Effect of β-asarone on autophagy in Alzheimer's disease model mice. Transmission electron microscopy (×30,000 magnification) demonstrated that autophagosome formation was barely observed in the normal group. In addition, there were more autophagosomes in the model- and rapamycin-treated groups compared with the 3-MA and β-asarone treated groups. A, Normal group; B, model group; C, low-dose β-asarone group; D, medium-dose β-asarone group; E, high-dose β-asarone group; F, 3-MA-treated group; and G, the rapamycin-treated group. Data are presented as the mean ± SD of 3 mice. Black arrows indicate autophagosomes. **P<0.01 vs. normal group; ##P<0.01 vs. model group; $P<0.05 and $$P<0.01 vs. rapamycin-treated group; ¤¤P<0.01 vs. 3-MA-treated group. 3-MA, 3-methyladenine.