“…For example, plasma norepinephrine has been shown to correlate with increases in sexual arousal, reaching a peak during orgasm (Exton et al, 1999). Using vaginal photoplethysmography, there were facilitatory effects on sexual arousal of both pharmacological agents (Meston & Heiman, 1998;Rosen, Phillips, Gendrano, & Ferguson, 1999;Rubio-Aurioles et al, 2002) and non-pharmacological interventions (Brotto & Gorzalka, 2002;Meston & Gorzalka, 1995, 1996a, 1996bPalace & Gorzalka, 1990), which increase SNS activity. Meston, Gorzalka, and Wright (1997) found that clonidine, a selective a 2 -adrenergic agonist which inhibits SNS activity, inhibited genital arousal.…”