Gonadotropin-inhibitory hormone promoter-driven enhanced green fluorescent protein expression decreases during aging in female rats

Abstract

Gonadotropin-inhibitory hormone (GnIH) neurons project toGnRHneurons to negatively regulate reproductive function. To fully explore the projections of the GnIH neurons, we created transgenic rats carrying an enhanced green fluorescent protein (EGFP) tagged to the GnIH promoter. With these animals, we show that EGFP-GnIH neurons are localized mainly in the dorsomedial hypothalamic nucleus (DMN) and project to the hypothalamus, telencephalon, and diencephalic thalamus, which parallels and confirms immunocytochemical and gene expression studies. We observed an age-related reduction in c-Fos-positive GnIH cell numbers in female rats. Furthermore, GnIH fiber appositions toGnRHneurons in the preop..