The effect of brain-derived neurotrophic factor single nucleotide polymorphism on cognitive factors

Abstract

Background: The brain-derived neurotrophic factor (BDNF) is a neurotrophic factor in the brain associated with the growth, synap-tic plasticity, learning, and cognitive processes. Objectives: The presence of val66met polymorphism in codon 66 of the BDNF gene disturbs this protein’s secretion. The study investigates the effect of this polymorphism on attention, visuomotor performance, and implicit motor sequence learning. Methods: In the present study, 100 students from the University of Kashan, Iran, with the mean age of 21.60 ± 2.20 years, were enrolled. Following extraction of Genomic DNA, implementation of polymerase chain reaction (PCR), analyzing PCR, and DNA se-quencing, 46 students were recognized without val66met polymorphism, while 54 students were affected by the polymorphism. In the beginning, participants of each group performed the Stroop color-word test. The Stroop color-word test was performed on one day, and afterward, the serial reaction time test was performed on another day. Results: The results showed that students with the polymorphism were significantly performed weaker than those without the polymorphism in intervention time of the Stroop test (P = 0.001), visuomotor performance (P = 0.001), and implicit motor learning (P = 0.006). However, no significant difference between the groups was observed in intervention score of the Stroop test (P = 0.637). Conclusions: In general, the results show the effect of the polymorphism on visuomotor performance, implicit motor sequence learning, and selective attention. Therefore, this polymorphism in some individuals may weaken their ability, probably through disturbance in BDNF expression.