[An electrophysiological analysis of brain maturation in chicken embryogenesis]

Studies have been made on the development of the spontaneous bioelectrical activity in the brain of 13-21-day chick embryos and on the reactions of the brain to sonic and photic stimulation (single and rhythmic). It was shown that the onset of the evoked responses to afferent stimulation coincides with predominance of a periodic process in the bioelectrical activity (17-18th days of embryogenesis). The presence of ordered rhythmicity in the bioelectrical activity of the brain which coincides with a possibility of its transformation and synchronization with afferent stimuli is suggested to be an important index of the development of the brain.