Effects of intra-CA1 inhibition of NR2B -NMDARs on delayed matching-to-place water maze task. A. Escape latency for each of the 4 trials per day of all rats during pretraining with changing platform position every day. Cutoff time was 90 s. Inset: the small dot-line circle indicated the position of invisible platform in the training session. B. Intra-CA1 inhibition of NR2B-NMDARs impairs the performance of delayed matching-to-place (DMP) water maze task. The DMP water maze protocol. Rats are given 4 trials per day (T1-T4) with the hidden platform staying in the same location. The platform moves location between days. The interval between trials 1 and 2 is 30 s or 10 min (B1). Rats treated with Ro25-6981 or ifenprodil showed deficit in the performance of DMP task with 10-min delay (right) but not 30-s delay (left). Arrows indicate that intra-CA1 infusion (B2). Representative swimming traces of each group of rats at DMP task with 10-min delay (B3). C. Intra-CA1 infusion of Ro25-6981 or ifenprodil had no effect on the motor ability and the motivation of rats. Rats with intra-CA1 inhibition of NR2B-NMDARs showed no difference b in swimming speed at the trial 2 of DMP task with 10-min delay (C1) and the visible platform task (C2).