Arias Natalia, Méndez Marta, Vallejo Guillermo, Arias Jorge L
Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK; INEUROPA, Instituto de Neurociencias del Principado de Asturias, Spain.
Laboratorio de Neurociencias, Departamento de Psicología, Universidad de Oviedo, Plaza Feijoo s/n, 33003 Oviedo, Spain; INEUROPA, Instituto de Neurociencias del Principado de Asturias, Spain.
Brain Res. 2015 Nov 2;1625:18-28. doi: 10.1016/j.brainres.2015.08.021. Epub 2015 Aug 28.
Mastering the Morris water maze (MWM) requires the animal to consolidate, retain and retrieve spatial localizations of relevant visual cues. However, it is necessary to investigate whether a reorganization of the neural networks takes place when part of the spatial information is removed. We conducted four experiments using the MWM. A classical reference memory procedure was performed over five training days, RM5 (n=7), and eight days, RM8 (n=7), with the whole room and all the spatial cues presented. Another group of animals were trained in the same protocol, but they received an additional day of training with only partial cues, PC (n=8). Finally, a third group of animals performed the classical task, followed by an overtraining with partial cues for four more days, OPC (n=8). After completing these tasks, cytochrome c-oxidase activity (CO) in several brain limbic system structures was compared between groups. In addition, c-Fos positive cells were measured in the RM5, RM8, PC and OPC groups. No significant differences were found among the four groups in escape latencies or time spent in the target quadrant. CO revealed involvement of the prefrontal and parietal cortices, dorsal and ventral striatum, CA1 and CA3 subfields of the dorsal hippocampus, basolateral and lateral amygdala, and mammillary nuclei in the PC group, compared to the RM group. In the OPC group, involvement of the ventral striatum and anteroventral thalamus and the absence of amygdala involvement were revealed, compared to the PC group. C-Fos results highlighted the role of the prefrontal cortex, dorsal striatum, anterodorsal thalamus and CA3 in the PC group, compared to the OPC, RM5 and RM8 groups. The animals were able to find the escape platform even when only a portion of the space where the cues were placed was available. Although the groups did not differ behaviorally, energetic brain metabolism and immediate early gene expression revealed the engagement of different neural structures in the groups that received more training without the entire surrounding space.
掌握莫里斯水迷宫（MWM）要求动物巩固、保留并检索相关视觉线索的空间定位。然而，有必要研究当部分空间信息被去除时神经网络是否会发生重组。我们使用MWM进行了四项实验。在五个训练日进行经典的参考记忆程序，RM5（n = 7），以及在八个训练日进行，RM8（n = 7），呈现整个房间和所有空间线索。另一组动物按照相同方案进行训练，但他们额外接受了一天仅使用部分线索的训练，PC（n = 8）。最后，第三组动物执行经典任务，随后再进行四天使用部分线索的过度训练，OPC（n = 8）。完成这些任务后，比较了各组几个脑边缘系统结构中的细胞色素c氧化酶活性（CO）。此外，在RM5、RM8、PC和OPC组中测量了c-Fos阳性细胞。四组在逃避潜伏期或在目标象限花费的时间上未发现显著差异。与RM组相比，CO显示PC组中前额叶和顶叶皮质、背侧和腹侧纹状体、背侧海马体的CA1和CA3亚区、基底外侧和外侧杏仁核以及乳头体核参与其中。与PC组相比，OPC组显示腹侧纹状体和前腹侧丘脑参与其中，且杏仁核未参与。与OPC、RM5和RM8组相比，c-Fos结果突出了PC组中前额叶皮质、背侧纹状体、前背侧丘脑和CA3的作用。即使只有放置线索的部分空间可用，动物也能够找到逃生平台。尽管各组在行为上没有差异，但能量脑代谢和即刻早期基因表达揭示了在接受更多无整个周围空间训练的组中不同神经结构的参与情况。
