Val66Met Polymorphism of Brain-Derived Neurotrophic Factor (BDNF) is Associated with Individual Alpha Peak Frequency and Alpha Power in Adults

Abstract

Single-nucleotide polymorphism within the BDNF gene (Val66Met) influences activity-dependent secretion of the brain-derived neurotrophic factor (BDNF), which affects neuroprotection and synaptic plasticity. Several studies found associations between Met allele and lower power of the EEG α-rhythm determined in the standard frequency range in young adults. Along with the power, one of the highly heritable EEG correlates of brain functions is the individual α-peak frequency (IAPF). Although IAPF has independent functional significance, its association with the Val66Met BDNF polymorphism has not been studied. IAPF is also used to determine the boundaries of individual frequency ranges; in contrast to the standard ones, they reflect functional characteristics of rhythms to a greater extent. We explored in 192 subjects aged 18–78 years whether parieto-occipital IAPF is associated with BDNF polymorphism and tested genotypic differences in α-power calculated in standard (8−12 Hz) and individual (from (IAPF –2) to (IAPF +2) Hz) frequency ranges. IAPF was decreased in Val/Met in comparison to Val/Val. For individual frequency range, genetic differences were found in both eyes closed (Val/Met homozygous genotypes) and eyes open (Val-carriers Met/Met) condition. For standard frequency range – only in eyes open condition, which may be due to a shift of the α-functional range towards a region of low frequencies among Val/Met-carriers that showed a decrease in IAPF. The results indicate that the inclusion of Val/Met in the combined group of Met-carriers in the analysis of genetic differences in brain activity can eliminate the differences between Val/Val and Val/Met genotypes, as well as the advantage of using individual frequency bands in the analysis of BDNF-associated features of EEG.