Fundamental and Clinical Studies on the Neural Mechanism of Sleep

Publisher Summary This chapter discusses the fundamental and clinical studies on the neural mechanism of sleep. The low voltage fast neo-cortical pattern that had been considered to be characteristic of the waking state, could be recorded also during a fairly deep stage of sleep called activated sleep. The importance of this discovery lies not only in the paradoxical dissociation between the behavioral sleep with dreaming and the electrographic arousal pattern, but also in its contribution to the electrographic identification of the sleep cycle. By using adult cats with chronically implanted cortical and subcortical electrodes, the electric activity of various structures of the brain was recorded together with the eye movements, electromyography of the posterior neck muscles and electrocardiogram. The low voltage fast neocortical patterns during arousal and the S-A stage were very similar, however when analyzed by using the automatic frequency analyzer, the neocortical activity during the S-A stage contained more & activity compared with that of the arousal stage when the rapid eye movements were appearing. Evoked potentials in the specific sensory systems induced by direct electrical stimulation of the brain, such as potential in the visual cortex evoked by single shock to the optic tract, had short latency positive components and following negative components.