Mice overexpressing AC1 show superior initial as well as reversal learning in the Morris water maze. (A) Illustration of the Morris water maze training protocol. WT and AC1 TG mice were first trained to find the hidden platform (placed in the center of the arbitrarily defined quadrant 1) by one trial daily for 6 d, and tested by the first probe test on day 7. Starting from day 8, the same animals were subjected to the reversal platform training, during which the platform was moved from quadrant 1 to 3 (as illustrated). Animals were trained by one trial daily for 6 d (from day 8 to day 13), tested by the second probe test on day 14, further trained by one trial daily for another 4 d (i.e., from day 15 to day 18), and tested by the third probe test on day 19. Animals’ performance in escape latency (B1,C1), percentage of time spent in each quadrant (B2,C2), and number of crossings over the target platform location (B3,C3) during the hidden platform (B1–B3) and the reversal platform (C1–C3) training are expressed as average ± SEM. (*) P < 0.05; (ns) not significant.
