Sommer, H. and Kriebel, J. Neuropathological investigations of electrosleep in animal experiments (Rabbits). In Wageneder, F.M. and St. Schuy (Eds.) Electrotherapeutic Sleep and Electroanesthesia. Vol. II, Amsterdam, Excerpta Medica, Pp. 169-174, 1970.
Finding that the electrical parameters indicated for CES in humans did not produce sleep in rabbits, they gave 700 Hz square wave pulses with a pulse width of 0.4 mS, an average current of 0.5 mA, with a peak value of 4 mA. The animals were put into a sleep-like state 5 times per week for 15, 30, 45, or 60 minutes. Histological sections of the brains were made after 20 sessions. They found numerous pathological changes that were related to intensity of stimulation. One discussant noted that he had found such pathological changes in cats following CES experiments. At the end of the conference discussion, the authors stated that these results cannot be extrapolated to humans because these current parameters are not usually used in humans, and the conditions within the human brain are quite different from those encountered in the rabbit brain. No control animals were used.