Regulation of Tuberoinfundibular Dopamine (TIDA) Neurons by Kisspeptin Neurons

Abstract

Introduction A new bioactive neuropeptide, “kisspeptin”, the product of Kiss1 gene acting via GPR54 (also Kiss1 R) has recently been thought as an important gatekeeper of puberty onset and reproduction. Much of recent focus on the regulation of gonadotropin-releasing hormone (GnRH) secretion has been upon kisspeptin neurons located in the preoptic area (POA) and hypothalamus. Many studies suggest that kisspeptin plays a key role in mediating the feedback effects of gonadal steroid hormones on GnRH neuroactivity during puberty, the estrous cycle, and or seasonal reproductive transitions. The distribution of kisspeptin neurons has been identified by immunohistochemistry and in situ hybridization. In rodents, two distinguished populations have been reported: one is at the anteroventral periventricular (AVPV) nucleus which received positive feedback effect of sex steroids; the other located at the arcuate (ARC) nucleus which received negative feedback effect of sex steroids. Recently, we have found the interesting projection of kisspeptin neurons to the tuberoinfundibular dopamine (TIDA) neurons, which are thought to inhibit prolactin secretion of mammotrohps in the anterior pituitary. Here, we demonstrate interesting images indicating the neuronal communication between kisspeptin and TIDA neurons in the rat hypothalamus from recent our studies.