The present invention relates to neurotrophin-3 (NT-3), a newly discovered member of the BDNF gene family. It is based, in part, on the identification of regions of nucleic acid sequence homology shared by BDNF and NGF (U.S. patent application Ser. No. 07/400,591, filed Aug. 30, 1989, incorporated by reference herein). According to the present invention, these regions of homology may be used to identify new members of the BDNF/NGF gene family; such methodology was used to identify NT-3. The present invention provides for the genes and gene products of new BDNF/NGF related neurotrophic factors identified by these methods. According to the invention, NT-3 may be used in the diagnosis and/or treatment of neurologic disorders, including, but not limited to, Alzheimer's disease and Parkinson's disease. Because NT-3 has been observed to exhibit a spectrum of activity different from the spcificities of BDNF or NGF, NT-3 provides new and valuable options for enducing regrowth and repair in the central nervous system.