Expression of gonadotropin-releasing hormone receptor in cerebral cortical neurons of embryos and adult rats

Mammalian gonadotropin-releasing hormone (GnRH) was initially isolated from hypothalamus and its receptor from anterior pituitary, although extrapituitary GnRH receptors have been reported. The aim of the present study was to investigate whether GnRH receptor and its mRNA are expressed in cerebral cortical neurons of rat embryos and adult rats using immunohistochemical and reverse transcriptase polymerase chain reaction (RT-PCR) techniques. The immunohistochemistry and RT-PCR analysis showed expression of GnRH receptor and presence of its mRNA, in both cerebral cortical neurons of rat embryos and cerebral cortical tissues of adult rats. Additional experiments showed a decrease in the receptor mRNA expression when cultured neurons of rat embryos were treated with GnRH. It is possible that the presence of GnRH receptors in cortical neurons of rat may be involved in other physiological roles such as neurohormone or neuromodulator.