FIG. 2.

Developmental exposure to Mn increases sensitivity to locomotor dysfunction in adult male mice upon subsequent exposure. Total movement number was recorded in open-field activity chambers for each animal following exposure to Mn. No significant changes were detected in (A) female or (B) male juvenile (days 20–34) mice exposed to 10 and 30 mg/kg MnCl₂ or in (C) female or (D) male mice exposed to MnCl₂ only as adults (weeks 12–20). Likewise, there was no detectable change in total movement number in adult female mice preexposed as juveniles (E) but total movement number was decreased in adult male mice preexposed to 30 mg/kg MnCl₂ as juveniles, relative to controls (days 20–34 and weeks 12–20) (F) (*p < 0.05).