FNDC5 and Alzheimer disease: For example, Lourenco et al[98] found that hippocampal long-term potentiation (LTP) disappeared after injections of hairpin-Fndc5 RNA into mouse brains; similarly, the defects of memory and behavior and the failure of LTP occurred in an experimental AD model caused by the injection of amyloid-β oligomers (AβOs), but when recombinant irisin was administered along with AβOs, these behavioral deficits and LTP were reversed[98].