Our previous work demonstrated that ghrelin‐mediated AMPK phosphorylation, following intraperitoneal administration, was essential for its neuroprotective effects in a mouse model of Parkinson's Disease.[5] In this study, ghrelin‐PEG‐AuNRs induced AMPK phosphorylation at 30 and 60 min following intranasal administration, as evidenced by the increased pAMPKα/AMPKα ratio in brain lysates, measured by Western blotting (Figure 3C). This evidence concerns the gene GHRL and Parkinson disease.