Rattin,a humanin-like peptide,shared with Humanin ability to protect neurons against amyloid β protein(Aβ)-induced cellular toxicity.However,it is not well known about its neuroprotective molecular mechanism.In the present study,we observed the effects of Rattin on Aβ31-35-induced neurotoxocity,and investigated its possible signaling pathways in cultured primary rat hippocampal neurons by using CCK-8 assay,real-time PCR,flow cytometry and calcium image techniques.