The invention provides neurotrophic peptide derivatives represented by A6-A7 (wherein A6 and A7 are as defined in the specification) including ¢D-Ala1! HCNP. The neurotrophic peptide derivatives can regulate differentiation and maturation of neuronal cells to accelerate the acetylcholine synthesis in the tissue of medial septum nuclei which is rich in cholinergic neurons and are thus useful for the treatment of neuro-degenerative disorders and dementia.
