title: Selective localization of oxytocin receptors and vasopressin 1a receptors in the human brainstem.
abstract: Intranasal oxytocin (OT) affects a suite of human social behaviors, including trust, eye contact, and emotion recognition. However, it is unclear where oxytocin receptors (OXTR) and the structurally related vasopressin 1a receptors (AVPR1a) are expressed in the human brain. We have previously described a reliable, pharmacologically informed receptor autoradiography protocol for visualizing these receptors in postmortem primate brain tissue. We used this technique in human brainstem tissue to identify the neural targets of OT and vasopressin. To determine binding selectivity of the OXTR radioligand and AVPR1a radioligand, sections were incubated in four conditions: radioligand alone, radioligand with the selective AVPR1a competitor SR49059, and radioligand with a low or high concentration of the selective OXTR competitor ALS-II-69. We found selective OXTR binding in the spinal trigeminal nucleus, a conserved region of OXTR expression in all primate species investigated to date. We found selective AVPR1a binding in the nucleus prepositus, an area implicated in eye gaze stabilization. The tissue's postmortem interval (PMI) was not correlated with either the specific or nonspecific binding of either radioligand, indicating that it will not likely be a factor in similar postmortem studies. This study provides critical data for future studies of OXTR and AVPR1a in human brain tissue.
authors.affiliation: a California National Primate Research Center , University of California-Davis , Davis , CA , USA.
authors.forename: Sara M
authors.initials: SM
authors.lastname: Freeman
authors.affiliation: b Center for Translational Social Neuroscience, Yerkes National Primate Research Center , Emory University , Atlanta , GA , USA.
authors.forename: Aaron L
authors.initials: AL
authors.lastname: Smith
authors.affiliation: c Department of Radiology and Imaging Sciences, Center for Systems Imaging , Emory University , Atlanta , GA , USA.
authors.forename: Mark M
authors.initials: MM
authors.lastname: Goodman
authors.affiliation: d Department of Psychology , University of California-Davis , Davis , CA , USA.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Bales
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D001345:Autoradiography; D001933:Brain Stem / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018045:Receptors, Oxytocin / Q000378:metabolism*; D017483:Receptors, Vasopressin / Q000378:metabolism*; D055815:Young Adult
chemical_list: C000599871:AVPR1A protein, human; C569600:OXTR protein, human; D018045:Receptors, Oxytocin; D017483:Receptors, Vasopressin; D000110:Acetylcholinesterase
keywords: Brainstem; neuropeptides; nucleus prepositus; receptor autoradiography; spinal trigeminal nucleus