Pediatric neuroimaging studies1,2,3,4,5, up to now exclusively cross sectional, identify linear decreases in cortical gray matter and increases in white matter across ages 4 to 20. In this large-scale longitudinal pediatric neuroimaging study, we confirmed linear increases in white matter, but demonstrated nonlinear changes in cortical gray matter, with a preadolescent increase followed by a postadolescent decrease. These changes in cortical gray matter were regionally specific, with developmental curves for the frontal and parietal lobe peaking at about age 12 and for the temporal lobe at about age 16, whereas cortical gray matter continued to increase in the occipital lobe through age 20.

Brain development during childhood and adolescence: a longitudinal MRI study.

The adolescent brain and age-related behavioral manifestations

We report the dynamic anatomical sequence of human cortical gray matter development between the age of 4–21 years using quantitative four-dimensional maps and time-lapse sequences. Thirteen healthy children for whom anatomic brain MRI scans were obtained every 2 years, for 8–10 years, were studied. By using models of the cortical surface and sulcal landmarks and a statistical model for gray matter density, human cortical development could be visualized across the age range in a spatiotemporally detailed time-lapse sequence. The resulting time-lapse “movies” reveal that (i) higher-order association cortices mature only after lower-order somatosensory and visual cortices, the functions of which they integrate, are developed, and (ii) phylogenetically older brain areas mature earlier than newer ones. Direct comparison with normal cortical development may help understanding of some neurodevelopmental disorders such as childhood-onset schizophrenia or autism.

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Dynamic mapping of human cortical development during childhood through early adulthood

e w id r as e, se er t st al h r Overweight or obesity in adolescents has reache epidemic proportions in the USA and other industr alized countries. These conditions, although ofte lumped together in research and in commentarie reflect adolescents’ being toward the heavier point a continuum that would range from underweight morbidly obese. The terms may be used interchang ably, but there is no doubt that, in the US a considerable percentage of adolescents suffer fro too much body fat. The prevalence of obesity (bod mass index [BMI] >95th percentile) among adole cents aged 12–19 years is now one in six (17.6%); an one in three (34.9%) US adolescents are overweight obese (BMI>85th percentile) (Story et al. 2009). Oth industrialized countries, such as Canada, Japa Germany, and China also are beginning to experien increasing problems related to obesity (Cornette 2008 Being on the overweight side of the weight continuu means being afflicted with a serious, chronic disea that can cause substantial harm to adolescents’ curre and future health. Although terms may be used loosely, individua only are formally deemed obese by physicians. The are some rules of thumb and formulas that often a used, especially in social science studies, but physician diagnose whether adolescents are obese. Discussion measurements tends to focus on that diagnos A diagnosis of obesity typically involves using a bod mass index (BMI). BMI is a measure of weight propo tionate to height, which is deemed a useful measure the amount of body fat. Although there are other mo precise ways to measure excess fat, experts now recom mend using BMI because it is easily obtained, strong

Obesity and Overweight

Adolescence is a developmental period characterized by suboptimal decisions and actions that are associated with an increased incidence of unintentional injuries, violence, substance abuse, unintended pregnancy, and sexually transmitted diseases. Traditional neurobiological and cognitive explanations for adolescent behavior have failed to account for the nonlinear changes in behavior observed during adolescence, relative to both childhood and adulthood. This review provides a biologically plausible model of the neural mechanisms underlying these nonlinear changes in behavior. We provide evidence from recent human brain imaging and animal studies that there is a heightened responsiveness to incentives and socioemotional contexts during this time, when impulse control is still relatively immature. These findings suggest differential development of bottom-up limbic systems, implicated in incentive and emotional processing, to top-down control systems during adolescence as compared to childhood and adulthood. This developmental pattern may be exacerbated in those adolescents prone to emotional reactivity, increasing the likelihood of poor outcomes.

The Adolescent Brain

1. Interest in the morphologic development of the corpus callosum (CC) during childhood and adolescence stems from adolescent changes in cognitive functions subserved by the CC, reports of CC anomalies for a wide variety of childhood neuropsychiatric illnesses, and controversy regarding sexual dimorphism. 2. Characterization of the normal developmental pattern of the CC is hindered by enormous variability of its size. This is especially problematic for cross-sectional studies seeking to assess possible non-linear developmental curves. 3. To more accurately characterize developmental changes, a longitudinal brain magnetic resonance imaging study with subjects rescanned at approximately 2 year intervals was conducted resulting in 251 scans from 139 healthy children and adolescents. 4. Midsagittal area of the CC, especially the posterior regions, increased robustly from ages 5 to 18 years. 5. Although the genu of the CC was significantly larger in males there were no sex differences in mean area after adjustment for total cerebral volume and the growth patterns did not differ between sexes. 6. Analysis revealed a non-linear increase in the splenium, the most posterior region, with increases greatest in the younger years. 7. The results of this longitudinal study, in addition to confirming and extending previous cross-sectional reports, provide an increasingly accurate yardstick from which to assess pathological development.

Development of the human corpus callosum during childhood and adolescence: a longitudinal MRI study.

Childhood-onset schizophrenia: progressive brain changes during adolescence.

https://www.cbica.upenn.edu/sbia/papers/123.pdf

Hong Liu

Papers

Brain development during childhood and adolescence: a longitudinal MRI study.

Development of the human corpus callosum during childhood and adolescence: a longitudinal MRI study.

Childhood-onset schizophrenia: progressive brain changes during adolescence.

Automated morphometric study of brain variation in XXY males

Corpus callosum development in childhood-onset schizophrenia.