92–94). Research has indicated that ex vivo adult cortical slices expressing FNDC5/irisin, as well as recombinant irisin, can activate the cAMP/PKA/CREB signalling pathway in human cortical slices (Ref. 95). Irisin promotes the generation of brain-derived neurotrophic factor via the cAMP/PKA/CREB pathway, interrupts the binding of AβO to neurons, thus preserving synaptic plasticity in the brains affected by AD, and promoting neurogenesis and dendritogenesis (Ref. 95). This evidence concerns the gene FNDC5 and Alzheimer disease.