BDNF and neurodegenerative disease: Finally, we confirmed the expression of BDNF in 3 × Tg hippocampus, as well as the up-regulated genes such as Npy, Tac1, and Crh, as shown in Figure 7A. Interestingly, Npy is a secreted neurotransmitter or neuromodulator that performs a variety of roles in neurodegenerative diseases, including neuroprotection, increased trophic support, decreased excitotoxicity, calcium homeostasis regulation, and neuroinflammation attenuation.62