PPARGC1A and Alzheimer disease: To investigate the role of PGC-1α in regulating neuron population and its potential mechanisms, we induced PGC-1α overexpression in the hippocampal DG of 2 × Tg-AD mice by microinjecting AAV-PGC-1α (AAV-CMV-Ppargc1α-m-FLAG-HA) or AAV-Control bilaterally (Figures 1A–D).