Fig. 7
Neuron loss and activation of caspase-3 expression based on Nissl staining and IHC in the cerebellum, hippocampus, and cortex after 6 months of exposure to particulate matter with an aerodynamic diameter of < 2.5 μm (PM2.5; exposure group). For Nissl staining, the neuron number had significantly decreased in the hippocampus after 6 months of PM2.5 exposure (arrow). Neuron signals were also reduced in the cerebellum, hippocampus, and cortex after 6 months of PM2.5 exposure compared to the high-efficiency particulate air (HEPA) control. Caspase-3 signals were significantly activated in the cerebellum, hippocampus, and cortex by PM2.5 exposure compared to the control (HEPA). DAPI, blue; neurons, green; caspase-3, red. The scale bar for Nissl stain is 200 μm. The images for DAPI, neuron and caspase-3 were taken at 10x magnification