Cognition, Behavior, and Memory
Author: Marcelo Giachero | email: mpgiachero@gmail.com
Marcelo Giachero 1°, Belén Vitullo 1°, Noelia Weisstaub 1°, Pedro Bekinschtein 1°
1° Laboratorio de Memoria y Cognición Molecular, Instituto de Neurociencia Cognitiva y Traslacional, CONICET-Fundación INECO-Universidad Favaloro
Reconsolidation (RE) can be triggered by memory recall, allowing established memories to be modified. However, very aversive memories are often resistant to this process. Here, after the induction of a resistant fear memory in mice, we examine whether it is possible to render it susceptible to pharmacological disruption according to the degree of generalized fear (GF). For this, based on the perceptual similarity between the associated context (CA) and non-associated contexts (CB, CC, and CD) to the aversive event, we established an ordered gradient of GF. In non-stressed mice, we observed that as the exposure context became less similar to CA, the conditioned response run lower. In stressed mice, the formation of a more robust memory using acute stress prior to conditioning brought about a distortion of the generalization gradient, suggesting an alteration of the adaptive value of this phenomenon. Then, in conditioned mice, we injected propranolol (PROP), a known RE interferent, after exposure to the different contexts. In unstressed mice, PROP treatment resulted in a decreased fear response after exposure to CA, CB, or CC, but not to CD compared to the control group. In contrast, in stressed mice, decreased fear response by PROP was observed after exposure to CC or CD, but not to CA or CB compared to controls. These results indicate the possibility of indirect capture and manipulation of a robust contextual fear memory by controlling the level of GF during recall.