Laboratory of Psychobiology, Campus Santiago Ramón y Cajal, University of Sevilla, Sevilla, Spain.
Behav Brain Res. 2010 Dec 25;214(2):480-7. doi: 10.1016/j.bbr.2010.06.010. Epub 2010 Jun 19.
Strong evidence suggests that the ventral region of the lateral telencephalic pallium of teleost fish, a structure involved in allocentric spatial cognition, is homologous to the hippocampus of tetrapods. This homology was first proposed on basis of anatomical data, and subsequently confirmed by developmental, functional and behavioural studies. Nonetheless, Saito and Watanabe [30,32] claim that not the lateral but, rather, the medial pallium participates in goldfish spatial navigation and should be considered the homologue of the hippocampus. Here, we further investigate the effects of selective pallial lesions on the spatial cognition abilities of goldfish, trained in a "hole-board" analogue task, to find the baited feeder within a 5 x 5 feeder matrix surrounded by visual cues. The task in the present experiment is similar to that used by Saito and Watanabe, but including thorough probe tests that enabled to define clearly the spatial strategies employed by the animals, and, therefore, the spatial deficits caused by the pallial lesions. The results showed that the lateral, but not the medial pallium lesions, produced a dramatic impairment in the implementation of allocentric spatial strategies. Thus, only lateral pallium lesioned goldfish, like hippocampus lesioned tetrapods, failed to reach the goal when the cues in its proximity were excluded, indicating that they used a guidance strategy. These results do not replicate Saito and Watanabe's, but are consistent to previous data indicating a close functional similarity between the lateral pallium of teleost fish and the hippocampus of amniotes.
大量证据表明，硬骨鱼类侧脑室大脑皮层腹侧区域（参与自我中心空间认知的结构）与四足动物的海马体同源。这种同源性最初是基于解剖学数据提出的，随后通过发育、功能和行为研究得到了证实。然而，Saito 和 Watanabe [30,32] 声称，参与金鱼空间导航的不是外侧脑皮层，而是内侧脑皮层，应该被认为是海马体的同源物。在这里，我们进一步研究了选择性脑皮层损伤对在“洞板”类似任务中接受训练的金鱼的空间认知能力的影响，以便在被视觉线索包围的 5 x 5 饲料矩阵中找到诱饵饲料。本实验中的任务与 Saito 和 Watanabe 使用的任务相似，但包括彻底的探测测试，使我们能够清楚地定义动物使用的空间策略，从而确定脑皮层损伤引起的空间缺陷。结果表明，只有外侧脑皮层损伤，而不是内侧脑皮层损伤，会导致金鱼实施自我中心空间策略的能力严重受损。因此，只有当周围的线索被排除时，外侧脑皮层损伤的金鱼才会像海马体损伤的四足动物一样无法到达目标，这表明它们使用了一种引导策略。这些结果与 Saito 和 Watanabe 的结果不一致，但与之前的数据一致，这些数据表明硬骨鱼类的外侧脑皮层与羊膜动物的海马体具有密切的功能相似性。
