Different responses to facilitatory rTMS according to BDNF genotype

- High-frequency rTMS significantly induces the facilitation of cortical excitability regardless of brain-derived neurotrophic factor (BDNF) genotype.
- BDNF genotype influence rTMS-induced plasticity based on the rTMS intensity.
- Our findings suggest that the individual rTMS strategy will be needed according to the brain-derived neurotrophic factor genotype.

ObjectiveTo investigate whether there is a relation between the plasticity induced by different intensities of facilitatory rTMS with different intensities and brain-derived neurotrophic factor (BDNF) genotype.MethodsForty healthy volunteers (14 men, mean age 27.3 years) were enrolled. All participants received three high-frequency rTMS applications in random order over the non-dominant primary motor cortex with more than a 24-h washout period: 1st condition, rTMS with sub-threshold intensity; 2nd condition, rTMS with supra-threshold intensity; and 3rd condition, sham rTMS. Cortical excitability was assessed before and after rTMS using motor-evoked potentials (MEPs). Data were analyzed using the BDNF genotype.ResultsTwelve, 19, and 9 participants were classified into Val/Val, Val/Met, and Met/Met groups, respectively. In each group, there were significant increases in the amplitude of MEPs after 1st and 2nd conditions (P < 0.05), but not after 3rd condition. In Val/Val group, the increase ratio of MEPs' amplitude after 2nd condition was significantly higher than 1st condition (P < 0.05). However, no significant amplitude differences in Val/Met and Met/Met groups were observed after 1st and 2nd conditions.ConclusionsHigh-frequency rTMS induces the facilitation of cortical excitability regardless of BDNF genotype. BDNF genotype might influence on different responses of plasticity based on the rTMS intensity.SignificanceBDNF genotype is one of influence factors on the plasticity after the facilitatory rTMS.