Méndez-Couz M, Conejo N M, Vallejo G, Arias J L
Laboratory of Neuroscience, Department of Psychology, Instituto de Neurociencias del Principado de Asturias (INEUROPA), University of Oviedo, Plaza Feijóo s/n, 33003 Oviedo, Spain.
Laboratory of Neuroscience, Department of Psychology, Instituto de Neurociencias del Principado de Asturias (INEUROPA), University of Oviedo, Plaza Feijóo s/n, 33003 Oviedo, Spain.
Behav Brain Res. 2014 Mar 1;260:101-10. doi: 10.1016/j.bbr.2013.11.032. Epub 2013 Dec 4.
While the neuronal basis of spatial memory consolidation has been thoroughly studied, the substrates mediating the process of extinction remain largely unknown. This study aimed to evaluate the functional contribution of selected brain regions during the extinction of a previously acquired spatial memory task in the Morris water maze. For that purpose, we used adult male Wistar rats trained in a spatial reference memory task. Learning-related changes in c-Fos inmunoreactive cells after training were evaluated in cortical and subcortical regions. Results show that removal of the hidden platform in the water maze induced extinction of the previously reinforced escape behavior after 16 trials, without spontaneous recovery 24h later. Extinction was related with significantly higher numbers of c-Fos positive nuclei in amygdala nuclei and prefrontal cortex. On the other hand, the lateral mammillary bodies showed higher number of c-Fos positive cells than the control group. Therefore, in contrast with the results obtained in studies of classical conditioning, we show the involvement of diencephalic structures mediating this kind of learning. In summary, our findings suggest that medial prefrontal cortex, the amygdala complex and diencephalic structures like the lateral mammillary nuclei are relevant for the extinction of spatial memory.
虽然空间记忆巩固的神经元基础已得到充分研究，但介导消退过程的底物在很大程度上仍不清楚。本研究旨在评估在莫里斯水迷宫中先前习得的空间记忆任务消退期间选定脑区的功能作用。为此，我们使用了在空间参考记忆任务中训练的成年雄性Wistar大鼠。在训练后，评估皮质和皮质下区域中c-Fos免疫反应性细胞的学习相关变化。结果表明，在水迷宫中移除隐藏平台在16次试验后诱导了先前强化的逃避行为的消退，24小时后无自发恢复。消退与杏仁核和前额叶皮质中c-Fos阳性核的数量显著增加有关。另一方面，外侧乳头体显示c-Fos阳性细胞数量高于对照组。因此，与经典条件反射研究的结果相反，我们表明间脑结构参与了这种学习。总之，我们的研究结果表明，内侧前额叶皮质、杏仁核复合体和外侧乳头核等间脑结构与空间记忆的消退有关。
