Experimental protocol. A total of 58 participants were recruited in this study. Blood samples were collected to identify the BDNF) genotype of each participant. The participants then underwent the TMS) (n = 45), magnetic resonance spectroscopy (MRS) experiments (n = 30), or both (n = 17). Single-pulse Motor-evoked potentials (MEPs) and inhibitory responses to TMS were measured 20 times each in two sessions, totaling 40 MEPs per condition, with 10 min intervals. The magnetic resonance (MR) data were collected in the following order: structural MRI, fMRI, and MRS. Abbreviations: BDNF, brain-derived neurotrophic factor; TMS, transcranial magnetic stimulation; Single, single-pulse; SICI, short-interval intracortical inhibition; LICI, long-interval intracortical inhibition; SAI_1, short-latency afferent inhibition with an ISI of 20 ms; SAI_2, short-latency afferent inhibition with an ISI of 25 ms; LAI, long-latency afferent inhibition; MR, magnetic resonance; MRI, magnetic resonance imaging; fMRI, functional magnetic resonance imaging; MRS, magnetic resonance spectroscopy.