title: Post-trial dopaminergic modulation of conditioned catalepsy: A single apomorphine induced increase/decrease in dopaminergic activation immediately following a conditioned catalepsy response can reverse/enhance a haloperidol conditioned and sensitized catalepsy response.
abstract: Haloperidol can induce catalepsy and this drug effect can be conditioned as well as sensitized to contextual cues. We used a paired/unpaired Pavlovian conditioning protocol to establish haloperidol catalepsy conditioned and sensitized responses. Groups of rats were given 10 daily catalepsy tests following administration of vehicle (n=24) or haloperidol (1.0mg/kg) either paired (n=18) or unpaired (n=18) to testing. Subsequently, testing for conditioning was conducted and conditioning and sensitization of catalepsy were observed selectively in the paired group. Immediately following a second test for catalepsy conditioning, the groups were subdivided into 4 vehicle groups, 3 unpaired haloperidol groups and 3 paired haloperidol groups and were given one of three post-trial treatments (vehicle, 0.05mg/kg or 2.0mg/kg apomorphine). One day later the conditioned catalepsy test 3 was carried out and on the next day, a haloperidol challenge test was performed. The post-trial apomorphine treatments had major effects on the paired groups upon both conditioning and the haloperidol challenge test. The low dose apomorphine post-trial treatment enhanced both the conditioned and the haloperidol sensitized catalepsy responses. The high dose apomorphine post-trial treatment eliminated conditioned catalepsy and eliminated the initial acute catalepsy response to haloperidol that was induced in the vehicle control groups. These results demonstrate the sensitivity of conditioned drug cues to modification by increases/decreases in activity of the dopamine system in the immediate post-trial interval after a conditioning trial. This demonstration that post-trial dopaminergic drug treatments can modify conditioned drug behavior has broad implications for conditioned drug effects.
authors.affiliation: Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes, 28013-602 RJ, Brazil.
authors.forename: Lucas Rangel
authors.initials: LR
authors.lastname: Oliveira
authors.affiliation: Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes, 28013-602 RJ, Brazil.
authors.forename: Flávia Regina Cruz
authors.initials: FRC
authors.lastname: Dias
authors.affiliation: Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes, 28013-602 RJ, Brazil.
authors.forename: Breno Garone
authors.initials: BG
authors.lastname: Santos
authors.affiliation: Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes, 28013-602 RJ, Brazil.
authors.forename: Jade Leal Loureiro
authors.initials: JLL
authors.lastname: Silva
authors.affiliation: The Central New York Research Corporation and Department of Psychiatry SUNY Upstate Medical University, 800 Irving Avenue, Syracuse, NY 13210, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Carey
authors.affiliation: Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes, 28013-602 RJ, Brazil. Electronic address: marinete@uenf.br.
authors.forename: Marinete Pinheiro
authors.initials: MP
authors.lastname: Carrera
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D002375:Catalepsy / Q000139:chemically induced* / Q000188:drug therapy* / Q000378:metabolism; D003214:Conditioning, Classical / Q000187:drug effects* / Q000502:physiology; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D018491:Dopamine Agonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D017208:Rats, Wistar
chemical_list: D018491:Dopamine Agonists; D006220:Haloperidol; D001058:Apomorphine; D004298:Dopamine
keywords: Apomorphine; Catalepsy; Haloperidol; Pavlovian conditioning; Post-trial; Sensitization