Fig. 3

Male and female ApoE3-KI and ApoE4-KI mice exposed to lead do not exhibit overt anxiety in the open field test or elevated plus maze. The open field test was used to determine if lead treatment causes anxiety, measured as more time or distance in the margin, less time or distance in the center, or reduced center entries. There was a significant main effect of lead treatment in female mice on center distance and center entries (Two-way ANOVA: center distance, F_(1,31) = 5.936, p = 0.0208; center entries, F_(1,31) = 14.76, p = 0.0006). Post-hoc analyses found that there were no significant differences between lead-treated ApoE3-KI and ApoE4-KI mice (males and females) on the (a) time or (b) distance traveled in the margins, the (c) time or (d) distance traveled in the center, or the (e) number of center entries in the open field test. D, ApoE3-KI females treated with lead traveled a slightly greater distance in the center and E, made more center entries than controls. There were no significant differences between control and lead-treated ApoE4-KI females, ApoE3-KI males, or ApoE4-KI males in the open field test. f Representative open field track plots from female control and lead-treated ApoE3-KI and ApoE4-KI mice. In the elevated plus maze, both male and female ApoE3-KI and ApoE4-KI mice exposed to lead spent a (g) similar or greater amount of time and traveled a (h) similar or greater distance in the open arms of the maze compared to controls. Lead-treated males and females did not exhibit reduced (i) open arm or (j) open arm end entries compared to control animals. Data are mean ± SEM with n = 8–13 per genotype/treatment. Two-way ANOVA with Holm-Sidak post-hoc tests: n.s., not significant; * p < 0.05; *** p < 0.001