Trophic factors are proteins that support and protect subpopulations of cells. A number have
been reported to act on dopaminergic neurons in vitro and in vivo, making them potential
therapeutic candidates for Parkinson's disease. All of these candidate factors protect
dopaminergic neurons if given prior to, or with, selective neurotoxins. Fewer trophic factors,
primarily glial-derived neurotrophic factor (GDNF) and its relative, neurturin (NRTN; also
known as NTN), have been shown to restore function in damaged dopamine neurons after …