The invention provides human- or rat-derived neurotrophic peptides and derivatives thereof, precursor peptides thereof, genes encoding the same, transformants containing recombinant expression vectors bearing the genes, and compositions comprising as an effective ingredient these neurotrophic peptides or derivatives thereof. The neurotrophic peptide or its derivatives of the present invention have a neurotrophic activity and are useful for the treatment of neuro-degenerative disorders and dementia.
