Fig. 4.

Post-training neurotoxic lesions of the BLA and freezing. Mean ± SEM percentage of freezing during the 3 min period before foot shock on the conditioning day (Pre-shock) and during the 8 min context extinction tests conducted 1 week after conditioning and recovery from surgery (test 1) and 24 hr after reacquisition (test 2). Rats received either 1 or 25 conditioning trials consisting of the delivery of unsignaled foot shock. Data are shown from rats that received sham surgery (SH; black bars), or intra-amygdaloid infusion of NMDA. Intra-amygdaloid NMDA resulted in either partial lesions of the basolateral amygdala (BL-Partial; hatched bars) or total lesions of the basolateral amygdala (BL-Total;gray bars).