Figure 6.

Auditory-cued and contextual fear memory in 10-to 16-week-old control (filled bars and symbols) and cGKIα smooth muscle rescue (open bars and symbols) mice. Animals were exposed to a single 2 s foot shock coterminating with a 30 s tone. Fear memory was assessed by the percentage of the total time animals spent freezing. A–C, Separate litter-matched batches (9–15 animals for all groups) were tested before conditioning (pre-cond) and either 2 h, 1 d, or 7 d after conditioning in a neutral context (cylinder) for 3 min without (no tone) followed by 3 min with presentation of the conditioned stimulus (tone), respectively. Bottom rows show plots of the time course of freezing analyzed in 30 s intervals before (0–180 s) and during (180–360 s) tone presentation. D, Freezing during reexposure of the experimental animals to the conditioning context (box) 1 and 7 d after conditioning, respectively. E, Pain threshold determined by the minimal intensity of the foot shock causing the behavioral responses vocalizing and jumping. *p < 0.05.