The naturally-occurring dipeptide carnosine (β-alanyl-L-histidine) and the tripeptide glutathione (L-γglutamyl- L-cysteinylglycine) are found extensively in animal tissues such as brain and skeletal muscle. Central functions for excitation and sedation of them and their derivatives were screened.
Keywords: Dipeptides, carnosine, glutathione, excitation, sedation