title: Heritability of intracortical inhibition and facilitation.
abstract: The present twin study investigates heritability of motor cortex excitability, measured by the paired pulse transcranial magnetic stimulation technique. Specifically, intracortical facilitation (ICF) and inhibition (ICI) and corticospinal excitability were tested in monozygotic (MZ), dizygotic (DZ), and unrelated pairs (UP). Robust ICF and ICI effects were found, with a higher similarity of MZ than DZ and UP pairs. Heritability estimates (h(2)) were 0.80 for ICI and 0.92 for ICF. However, corticospinal excitability did not show significant differences between MZ and DZ pairs, whereas both significantly differed from UP. Hence, the study provides--for the first time--a clear evidence of heritable individual differences in motor cortex excitability.
authors: Istituto di Ricovero e Cura a Carattere Scientifico San Giovanni di Dio, Fatebenefratelli, Brescia 25125, Italy.
authors: Maria Concetta
authors: MC
authors: Pellicciari
authors: Domenica
authors: D
authors: Veniero
authors: Cristina
authors: C
authors: Marzano
authors: Fabio
authors: F
authors: Moroni
authors: Cornelia
authors: C
authors: Pirulli
authors: Giuseppe
authors: G
authors: Curcio
authors: Michele
authors: M
authors: Ferrara
authors: Carlo
authors: C
authors: Miniussi
authors: Paolo Maria
authors: PM
authors: Rossini
authors: Luigi
authors: L
authors: De Gennaro
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000235:genetics; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D009433:Neural Inhibition / Q000235:genetics*; D011712:Pyramidal Tracts / Q000502:physiology; D011930:Reaction Time / Q000235:genetics; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D018433:Twin Studies as Topic; D014429:Twins, Dizygotic / Q000235:genetics*; D014430:Twins, Monozygotic / Q000235:genetics*; D055815:Young Adult