title: Time-dependent effects of corticosterone on reward-based decision-making in a rodent model of the Iowa Gambling Task.
abstract: Corticosteroid hormones, released after stress, are known to change neuronal activity in two time-domains: within minutes via non-genomic pathways and with a delay of >1 h through pathways involving transcriptional regulation. Recent evidence in rodents and humans indicates that these two modes of corticosteroid action differently affect cognitive tasks. Here, we investigated whether reward-based decision-making, in a rat model of the Iowa Gambling Task (rIGT), is also differently altered by rapid versus delayed actions of corticosterone. We targeted the rapid and delayed time domain by injecting corticosterone (CORT, 1 mg/kg, s.c.) at 30 min (rapid) or 180 min (delayed) respectively prior to behavioural testing, during the final 3 days of the behavioural paradigm. In saline treated rats, the number of visits to the disadvantageous arm decreased over trial blocks, whilst this was attenuated when CORT was administered 30 min before testing. This attenuation was associated with a significantly increased c-Fos expression in the lateral orbitofrontal cortex and insular cortex, and a trend for an increase in the infralimbic cortex. The rapid corticosteroid effect contrasted with treatment 180 min before testing, where the number of visits to the disadvantageous arm as well as c-Fos labelling was not affected. These findings indicate that rapid corticosteroid actions impair reward-based decision-making.
authors.affiliation: Department of Neuroscience & Pharmacology, Rudolf Magnus Institute, University Medical Centre Utrecht, The Netherlands.
authors.forename: Susanne
authors.initials: S
authors.lastname: Koot
authors.forename: Annemarie
authors.initials: A
authors.lastname: Baars
authors.forename: Peter
authors.initials: P
authors.lastname: Hesseling
authors.forename: Ruud
authors.initials: R
authors.lastname: van den Bos
authors.forename: Marian
authors.initials: M
authors.lastname: Joëls
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects; D003345:Corticosterone / Q000494:pharmacology*; D003657:Decision Making / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005625:Frontal Lobe / Q000187:drug effects; D005715:Gambling / Q000188:drug therapy / Q000523:psychology*; D008297:Male; D023421:Models, Animal; D008960:Models, Psychological; D017397:Prefrontal Cortex / Q000187:drug effects; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D012201:Reward; D013997:Time Factors
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D003345:Corticosterone