Evidence for oestrogen receptor α-immunoreactivity in gonadotrophin-releasing hormone-expressing neurones

Having used the cingulate cortex to demonstrate the validity of our methods for detecting hitherto unrecognized oestrogen receptor alpha (ER alpha)-immunoreactive neurones, we have now employed immunoprecipitation and double-label immunohistochemistry to investigate whether the ER alpha protein is present in gonadotrophin-releasing hormone (GnRH)-containing cells. The immortalized GnRH cell line GT1-7 and GnRH neurones within the rat preoptic area were found to possess ER alpha-immunoreactivity (ER alpha-IR). These observations indicate that oestrogen may regulate the synthesis and release of GnRH by direct actions on GnRH neurones.