TY - JOUR
T1 - Age-Related changes in the thickness of cortical zones in humans
AU - McGinnis, Scott M.
AU - Brickhouse, Michael
AU - Pascual, Belen
AU - Dickerson, Bradford C.
N1 - Funding Information:
Acknowledgment This study was supported by grants from the NIA R01-AG29411, R21-AG29840, P50-AG005134, and NCRR P41-RR14075, U24-RR021382, Harvard NeuroDiscovery Center, and the Alzheimer’s Association.
PY - 2011/10
Y1 - 2011/10
N2 - Structural neuroimaging studies have demonstrated that all regions of the cortex are not affected equally by aging, with frontal regions appearing especially susceptible to atrophy. The ''last in, first out'' hypothesis posits that aging is, in a sense, the inverse of development: late-maturing regions of the brain are preferentially vulnerable to age-related loss of structural integrity. We tested this hypothesis by analyzing age-related changes in regional cortical thickness via three methods: (1) an exploratory linear regression of cortical thickness and age across the entire cortical mantle (2) an analysis of age-related differences in the thickness of zones of cortex defined by functional/cytoarchitectural affiliation (including primary sensory/motor, unimodal association, heteromodal association, and paralimbic zones), and (3) an analysis of agerelated differences in the thickness of regions of cortex defined by surface area expansion in the period between birth and early adulthood. Subjects were grouped as young (aged 18-29, n = 138), middle-aged (aged 30-59, n = 80), young-old (aged 60-79, n = 60), and old-old (aged 80+, n = 38). Thinning of the cortex between young and middle-aged adults was greatest in heteromodal association cortex and regions of high postnatal surface area expansion. In contrast, thinning in old-old age was greatest in primary sensory/motor cortices and regions of low postnatal surface area expansion. In sum, these results lead us to propose a sequential "developmental-sensory" model of aging, in which developmental factors influence cortical vulnerability relatively early in the aging process, whereas later-in more advanced stages of aging-factors specific to primary sensory and motor cortices confer vulnerability. This model offers explicitly testable hypotheses and suggests the possibility that normal aging may potentially allow for multiple opportunities for intervention to promote the structural integrity of the cerebral cortex.
AB - Structural neuroimaging studies have demonstrated that all regions of the cortex are not affected equally by aging, with frontal regions appearing especially susceptible to atrophy. The ''last in, first out'' hypothesis posits that aging is, in a sense, the inverse of development: late-maturing regions of the brain are preferentially vulnerable to age-related loss of structural integrity. We tested this hypothesis by analyzing age-related changes in regional cortical thickness via three methods: (1) an exploratory linear regression of cortical thickness and age across the entire cortical mantle (2) an analysis of age-related differences in the thickness of zones of cortex defined by functional/cytoarchitectural affiliation (including primary sensory/motor, unimodal association, heteromodal association, and paralimbic zones), and (3) an analysis of agerelated differences in the thickness of regions of cortex defined by surface area expansion in the period between birth and early adulthood. Subjects were grouped as young (aged 18-29, n = 138), middle-aged (aged 30-59, n = 80), young-old (aged 60-79, n = 60), and old-old (aged 80+, n = 38). Thinning of the cortex between young and middle-aged adults was greatest in heteromodal association cortex and regions of high postnatal surface area expansion. In contrast, thinning in old-old age was greatest in primary sensory/motor cortices and regions of low postnatal surface area expansion. In sum, these results lead us to propose a sequential "developmental-sensory" model of aging, in which developmental factors influence cortical vulnerability relatively early in the aging process, whereas later-in more advanced stages of aging-factors specific to primary sensory and motor cortices confer vulnerability. This model offers explicitly testable hypotheses and suggests the possibility that normal aging may potentially allow for multiple opportunities for intervention to promote the structural integrity of the cerebral cortex.
KW - Aging
KW - Cortex
KW - Magnetic resonance imaging
KW - Morphometry
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U2 - 10.1007/s10548-011-0198-6
DO - 10.1007/s10548-011-0198-6
M3 - Article
C2 - 21842406
AN - SCOPUS:80755172334
SN - 0896-0267
VL - 24
SP - 279
EP - 291
JO - Brain Topography
JF - Brain Topography
IS - 3-4
ER -