This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Meccariello, R. Articles by Fasano, S. Search for Related Content PubMed PubMed Citation Articles by Meccariello, R. Articles by Fasano, S.

Interplay between the Endocannabinoid System and GnRH-I in the Forebrain of the Anuran Amphibian Rana esculenta

Dipartimento di Studi delle Istituzioni e dei Sistemi Territoriali (R.M.), Università di Napoli "Parthenope," 80133 Napoli, Italy; Dipartimento di Biologia Animale e dell’Uomo (M.F.F., E.C., D.D., A.G.), Laboratorio di Anatomia Comparata, Università degli Studi di Torino, 10123 Torino, Italy; and Dipartimento di Medicina Sperimentale (R.C., D.S., G.C., R.P., S.F.), Sez. "F. Bottazzi," II Università di Napoli, 80138 Napoli, Italy

Address all correspondence and requests for reprints to: Professor Riccardo Pierantoni, Seconda Università di Napoli, Dipartimento di Medicina Sperimentale, Sez. "F.Bottazzi," via Costantinopoli 16, 80138 Napoli, Italy. E-mail: riccardo.pierantoni{at}unina2.it.

The morphofunctional relationship between the endocannabinoid system and GnRH activity in the regulation of reproduction has poorly been investigated in vertebrates. Due to the anatomical features of lower vertebrate brain, in the present paper, we chose the frog Rana esculenta (anuran amphibian) as a suitable model to better investigate such aspects of the reproductive physiology. By using double-labeling immunofluorescence aided with a laser-scanning confocal microscope, we found a subpopulation of the frog hypothalamic GnRH neurons endowed with CB1 cannabinoid receptors. By means of semiquantitative RT-PCR assay, we have shown that, during the annual sexual cycle, GnRH-I mRNA (formerly known as mammalian GnRH) and CB1 mRNA have opposite expression profiles in the brain. In particular, this occurs in telencephalon and diencephalon, the areas mainly involved in GnRH release and control of the reproduction. Furthermore, we found that the endocannabinoid anandamide is able to inhibit GnRH-I mRNA synthesis; buserelin (a GnRH agonist), in turn, inhibits the synthesis of GnRH-I mRNA and induces an increase of CB1 transcription. Our observations point out the occurrence of a morphofunctional anatomical basis to explain a reciprocal relationship between the endocannabinoid system and GnRH neuronal activity.