Figure 1.
Sensory preconditioning of an association between S2 and a neutral S1. A, Behavioral demonstration of sensory preconditioning (Experiment 1A: Group PP, n = 7; Group PU, n = 8; and Group UP, n = 8). Left, Freezing to S2 during the test for sensory preconditioned fear. Right, Freezing to S1 during the test for first-order conditioned fear. B, The roles of the PRh and BLA in the acquisition of a sensory preconditioned association (Experiment 1B: Group PRh-VEH, n = 10; Group PRh-MUS, n = 7; Group BLA-VEH, n = 8; Group BLA-MUS, n = 8). Left, Freezing to S2 during the test for sensory preconditioned fear. Right, Freezing to S1 during the test for first-order conditioned fear. C, The involvement of PRh NMDAR in acquisition of a sensory preconditioned association (Experiment 1C: Group VEH, n = 14; Group IFEN, n = 14). Left, Freezing to S2 during the test for sensory preconditioned fear. Right, Freezing to S1 during the test for retention of first-order conditioned fear. Data shown are means ± SEM.