Microdissected brain tissues, including prefrontal cortex, striatum, hippocampus and cerebellum, were collected from mice that were intranasally instilled with MnCl2 (5 mg/kg) or water. The steady-state concentrations of manganese were quantified by inductively coupled plasma mass spectrometry (ICP-MS; n = 7–8 per group). Empty and closed bars represent wild-type (Hfe+/+) and Hfe-deficient (Hfe−/−) mice, respectively. Data were presented as mean ± SEM and were analyzed using two-way ANOVA, followed by post-hoc comparisons. Hfe x Mn, an interaction effect between Hfe deficiency and olfactory Mn exposure.