Ratio of gene/actin (Fold) Control 1.25mg/kg 2.5mg/kg 5mg/kg NR1 1.02 ± 0.15 0.85 ± 0.11 0.36 ± 0.06** 0.25 ± 0.04** NR2A 0.84 ± 0.09 0.55 ± 0.06* 0.27 ± 0.03** 0.21 ± 0.02** NR2B 0.68 ± 0.07 0.45 ± 0.04* 0.29 ± 0.04** 0.18 ± 0.02*** CaMKII 1.13 ± 0.15 0.88 ± 0.12 0.49 ± 0.05** 0.31 ± 0.03*** PSD-95 0.72 ± 0.08 0.47 ± 0.05* 0.32 ± 0.03** 0.21 ± 0.01*** SynGAP 0.37 ± 0.02 0.62 ± 0.04* 0.81 ± 0.06* 0.98 ± 0.09** ERK1/2(Mapk1) 4.57 ± 0.35 2.96 ± 0.24* 2.44 ± 0.22* 1.84 ± 0.19** Dexras1 3.94 ± 0.29 2.46 ± 0.21* 1.56 ± 0.18** 1.01 ± 0.12*** CAPON 0.67 ± 0.08 0.42 ± 0.05* 0.34 ± 0.03** 0.25 ± 0.02** PAP7 1.27 ± 0.13 0.75 ± 0.08* 0.42 ± 0.04** 0.21 ± 0.02*** nNOS 3.72 ± 0.31 5.05 ± 0.46* 6.39 ± 0.57* 10.56 ± 1.08*** DMT1 0.85 ± 0.07 0.54 ± 0.05* 0.36 ± 0.04** 0.22 ± 0.02*** *p<0.05, **p<0.01, and ***p<0.01. Values represent means ± SD (N=5).

Table 3: Effect of TiO2 NPs on mRNA expression of gene in mouse hippocampus after nasal administration of TiO2 NPs for six consecutive months.