[Optic nerve regeneration in adult mammals].
Axons of central neurons can regenerate in a peripheral nervous system milieu, by macrophage activation or by inhibition of Rho pathways. Among retinal ganglion cells (RGCs) with axons regenerating into a transplanted peripheral nerve segment, Alpha/Y cells have the highest ability to regenerate axons and their axons extend fastest. OFF-center RGCs regenerate axons less effectively and are more vulnerable to axotomy than ON-center ones. RGC axons extended beyond the crushed site when oxidized galectine-1, a macrophage activator, was vitreously injected. Rho inhibitors were added to cultured retinae to learn their effect on axonal regeneration. Neurite extension from the retinae was promoted with 10-300 microM Y-27632 or 1-20 microM Y-39983 whereas glial processes extended in 100-300 microM Y-27632, 1-20 microM Y-39983 or 10-100 microM Fasudil. The injection of 100 microM Y-27632 or 10 microM Y-39983 into the vitreous and crush site resulted in robust regeneration of RGC axons while 10 microM Y-276932 caused fewer regenerated fibers and Fasudil caused no fibers. Thus neurite extension may be crucial for axonal regeneration and glial process extension may be beneficial for the regeneration.
Watanabe
Masami
M
Department of Perinatology, Institute for Developmental Research, Aichi Human Service Center, Kasugai 480-0392, Japan. mwatanabe@inst-hsc.jp
D000577:Amides / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D037483:Galectin 1 / Q000494:pharmacology; D008262:Macrophage Activation / Q000502:physiology; D009416:Nerve Regeneration / Q000187:drug effects; D016501:Neurites / Q000502:physiology; D009900:Optic Nerve / Q000502:physiology*; D010525:Peripheral Nerves / Q000637:transplantation; D011725:Pyridines / Q000494:pharmacology; D012165:Retinal Ganglion Cells / Q000502:physiology; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors
D000577:Amides; D004791:Enzyme Inhibitors; D037483:Galectin 1; D011725:Pyridines; C520365:Y-39983; C108830:Y 27632; D054460:rho-Associated Kinases