Neuronal growth factors regulate many aspects of nervous system development including survival, differentiation, axon guidance and circuit formation. These same factors are also critical for maintenance and plasticity of the adult nervous system. The Pierchala laboratory investigates the mechanisms of action of these growth factors, focusing attention on the Glial Cell Line-Derived Neurotrophic Factor (GDNF) family and the neurotrophins. The potent survival and trophic activities of neuronal growth factors, particularly the GDNF family, have led to their development as therapeutic agents for the treatment of diseases and injuries of the nervous system. Therefore, an understanding of receptors complexes and signal transduction pathways regulated by neurotrophic factors under physiologic conditions will aid in the design of treatment regimens that utilize these factors.