Serotonin Transporter 5-HTTLPR Genotype Modulates the Aging-Related Changesin Background Brain Activity in Men
Polymorphism of the serotonin transporter gene is associated with age- and –sex-related plastic reconstructions of the structure and activity of the brain throughout life. In this study we investigated the association between the serotonin transporter gene 5-HTTLPR polymorphism and the background EEG activity in healthy young (19–35 years, n = 89) and elderly (55–80, n = 60) men. We analyzed the EEG power calculated in individual frequency ranges from delta to gamma rhythms. Although the genotyping showed that there are three alleles SA, LG and LA, we divided the subjects into groups with high (LA/LA), intermediate (L /LG, LA/SA) and low transcription activity (S/SA, SA/LG), which were labeled respectively as L''/ L'', S''/L'' and S''/ S''. We observed age-related differences in the association of the serotonin transporter gene 5‑HT-TLPR polymorphism with the background EEG power in theta and alpha-1 frequency ranges. Among the carriers of L''/L'' and S''/L'' genotypes, older men had lower theta and alpha 1 rhythm power than younger ones. Genetic differences in the power of these rhythms were only observed in older men: the power was lower in S''/L'' genotype carriers in comparison with S''/S'' and L''/L''. The obtained results contribute to the understanding of the mechanisms of heterogeneity of age-related changes in brain activity and the associated changes in mental and affective functions regulated by the serotonergic system of the brain.