In a rat STZ-induced model of cognitive impairment (i.c.v. injection), daily oral carnosine (100 mg/kg) supplementation, along with swimming paradigm, contributes by restoring hippocampal FNDC5/irisin expression, improving insulin signaling, and reducing Aβ and phosphorylated tau levels. The gene discussed is FNDC5; the disease is Cognitive impairment.