title: BDNF Val66Met polymorphism is associated with abnormal interhemispheric transfer of a newly acquired motor skill.
abstract: Recent data suggest that the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene can alter cortical plasticity within the motor cortex of carriers, which exhibits abnormally low rates of cortical reorganization after repetitive motor tasks. To verify whether long-term retention of a motor skill is also modulated by the presence of the polymorphism, 20 participants (10 Val66Val, 10 Val66Met) were tested twice at a 1-wk interval. During each visit, excitability of the motor cortex was measured by transcranial magnetic stimulations (TMS) before and after performance of a procedural motor learning task (serial reaction time task) designed to study sequence-specific learning of the right hand and sequence-specific transfer from the right to the left hand. Behavioral results showed a motor learning effect that persisted for at least a week and task-related increases in corticospinal excitability identical for both sessions and without distinction for genetic group. Sequence-specific transfer of the motor skill from the right hand to the left hand was greater in session 2 than in session 1 only in the Val66Met genetic group. Further analysis revealed that the sequence-specific transfer occurred equally at both sessions in the Val66Val genotype group. In the Val66Met genotype group, sequence-specific transfer did not occur at session 1 but did at session 2. These data suggest a limited impact of Val66Met polymorphism on the learning and retention of a complex motor skill and its associated changes in corticospinal excitability over time, and a possible modulation of the interhemispheric transfer of procedural learning.
authors.affiliation: Université de Montréal, Montreal, Quebec, Canada;
authors.forename: Olivier
authors.initials: O
authors.lastname: Morin-Moncet
authors.affiliation: Université de Montréal, Montreal, Quebec, Canada;
authors.forename: Vincent
authors.initials: V
authors.lastname: Beaumont
authors.affiliation: Université du Québec à Trois-Rivières, Montreal, Quebec, Canada; and.
authors.forename: Louis
authors.initials: L
authors.lastname: de Beaumont
authors.affiliation: Université de Montréal, Montreal, Quebec, Canada;
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Lepage
authors.affiliation: Université de Montréal, Montreal, Quebec, Canada; Hôpital Sainte-Justine Research Center, Montreal, Quebec, Canada hugo.theoret@umontreal.ca.
authors.forename: Hugo
authors.initials: H
authors.lastname: Théoret
mesh_terms: D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D005838:Genotype; D060005:Genotyping Techniques; D006225:Hand / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D009483:Neuropsychological Tests; D020641:Polymorphism, Single Nucleotide; D011712:Pyramidal Tracts / Q000502:physiology; D011930:Reaction Time; D013647:Task Performance and Analysis; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation; D014163:Transfer, Psychology / Q000502:physiology*; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor
keywords: brain-derived neurotrophic factor; interhemispheric transfer; motor learning; serial reaction time task; transcranial magnetic stimulation