Homosexual is allegedly influenced by levels of serotonin hormones in the brain. Scientists from Peking University and National Institute of Biological Sciences in Beijing found links of hormones and sexual preferences in rats.
Serotonin hormones regulate sexual behavior, such as erection, ejaculation and orgasm, both in rats and as well as in men. Neuroscientist Yi Rao of Peking University and National Institute of Biological Sciences in Beijing and his team showed that serotonin also underlie the decision to choose male or female.
Rao and his team reversed genetic male rats who lack either the production of serotonin or reversed protein substances which affect the production of serotonin in the brain. Both types of rats are made to not be able to make serotonin.
The research published in the Nature journal, March 24 edition, states that rats lacking serotonin shows sexual orientation not interested in female rats and more accepting male rats. Those rats also did not like the smell of female genitals.
Instead, they preferred male rats and made voices that showed attraction. Male rats normally makes the sound of these voices when meeting female rats to make them more open to mate. While those who have enough serotonin, were more interested in female rats.
“Nearly half of the rats lacking serotonin pick male before the female and sniffs the smell of male rats than females about 60 percent more,” he said, according to LiveScience.
When researchers injected the compound into the rats to restore serotonin levels as usual, the rats were again more interested in female rats than in male rats. But an excess of serotonin instead reduce attractiveness in female and male. “This shows the amount of serotonin must be settled within a certain time to assist the development of heterosexual, ‘he said.
However, Rao continued, whether the levels of serotonin have the same sexual effect on other animals, is still unknown.
One of the author of the study, neuroscientist Zhou-Feng Chen from Washington University, warned not to rush and speculate the relationship of these hormones on human sexual orientation.
Elaine Hull, an expert in sexual behavior in rodents from Florida State University says that the findings may have implications for homosexuality or bisexuality in human behavior. “This can help to guide sexual development (human),” said Hull, who was not involved in the research.
However, he agreed with Chen, to not interpret the results of this study in a hurry.
“More information is needed before concluding serotonin is a factor that inhibits male sexual attraction,”she said.
