On April 21, 2022, Nature, the top international scientific journal, released a brain chart spanning the entire human life cycle and published this lifelong milestone study of the human brain in the form of a website headline. This is a three-year-long international large-scale brain science research project jointly initiated by the University of Cambridge and the University of Pennsylvania, and researchers from more than 200 research units around the world were invited to participate in the formation of the "International Human Brain Chart Alliance", based on the standardized growth chart statistical modeling method recommended by the World Health Organization, the first normal model brain chart of human lifelong development was established, revealing the milestones of the lifelong development of the human brain. Although the World Health Organization and health departments around the world have previously released various growth charts (such as height, weight, and head circumference) to measure children's growth and development, there is a lack of reference charts to quantify brain maturity and aging.
Chinese brain scientists participate in international large-scale open brain science projects
Facing the global strategic need and scientific challenge of "building a brain chart of the human life cycle", the alliance adopts a team-based, distributed, open and collaborative innovative research paradigm, and builds big data from 101457 volunteers to 123984 mr. magnetic resonance brain scans by gathering more than 100 brain imaging research resources in the past few decades, covering the human life cycle from 16 weeks of gestation to 100 years old.
Zuo Xinian's team at the State Key Laboratory of Cognitive Neuroscience and Learning at Beijing Normal University in China and Qiu Jiang's team from the Department of Psychology of Southwest University were invited to participate in this large-scale international open brain science project, based on the "China Color Nest Program (CCNP)", "3R-BRAIN Alliance(3R-BRAIN)", "Southwest Longitudinal Multimodal Brain Imaging Database (SLIM)" and "Southwest Adult Lifelong Development Database (SALD)", and completed more than 2,000 times6- The 85-year-old Chinese volunteers analyzed, extracted and shared the morphological measurement indicators of brain imaging, and made forward-looking contributions to the statistical modeling of the Alliance Brain Chart. In response to this global science project, Nature published an editor's note: "It's time to recognize open data authors, scientifically evaluate and fairly approve data sharing and contributions."
Brain chart model fitting was performed on individual brain tissue measurement samples to define milestones in the development of the whole life cycle of the human brain
The consortium first fitted the brain chart model of individual brain tissue, including the total volume of cortex gray matter, the total volume of white matter, the total volume of subcortical gray matter and the total volume of cerebrospinal fluid, and defined many milestones in the development of the whole life cycle of the human brain: the total volume of gray matter in the cortex has grown rapidly since the second trimester. It peaks at 5.9 years and then shows a near-linear decline; total white matter volume also increases rapidly from the second trimester of pregnancy to early childhood, but at a peak age of 28.7 years, and the total volume of white matter decreases at the age of 50 years; the total volume of gray matter under the cortex is manifested as an intermediate growth pattern between the total volume of gray matter in the cortex and the total volume of white matter, reaching a peak at 14.4 years of age in adolescence; the total volume of cerebrospinal fluid increases before the age of 2 years, then remains stable until the age of 30, and then shows a slow linear growth from the age of 60; from the perspective of individual differences, the individual differences in the total volume of gray matter in the cortex gradually increase early and reach a peak at age 4 years The variability of the total volume of gray matter under the cortex peaked in late puberty, and the total volume of white matter varied the most among individuals around the age of 40; the total area of the human cerebral cortex and the total volume of the brain showed a similar life cycle development trajectory, both of which peaked at 11-12 years of age; in contrast, the thickness of the cortex peaked at age 1.7 years.
It can be seen that only the peak milestone of total volume development of gray matter in the cortex is before puberty, the peak milestone of total volume of gray matter under the subcortex is in the middle of adolescence, and the peak milestone of total white matter volume development is adolescence; the growth rate of total volume of gray matter in the cortex, total volume of gray matter under the cortex and total volume of white matter reaches peak in infancy and infancy, while the growth rate of total brain volume reaches a peak at about 7 months; the two main milestones of total brain volume and total volume of gray matter under the cortex (peaks in size and rate) Coincided with the peak rate of height and weight change in the early neonatal and adolescent periods; the peak rate of average cortex thickness was even earlier, about the second trimester; from the first month of life to about three years of age, the ratio of total volume of gray matter in the cortex to the total volume of white matter gradually changed from the total volume of white matter to the total volume of gray matter in the cortex, and the differentiation of this ratio reflected the formation of the pulp sheath of the underlying microscopic or synaptic growth, and the dynamic changes in brain metabolism (0-3 months of age), resting metabolic rate (minimum 7 months of age, Maximum 4.2 years), motor capacity acquisition and other typical periods of early pediatric milestones coincide with the period of rapid growth and development of total brain volume.
Examine the effect of standardized brain chart applications to reveal three major types of brain diseases
The consortium further improves the accuracy of brain chart modeling and analysis. Significant differences in neurodevelopmental milestones in different brain regions were found, with the age at which the total volume of gray matter in the cortex reached its peak at age 5.9 years, ranging from 2 years to 10 years (the difference between the maximum 8 years of age coincided with previous functional studies by the Zuo Xi Nian team), the primary sensory region was the earliest, and the frontotemporal combined cortex region was later; overall, the volume of the cortical layer in the ventral-caudal region that matured earlier decreased faster after peaking, while the dorsal side of the late maturity — The post-peak volume decline of the beaked cortex was slower; the spatial distribution pattern of this milestone reproduced the "basic perception-high-order union" or single-mode-cross-mold"cortical hierarchical tissue gradient of human brain structural function.
The consortium examines the effect of standardized brain chart applications. Based on this big data clustering of clinically individualized percentiles of brain imaging, three major types of brain diseases (neurodegenerative diseases, mood/anxiety, and neurodevelopmental disorders) are revealed, and the shared and unique mechanisms between them are demonstrated. Across different stages of the life cycle, cases are always more individualized percentiles than controls, regardless of the type of diagnosis. Maximized differences occur in late adulthood as well as in adolescence, with late adult individuals at increased risk of developing dementia, and puberty, a period of high incidence of mental illness. The mean percentile of whole brain tissue correlates with two indicators of preterm birth, and the higher the gestational age and birth weight, the higher the mean percentile. The twin validity test showed that brain phenotype percentiles were able to detect a more pronounced genetic basis. In summary, the percentile norm based on brain charts can detect case-control differences and the long-term effects of genetic factors, as well as preterm birth.
The alliance verified the reproducibility and generalizability of the human brain chart. In multiple retest datasets, the out-of-sample percentiles were found to be highly reliable and very robust to changes in image processing tools (Robust, robust and robust). The analysis shows that a study with a scanned sample size greater than 100 is sufficient to steadily and unbiasedly estimate the extra-percentile of the sample, and the need for this sample size shows that in order to ensure the reproducibility of the study, the information of the normal mode brain chart will greatly reduce the need for the sample size of the study, which is in stark contrast to a recent study on impermanent mode information blessing that shows that thousands of sample sizes are required.
It is believed that in the future, with the accumulation of more and more high-quality and diversified brain imaging data, the increase of more and more high-space-time precision multimodal neuroimaging phenotypes, and the continuous promotion and popularization of open large-team scientific research practices, the human life cycle brain chart will be continuously updated iteratively.
(Author: Xing Xiaofeng)
Source: Educator Magazine