Study On MERG, Synchronized Firings And Ultrastructure Pathology In The Visual Cortex Of Monocular Deprived Kittens

Purpose: We want to determine whether the monocular deprivation can be harmful to retinal and visual cortex. On the other hand, we want to investigate whether the synchronized firings in the visual cortex can be observed and the characteristics of synchronization in the monocularly deprived cats.Methods: For monocular deprivation eight kittens were dark reared until the fourth week. Subsequently one eye was sutured closed and the kittens grew up in a normal-house environment as six normal kittens until they were 4-6months old. We detect the normally raised cats and monocularly deprived cats with multifocal electroretinogram(mERG), flash visual evoked potential(FVEP) and multi-electrode recording methods. In addition, we further study the ultrastructure pathology of these cats to see what are differences between them. Results: Firstly, the latencies increased and response densities decreased in the monocularly deprived cats for the second order kernel in mERG and similar changes in FVEP. Secondly, the synchronization can be observed in normally raised and monocularly cats, whereas the synchronization significantly reduced in the latter. Thirdly, the neuronsdegenerated and the number of synapses decreased. Conclusion: Monocular deprivation can cause damages to retinal and visual cortex altogether and it can cause clearly effects on morphology and physiology of cells in the cat's visual cortex. Furthermore, the results show a direct causal link between early abnormal visual experience and permanent deficits in visual function.