Exposure to threatening stimuli results in excessive fear and anxiety responses, a process defined as Emotional Sensitization. The Basolateral Complex of the amygdala (BLA) plays a key role in the processing of aversive information. It is known that the amygdalar MAPK signaling pathway is crucially involved in the formation of fear memories. The purpose of this study was to assess the stress influence on the behavioural and neurochemical changes associated with weak contextual fear training (CFC). Male Wistar rats (280-300g) were used to perform the experiments. Animals were injected either systemically or intra-BLA with midazolam (MDZ) prior to restraint, and one day later subjected to CFC (0,3mAx1 footshock). The behavioural test was conducted 24 h after CFC. We observed high freezing levels only in VEH stressed animals, and MDZ prevented the enhanced fear expression induced by stress. Western blot showed a significant pERK2 increase in BLA 30 min after CFC just in stressed animals. This effect was attenuated in MDZ pretreated rats. We suggest that ERK2 activation in BLA would be necessary to install the negative emotional state induced by stress whereas stimulating BLA GABAergic neurotransmission impaired the promoting influence of the aversive stimulus.