Scientific Experiments Confirm that Strains of Androstadienone and Estratetraenol Attract the Opposite Sex.

Ian Sample,
Science Correspondent

Using a brain scanning technique called positron emission tomography; scientists found that a potent chemical (Androstadienone) lurking in male sweat causes a rush of electrical activity only in the brains of (straight women).

Ivanka Savic, a Neuroscientist at the Stockholm Brain Institute who led the study, said the finding suggested specific brain circuits were engaged when we were exposed to chemicals we found sexually stimulating. She added that the scans did not reveal whether sexual behavior was learned or hard-wired in our brains at birth.

In the study, 3 groups of 12 volunteers, including (lesbians), (straight women) and (straight men), were asked to sniff a variety of odors. They included odorless air, four common scents and a potent chemical, known as Androstadienone which is 10 times more abundant in male than female sweat and is suspected of acting as a potent male pheromone.

After smelling the odors, the volunteers were given brain scans that revealed which regions of their brains had the greatest increase in blood flow (a measure of how much they had been stimulated). The scans showed that after sniffing Androstadienone, a region of the brain called the anterior hypothalamus lit up only in (straight women).

The research team also found that only (straight men) responded the same way to a potent female pheromone called Estratetraenol. Brain scans showed that clusters of neurons lit up in the brains of both groups when they smelled the odor.

"This is the first study to prove that these chemicals activate specific sexual brain circuits," Dr Savic said.

This study appears in the Journal Proceedings of the National Academy of Sciences.