Akt1 deficiency modulates reward learning and reward prediction error in mice.
Genes Brain Behav
; 11(2): 157-69, 2012 Mar.
Article
em En
| MEDLINE
| ID: mdl-22151747
ABSTRACT
In contemporary reinforcement learning models, reward prediction error (RPE), the difference between the expected and actual reward, is thought to guide action value learning through the firing activity of dopaminergic neurons. Given the importance of dopamine in reward learning and the involvement of Akt1 in dopamine-dependent behaviors, the aim of this study was to investigate whether Akt1 deficiency modulates reward learning and the magnitude of RPE using Akt1 mutant mice as a model. In comparison to wild-type littermate controls, the expression of Akt1 proteins in mouse brains occurred in a gene-dosage-dependent manner and Akt1 heterozygous (HET) mice exhibited impaired striatal Akt1 activity under methamphetamine challenge. No genotypic difference was found in the basal levels of dopamine and its metabolites. In a series of reward-related learning tasks, HET mice displayed a relatively efficient method of updating reward information from the environment during the acquisition phase of the two natural reward tasks and in the reverse section of the dynamic foraging T-maze but not in methamphetamine-induced or aversive-related reward learning. The implementation of a standard reinforcement learning model and the Bayesian hierarchical parameter estimation show that HET mice have higher RPE magnitudes and that their action values are updated more rapidly among all three test sections in T-maze. These results indicate that Akt1 deficiency modulates natural reward learning and RPE. This study showed a promising avenue for investigating RPE in mutant mice and provided evidence for the potential link from genetic deficiency, to neurobiological abnormalities, to impairment in higher-order cognitive functioning.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Recompensa
/
Comportamento Animal
/
Corpo Estriado
/
Proteínas Proto-Oncogênicas c-akt
/
Aprendizagem
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Genes Brain Behav
Assunto da revista:
CIENCIAS DO COMPORTAMENTO
/
GENETICA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Taiwan