大鼠的迷宫外线索顺序时，甚至也观察到了这种改善。然而，如果空间线索被帘子包围并覆盖，将动物维持在平台上，或者在没有逃生平台和帘子的迷宫中进行游泳训练，均不能逆转这一缺陷。这些发现表明，在空间任务预训练期间学到的以下单独要素，均无助于SNc大鼠学习迷宫内线索任务：游泳技能的提高或对逃生平台存在的认知；平台与水池边界之间的距离；特定迷宫外线索的位置；迷宫外线索之间的关系。然而，在预训练期间同时存在逃生平台和迷宫外线索（无论其关系配置如何），被证明是产生这种改善效果所必需的。
