Gly-Pro-Glu is a neuroprotective compound and the N-terminal tripeptide of IGF-1. Gly-Pro-Glu is neuroprotective after central administration in animal models of neurodegenerative processes, such as Huntington's, Parkinson's, Alzheimer's diseases, and varies acute brain injury animal models. The neuroprotective activity is not related to its affinity to glutamate receptor. Findings indicate that GPE mimics insulin-like growth factor I effects on the somatostatin system through a mechanism independent of β-amyloid clearance that involves modulation of calcium and glycogen synthase kinase 3β signaling.