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

Abstract

—A single nucleotide polymorphism in the brain-derived neurotrophic factor (BDNF) gene (Val66Met) functions to regulate activity-dependent secretion of (BDNF), which plays an important role in neuroprotection and synaptic plasticity. In several studies, the Met allele was associated with lower electroencephalogram (EEG) α-power values, calculated in the standard frequency range, in young subjects. In addition to α-power, one of the inherited EEG correlates of brain functioning is individual alpha peak frequency (IAPF). Although IAPF has a separate functional role, its association with BDNF Val66Met polymorphism has not been studied. IAPF is also used to determine the boundaries of individual frequency ranges, which, unlike the standard ones, are more consistent with functional rhythm characteristics. Using a sample of 192 subjects aged 18–78 years, the association between parietal-occipital IAPF and BDNF polymorphism, as well as the genotype differences in α-power calculated in standard (8–12 Hz) and individual frequency ranges (from (IAPF –2) to (IAPF +2) Hz) were examined. A decrease of IAPF in Val/Met compared to Val/Val was observed. For power calculated in the individual frequency range, genetic differences in both eyes-closed (Val/Met > homozygous genotypes) and eyes-open (Val-carriers > Met/Met) conditions were revealed. Analysis within the standard frequency range showed differences only in the eyes-open condition, which could be due to a shift of power indicators calculated in the α-rhythm functional range to the low frequency region among Val/Met carriers, which showed a decrease in IAPF. The results suggest that the inclusion of Val/Met in the pooled group of Met carriers in the analysis of genetic differences in brain activity may level out the differences between the Val/Val and Val/Met genotypes and show the advantage of using individual frequency bands in the analysis of BDNF Val66Met-associated EEG features.