[Brain-derived growth factor: current aspects].

The neurotrophins are a family of proteins which are closely related structurally and functionally and include nerve growth factor (NGF), brain derived nerve factor (BDNF) and neurotrophin-3 (NT-3), neurotrophin-4/5 (NT-4/5) and more recently neurotrophin-6 (NT-6). BDNF is one of the most important endogenous proteins for control of survival, growth and differentiation of certain neurone populations both in the peripheral and central nervous systems.The ARNmt of the BDNF is found in nearly all regions of the brain. The highest levels are those of the hippocampus and cerebral cortex. The large number of effects attributed to BDNF are probably due to the union of this protein to its specific receptor on the cell surface, which leads to the formation of a complex which enables transmission of the signal caused by activation of the specific neurone pathway. Since discovery, BDNF has been detected and/or measured by different methods from biological assay to the application of molecular biology techniques. These methods have permitted analysis of the biochemical characteristics of this factor and its behaviour in different tissues.In this paper we review the most relevant aspects of distribution, biological actions of BDNF on different neurone populations, its clinical usefulness in neurological disorders, routes of administration and side effects.