Figure 2

MWM analysis of lead-exposed and control rats over 42 days of MWM acquisition revealed a statistically significant behavioral deficit. (A) Escape latency (mean ± standard deviation) of the two groups. (B) Swimming distance (mean ± standard deviation) of the two groups. Baselines of pretraining latency and distance traveled were not significantly different between the two groups (P = 0.39 and P = 0.22, n = 8). With training proceeding, controls had higher learning efficiency and shorter goal latencies and distance than lead-exposed rats (P = 0.001 and P < 0.001 by repeated-measures analysis of variance, n = 8). (C) Rate (mean ± standard deviation) of reaching goal of the two groups. On PND35, PND 42, and PND 72, all the control rats found the platform within 120 seconds whereas some of lead-exposed rats failed to do so.