{"pk":5267,"title":"Role of Opioid Receptors in Incentive Contrast","subtitle":null,"abstract":"A downshift from a more preferred to a less preferred incentive leads to a transient rejection of the lower incentive. This phenomenon, known as successive negative contrast (SNC), has been reported in studies with mammals, but not with fish, amphibians, or reptiles, all showing gradual adjustments to the new incentive conditions. It is assumed that an understanding of the brain systems involved in the onset of SNC in mammals will suggest likely brain areas for a comparative analysis in non mammalian vertebrates. Studies reviewed in this article show that opioid receptors are normally engaged during SNC, participate in the detection of the incentive downshift, play a role in SNC onset (delta receptors), and modulate recovery from SNC (kappa receptors). However, opioid receptors do not seem to be involved in the consolidation of the downshift memory. These results suggest a relationship between the evolution of the opioid system and the evolution of learning mechanisms involved in the adjustment to incentive downshifts in vertebrates.","language":"en","license":{"name":"Creative Commons Attribution 4.0","short_name":"CC BY 4.0","text":"Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.\r\n\r\nNo additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.","url":"https://creativecommons.org/licenses/by/4.0"},"keywords":[{"word":"International Journal of Comparative Psychology"},{"word":"Behavior"},{"word":"Behaviour"},{"word":"Communication"},{"word":"vocalization"},{"word":"learning"},{"word":"Behavioral Taxonomy"},{"word":"cognition"},{"word":"Cognitive Processes"},{"word":"Intelligence"},{"word":"Choice"},{"word":"Conditioning"},{"word":"Language"},{"word":"Opioids"},{"word":"Rat"},{"word":"Incentive contrast"},{"word":"Downshift"}],"section":"Research Article","is_remote":true,"remote_url":"https://escholarship.org/uc/item/0zk5h8n2","frozenauthors":[{"first_name":"Mauricio","middle_name":"R.","last_name":"Papini","name_suffix":"","institution":"Texas Christian University","department":"None"}],"date_submitted":"2013-11-20T03:16:45Z","date_accepted":"2013-11-20T03:16:45Z","date_published":"2009-08-01T07:00:00Z","render_galley":null,"galleys":[{"label":"","type":"","path":"https://journalpub.escholarship.org/uclapsych_ijcp/article/5267/galley/3146/download/"}]}