Yi Rao et al:
Wild-type male mice preferred females over males, but males lacking central serotonergic neurons lost sexual preference...

BBC:
Male mice bred without serotonin lose their preference for females

Yi Rao et al:
These results indicate that 5-HT and serotonergic neurons in the adult brain regulate mammalian sexual preference.

BBC:
a neurotransmitter has been shown to play a role in sexual preference in mammals.

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