TWEET "serotonin"

Friday, May 31, 2013

Hormonal influence on homosexuality

Rodent data so far only

A chemical usually associated with how happy we feel could also play a pivotal role in our sexual preferences, researchers have discovered.

A Chinese team found that blocking serotonin, known as the brain's 'happy chemical' caused female mice to switch their sexual preferences.

It is the first time that sexual preference has been reversed in animals without sex hormones.

Yi Rao of Peking University in Beijing, China, and his colleagues genetically engineered female mice so that they could no longer make or respond to serotonin.

'Female mouse mutants lacking either central serotonergic neurons or serotonin prefer female over male genital odors when given a choice, and displayed increased female–female mounting when presented either with a choice of a male and a female target or only with a female target,' the team wrote in their paper,  which is published in the journal PNAS.

'Our results indicate that serotonin controls sexual preference,' they say.

'It's possible that the well-known effect of early sex hormone levels on partner preference and the serotonin mechanism described here are completely independent mechanisms,' Simon LeVay of Stanford University told New Scientist.

'In other words, serotonin systems may be part of the cascade of signals that translate sex hormone levels during development into sexual partner preference in adulthood.'
SOURCE