Neuronal loss and apoptosis in the brains of the Tg mice. (A) Reduction of the brain mass of the 6-mo-old Tg mice. Whole brains were dissected and weighed. n = 5; P < 0.05. (B) Loss of neurons in the cortexes of the Tg mice. Coronal brain sections from 6-mo-old Tg and WT mice were immunostained with anti-NeuN. The average number of the neurons in the cortexes of the Tg mice was compared with that of the WT mice (right; n = 5 for each group and P < 0.05). Bars, 100 µm. (C) TUNEL assay of the brains of 6-mo-old Tg mice. Apoptotic nuclei are shown in green (arrows) and DAPI staining in blue. (D) Western blots of total brain extracts (cortexes + hippocampi) of 6-mo-old WT and Tg mice showing levels of total and active caspase-3 (n = 5 mice/group). Bars, 20 µm.