MTOR and early-onset autosomal dominant Alzheimer disease: In addition, the downstream effectors of PI3K/Akt, glycogen synthase kinase-3β (GSK-3β) and mammalian target of rapamycin (mTOR) have been found involved in hippocampal synaptic plasticity and neuronal regeneration, and their signaling has been shown to be impaired in neurodegenerative disorders, including Alzheimer’s disease (AD) (11, 12).