Protein expression (ng/g tissue) Control 1.25 mg/kg 2.5 mg/kg 5 mg/kg NR1 58.14 ± 3.91 49.05 ± 3.55 18.72 ± 1.93** 12.75 ± 1.52*** NR2A 49.56 ± 3.55 29.15 ± 2.46* 14.04 ± 1.52** 10.71 ± 1.25*** NR2B 40.12 ± 3.62 33.85 ± 2. 5 15.08 ± 1.85** 9.18 ± 1.21*** CaMKII 67.88 ± 5.12 56.64 ± 5.05 25.48 ± 2.27** 15.81 ± 1.32*** PSD-95 43.25 ± 3.61 24.91 ± 2.26* 16.64 ± 1.42** 10.71 ± 1.05*** SynGAP 18.53 ± 1.62 32.24 ± 2.83* 43.74 ± 3.58* 54.88 ± 4.89*** ERK1/2 182.86 ± 12.31 115.44 ± 8.51* 92.72 ± 6.36* 64.69 ± 5.33** Dexras1 236.48 ± 16.58 159.96 ± 11.26* 96.72 ± 8.85** 58.58 ± 6.39*** CAPON 40.22 ± 3.21 27.31 ± 2.36* 21.08 ± 2.23* 14.56 ± 1.38** PAP7 76.28 ± 5.85 48.75 ± 3.27* 26.04 ± 2.31** 12.18 ± 1.18*** nNOS 212.04 ± 13.62 257.95 ± 15.89 389.79 ± 25.68** 654.72 ± 45.71*** DMT1 51.55 ± 4.71 43.78 ± 3.59 19.88 ± 2.09** 12.98 ± 1.04*** *p<0.05, **p<0.01, and ***p<0.01. Values represent means ± SD (N=5).

Table 4: Effect of TiO2 NPs on levels of protein expression of gene in mouse hippocampus after nasal administration of TiO2 NPs for six consecutive months.