PRESENCE OF GONADOTROPIN-RELEASING-HORMONE MESSENGER-RNA IN THE RAT OLFACTORY PIRIFORM CORTEX

Gonadotropin releasing hormone (GnRH) neurons are known to be originat ed from the olfactory placode and to enter the forebrain regions durin g embryonic development. The present study aims to ascertain whether G nRH is locally expressed in the olfactory cortex. Northern blot hybrid ization and reverse transcription-polymerase chain reaction revealed t hat GnRH mRNA was present in the rat olfactory cortex as well as in th e olfactory bulb. The predicted size of GnRH mRNA is similar to that d etected in the hypothalamus. In situ hybridization histochemistry also showed that GnRH mRNA is highly concentrated in the olfactory pirifor m cortex. The present data indicate that GnRH is synthesized in the ol factory piriform cortex.