Developmental Changes in Organization of Structural Brain Networks

Abstract

Recent findings from developmental neuroimaging studies suggest that the enhancement of cognitive processes during development may be the result of a fine-tuning of the structural and functional organization of brain with maturation. However, the details regarding the developmental trajectory of large-scale structural brain networks are not yet understood. Here, we used graph theory to examine developmental changes in the organization of structural brain networks in 203 normally growing children and adolescents. Structural brain networks were constructed using interregional correlations in cortical thickness for 4 age groups (early childhood: 4.8-8.4 year; late childhood: 8.5-11.3 year; early adolescence: 11.4-14.7 year; late adolescence: 14.8-18.3 year). Late childhood showed prominent changes in topological properties, specifically a significant reduction in local efficiency, modularity, and increased global efficiency, suggesting a shift of topological organization toward a more random configuration. An increase in number and span of distribution of connector hubs was found in this age group. Finally, inter-regional connectivity analysis and graph-theoretic measures indicated early maturation of primary sensorimotor regions and protracted development of higher order association and paralimbic regions. Our finding reveals a time window of plasticity occurring during late childhood which may accommodate crucial changes during puberty and the new developmental tasks that an adolescent faces.

Generative models of rich clubs in Hebbian neuronal networks and large-scale human brain networks

“…One might expect, for example, that over the course of human development, periods during which cognitive capability is enhanced and Hebbian processes are particularly active may also correspond to increased salience of rich-club structures. This idea is supported by preliminary evidence from developmental neuroimaging studies which have revealed an increase in the number and importance of connector hubs in normally growing children and adolescents [45].…”

Structural Covariance of the Default Network in Healthy and Pathological Aging

“…Acquisition of 1.5 T MRI data was collected according to a standardized protocol (Jack et al, 2008). The scanning protocol included a high- resolution T1-weighted, rapid gradient echo (MP-RAGE) sequence.…”

“…This network is characterized by high intrinsic functional connectivity between posterior cingulate cortex (PCC), medial prefrontal cortex, inferior parietal lobule, and lateral and medial temporal lobes (Buckner et al, 2008). The functional integrity of the default network is reduced in older adults (Hafkemeijer et al, 2012), with further reductions in Alzheimer's disease (AD) (Greicius et al, 2004;Damoiseaux et al, 2012;Hafkemeijer et al, 2012;Sheline and Raichle, 2013). Functional connectivity within the default network differs in APOE 4 allele carriers, a risk factor for late-life pathological changes (Filippini et al, 2009;Sheline et al, 2010).…”

“…Functional connectivity within the default network differs in APOE 4 allele carriers, a risk factor for late-life pathological changes (Filippini et al, 2009;Sheline et al, 2010). Age-related functional changes to the default network have been reliably observed; regions of the network are also susceptible to AD neuropathology (Buckner et al, 2005;Hafkemeijer et al, 2012;Sheline and Raichle, 2013). The structural covariance of the default network, however, remains relatively unexplored.…”

Structural covariance of neostriatal and limbic regions in patients with obsessive–compulsive disorder

“…In this sense, while global brain volume is largely genetically deter mined, regional brain volumes, and therefore structural co variance measurements, are more flexibly determined by a number of factors. 3,4 Such factors range from genetic 5 and other developmental influences [6][7][8] to aging effects. 9,10 Other aspects related to the basic principles of brain organ ization, such as the existence of functional connectivity, or cor related spontaneous activity across time between distant struc tures, may also influence the patterns of structural covariance.…”