Is Homosexuality Based on a Brain Chemical?

By Janelle Weaver

| LiveScience

Flickr/illuminaut

A male mouse's desire to mate with either a male or a female is determined by the brain chemical serotonin, scientists report in a new study. The finding demonstrates for the first time that a neurotransmitter governs sexual preference in mammals.
Serotonin is known to regulate sexual behaviors, such as erection, ejaculation and orgasm, in both mice and men. The compound generally dampens sexual activity; for instance, antidepressants that increase the amount of serotonin in the brain sometimes decrease sex drive. [Top 10 Aphrodisiacs]

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