Reproduction is driven by the brain neurohormone gonadotropin releasing hormone (GnRH). Upstream regulation of GnRH secretion with in the brain is exerted by a number of neuronal systems, but kisspeptin has been recognised as a primary driver. Kisspeptin cells are located in the arcuate nucleus and the preoptic area of the brain, with the former being operative in the generation of pulsatile GnRH secretion. In addition, the sex-steroid feedback regulation of GnRH secretion is mediated by kisspeptin cells. Negative feedback is via that population of kisspeptin cells in the arcuate nucleus, whereas positive feedback involves the preoptic population of kisspeptin cells. The current status of kisspeptin neurons as ‘pulse generators’ for GnRH neurons will be discussed. Another recently discovered neuropeptide regulating GnRH secretion and action is gonadotropin inhibitory hormone (GnIH) produced in the neurons of the dorsomedial hypothalamic nucleus. These neurons appear to be the conduit for the negative effect of stress hormones on GnRH secretion. Recent advances in our understanding of GnIH function will be reviewed. Reproduction is also affected by nutritional status. The neuropeptide Y (NPY)neurons and pro-opiomelanocortin (POMC) neurons of the hypothalamus are able to sense metabolic status and also regulate GnRH secretion. Accordingly a network between kisspeptin, NPY and POMC neurons provides a substrate for the cross-talk between the metabolic and reproductive systems.