title: Corticospinal excitability in the non-dominant hand is affected by BDNF genotype.
abstract: The objective of this study was to assess the functional state of corticospinal projections in the non-dominant hand according to brain-derived neurotrophic factor (BDNF) Val66Met polymorphisms. We investigated this in 34 healthy right-handed individuals (12 men, mean age 27.4 ± 3.4 years) who underwent two experimental sessions consisting of corticospinal excitability measurements with single-pulse transcranial magnetic stimulation (TMS) and hand motor function assessments with a sequential finger motor task of the non-dominant hand. Experimental sessions were separated by periods of at least 2 days to avoid carryover effects. Data were analyzed according to BDNF polymorphism (Val/Val vs. Val/Met vs. Met/Met group). Ten (29.4%), seventeen (50.0%), and seven (20.6%) participants were allocated to the Val/Val, Val/Met, and Met/Met groups, respectively. Motor thresholds to TMS did not differ among groups, but the amplitude of the motor-evoked potentials in the non-dominant hand induced by suprathreshold (120% of MT) TMS was significantly lower in the Met/Met group than in the other two groups (p < 0.05). Movement accuracy and reaction time in the sequential finger motor task showed no significant differences among groups. These results indicate that Met/Met BDNF homozygote status affects corticospinal excitability, and should be controlled for in studies of motor system function using brain stimulation. Our findings may have clinical implications regarding further investigation of the impact of BDNF genotype on the human motor system.
authors: Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Won Hyuk
authors: WH
authors: Chang
authors: Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Jung Min
authors: JM
authors: Hwang
authors: Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Kyeong Eun
authors: KE
authors: Uhm
authors: Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors: Alvaro
authors: A
authors: Pascual-Leone
authors: Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. yunkim@skku.edu.|Department of Health Science and Technology, Department of Medical Device Management and Research, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea. yunkim@skku.edu.
authors: Yun-Hee
authors: YH
authors: Kim
mesh_terms: D000328:Adult; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D005838:Genotype; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D020641:Polymorphism, Single Nucleotide; D011712:Pyramidal Tracts / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human
keywords: BDNF; Corticospinal excitability; Polymorphism; Transcranial magnetic stimulation