Kisspeptin peptide is a peptide that promotes fertility in humans by increasing the levels of luteinizing hormone (LH) and adiponectin. It also improves mood and reduces anxiety.
The peptide is made from the gene KISS1 which was first discovered in mice. It is known to play a critical role in the control of human reproduction, behavior, and metabolism.
An interesting connection between kisspeptin and melatonin has recently been revealed. Exposure to daylight was shown to increase the levels of kisspeptin while darkness reduced it in mice. This effect is believed to be responsible for reducing a person’s risk of developing cancer.
Reproductive and Emotional Brain Processing
Kisspeptin has been identified in key limbic structures that orchestrate emotion such as the amygdala, hippocampus, and cingulate as well as paralimbic structures that feed into these areas such as the accumbens, stria terminalis, putamen, and globus pallidus [25,26]. The mRNA for the receptor GPR54 (aa112-121) is expressed in these regions as well.
Mood and Anxiety Neurons in the Amygdala
In rodent studies, neuronal mRNA for the kisspeptin receptor (Kiss1) is expressed in the medial amygdala, which is involved in emotions and social behaviours such as affiliation and reward. Kisspeptin neurones in the amygdala are closely associated with vasopressinergic and dopaminergic afferents. This suggests that kisspeptin signalling may integrate olfactory cues and social behaviours with the hypothalamic-pituitary-gonadal (HPG) axis via a neuroendocrine pathway.
The interplay between these various facets of sexual and emotional brain processing is likely to be further explored in future research.