1 hr after water maze training, mIPSC frequency(A), amplitude(B), decay-time constant(C) and 10%–90% rise time(D) of the Learning group were compared with Swimming control and Cage control levels; (A) mIPSC frequency of the Learning group were significantly above control levels. (F(2, 44)=8.954, p < 0.001, one way ANOVA; **P<0.01, ***P<0.001); (B), (C) and (D): mIPSC amplitude(b), decay time constant(c) and 10%-90% rise time(d) of the Learning group were not significantly different from control levels.