Brain-derived neurotrophic factor is an anterograde survival factor in therat visual system

Background: The neurotrophins, which include nerve growth factor (NGF), bra in-derived neurotrophic factor (BDNF) neurotrophin-3 (NT-3), NT-4/5 and NT- 6, are a family of proteins that play fundamental roles in the differentiat ion, survival and maintenance of peripheral and central neurons. Much resea rch has focused on the role of neurotrophins as target-derived, retrogradel y transported trophic molecules. Although there is recent evidence that BDN F and NT-3 can be transported in an anterograde direction along peripheral and central axons, there is as yet no conclusive evidence that these antero grade factors have direct post-synaptic actions, Results: We report that BDNF travels in an anterograde direction along the optic nerve, The anterogradely transported BDNF had rapid effects on retina l target neurons in the superior colliculus and lateral geniculate nucleus of the brain. When endogenous BDNF within the developing superior colliculu s was neutralised, the rate of programmed neuronal death increased. Convers ely, provision of an afferent supply of BDNF prevented the degeneration of geniculate neurons after removal of their cortical target. Conclusions: BDNF released from retinal ganglion cells acts as a survival f actor for post-synaptic neurons in retinal target fields. (C) 2000 Elsevier Science Ltd. All rights reserved.