gene in humans and the Tacr3 gene in mice and other rodents. High concentrations of the NK3R receptor are found in both the central nervous system and the spinal cord. Additional NK3R receptors have also been found in various other places in the body including: uterus, mesenteric vein, gut neurons, and placenta. Neurokinin B has also been found to co-localize certain gonadal steroid hormone receptors. These include the estrogen receptor (ERα), progesterone receptor (PR), and androgen receptor. It has been found that co-localization of the NKB neurons near these receptors is at a much higher concentration than even that of other peptides and chemicals. The kisspeptin, neurokinin B, and dynorphin cell groups are found to be co-localized to more than 95% of all of the aforementioned receptors in the arcuate nucleus. Role of gonadotropin-releasing hormone Mutations or defects in the TAC3 or TAC3R gene can lead to steroidal feedback problems in the GnRH pulse generator loop, causing GnRH to be understimulated. Lack of GnRH ultimately leads to hypogonadism. A review of neurokinin B and its sister peptides, kisspeptin and dynorphin, in sheep found that these KNDy cell groups (kisspeptin, neurokinin B, dynorphin), are in direct contact with the GnRH neuronal bodies in both the preoptic area and the mediobasal hypothalamus. Researchers found this to be feature to be conserved among species including humans. Due to the high percentage of co-localization found with neurokinin B cell bodies and receptor groups, it is suggested that Neurokinin B along with kisspeptin and dynorphin play a role in the release of GnRH. These findings are important since GnRH release plays such a pivotal role in regulating hormonal control in the bodies of humans. Role in pre-eclampsia Pre-eclampsia is a disorder found in around 5% of pregnant women, usually presenting in the 37th week of gestation, with prognosis ranging from mild to severe. While mild forms of the disease do not significantly impact mother or fetus, more severe cases may lead to blood vessel constriction, increased blood pressure, and reduced blood flow. This in turn can damage various organ systems including the brain, liver, kidneys, and heart. Dangers to the fetus occur when restricted blood flow due to high pressures causes a lack of blood flow to the uterus. This can result in a number of problems for the fetus including poor growth, lack of amniotic fluid, and placental abruption. The cause of pre-eclampsia is