Gangliosides attenuate axonal loss after optic nerve injury.

Gangliosides have been shown to be capable of protecting nerve tissue from mechanical and biochemical insults and promoting their repair. The present study provides morphologic evidence that monosialogangliosides attenuate the degenerative process at the distal stump of the rat optic nerve after crush injury. Injured rat optic nerves were treated for 7 days after injury with daily intraperitoneal injections of monosialogangliosides (30 mg/kg/day), and compared with untreated injured controls with respect to the number of viable axons 2 and 4 weeks after injury, as indicated by transmission electron microscopy. After 2 weeks, the mean number of viable axons in the treated optic nerves (n = 5) was slightly higher than in the controls (n = 5). Four weeks after injury, although the absolute number in both the experimental and the control groups had dropped, it was about seven-fold higher in the treated animals (1696 +/- 1149, n = 7) than in the untreated animals (216 +/- 65, n = 6); this difference was statistically significant. These findings, which offer some insight as to how monosialogangliosides affect injured nerves, may have important implications for treatment in cases of optic nerve injury.