Changes in the Mouse Electrocorticograms (ECoG) after X-Irradiation

The effects of X-rays on the electrocorticograms (ECoG) of mice which had received 300 R of X-rays to the head were studied. The ECoG were recorded in half-restrained animals with chronically implanted cortical electrodes, and were stored on FM magnetic tape. The ECoG recordings were classified into 7 frequency bands by means of an EEG frequency analyzer, and the amplitude of each wave was measured. After X-irradiation the percentage of the waking pattern in the ECoG decreased and reached a minimum 2 to 5 hours after exposure. This was followed by a gradual increase, and a return to control level on the 5th day. Bursts which were composed of 2-4 sec trains of 9-11 c/sec occurred more frequently after exposure. The amplitude of δ2, δ1, θ and α waves was above control level for 5 days after irradiation. The implications of the effects of X-rays on the mouse ECoG are discussed. Copyright © 1971 Japan Radiation Research Society.