Study finds how brain cells increases hopes for fertility treatments

A latest research has shown how a specific type of neuron in the brain influences the release of hormones that control ovarian function in females such as follicular development and ovulationResearchers from Nagoya Universitys Graduate School of Bioagricultural Sciences and Japans National Institute of Physiological Sciences and their findings published in the journal Scientific Reports might help researchers better understand and treat reproductive problems in both animals and humansKisspeptin neurons in the brain regulate the release of hypothalamic gonadotropinreleasing hormone GnRH and pituitary folliclestimulating hormoneluteinizing hormone LH This process is important for reproduction as pituitary hormones stimulate the ovaries to perform their reproductive functions Examples include follicular development and ovulation in all mammals including humansThere are two main areas of the brain involved in the process the arcuate nucleus ARC in which kisspeptin neurons maintain the regular rhythmic pulsatile secretion of GnRHLH that maintains normal follicular development and sex steroid production and the anteroventral periventricular nucleus AVPV in which kisspeptin neurons trigger a surge of GnRHLH that leads to ovulationThe researchers focused on the fact that kisspeptin neurons in the ARC produce and respond to dynorphin an inhibitory substance Kisspeptin neurons in the ARC express both dynorphin and its receptor whereas those in the AVPV express the receptor only suggesting a particular role of such kisspeptin neurons in fertilization Mayuko Nagae a postdoctoral fellow and Yoshihisa Uenoyama an associate professor at Nagoya University in Japan and corresponding author of the paper explained in a joint statementHowever the exact role of dynorphin and its receptor in the regulation of kisspeptin neurons was not clearly understoodTo investigate this the researchers genetically modified female rats to delete Kiss1 a gene that codes for kisspeptin only in neurons that expressed the dynorphin receptor They found that the genetically modified rats with deleted Kiss1 in dynorphin receptorexpressing cells had only 337 of kisspeptin neurons in the ARC and 5037 in the AVPV The rats were still fertile but they had a longer estrous cycle lower ovarian weight and fewer pups than normal ratsThe results indicate that kisspeptin neurons with dynorphin receptors are important for normal female rat reproduction as they allow proper hormone secretion and ovulation This is the first report to show that kisspeptin neurons receiving direct input of dynorphin are needed to fully generate the GnRHLH pulse and surge in female rats says Professor Hiroko Tsukamura from Nagoya University the principal investigator of the research group and another corresponding author of the paperProfessor Tsukamura is excited about the prospect of more studies to understand the molecular mechanism that controls kisspeptin neuronal activity She says Our findings can help our understanding of the central mechanism underlying reproduction and have applications in the treatment of ovarian disorders in livestock and infertility in humansThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoever