Different responses to facilitatory rTMS according to BDNF genotype

Area of Science:

• Neuroscience
• Genetics
• Neurorehabilitation

Background:

• Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique.
• Brain-derived neurotrophic factor (BDNF) plays a crucial role in neuronal plasticity.
• Genetic variations in BDNF may affect individual responses to neurostimulation.

Purpose of the Study:

• To examine the relationship between rTMS-induced plasticity and BDNF genotype.
• To investigate how different rTMS intensities affect cortical excitability in relation to BDNF genotype.

Main Methods:

• Forty healthy volunteers underwent three conditions of high-frequency rTMS (sub-threshold, supra-threshold, sham) over the motor cortex.
• Cortical excitability was measured using motor-evoked potentials (MEPs) before and after each rTMS condition.
• Participants were genotyped for BDNF (Val/Val, Val/Met, Met/Met).

Main Results:

• All rTMS conditions significantly increased MEP amplitudes compared to sham, indicating induced plasticity.
• The Val/Val genotype showed a greater increase in MEP amplitude with supra-threshold rTMS compared to sub-threshold rTMS.
• No significant differences in MEP amplitude changes were observed between sub-threshold and supra-threshold rTMS in Val/Met and Met/Met genotypes.

Conclusions:

• High-frequency rTMS consistently facilitates cortical excitability across different BDNF genotypes.
• BDNF genotype appears to modulate the extent of plasticity induced by varying rTMS intensities.
• Individual genetic makeup, specifically BDNF genotype, is a factor influencing neuroplasticity responses to rTMS.