Sleep-related penile erections do not occur in rats during carbachol-induced rapid eye movement sleep

This study was undertaken to find out whether sleep-related penile erections occur in the carbachol-induced rapid eye movement sleep model in rats. Bulbospongiosus EMG, as a measure of penile erection, was recorded along with EEG, EMG, and EOG during normal sleep-wakefulness. These parameters were again recorded after injection of carbachol into the pontine tegmentum. Carbachol-induced rapid eye movement sleep was not accompanied by penile erections.