Fig. 3

Deposition of NP in the brain. After the mice were intranasally instilled with either vehicle (sterile PBS, control group) or NPs in PBS (8 mg/kg, NP group) once per day for 81 days, the mice were sacrificed and the brains were harvested, fixed, sectioned, and stained with anti-FITC antibody. Three non-overlapping fields in the mPFC as well as the CA1, CA3, and DG in the hippocampus were then imaged using confocal microscopy. a Representative images of the mPFC, CA1, CA3, and DG in the control group (upper panel) and NP group (middle panel) taken with a 20X objective lens. Scale bar: 50 μm. b Representative images of the mPFC in the NP group taken with a 63X oil lens. Scale bar: 20 μm. NP are highlighted by white arrows