[Depression of responsivity of the preoptic region to repetitive electric stimulation during desynchronized sleep]

Respiratory effects of preoptic and vagal repetitive electrical stimulation were studied in unrestrained cats during sleep. Preoptic stimulation influenced breathing during synchronized sleep, but not during desynchronized sleep. Breathing was affected by vagal stimulation during both synchronized and desynchronized sleep, although an increase in threshold was apparent during the latter stage of sleep. The results show that the depression of preoptic responsiveness during desynchronized sleep is non-specific.