Spatial cognition and its neural basis in teleost fishes

The present review is focused on recent laboratory studies revealing that the spatial behaviour of fishes is as complex and elaborate as described in land vertebrates. In addition, the data presented here indicate that the remarkable richness and plasticity of spatial behaviour in fishes are based on learning and memory mechanisms and cognitive processes that depend on particular brain circuits, possibly homologous to those identified in mammals and birds. For example, there is evidence that the fish hippocampal pallium is essential for processing and encoding complex spatial information to form map-like representations of the environment. In contrast, body-centred orientation strategies or emotional learning are subserved by different cerebral structures, such as the optic tectum, the cerebellum or the amygdalar pallium. These results that suggest a striking similarity in some cognitive processes and their neural basis between fish and land vertebrates are consistent with the possibility that these vertebrate groups share a common basic pattern of brain and behaviour organisation inherited from a common ancestor and conserved through a long history of separate evolution.