Fig. 1. Effect of Hfe deficiency on recognition memory in manganese-instilled mice. Hfe+/+ and Hfe−/− mice exposed to olfactory manganese were tested for the novel recognition memory task in an open field. Following 30-min of acclimation with two identical objects, one object was replaced with a different object and mouse behavior was recorded for 5 min. Time of interaction with each object was recorded to quantify a shortterm recognition index (A). Mice were tested 24 hr later with another novel object in order to determine 24-hr recognition index (B). Empty and closed bars represent water-instilled and MnCl2-instilled mice, respectively. Data were presented as means ± SEM (n = 7~11 per group) and were analyzed using two-way ANOVA followed by post-hoc comparisons. a p < 0.05 for manganese effect in Hfe+/+ mice; b p < 0.05 for Hfe effect in MnCl2-instilled mice.
