Facilitation of the labilization/reconsolidation process of a resistant fear memory

ESPEJO PJ, GIACHERO M, BUSTOS SG, MOLINA VA

Córdoba, Argentina

Congreso; I Reunión Internacional de Ciencias Farmacéuticas; 2010

The memory consolidation theory propose that recent learning can be transiently modified, however once this process is complete, this trace is consolidated and insensitive to further modifications, including pharmacological intervention (1). In the last years, numerous studies have proposed that recalling a previously consolidated memory can render this trace vulnerable to interference (2-5), for instance to benzodiazepine ligands such as Midazolam (MDZ) (6), this process is followed by a stable phase termed memory reconsolidation (4,7). There are, however boundary conditions that place constraints on the onset of the labile phase after retrieval (8). For instance, memory age, the duration of the reactivation period and the interaction between these factors have a crucial influence on retrieval-induced lability (9-11). In addition, activation of NMDA sites seems to be a prerequisite for the emergence of memory reconsolidation (12). It is known that exposure to a stressful event prior to fear learning induces resistance to the emergence of the unstable phase after recall (13).  The main goal of this study was to evaluate the vulnerability to MDZ after the retrieval of consolidated fear memory in animals that have experienced a single stressful situation and the influence of D-cycloserine (DCS), a partial NMDA agonist, on the disruptive effect of MDZ on memory reconsolidation.