Alzheimer’s disease (AD) is characterized by progressive neuronal degeneration throughout different cerebral regions, a process initiated at the basal forebrain. Researchers from the Cajal Institute have proposed a hypothesis to explain this dynamic process. They propose the existence of a feedback cycle that propagates neuronal degeneration in the AD brain. Oxidative stress would favor the expression of NGF, a neurotrophin known to activate the membrane receptor p75 triggering cell cycle progression and DNA duplication. Cell cycle reactivation in neurons has been shown to induce the expression of amyloid-beta, and this molecule can induce oxidative stress in adjacent structures, thus propagating the degenerative process. Morphological and functional changes in neurons affected by DNA duplication could underlie the basis for subsequent neuronal degeneration.