IGF1 and neurodegenerative disease: As shown in the volcano plot, the altered genes in the hippocampus of the IGF-1-injected APP/PS2 mice were roughly associated with synapse connectivity, the GABA system, astrocyte reactivation, neurogenesis, neural differentiation, the autophagy system, depressive behaviors, and cognition involving neuropsychiatric and neurodegenerative disease pathology.