Kisspeptin Administration and mRNA Expression in Adult Syrian Hamsters

Kisspeptin (<i>Kiss1</i>) and kisspeptin 1 receptor (<i>Kiss1R</i>) are vital in regulating various functions across many species, primarily those relating to reproduction. The kisspeptin system has recently attracted clinical interest as a potential therapeutic treatment for patients with hypoactive sexual desire disorder. This study maps the distribution of <i>Kiss1</i> and <i>Kiss1R</i> mRNA in the Syrian hamster forebrain using dual-labeled RNAscope. In our study, the distributions of kisspeptin and its receptor were mapped across adult males and females on day 1 or day 2 of their estrous cycle. Conditioned place preference was used to observe the potential effect of kisspeptin on sexual reward in female hamsters. The expression of kisspeptin was greater in females than males, with the estrous cycle having no effect on expression. A comparison of these findings to those in other species revealed that the expression in Syrian hamsters was similar to that reported for other species, demonstrating the conservation of expression. Kisspeptin did not influence sexual reward in females, nor did it affect measures of their primary sexual behavior. These findings provide additional insights into the expression and function of kisspeptin across novel species and add to ongoing research in understanding how kisspeptin may influence sexual desire in animals, including humans.