Glial cell-derived neurotrophic factor (GDNF) is a neurotrophic factor that promotes the survival of different neuronal subpopulations at different stages of both central and peripheral nervous system development. Functional human GDNF ligand is a disulfide-linked homodimer consisting of two 15 kDa polypeptide chains.GDNF is produced by support cells, type 1 astrocytes, Schwann cells, neurons, pineal cells, and skeletal muscle cells, and is a secreted protein that promotes the survival of motoneurons, midbrain dopaminergic neurons, Purkinje cells, and sympathetic neurons.The effect of GDNF on the survival of spinal motor neurons is 100-fold more efficient than neurotrophic proteins. In a mouse model of Parkinson’s disease, GDNF was found to improve conditions such as bradykinesia, rigidity and postural instability.