The Changes Of Visual Pathway Of Mice After ⁶⁰CO-γWhole Brain Ray Irradiation

Objective: To observe the changes of visual pathway of mice after ⁶⁰co-γwhole brain ray irradiationMethods: 20 mice were randomly divided into 2 groups: control group and 30Gy-irradiated group (large dose irradiated group). After one month of irradiation, 7 mice were randomly selected in each group to evaluate the visual pathway changes, with the methods of retinal preparation and fluorogold (FG) retrograde tracing technique. The last 3 mice were selected to make into ultrathin sections.The uhrastructural changes of lateral geniculate nucleus and optic nerve were observed by electronic microscope.Results: 1. compared to the control group , the FG-positive cells in 30Gy group were significantly decreased (P<0.01) in one month after irradiation. 2. The optic nerve of optic tract (opt) in control group at myelin, uniform axoplasm, membrane structure between two layers integrity, the axis between the layers and layers arranged in neat, axonal mitochondria, microtubules and microfilaments were clearly visibled. There is no significant difference in control group. The myelin was dissolved in 30Gy group, the gap emerged between most of the axis of the axon membrane and the myelin sheath, swelled mitochondria was visibled, the axoplasm was electron density, granular degeneration.Conclusion: The visual pathway of mouse maybe change, the uhrastructural changes of lateral geniculate nucleus and optic nerve ,the amount of FG positive cells were observed after large dose whole brain ray irradiation.