An in vitro study of the effects of methylprednisolone on lesioned and uninjured mammalian spinal neurons.

Cultured spinal neurons were subjected to dendrite amputation 100 microns from the perikaryon and treated with methylprednisolone (MP). Survival was significantly increased by 30 micrograms/ml MP but not by 10, 20 or 60 micrograms/ml. Survival was reduced by 100 micrograms/ml MP. These results suggest: (1) MP protects neurons subjected to physical trauma, and (2) the effective dose range is very narrow. These findings may have implications for MP's observed bimodal effects in spinal cord injury.