Spreading EEG Depression in Chickens

Abstract

LEÃO (1944) reported originally the depression of spontaneous electrical activity of the cerebral cortex, caused by electrical or mechanical stimulation, in rabbits, and he designated this response as “spreading depression.” Spreading depression (SD) accompanied by a slow potential change of the cortex has been reported in many mammalia (Marshall, 1959). In lower vertebrates, similar phenomenon has been observed in the retina of the toad (Gouras, 1958). In pigeons, Leão (1944) also mentioned the occurrence of SD, and recently Bureš et al. (1960) have reported this phenomenon in pigeons using slow potential changes as the main indicator of SD. We have observed a similar phenomenon of SD on EEG of chicks and adult chickens as herein reported.Forty White Leghorn cocks, aged 3 to 8 months old, and sixteen male White Leghorn chicks, 1 to 23 days after hatching, were used. The bird was fixed to the stereotaxic apparatus under nembutal…