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Sysoeva O.V.,Russian Academy of Sciences | Tonevitsky A.G.,Russian Research Institute of Sport and Physical Education | Wackermann J.,Institute for Frontier Areas of Psychology and Mental Health
PLoS ONE | Year: 2010

Background: The present study investigates neurobiological underpinnings of individual differences in time perception. Methodology: Forty-four right-handed Russian Caucasian males (18-35 years old) participated in the experiment. The polymorphism of the genes related to the activity of serotonin (5-HT) and dopamine (DA)-systems (such as 5-HTT, 5HT2a, MAOA, DAT, DRD2, COMT) was determined upon the basis of DNA analysis according to a standard procedure. Time perception in the supra-second range (mean duration 4.8 s) was studied, using the duration discrimination task and parametric fitting of psychometric functions, resulting in individual determination of the point of subjective equality (PSE). Assuming the 'dual klepsydra model' of internal duration representation, the PSE values were transformed into equivalent values of the parameter k (kappa), which is a measure of the 'loss rate' of the duration representation. An association between time representation parameters (PSE and k, respectively) and 5-HT-related genes was found, but not with DArelated genes. Higher 'loss rate' (k) of the cumulative duration representation were found for the carriers of genotypes characterized by higher 5-HT transmission, i.e., 1) lower 5-HT reuptake, known for the 5-HTTLPR SS polymorphism compared with LL, 2) lower 5-HT degradation, described for the 'low expression' variant of MAOA VNTR gene compared with 'high expression' variant, and 3) higher 5-HT2a receptor density, proposed for the TT polymorphism of 5-HT2a T102C gene compared with CC. Conclusion: Convergent findings of the present study and previous psychopharmacological studies suggest an action path from 5-HT-activity-related genes, via activity of 5-HT in the brain, to time perception. An involvement of the DA-system in the encoding of durations in the supra-second range is questioned. © 2010 Sysoeva et al. Source

Trushkin E.V.,Russian Research Institute of Sport and Physical Education | Timofeeva M.A.,Russian Research Institute of Sport and Physical Education | Sysoeva O.V.,Russian Research Institute of Sport and Physical Education | Davydov Y.I.,Russian Research Institute of Sport and Physical Education | And 3 more authors.
Bulletin of Experimental Biology and Medicine | Year: 2011

The incidence of SLC6A4 gene 5HTTLPR polymorphism alleles was evaluated in 223 male athletes engaged in endurance sports, the results were compared with those in 177 male nonathletes. Association between 5-HTTLPR genotypes and the effect of exhaustive treadmill running on simple and complex visual reactions and critical fl icker frequency threshold was studied. We found that the incidence of LL genotype was signifi cantly higher in athletes in comparison to nonathletes; after exercise, the velocity of visual reactions and critical fl icker frequency increased; exercise did not change the velocity of complex visual reaction in LL-carriers, and increased it in SS-carriers. We conclude that exhausting treadmill running leads to facilitation sensory information processing in athletes and that SS-carriers are more susceptible to the effect of exhaustive treadmill running than LL-carriers. © 2011 Springer Science+Business Media, Inc. Source

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