title: Post-retrieval propranolol treatment does not modulate reconsolidation or extinction of ethanol-induced conditioned place preference.
abstract: The reconsolidation hypothesis posits that established emotional memories, when reactivated, become labile and susceptible to disruption. Post-retrieval injection of propranolol (PRO), a nonspecific β-adrenergic receptor antagonist, impairs subsequent retention performance of a cocaine- and a morphine-induced conditioned place preference (CPP), implicating the noradrenergic system in the reconsolidation processes of drug-seeking behavior. An important question is whether post-retrieval PRO disrupts memory for the drug-cue associations, or instead interferes with extinction. In the present study, we evaluated the role of the β-adrenergic system on the reconsolidation and extinction of ethanol-induced CPP. Male DBA/2J mice were trained using a weak or a strong conditioning procedure, achieved by varying the ethanol conditioning dose (1 or 2 g/kg) and the number of ethanol trials (2 or 4). After acquisition of ethanol CPP, animals were given a single post-retrieval injection of PRO (0, 10 or 30 mg/kg) and tested for memory reconsolidation 24 h later. Also, after the first reconsolidation test, mice received 18 additional 15-min choice extinction tests in which PRO was injected immediately after every test. Contrary to the prediction of the reconsolidation hypothesis, a single PRO injection after the retrieval test did not modify subsequent memory retention. In addition, repeated post-retrieval administration of PRO did not interfere with extinction of CPP in mice. Overall, our data suggest that the β-adrenergic receptor does not modulate the associative processes underlying ethanol CPP.
authors.affiliation: Department of Behavioral Neuroscience and Portland Alcohol Research Center, Oregon Health & Science University, 3181 Sam Jackson Park Road, Portland, OR 97239, USA. laura.font@uji.es
authors.forename: Laura
authors.initials: L
authors.lastname: Font
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Cunningham
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D003213:Conditioning, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage*; D005108:Extinction, Psychological / Q000187:drug effects*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D011433:Propranolol / Q000494:pharmacology*
chemical_list: D000319:Adrenergic beta-Antagonists; D000431:Ethanol; D011433:Propranolol