Kisspeptin neurons as an integration center of reproductive regulation: Observation of reproductive function based on a new concept of reproductive regulatory nervous system

Abstract

Background: Regulation of the reproductive system has been explained by the actions and feedback of gonadotropin releasing hormone-luteinizing hormone/follicle stimulating hormone (GnRH-LH/FSH) -sex steroids; however, the discovery of kisspeptin neurons and a kisspeptin-GnRH-LH/FSH axis has prompted this regulation to be reviewed. Methods: We investigated changes in kisspeptin neurons and associated changes in the hypothalamic-pituitary-gonadal (HPG) axis under various situations and experimental conditions using histochemical methods. Main findings (Results): Kisspeptin neurons play an important role in receiving and integrating information from internal and external environmental factors and communicating it to the conventional HPG axis. Conclusion: The recently described Kisspeptin-GnRH-LH/FSH-gonad system regulates reproductive function via mechanisms that until recently were not completely understood.