Modulation of the COMT Val(158)Met polymorphism on resting-state EEG power.

Silvia Solís-Ortiz,Mayra Gutiérrez-Muñoz,Elva Pérez-Luque

doi:10.3389/fnhum.2015.00136

Silvia Solís-Ortiz, Mayra Gutiérrez-Muñoz + Show 1 more

Open Access

https://doi.org/10.3389/fnhum.2015.00136

Copy DOI

Abstract

The catechol-O-methyltransferase (COMT) Val158Met polymorphism impacts cortical dopamine (DA) levels and may influence cortical electrical activity in the human brain. This study investigated whether COMT genotype influences resting-state electroencephalogram (EEG) power in the frontal, parietal and midline regions in healthy volunteers. EEG recordings were conducted in the resting-state in 13 postmenopausal healthy woman carriers of the Val/Val genotype and 11 with the Met/Met genotype. The resting EEG spectral absolute power in the frontal (F3, F4, F7, F8, FC3 and FC4), parietal (CP3, CP4, P3 and P4) and midline (Fz, FCz, Cz, CPz, Pz and Oz) was analyzed during the eyes-open and eyes-closed conditions. The frequency bands considered were the delta, theta, alpha1, alpha2, beta1 and beta2. EEG data of the Val/Val and Met/Met genotypes, brain regions and conditions were analyzed using a general linear model analysis. In the individuals with the Met/Met genotype, delta activity was increased in the eyes-closed condition, theta activity was increased in the eyes-closed and in the eyes-open conditions, and alpha1 band, alpha2 band and beta1band activity was increased in the eyes-closed condition. A significant interaction between COMT genotypes and spectral bands was observed. Met homozygote individuals exhibited more delta, theta and beta1 activity than individuals with the Val/Val genotype. No significant interaction between COMT genotypes and the resting-state EEG regional power and conditions were observed for the three brain regions studied. Our findings indicate that the COMT Val158Met polymorphism does not directly impact resting-state EEG regional power, but instead suggest that COMT genotype can modulate resting-state EEG spectral power in postmenopausal healthy women.

Highlights

Catechol-O-methyl transferase (COMT) is the major mammalian enzyme involved in the metabolic degradation of released dopamine (DA) and accounts for more than 60% of DA degradation in the frontal cortex (Bertocci et al, 1991)
The omnibus analysis revealed main effects of Genotype (F(1) = 7.16, p = 0.008), Band (F(5) = 541.24, p = 0.000001), Region (F(2) = 7.41, p = 0.0007) and Condition (F(1) = 38.25, p = 0.000001), indicating that individuals with Val/Val and Met/Met genotypes differed in the absolute power of their EEG and that the differences varied by band, region and condition
The results of this study demonstrate the effects of the COMT Val158Met polymorphism on resting-state EEG power during the eyes-closed and eyes-open states in healthy women

Summary

Introduction

Catechol-O-methyl transferase (COMT) is the major mammalian enzyme involved in the metabolic degradation of released dopamine (DA) and accounts for more than 60% of DA degradation in the frontal cortex (Bertocci et al, 1991). The human COMT gene contains a functional polymorphism in the coding sequence. As a result of the allelic differences in enzymatic activity, Val carriers have less DA activity in the prefrontal cortex. The more robust statistical differences in COMT have been observed in heterozygous individuals with the Val/Val or Met/Met genotypes. Several experimental animal and human studies implicate COMT allelic variations in tuning cortical DA levels and consequent function (Diamond, 2007; Witte and Flöel, 2012). These studies indicate that this functional polymorphism accounts for most of the human variation in peripheral COMT activity. An individual’s COMT genotype might contribute to differences in prefrontal function (Akil et al, 2003)

Objectives

Methods

Results

Conclusion