EFFECT OF 5-HTTLPR ON CURRENT SOURCE DENSITY, CONNECTIVITY, AND TOPOLOGICAL PROPERTIES OF RESTING STATE EEG NETWORKS

Brain Research. 2018. Vol. 1697. P. 67–75.

Proshina E.A., Savostyanov A. N., Bocharov A. V., Knyazev G. G.

The S allele of serotonin transporter gene (5-HTTLPR) has been found to increase the risk of depression
and other mental health problems, but some evidence suggests that S-allele carriers outperform subjects
carrying the long allele in an array of cognitive tasks. Evidence linking this polymorphism with individual
variation in electrophysiological properties of resting state brain networks is very limited. This study
investigated the effect of 5-HTTLPR polymorphism on EEG current source density, connectivity, and topological
properties of resting state networks. We collected genetic and resting state EEG data in 113
Caucasians. As compared to L-homozygotes, S-allele carriers showed lower current source density and
connectivity in most frequency bands in areas overlapping with the default mode and emotion regulation
regions. The analysis of graph-theoretical measures showed that S-allele carriers, as compared to Lhomozygotes,
have less optimal topological properties of brain networks in theta, but more optimal in
alpha band. This dissociation may reflect the predisposition to emotional disorders, which is inherent
to S-allele carriers, and, on the other hand, their superior functioning in some cognitive domains.

Keywords: EEG, connectivity, graph theory, Resting state EEG, 5-HTTLPR