AIM:To investigate the effect of minocycline on retinal ganglion cells(RGCs)of experimental optic neuritis in Wistar rats.METHODS:Twenty-two female experimental Wistar rats were assigned to two groups randomly:normal control group and experimental group.Then the rats of experimental group were assigned to three groups randomly:experimental control group(EAE group),minocycline group,methylprednisolone group(MP group).We observed the pathological changes of optic nerve and retina,detected the apoptosis of RGCs by TdT-mediated dUTP-biotin nick end labeling(TUNEL)method.RESULTS:In EAE group,the optic nerve fibers showed bulb-like degeneration,the axis irregularity swelling,a quantity of inflammatory cell infiltrating under light microscope,the axons showed bulb-like degeneration,myelin sheaths were loose,microtubule and microfilament disappeared under electron microscopy,the animal model we induced showed typical pathological changes of the optic nerve in EAE.Demyelination occured in the optic nerve.The area percentage of axons:there was very significant difference(P<0.01),when EAE group,minocycline group and MP group compared with normal control group.There was significant difference(P<0.05),when minocycline group and MP group compared with EAE group.There was little apoptosis of RGCs in normal rats.There was very significant difference(P<0.01),when EAE group,minocycline group and MP group compared with normal control group.There was significant difference(P<0.05),when EAE group and MP group compared with minocycline group,as well as MP group compared with EAE group.CONCLUSION:The pathological changes of optic nerve in EAE model are consistent with demyelinated optic neuritis,the EAE animal model can be used for the research of demyelinated optic neuritis.Minocycline can reduce axonal degeneration in demyelinated optic neuritis,which effect is similar with methylprednisolone.Minocycline can inhibit the apoptosis of RGCs that form the axons of optic nerve in demyelinated optic neuritis,but methylprednisolone does not have any effects on the survival of RGCs in demyelinated optic neuritis.