Four experiments used a sensory preconditioning protocol to examine how a dangerous context influences learning about innocuous events. In Experiments 1, 2, and 3, rats were exposed to presentations of a tone followed immediately or 20-sec later by presentations of a light. These tone-light pairings occurred in a context that was either familiar…

Ample evidence suggests that activation of NMDA receptors (NMDAr) in the basolateral complex of the amygdala (BLA) is necessary for context fear conditioning. The present series of experiments examined whether this activation was still required when the to-be-shocked context had a history. We found that BLA infusion of the selective NMDAr…