Abstract：
The medial pallium (MP) of amphibians is the homologue of the mammalian hippocampus, and previous research has implicated MP for locating a using the boundary geometry of an environment. MP-lesioned, sham-operated and intact control terrestrial toads, Rhinella arenarum, were trained to locate a goal in a rectangular arena with a visual feature cue placed on one of the short walls. Whereas the sham-operated and intact subjects successfully learned to locate the goal, the MP-lesioned toads showed no evidence of learning. The data support the hypothesis that the amphibian MP is involved when the boundary geometry of an environment is used to locate a goal, which is consistent with evidence from other vertebrate groups. Curious, however, is that the MP lesions also resulted in the toads\' inability to locate the goal based on the visual feature cue. This result supports previous research and suggests that, in contrast to the hippocampal homologue of amniotes, the amphibian medial pallium plays a broader role in spatial learning processes.
摘要：
两栖动物的内侧皮层（MP）是哺乳动物海马的同源物，和先前的研究已经暗示MP使用环境的边界几何形状来定位。MP损伤,假手术和完整对照陆生蟾蜍，红藻,被训练为在矩形竞技场中定位目标，并在其中一个短墙上放置视觉特征提示。尽管假手术和完好无损的受试者成功地学会了定位目标，MP损伤的蟾蜍没有表现出学习的证据.数据支持以下假设：当使用环境的边界几何形状来定位目标时，会涉及两栖动物MP，这与其他脊椎动物群体的证据一致。好奇,然而,MP病变也导致蟾蜍无法根据视觉特征提示定位目标。这一结果支持了先前的研究，并表明，与羊膜动物的海马同源物相反，两栖动物内侧皮层在空间学习过程中起着更广泛的作用。
