Sleep-wake disorganization in cats exposed to ozone.

The effects of the exposure to ozone in the central nervous system are unknown, as it is doubtful if ozone enters beyond the respiratory tract. However, ozone exposure impairs human performance and induces subjective complaints such as fatigue, lethargy and headache. We studied electrographic aspects of sleep-wake organization in cats, and found that paradoxical sleep was promptly reduced during ozone exposure, followed by a dose-related increase of slow-wave sleep. These findings suggest that high concentrations of ozone or its reaction products induce striking changes in sleep patterns.