Prolonged administration of NT-4/5 fails to rescue most axotomized retinal ganglion cells in adult rats.
The survival of axotomized RGCs was increased by intravitreal NT-4/5 given by repeated injections or osmotic minipumps, but the effects were less complete than predicted. Compared to a single injection of the neurotrophin on day 0, second injections on days 3 or 7 only sustained an additional 10-20% of the RGCs on day 10. Minipumps augmented RGC survival up to 4-fold (50%) at 2 weeks but most RGCs were lost by 1 month. Thus, specific neurotrophins can rescue many RGCs soon after injury but long-term neuronal survival may require a better understanding of changes in neurotrophin receptors and interactions with other molecules.
Clarke
D B
DB
Centre for Research in Neuroscience, Montreal General Hospital Research Institute, Québec, Canada.
Bray
G M
GM
Aguayo
A J
AJ
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D019771:Axotomy; D002470:Cell Survival; D005260:Female; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009900:Optic Nerve / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000473:pathology*; D013997:Time Factors
D009414:Nerve Growth Factors; C071951:neurotrophin 5; C073922:neurotrophin 4