This chapter offers a selective review of the spatial cognitive abilities of amphibians as manifested under natural conditions and in the laboratory, and the importance of the medial pallium, the hippocampus homologue in amphibians, for those abilities. In the field, amphibians display extraordinary navigational abilities associated with breeding behavior. In the lab, amphibians are capable of navigating to goal locations using either an egocentric turn strategy or a beacon-guidance strategy. More importantly, amphibians learn map-like representations of goal locations that resemble so-called cognitive maps, an ability supported by the medial pallium. Assuming similarity between the medial pallium of extant amphibians and the medial pallial-hippocampal homologue of the stem tetrapods, the ancestors of modern amniotes, we hypothesize that the evolution of the amniote hippocampus began with a medial pallium characterized by a relatively undifferentiated cytoarchitecture and a broad role in associative learning and memory processes, which included the map-like representation of space.

The hippocampus of mammals, birds, reptiles, and amphibians is a fundamental brain structure for certain forms of relational memory. We review here the experimental evidence indicating that the hippocampal pallium of teleost fish, like the hippocampus of land vertebrates, is involved in relational map-like spatial memory, endowing fish behavior with the capability for allocentric navigation and allowing the flexible expression of spatial memory. In addition, recent evidence suggests that the teleost fish hippocampal pallium plays an important role in the processing of the temporal dimensions of relational memory. The functional similarities in the hippocampal pallium of taxa that diverged millions of years ago suggest the possibility that some features of the hippocampal networks allowing the processing of the spatial as well the temporal dimensions of relational associative memories appeared early in vertebrate evolution and were conserved through phylogenesis.