Open AccessBrain‐Derived Neurotrophic Factor Polymorphism Influences Response to Single‐Pulse Transcranial Magnetic Stimulation at Rest
Author(s) -
ShahBasak Priyanka,
Harvey Denise Y.,
Parchure Shreya,
Faseyitan Olufunsho,
Sacchetti Daniela,
Ahmed Ahmed,
Thiam Abdou,
Lohoff Falk W.,
Hamilton Roy H.
Publication year - 2021
Publication title -
neuromodulation: technology at the neural interface
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 60
eISSN - 1525-1403
pISSN - 1094-7159
DOI - 10.1111/ner.13287
Subject(s) - transcranial magnetic stimulation , medicine , stimulation , neuroplasticity , brain stimulation , neuroscience , neurotrophic factors , brain derived neurotrophic factor , psychology , receptor
Abstract Objectives The ability of noninvasive brain stimulation to modulate corticospinal excitability and plasticity is influenced by genetic predilections such as the coding for brain‐derived neurotrophic factor (BDNF). Otherwise healthy individuals presenting with BDNF Val66Met (Val/Met) polymorphism are less susceptible to changes in excitability in response to repetitive transcranial magnetic stimulation (TMS) and paired associative stimulation paradigms, reflecting reduced neuroplasticity, compared to Val homozygotes (Val/Val). In the current study, we investigated whether BDNF polymorphism influences “baseline” excitability under TMS conditions that are not repetitive or plasticity‐inducing. Cross‐sectional BDNF levels could predict TMS response more generally because of the ongoing plasticity processes. Materials and Methods Forty‐five healthy individuals (23 females; age: 25.3 ± 7.0 years) participated in the study, comprising two groups. Motor evoked potentials (MEP) were collected using single‐pulse TMS paradigms at fixed stimulation intensities at 110% of the resting motor threshold in one group, and individually‐derived intensities based on MEP sizes of 1 mV in the second group. Functional variant Val66Met (rs6265) was genotyped from saliva samples by a technician blinded to the identity of DNA samples. Results Twenty‐seven participants (60.0%) were identified with Val/Val, sixteen (35.5%) with Val/Met genotype, and two with Met/Met genotype. MEP amplitudes were significantly diminished in the Val/Met than Val/Val individuals. These results held independent of the single‐pulse TMS paradigm of choice ( p = 0.017110% group; p = 0.035 1 mV group), age, and scalp‐to‐coil distances. Conclusions The findings should be further substantiated in larger‐scale studies. If validated, intrinsic differences by BDNF polymorphism status could index response to TMS prior to implementing plasticity‐inducing protocols.