Background. Sex, emotion, and reproduction are fundamental and tightly entwined aspects of human behaviour. At a population level in humans, both the desire for sexual stimulation and the desire to bond with a partner are important precursors to reproduction. However, the relationships between these processes are incompletely understood. The limbic brain system has key roles in sexual and emotional behaviours, and is a likely candidate system for the integration of behaviour with the hormonal reproductive axis. We investigated the effects of kisspeptin, a recently identified key reproductive hormone, on limbic brain activity and behaviour.
Methods. Using a combination of hormonal, functional neuroimaging and psychometric analyses we compared the effects of kisspeptin versus vehicle administration in 29 healthy heterosexual young men.
Results. We demonstrate that kisspeptin enhances limbic brain activity specifically in response to sexual and couple-bonding stimuli. Furthermore, kisspeptin’s enhancement of limbic brain structures correlated with psychometric measures of reward, drive, mood and sexual aversion providing functional significance. In addition, kisspeptin administration attenuated negative mood.
Conclusion. Collectively, our data provide evidence of a novel role for kisspeptin in the integration of sexual and emotional brain processing with reproduction in humans, and have important implications for our understanding of reproductive biology highly relevant to the current pharmacological development of kisspeptin as a potential therapeutic agent for patients with common disorders of reproductive function.