title: Neocortical maturation during adolescence: change in neuronal soma dimension.
abstract: During adolescence, cognitive abilities increase robustly. To search for possible related structural alterations of the cerebral cortex, we measured neuronal soma dimension (NSD = width times height), cortical thickness and neuronal densities in different types of neocortex in post-mortem brains of five 12-16 and five 17-24 year-olds (each 2F, 3M). Using a generalized mixed model analysis, mean normalized NSD comparing the age groups shows layer-specific change for layer 2 (p < .0001) and age-related differences between categorized type of cortex: primary/primary association cortex (BA 1, 3, 4, and 44) shows a generalized increase; higher-order regions (BA 9, 21, 39, and 45) also show increase in layers 2 and 5 but decrease in layers 3, 4, and 6 while limbic/orbital cortex (BA 23, 24, and 47) undergoes minor decrease (BA 1, 3, 4, and 44 vs. BA 9, 21, 39, and 45: p = .036 and BA 1, 3, 4, and 44 vs. BA 23, 24, and 47: p = .004). These data imply the operation of cortical layer- and type-specific processes of growth and regression adding new evidence that the human brain matures during adolescence not only functionally but also structurally.
authors.affiliation: University of Lausanne, Division of Neuropathology, CH-1000 Lausanne, Switzerland.
authors.forename: Theodore
authors.initials: T
authors.lastname: Rabinowicz
authors.forename: Jean Macdonald-Comber
authors.initials: JM
authors.lastname: Petetot
authors.forename: Jane C
authors.initials: JC
authors.lastname: Khoury
authors.forename: Gabrielle M
authors.initials: GM
authors.lastname: de Courten-Myers
mesh_terms: D000293:Adolescent; D041923:Adolescent Development; D000375:Aging / Q000502:physiology; D002452:Cell Count; D048429:Cell Size; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000166:cytology* / Q000254:growth & development*; D002648:Child; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D019579:Neocortex / Q000033:anatomy & histology / Q000166:cytology / Q000254:growth & development*; D009474:Neurons / Q000166:cytology*; D055815:Young Adult