CORT and Anxiety: To obtain another index of stress/anxiety, we measured the serum levels of corticosterone (CORT) in mice, ~15 min after they finished the last trial of the MWM (Group 1) or the PPT (Group 2), and found a dramatic CORT elevation in mice that were just subjected to the MWM, while the CORT levels of mice that had just finished the PPT were comparable to naive mice (BALB/c females, n = 5, range = 17–82 ng/mL).