Kisspeptin fiber and receptor distribution analysis suggests its potential role in central sensorial processing and behavioral state control.

Background: Kisspeptin (KP) signaling in the brain is defined by the anatomical distribution of KP-producing neurons, their fibers, receptors, and connectivity. Technological advances have prompted a re-evaluation of these chemoanatomical aspects, originally studied in the early years after the discovery of KP and its receptor Methods: In this study, we mapped KP fiber distribution in rats and mice using immunohistochemistry under intact and short- and long-term post-gonadectomy conditions. Results: We identified KP fibers in 118 brain regions, primarily in extra-hypothalamic areas associated with sensorial processing and behavioral state control. KP-immunoreactive fiber density and distribution were largely unchanged by gonadectomy. Conclusion: These findings enhance our understanding of KP signaling beyond reproductive functions, particularly in sensorial and behavioral state regulation. This study opens new avenues for investigating KP's role in controlling complex physiological processes, including those not related to reproduction.