Dopamine would be necessary for aversive learning in a crab

MARTÍN KLAPPENBACH; HÉCTOR MALDONADO

Huerta Grande, Córdoba, Argentina

Congreso; First Joint Meeting of the Argentine Society for Neuroscience (SAN) and the Argentine Workshop in Neurosciences (TAN); 2009

Sociedad Argentina de Neurociencias

Dopamine (DA) is a biogenic amine involved in a variety of physiological processes. Regarding cognition, it has been proposed that DA could act in the signaling of an aversive stimulus, while other amine, octopamine, could mediate a positive reinforcement. However, a recent paper from LNM has challenged this idea, proposing that the function of the amines is not reduced to only one kind of learning. It has been proved that octopamine is not only necessary for appetitive learning, but also interferes with an aversive one. Here, we show preliminary results using CSM, an aversive paradigm extensively used in the laboratory. When Chlorpromazine, a D2- like antagonist, is administered before training no memory is disclosed attest session. This result supports the idea that DA is necessary for an aversive learning. In order to further characterize DA role in learning, we developed a new aversive paradigm trying to reproduce natural conditions. In this, we use a device with a hole in the center resembling the animal’s burrow. Our first results indicate that, at training session, the presentation of the visual danger stimulus elicits a defensive response of the animals, getting into the holes, which is very similar to the behavior observed at the field. Next day, at test session, trained animals make more entrances into the burrows than controls. This result may indicate that the hole is actually being recognized as a “safe place” which trained animal prefer when being reinstalled at the learning context. Our next step is to fully characterize dopaminergic involvement in this new aversive paradigm.