Effect of lesions of the medial pallium on the use of visual cues and turn response in spatial learning in amphibians.

DANERI, M. FLORENCIA; CASANAVE, EMMA B.; MUZIO, RUBEN N.

Almería

Congreso; XXII Congreso de la Sociedad Española de Psicología Comparada.; 2010

Sociedad Española de Psicología Comparada

We are analyzing the neural mechanisms that rule the spatial learning, looking for common patterns potentially present in a common ancestor to several classes of vertebrates. It is known that the mammalian hippocampus is an important structure involved in spatial learning; but yet, its function in other vertebrates such as amphibians is unknown. Amphibians have an area supposed to be homologous to the mammalian hippocampus, the medial pallium. The main goal of the present work was to study the implication of this structure in two simple spatial orientation tasks. Partially dehydrated toads (Bufo arenarum) were divided in 3 groups: Medial pallium lesioned, Intact and Sham controls. Animals were daily trained in a plus maze (3 trials per session) for the acquisition of two basic spatial orientation strategies: in the first experiment the use of a visual cue, in the second one the use of a turn strategy to reach a container full of water. Animals of both control groups acquired the spatial orientation, but the lesioned animals never reached the goal. This result suggests that medial pallium is involved in basic spatial orientation strategies in amphibians and, therefore, it is possible that hippocampus and medial pallium be partially functional equivalents.