title: Increased gray matter volume of left pars opercularis in male orchestral musicians correlate positively with years of musical performance.
abstract: OBJECTIVE
  To compare manual volumetry of gray matter (GM) / white matter (WM) of Broca's area subparts: pars opercularis (POP) and pars triangularis (PTR) in both hemispheres between musicians and nonmusician, as it has been shown that these regions are crucial for musical abilities. A previous voxel-based morphometric (VBM) study conducted in our laboratory reported increased GM density in Broca's area of left hemisphere in male orchestral musicians. Functional segregation of POP/PTR justified separate volumetric analysis of these parts.
  
  
  METHODS
  We used the same cohort for the VBM study. Manual morphometry (stereology) was used to compare volumes between 26/26 right-handed orchestral musicians/nonmusicians.
  
  
  RESULTS
  As expected, musicians showed significantly increased GM volume in the Broca's area, specifically in the left POP. No significant results were detected in right POP, left/right PTR GM volumes, and WM volumes for all regions. Results were positively correlated with years of musical performance (r = 0.7, P = 0.0001).
  
  
  CONCLUSIONS
  This result corroborates the VBM study and is in line with the hypothesis of critical involvement of POP in hearing-action integration being an integral component of frontoparietotemporal mirror neuron network. We hypothesize that increased size of musicians' left POP represent use-dependent structural adaptation in response to intensive audiomotor skill acquisition.
authors.affiliation: School of Health Sciences, University of Liverpool, Liverpool, UK. Ihssan.abdulkareem@liv.ac.uk
authors.forename: Ihssan A
authors.initials: IA
authors.lastname: Abdul-Kareem
authors.forename: Andrej
authors.initials: A
authors.lastname: Stancak
authors.forename: Laura M
authors.initials: LM
authors.lastname: Parkes
authors.forename: Vanessa
authors.initials: V
authors.lastname: Sluming
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005625:Frontal Lobe / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009146:Music; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000166:cytology* / Q000502:physiology*; D009929:Organ Size / Q000502:physiology; D013223:Statistics as Topic; D055815:Young Adult