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 projectio ns and AVP receptors was examined in the brain of common marmosets (Ca llithrix jacchus) using in situ hybridization, immunocytochemistry and receptor autoradiography. Clusters of cells labeled for AVP mRNA or s tained for AVP immunoreactivity (AVP-ir) were found in the paraventric ular (PVN), supraoptic (SON) and suprachiasmatic nuclei (SCN) of the h ypothalamus. Scattered AVP producing cells were also found in the late ral hypothalamus and the bed nucleus of the stria terminalis (BST). Ne ither AVP mRNA-labeled nor AVP-ir cells were detected in the amygdala. Although AVP-ir fibers were evident outside of the hypothalamic-neuro hypophyseal tract, a plexus of fibers in the lateral septum, as observ ed in the rat brain, was not detected. Receptor autoradiography using I-125-linear-AVP revealed specific binding for AVP receptors in the nu cleus accumbens, diagonal band, lateral septum, the BST, SCN, PVN, amy gdala, anterodorsal and ventromedial nucleus of the hypothalamus, indi cating sites for central AVP action in the marmoset brain. Together, t hese data provide a comprehensive picture of AVP pathways in the marmo set brain, demonstrating differences from rodents in the distribution of cell bodies, fibers and receptors. (C) 1997 Elsevier Science B.V.