Iron is known to be involved in neuronal diseases such as neurodegenerative diseases, brain ischemia and epilepsy. However, it is unclear if a high level of peripheral iron induces these pathological conditions. Since ferric nitrilotriacetate (Fe-NTA), a low molecule iron chelate, causes kidney carcinoma and diabetes in animals due to its strong and unique oxidative stress, it is also considered to cause pathological conditions in the brain. Therefore, we studied brain changes after intraperitoneal (i.p.) injection of Fe-NTA. We investigated iron distribution in the brain and evaluated heme oxygenase (HO)-1 mRNA, IL-6 mRNA and 4-hydroxy-2-nonenal (4-HNE) quantitatively. In addition, changes in muscarinic acetylcholine receptor mRNAs were measured. It was found that iron was localized in the cortex and the hypothalamus, but not in other areas of the brain. HO-1 was induced in both the cortex and hypothalamus, and the levels of IL-6 and 4-HNE were raised in the hypothalamus, but not in the cortex. In the cortex, expression in M1 and M2 mAChRs were suppressed. In conclusion, iron reached the brain parenchyma after i.p. injection of Fe-NTA, and Fe-NTA caused oxidative reactions and suppression of mAChRs in the brain.