Using the 5xFAD AD model mouse which develops severe AD-like pathology at an early age and cognitive dysfunction, it was found that inducing adult hippocampal neurogenesis (AHN) alone did not reverse cognitive dysfunction or pathology, but inducing AHN and BDNF levels through exercise resulted in reduced Aβ load, increased expression of synaptic proteins and improved cognition [90]. This evidence concerns the gene BDNF and Alzheimer disease.