title: Differential contributions of vasopressin V1A and oxytocin receptors in the amygdala to pain-related behaviors in rats.
abstract: Neuroplastic changes in the amygdala account for emotional-affective aspects of pain and involve neuropeptides such as calcitonin gene-related peptide and corticotropin-releasing factor. Another neuropeptide system, central arginine vasopressin, has been implicated in neuropsychiatric disorders, but its role in pain-related emotional expression and neuroplasticity remains to be determined. Here, we tested the hypothesis that arginine vasopressin in the amygdala contributes to pain-related emotional-affective responses, using stereotaxic applications of arginine vasopressin and antagonists for G-protein coupled vasopressin V1A and oxytocin receptors in adult male Sprague-Dawley rats. In normal animals, arginine vasopressin increased audible and ultrasonic vocalizations and anxiety-like behavior (decreased open-arm preference in the elevated plus maze). The facilitatory effects were blocked by a selective V1A antagonist (SR 49059, Relcovaptan) but not by an oxytocin receptor antagonist (L-371,257). L-371,257 had some facilitatory effects on vocalizations. Arginine vasopressin had no effect in arthritic rats (kaolin/carrageenan knee joint pain model). SR 49059 inhibited vocalizations and anxiety-like behavior (elevated plus maze) in arthritic, but not normal, rats and conveyed anxiolytic properties to arginine vasopressin. Arginine vasopressin, SR 49059, and L-371,257 had no significant effects on spinal reflexes. We interpret the data to suggest that arginine vasopressin through V1A in the amygdala contributes to emotional-affective aspects of pain (arthritis model), whereas oxytocin receptors may mediate some inhibitory effects of the vasopressin system.
authors.affiliation: Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.|Department of Psychiatry, University of Miami Miller School of Medicine, FL, USA.
authors.forename: Bryce
authors.initials: B
authors.lastname: Cragg
authors.affiliation: Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
authors.forename: Guangchen
authors.initials: G
authors.lastname: Ji
authors.affiliation: Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA volker.neugebauer@ttuhsc.edu.|Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
authors.forename: Volker
authors.initials: V
authors.lastname: Neugebauer
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001168:Arthritis / Q000139:chemically induced / Q000150:complications; D048588:Benzoxazines / Q000494:pharmacology; D002351:Carrageenan / Q000633:toxicity; D004195:Disease Models, Animal; D006727:Hormone Antagonists / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D007616:Kaolin / Q000633:toxicity; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D017551:Microdialysis; D010146:Pain / Q000209:etiology / Q000473:pathology*; D010880:Piperidines / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018045:Receptors, Oxytocin / Q000378:metabolism*; D017483:Receptors, Vasopressin / Q000378:metabolism*; D012018:Reflex / Q000187:drug effects; D014828:Vocalization, Animal / Q000187:drug effects
chemical_list: D048588:Benzoxazines; D006727:Hormone Antagonists; D007211:Indoles; C096766:L 371257; D010880:Piperidines; D011759:Pyrrolidines; D018045:Receptors, Oxytocin; D017483:Receptors, Vasopressin; D007616:Kaolin; D002351:Carrageenan; C082134:relcovaptan
keywords: Vasopressin; amygdala; anxiety; oxytocin; pain