Method for diagnosis or prognosis of neurodegenerative diseases

By detecting the serine (serine) phosphorylation whether the time 293 residues of nNOS (neuronal nitric oxide synthase) a method of diagnosing or predicting a degenerative brain disease, which phosphorylate serine (serine) 293 times residues of nNOS (neuronal nitric oxide synthase) CDK5 (cyclin-dependent kinase 5) is a degenerative brain disease prophylactic or therapeutic pharmaceutical composition is disclosed which contains an inhibitory substance as an active ingredient.