A dopamine antagonist impairs an aversive memory with a narrow windowof effect in the crab Chasmagnathus

MARTÍN KLAPPENBACH; HÉCTOR MALDONADO

Huerta Grande, Córdoba, Argentina

Congreso; SecondJoint Meeting of the Argentine Society for Neuroscience (SAN) and the Argentine Workshop in Neurosciences (TAN); 2010

Sociedad Argentina de Neurociencias

Several studies in insects converge on the idea that dopamine (DA) mediates the negative reinforcement in aversive conditioning. Here we studied the role of DA in a novel aversive learning paradigm in the crab Chasmagnathus granulatus. It is shown that the administration ofchlorpromazine (D2-like DA antagonist) 30 min before training impairs memory retention at test session, performed the next day. However, this amnesic effect is not found when the drug is applied 15 or 45 min before training or 1h after it, revealing a very narrow time window of effect. These results are in agreement with the idea that DA could act as the internal reinforcement of the aversive stimulus in associative learning. Our next step will be to analyze the action of DA in an appetitive paradigm, with the hypothesis that it would interfere with the consolidation of an appetitive memory. As it was found for octopamine (Kaczer & Maldonado, 2009), another biogenic amine, we propose that DA would have a contrasting role in memory processes of opposite sign.