by Bailey Haack
Serotonin, a chemical in the brain, has been shown by new research to play a role in the sexual preference of mice, with a lack of the chemical causing males to lose their preference for female partners.
Researchers said that "this is the first time," according to BBC News, "that a neurotransmitter has been shown to play a role in sexual preference in mammals."
A series of experiments was conducted to reach these results, said BBC. The research team bred mice whose brains were not receptive to serotonin, which caused the mice to show no overall preference for males or females.
A different set of mice were bred without the tryptonphan hydroxylase 2 gene, which is necessary to create serotonin.
These mice showed similar results said BBC, and when a male was introduced alone in a cage with a modified male, the modified males were more likely to demonstrate sexual behaviors.
The behaviors were reversed when the researchers restored serotonin to the modified mice, according to a FOX News article.
The article said that researchers haven't looked at how these experiments would work with female mice, and said that researchers cautioned that "the behavior of the mice cannot be extrapolated and applied to humans."