title: Hand cortical representation at rest and during activation: gender and age effects in the two hemispheres.
abstract: OBJECTIVE
  To characterize the age- and gender- dependence of sensory hand cortical representation in the two hemispheres in healthy population.
  
  
  METHODS
  In 57 adults, the cerebral activity from rolandic areas as detected by magnetoencephalography was considered both in a resting state (spectral power properties) and in response to the electrical stimulation of the contralateral median nerve (M20 and M30 cortical sources).
  
  
  RESULTS
  We found a dependence of rest and evoked activity on age (alpha rhythm slowing, high frequency power increase, M20 latency increase, M20 strength increase, no change in M30) and on gender (higher alpha frequency, higher beta power, higher spectral entropy, lower M20 amplitude in women). These changes were quite symmetrical in the two hemispheres, making the interhemispheric differences non-dependent on age and gender. Moreover, lower total power and faster alpha rhythm appeared in the dominant hemisphere.
  
  
  CONCLUSIONS
  Age and gender have a significant effect on spontaneous and evoked activity at the primary sensorimotor cortex.
  
  
  CONCLUSIONS
  The results consolidate the reference base in healthy population, to study pathological conditions. Inter-hemispheric asymmetries are confirmed as a sensitive indicator for the early identification of possible neuronal rearrangements due to unilateral brain injuries.
authors.affiliation: ISTC-CNR, Roma, Italy. filippo.zappasodi@istc.cnr.it
authors.forename: Filippo
authors.initials: F
authors.lastname: Zappasodi
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pasqualetti
authors.forename: Mario
authors.initials: M
authors.lastname: Tombini
authors.forename: Matilde
authors.initials: M
authors.lastname: Ercolani
authors.forename: Vittorio
authors.initials: V
authors.lastname: Pizzella
authors.forename: Paolo M
authors.initials: PM
authors.lastname: Rossini
authors.forename: Franca
authors.initials: F
authors.lastname: Tecchio
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D019277:Entropy; D005071:Evoked Potentials / Q000502:physiology / Q000528:radiation effects; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006225:Hand / Q000294:innervation / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects; D012146:Rest / Q000502:physiology*; D012727:Sex Characteristics; D013057:Spectrum Analysis