CREB1 and Alzheimer disease: 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).