Compositions containing 5-substituted-3-oxadiazolyl-1,6-naphthyridin-2(1h)-one derivatives for the prevention and treatment of neurodegenerative diseases

Medicines for the prevention and treatment of neurodegenerative diseases which are useful in the prevention and/or treatment of neurodegenerative diseases such as Alzheimer's disease and schizophrenia of mammals (including human beings) through the retardation or inhibition of neurodegeneration due to hypofunction of glutamic acid receptor and which contain as the active ingredient 5-substituted -3-oxadiazolyl-1,6-naphthyridin-2(1H)-one derivatives of the general formula (I) or physiologically acceptable acid-addition salts thereof wherein Het is oxadiazolyl; R1 is hydrogen, lower alkyl, lower cycloalkyl, lower alkenyl, lower alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or the like; and R2 is hydrogen, lower alkyl, lower cycloalkyl, substituted or unsubstituted aryl, or the like.