MANF is a trophic factor for midbrain dopamine neurons in vivo. It prevents the 6-OHDA- induced degeneration of dopamine neurons in rodent models of Parkinson's disease (Lindholm et al., 2008, Voutilainen et al., 2009). When administered after 6-OHDA-lesioning it restores the dopaminergic function and prevents degeneration of dopamine neurons in substantia nigra pars compacta.