Figure 2.

(a) Mean (±SE) successful findings, latencies (s), and behavioral scores of exploration strategies of the six experimental groups in the MWM paradigm. On the basis of the performance levels reached in Place II sessions, two different learning profiles were evidenced. The first one [O+H, Control, and Retention groups (Upper)] was characterized by high levels of learning (*, P < 0.05, Tukey's test: O+H vs. Control group), whereas the second one [H, OH+H, and H+O groups (Lower)] was characterized by flattened learning curves (statistical comparisons are reported in Table 1). (b) Individual swimming trajectories of specimens of the six experimental groups during representative trials. O+H and Control rats exhibited searching behaviors extending around the pool in the early trials and direct platform findings in the successive phases. Retention rats exhibited direct trajectories to the platform from the very first trials. Conversely, H, OH+H, and H+O animals displayed peripheral circling in all task phases, with infrequent successful findings.