Memory of rats with amygdala lesions induced 30 days after footshock-motivated escape training reflects degree of original training.

This experiment was conducted to determine whether the amount of preoperative training influences the effects, on retention, of amygdala lesions induced 30 days after escape training. Rats received 1 or 10 footshock-motivated escape training trials; 30 days later, sham or neurotoxic amygdala lesions were induced. Results of an inhibitory avoidance test performed 4 days after surgery indicated that amygdala lesions impaired retention performance; however, increased preoperative training partially attenuated the retention deficit. Increased preoperative training also attenuated the impairing effects of the lesions on retention assessed in a continuous multiple-trial inhibitory avoidance task given 36 days after the original escape training. The finding that amygdala-lesioned rats remembered the escape training suggests that the amygdala is not a critical locus of the changes underlying the long-term retention of footshock-motivated escape training.