Figure 4.

BLA neurons and fear extinction learning. a, AAV-CaMKIIα-eYFP or eNpHr3.0 was applied to BLA. b, AAV expression for animals receiving fear conditioning, extinction, and fear reacquisition, with each rat represented at 10% opacity. Black circles represent the ventral tip of the fiber optic cannulae. c, AAV expression for animals receiving fear conditioning, extinction, and appetitive conditioning, with each rat represented at 10% opacity. d, eYFP (n = 14) and eNpHR3.0 (n = 11) groups received extinction training with photoinhibition during shock omission. Photoinhibition augmented fear loss during extinction. A suppression ratio of 0.5 indicates no fear, and a suppression ratio of 0 indicates high fear. e, eYFP and eNpHr3.0 groups were retrained in fear or appetitive conditioning and showed selective impairments in fear relearning. For aversive conditioning, a suppression ratio of 0.5 indicates no fear, and a suppression ratio of 0 indicates high fear. For appetitive conditioning, an elevation ratio >0.5 indicates CS-elicited magazine entries. f, AAV-CaMKIIα-eYFP or eNpHr3.0 was applied to BLA. AAV expression across all animals, with each rat represented at 10% opacity. Black circles represent the ventral tip of the fiber optic cannulae. g, Control eYFP (n = 7) and eNpHr3.0 (n = 5) groups received extinction training with photoinhibition randomly during the ITI. Photoinhibition had no effect on extinction learning. Data are mean ± SEM. *p < 0.05.