Laboratorio de Psicobiología, Campus Santiago Ramón y Cajal, University of Sevilla, 41018 Sevilla, Spain.
Neurobiol Learn Mem. 2011 Sep;96(2):297-305. doi: 10.1016/j.nlm.2011.06.003. Epub 2011 Jun 13.
The present work shows that the dorsomedial telencephalic pallium of teleost fish, proposed as homologous to the amygdala of mammals, is involved in taste aversion learning (TAL). To analyze the behavioral properties of TAL in goldfish, in Experiment 1, we used a delayed procedure similar to that employed with mammals, which consists of the presentation of two flavors on different days, one followed by lithium chloride and the other by saline, both after a 10-min delay. The results showed that goldfish developed a strong aversion to the gustatory stimulus followed by visceral discomfort and that, as in mammals, this learning was rapidly acquired, highly flexible and maintained for a long time. Experiment 2 showed that dorsomedial pallium lesions and the ablation of the telencephalic lobes impaired the acquisition of taste aversion in goldfish, whereas damage to the dorsolateral pallium (hippocampus homologue) or cerebellar corpus did not produce significant changes in this learning. Experiment 3 showed that these TAL deficits were not due to a lesion-related disruption of taste discrimination; goldfish with telencephalon ablation were able to learn to distinguish between the two tested flavors in a differential conditioning procedure. These functional data demonstrate that the dorsomedial pallium in teleosts is, like the amygdala, an essential component of the telencephalon-dependent taste aversion memory system and provide further support concerning the homology between both structures.
本研究表明，硬骨鱼类的背内侧端脑皮层（被提议为与哺乳动物的杏仁核同源）参与了味觉厌恶学习（TAL）。为了分析金鱼 TAL 的行为特性，在实验 1 中，我们使用了类似于哺乳动物的延迟程序，该程序包括在两天内呈现两种不同的味道，一种味道后紧接着给予氯化锂，另一种味道后紧接着给予生理盐水，两次之间有 10 分钟的延迟。结果表明，金鱼对随后出现的内脏不适的味觉刺激产生了强烈的厌恶感，而且与哺乳动物一样，这种学习过程快速获得、高度灵活且能长时间保持。实验 2 表明，背内侧端脑皮层损伤和端脑叶切除会损害金鱼的味觉厌恶学习能力，而背外侧端脑皮层（类海马体）或小脑蚓部的损伤则不会对这种学习产生显著影响。实验 3 表明，这些 TAL 缺陷不是由于损伤相关的味觉辨别障碍引起的；端脑叶切除的金鱼能够在差异条件反射程序中学会区分两种测试味道。这些功能数据表明，硬骨鱼类的背内侧端脑皮层与哺乳动物的杏仁核一样，是端脑依赖的味觉厌恶记忆系统的重要组成部分，进一步支持了这两种结构的同源性。
