SIRT1 and Alzheimer disease: Indeed, positive modulation of the expression levels and activity of SIRT1 successfully improved energy expenditure in several animal models for neurodegenerative diseases associated with mitochondrial dysfunction (Donmez, 2012), and in case of AD it is able to diminish the memory deficits (Kim et al., 2007), but the mechanism that confers neuroprotection is still poorly understood.