Involvement of NMDA receptors in the acquisition of contextual fear memory in preweanling and weanling rats trained in the CPFE paradigm

PISANO, M.V.; PAGLINI, M.G.; ARIAS, C.

Huerta Grande

Congreso; Sociedad Argentina de Neurociencias; 2012

Sociedad Argentina de Neurociencias

The capability to acquire contextual fear learning emerge around weanling inrats, and that this capability is NMDA-type glutamate receptors (NMDAr) dependent. A recent study using the Context Preexposure Facilitation Effect procedure demonstrated evidences of contextual fear conditioning in preweanling rats. Additionally, it was observed that preweanling and weanling rats trained with an immediate-shock procedure showed evidences of fear conditioning. In this study the observation of contextual fear conditioning at this age was facilitated by the temporal analysis of multiple behaviors. The aim ofthis study was to study the involvement of the NMDAr in the acquisition of contextual fear in weanling and preweanling rats and to evaluate their involvement in fear conditioning induced by an immediate-shock procedure.Results obtained in these experiments showed that contextual fear memory is NMDAr-dependent at both ages. The behavioral pattern expressed by preexposed subjects treated with MK-801 during the preexposure phase was identical to non-preexposed rats. Finally, fear memory induced by the immediate-shock treatment was not affected by the administration of MK-801. We conclude that NMDAr modulate the acquisition of contextual fear conditioning in preweanling and weanling rats.