Interrelation of EEG reactions in conditions of recognition of emotional vocabulary in Yakuts with allele polymorphisms of the serotonin transporter

Allelic polymorphism of serotonin transporter 5-HTTLPR is connected with higher risk of vulnerability to the mental pathologies which are associated with disorders in regulation of emotional behavior. However, the influence of this polymorphism on predisposition to disorders significantly differs between different ethnic groups. The aim of our study is exploration of the 5-HTTLPR effects on the change of theta-band spectral power in EEG in the condition of recognition of written emotional sentences among Yakuts in comparison with Russians. 78 healthy Yakutian students and 82 healthy Russian students participated in the study. In EEG experiment, the participants were to find grammatical errors in the sentences written in Russian. These sentences contained implicit conditions: some of the sentences described unanimated objects, anxiety of participants, anxiety of other people, participants’ aggression, or aggression of other people. The probes of blood or buccal epithelium were taken from each participant for genetic analysis. It was revealed that the frequency of occurrence of S-allele of the 5-HTT gene was significantly higher among Yakuts (73%) than that among Russians (39%). According to EEG, the emotional sentences induced higher amplitude of theta-band synchronization in comparison with the neutral sentences among all the participants. The participants with the genotypes LS and SS showed essentially smaller differences in amplitude of EEG reaction after onset of sentences from different categories in comparison with the LL genotype carriers. Our study supports the hypothesis that S- allele of 5-HTTLPR is associated with lower sensitivity to emotion-related stimuli. It could be connected with the risk of affective pathologies among people with such an allele.

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