CONICET | Buscador de Institutos y Recursos Humanos

The traditionally, associative learning paradigm in the crab (Chasmagnathus granulatus) is based on its escape response elicited by the presentation of a visual danger stimulus (VDS), an opaque rectangle passing over the animal. Upon the iterative presentation of VDS, the crab´s escape-response declines and a strong freezing-response is built up. This paradigm is based on the association between the environmental features of the training site (the context) and the features of the screen moving over the animal (the signal). Thus, such memory was termed as the context-signal memory (CSM). In this work, we developed a new pavlovian-conditioning for an associative learning designed to/for increase the contingency between the context and the VDS. This new paradigm, consist on the same number of VDSs presentation but paired with a light from above; during the intertrial interval the light is presented from below. The above illuminated context constitutes the CS. Previous results demonstrated that the light from below determine the CS offset (Pérez-Cuesta et al, 2007; Hepp and Pedreira, submitted). We found that this new paradigm, as well as the classical one, is context specific and also depends on protein synthesis. We also demonstrate that a brief reexposure to the light (27 seg) is sufficient to induce the reconsolidation process.