title: Thalamocortical connectivity in healthy children: asymmetries and robust developmental changes between ages 8 and 17 years.
abstract: OBJECTIVE
  Thalamocortical connections play a crucial role in complex cognitive functioning, and several neuropsychiatric disorders may involve aberrant thalamocortical circuitry. Here, we quantified the cortical pattern and age-related changes of thalamocortical connections by using probabilistic tractography in children and adolescents. We hypothesized that detectable asymmetry (left>right) exists in thalamocortical fiber connections and the connectivity increases with age during maturation.
  
  
  METHODS
  Diffusion tensor imaging was acquired in 15 normally developing children (age range, 8.3-17.3 years; 11 males), and fiber tracking was initiated from the thalami. The cortical distribution of ipsilateral thalamocortical fibers was quantified by using a landmark-constrained conformal mapping technique. Furthermore, hemispheric asymmetries and potential age-related changes in regional thalamocortical connections were assessed.
  
  
  RESULTS
  The left thalamus had significantly higher overall cortical connectivity than the right thalamus (P < .001). Left prefrontal cortical areas showed significantly higher thalamic connectivity compared with homotopic regions of the right hemisphere (P < .001), regardless of the applied parameters. There was an increase of overall thalamocortical connectivity with age, with the most pronounced age-related increases in bilateral prefrontal areas (P < .002). However, thalamic connectivity of some other cortical regions (right sensorimotor, left inferior temporal) showed a decrease with age.
  
  
  CONCLUSIONS
  Our results indicate a region-specific left>right asymmetry and robust developmental changes in thalamocortical (particularly thalamo-prefrontal) connectivity during late childhood and adolescence. These data further add to our knowledge about structural lateralizations and their development in the maturing brain.
authors: Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Children’s Hospital of Michigan, Detroit, USA.
authors: B
authors: B
authors: Alkonyi
authors: C
authors: C
authors: Juhász
authors: O
authors: O
authors: Muzik
authors: M E
authors: ME
authors: Behen
authors: J-W
authors: JW
authors: Jeong
authors: H T
authors: HT
authors: Chugani
mesh_terms: D000293:Adolescent; D000375:Aging / Q000473:pathology*; D002540:Cerebral Cortex / Q000033:anatomy & histology*; D002648:Child; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology*; D013788:Thalamus / Q000033:anatomy & histology*