BAX and Cognitive impairment: Consistently, our results showed that NGF could attenuate spatial cognitive impairment (MWM test), repair neuropathological changes (H&E staining), recover the synaptic structure (Golgi staining, NR2A expression), inhibit neuronal oxidative stress (ROS/SOD/MDA level) and nerve cells apoptosis (Tunnel staining, Bax/Bcl2 expression).