A new discovery is opening the door to treating sexual dysfunction in men. Doctors from Northwestern University's School of Medicine say a specific gene in the brain regulates sexual desire, making it possible for scientists to increase or decrease these impulses.

Researchers say the key is a gene called aromatase. In a certain area of the brain, this gene converts testosterone to estrogen and helps the male sex drive. Until now, scientists weren't sure how big of a role aromatase played in this process.

"This is the first key finding to explain how testosterone stimulates sexual desire," senior author Dr. Serdar Bulun says in a media release. "For the first time, we demonstrated conclusively that the conversion of testosterone to estrogen in the brain is critical to maintain full sexual activity or desire in males. Aromatase drives that."