Sympathetic nervous system activity and female sexual arousal

The results of a series of human and animal studies that were conducted in an effort to better understand autonomic nervous system influences on female sexual arousal are presented. The effects of sympathetic nervous system (SNS) activation on self-report and vaginal photoplethysmographic measures of sexual arousal were examined in 4 studies using intense acute exercise, and in 1 study using ephedrine, to activate the SNS. The effects of SNS inhibition on sexual responses in the female rat were examined in 3 studies using clonidine, an alpha(2)-adrenergic agonist; guanethidine, a postganglionic noradrenergic blocker; and naphazoline, an alpha(2)-adrenoreceptor agonist, to inhibit sympathetic outflow. In humans, the effects of SNS inhibition on subjective and physiologic sexual arousal were also examined using clonidine to suppress SNS activity. Together, the findings from these studies suggest that SNS activation may facilitate, and SNS inhibition inhibit, the early stages of sexual arousal in sexually functional women and in women with low sexual desire.