Expression of the dopaminergic neurotrophin GDF-5 in developing rat ventral mesencephalon (VM) was found to begin at embryonic day (E) 12 and peak on E14, when dopaminergic neurones undergo terminal differentiation. In the adult rat, GDF-5 was found to be restricted to heart and brain, being expressed in many areas of the brain, including striatum and midbrain. This indicates a role for GDF-5 in the development and maintenance of dopaminergic neurones.