Effect of STIN2VNTR polymorphism of the serotonin transporter gene on background EEG in aged subjects depends on the intellectual environment of professional activity

Abstract

Previously, we found that associations between the STin2VNTR polymorphism of the serotonin transporter gene and cognitive characteristics during aging depend on the intellectual environment of professional activity. In this regard, the present study was aimed to investigate the age-related characteristics of the electrical activity of the brain depending on this polymorphism and long-term intellectual training. We examined EEG power indicators in subjects of the younger (YG, 18–35 years, N = 261) and older (OG, 55–80 years, N = 142) age groups. According to the intellectual richness of the professional activity environment, the subjects were divided into scientists (SA) and those engaged in non-scientific activities (NSA). All subjects were genotyped for the STin2VNTR polymorphism of the serotonin transporter gene. It was found that the power of delta-beta1 rhythms in older carriers of the 10/10 and 12/12 genotypes was opposite in SA and NSA groups (in the SA group 10/10 12/12, in the NSA 12/12 10/10) while similar effects in young subjects were absent. In the absence of cognitive training, genetic differences were determined by an age-related decrease in the power of delta-alpha3 rhythms in carriers of the 10/10 genotype with no age-related differences in carriers of the 12/12 genotype, suggesting the resistance of the 12/12 genotype to age-related changes. In contrast, under cognitive training conditions, there were no age differences in the 10/10 genotype, and a decrease in power was observed in the 12/12 genotype, suggesting an effect of cognitive training on both homozygous genotypes. The decrease in power observed for the 10/10 NSA and 12/12 SA genotypes appears to have different physiological significance, since it was accompanied by changes in attentional efficiency only in the NSA group. The work shows for the first time that the background EEG features associated with the STin2VNTR polymorphism of the serotonin transporter gene in elderly people are under the modulating influence of long-term cognitive training, determined by the specificity of professional activity.