The association between a haplotype block on the dopamine DRD2 gene and working memory is modulated by a nicotine receptor polymorphism on CHRNA4
Markett, S., Montag, C., and Reuter, M.
Differentielle Psychologie, Universität Bonn
A recent working memory (WM) theory emphasizes the link between WM and attention, a view strongly supported by neuroimaging studies on visuo-spatial WM. Dopamine is crucial for WM functioning while acetylcholine plays a role in attention. Pharmacological studies pinpoint toward an interaction between the dopaminergic and cholinergic system with respect to cognitive functions. Here, we provide additional evidence for this interaction using molecular genetics. We found a significant association between WM capacity and a haplotype consisting of three SNPs (DRD2 TaqIa, c957t, rs2283265) located on the dopamine receptor genes DRD2/ANKKI in a brief visuo-spatial array task. This effect was modulated by the CHRNA4 rs1044396 polymorphism which codes for the α-subunit of the nicotinergic acetylcholine receptor. Individuals who do not carry the TCT-haplotype performed worst when they are carriers of the TT-genotype of the CHRNA4 SNP, but outperformed TCT-haplotype carriers when they have at least one C-allele on the CHRNA4 SNP.