Abstract
Effects of X-rays on visual system were electrophysiologically studied in rabbits which were subjected to 250 R orf 500 R or head-only irradiation. Three types of the evoked potentials which were elicited in the visual cortex and in the lateral geniculate body by photic stimulation and in the visual cortex by electrical stimulation to the lateral geniculate body were recorded up to 10 days following irradiation. The amplitude and the duration of the evoked potential from the visual cortex by photic stimulation decreased and reached a minimum value 8 hours after irradiation. This was immediately followed by a gradual increase in amplitude and duration to levels close to the control on the first day, but the return to control was not complete, even at the end of 10 days. These reductions were more marked after irradiation of 500 R than that of 250 R. The changes of the two other potentials were very similar to that elicited in the visual cortex by photic stimulation. These results can be attributed to a depressing influence of X-rays on the whole visual system. This finding draws further attention to the fact that these potentials depend on events occurring in the reticular formation. Some implications of the effects of X-rays on the rabbit visual system are discussed.
