Vasopressin in the forebrain of common marmosets (Callithrix jacchus): studies with in situ hybridization, immunocytochemistry and receptor autoradiography

The distribution of vasopressin AVP producing cells, their projections and AVP receptors was examined in the brain of common . marmosets Callithrix jacchus using in situ hybridization, immunocytochemistry and receptor autoradiography. Clusters of cells labeled . . . for AVP mRNA or stained for AVP immunoreactivity AVP-ir were found in the paraventricular PVN , supraoptic SON and . suprachiasmatic nuclei SCN of the hypothalamus. Scattered AVP producing cells were also found in the lateral hypothalamus and the . bed nucleus of the stria terminalis BST . Neither AVP mRNA-labeled nor AVP-ir cells were detected in the amygdala. Although AVP-ir fibers were evident outside of the hypothalamic-neurohypophyseal tract, a plexus of fibers in the lateral septum, as observed in the rat brain, was not detected. Receptor autoradiography using 125 I-linear-AVP revealed specific binding for AVP receptors in the nucleus accumbens, diagonal band, lateral septum, the BST, SCN, PVN, amygdala, anterodorsal and ventromedial nucleus of the hypothalamus, indicating sites for central AVP action in the marmoset brain. Together, these data provide a comprehensive picture of AVP pathways in the marmoset brain, demonstrating differences from rodents in the distribution of cell bodies, fibers and receptors. q 1997 Elsevier Science B.V.