Kisspeptin is a naturally occurring hormone that
stimulates the release of other reproductive
hormones inside the body.
The hormone kisspeptin can enhance activity in brain
regions associated with sexual arousal and romantic
love, according to new research.
Collectively, data provide evidence of an
undescribed role for kisspeptin in integrating
sexual and emotional brain processing with
reproduction in humans.
These results have important implications for our
understanding of reproductive biology and are highly
relevant to the current pharmacological development
of kisspeptin as a potential therapeutic agent for
patients with common disorders of reproductive
The reproductive hormone kisspeptin (encoded by
KISS1) has emerged as a crucial activator of the
reproductive axis acting in the hypothalamus to
stimulate downstream secretion of reproductive
However, the expression of KISS1 and its cognate
receptor (encoded by KISS1R) is not limited to the
Significant KISS1/KISS1R expression has been
reported in limbic brain structures in rodents and
humans, but little is known about the role of
kisspeptin in these areas.
The limbic system has established roles in emotional
and reproductive behavior and so may provide a
physiological framework uniting sex, emotion, and
reproduction in humans.
The study involved a double-blind,
placebo-controlled trial in which 29 healthy
heterosexual young men were given either an
injection of kisspeptin or placebo.
In an MRI scanner the men were shown a variety of
images, including sexual and non-sexual romantic
pictures of couples, whilst researchers scanned
their brains to see how kisspeptin affected the
The researchers found that after the injection of
kisspeptin, when the volunteers were shown sexual or
romantic images of couples, there was enhanced
activity in structures in the brain typically
activated by sexual arousal and romance.
Kisspeptin did not appear to alter emotional brain
activity in response to neutral, happy or
However, when volunteers were shown negative images,
kisspeptin did enhance activity in brain structures
important in regulating negative moods, and study
participants reported a reduction in negative mood
in a post-scan questionnaires.
NIHR Research Professor Waljit Dhillo, the lead
author of the research from the Department of
Medicine at Imperial College London, said: "Most of
the research and treatment methods for infertility
to date have focussed on the biological factors that
may make it difficult for a couple to conceive
naturally. These of course play a huge part in
reproduction, but the role that the brain and
emotional processing play in this process is also
very important, and only partially understood."
As the research is at an early stage, the team of
researchers now want to do a follow on study to
analyse the effects of kisspeptin in a larger group,
including women as well as men.
As a result, the team are also interested in
investigating the possibility that kisspeptin might
be used for treating depression.
For more information
The Journal of Clinical Investigation
Kisspeptin modulates sexual and emotional brain
processing in humans
Imperial College London