title: Dopamine, norepinephrine, and the management of sensorimotor bindings: individual differences in updating of stimulus-response episodes are predicted by DAT1, but not DBH5'-ins/del.
abstract: Evidence suggests that the flexibility of managing (creating and updating) stimulus-response bindings is driven by the dopaminergic system. Given that striatal dopamine (DA) plays a crucial role in the updating of working memory, the present study tested whether individual differences in the efficiency of updating stimulus-response episodes (event files) are predicted by differences in genetic predisposition related to the efficiency of the striatal dopaminergic pathway. In view of contrasting claims that stimulus-response binding is related to norepinephrine, we also considered genetic predispositions regarding noradrenergic pathways. In a sample of 100 healthy adults, we studied whether the degree to which stimulus-response bindings affect ongoing performance is predicted by polymorphisms of the dopamine transporter gene (DAT1, associated with striatal DA levels) and DBH5'-ins/del (strongly correlated with dopamine beta-hydroxylase, the enzyme catalyzing the dopamine-norepinephrine conversion). The performance of 9-repeat carriers of the DAT1 gene was more affected by stimulus-response bindings than the performance of 10/10 homozygotes was, while DBH5'-ins/del polymorphism was not related to performance. This outcome pattern suggests a crucial role of the nigrostriatal dopaminergic pathway in the flexible management of stimulus-response episodes, whereas norepinephrine does not seem to play a role.
authors.affiliation: Department of Psychology, Cognitive Psychology Unit, Leiden Institute for Brain and Cognition, Leiden University, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands. colzato@fsw.leidenuniv.nl
authors.forename: Lorenza S
authors.initials: LS
authors.lastname: Colzato
authors.forename: Sharon
authors.initials: S
authors.lastname: Zmigrod
authors.forename: Bernhard
authors.initials: B
authors.lastname: Hommel
mesh_terms: D000293:Adolescent; D000328:Adult; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005260:Female; D005544:Forecasting; D006801:Humans; D054643:INDEL Mutation; D007206:Individuality; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D010775:Photic Stimulation / Q000379:methods; D011110:Polymorphism, Genetic / Q000235:genetics; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D055815:Young Adult
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; C493214:SLC6A3 protein, human; D004298:Dopamine; D009638:Norepinephrine