Histopathological mechanism of optic nerves of rats after transverse sectioned

Abstract

Objective To study the histopathological features and injured mechanism of optic nerves transaction of rats.Methods Twenty rats were divided into 2 groups randomly:normal group (n =4),no any interference; sectioned injured group(n =16),the optic nerve was completely sectioned 0.5 mm behind the eyeball.Animals were killed 4 weeks after treatment in both groups.The retinal ganglial cells were observed and counted.The regeneration of optic nerves was traced anterogrately with rhodamine-B.Results The structures of retina were clear in normal group,while that of sectioned injured group turn to thin.The number of peripheral retinal ganglial cells were 53.25 ± 1.96 in normal group and 4.06 ± 1.45 in sectioned injured group.The difference between the two groups was statistically significant (t =89.31,P ＜ 0.01).There were apparent clustered glial scar between the distal and proximal stumps of optic nerves in sectioned injured group,and fluorescence was blocked at the stumps.Conclusion There is no axon regeneration after suturing the sectioned optic nerves of rats.The most important factors that prevent the axon regeneration are the massive lose of retinal ganglial cells and the formation of the glial scars between the distal and proximal stumps of optic nerves. Key words: Injury, optic nerves; Regeneration, optic nerves; Histopathology; Mechanism