According to the United States National Library of Medicine's medical subject headings, the term neurotrophin may be used as a synonym for neurotrophic factor, but the term neurotrophin is more generally reserved for four structurally related factors: nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4).
De acordo coa terminoloxía médica da United States National Library of Medicine, o termo neurotrofina pode ser utilizado como sinónimo de factor neurotrófico, pero o termo neurotrofina é máis xeralmente reservado para referirse a catro factores relacionados estruturalmente: factor de crecemento nervioso (NGF), factor neurotrófico derivado do cerebro (BDNF), neurotrofina-3 (NT-3), e neurotrofina-4 (NT-4).