We observed that low doses of nano-TiO2 (50 mg/kg) did not change the histology of brain tissue in mice after i.p. exposure for 14 days (Fig. 8a, b). Treatment of mice with 100 mg/kg of nano-TiO2 resulted in ruptured and cracked nerve cell in the brain tissue (Fig. (Fig.8c).8c). Treatment of mice with 150 mg/kg of nano-TiO2 resulted in invasion of inflammatory cell in the brain tissue (Fig. (Fig.8d).8d). The results showed that high doses of nano-TiO2 can cause morphological damage to brain tissue, resulting in an inflammatory reaction.