Abstract: | When cats are subjected to an atmosphere of 100 percent oxygen at a sufficiently low pressure, their sleeping patterns are changed: paradoxical sleep disappears and drowsiness increases. This change appears when the pressure decreases to a level close to that at which the hemoglobin begins to dissociate. Return of a cat to a normal atmosphere produces a rebound: the cat spends more time in paradoxical sleep than it did during the base-line period. This finding suggests that a mechanism, closely related to the metabolism of oxygen in the brain, must play an important role in the production of paradoxical sleep. Yet the increase in paradoxical sleep after decompression indicates that still other mechanisms must merge to produce paradoxical sleep. |