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During the early second trimester, the cortical plate, or "the developing cortex", undergoes immensely complex and rapid development to complete its major complement of neurons. However, morphological development of the cortical plate and the precise patterning of brain structural covariance networks during this period remain unexplored. In this study, we used 7.0 T high-resolution magnetic resonance images of brain specimens ranging from 14 to 22 gestational weeks to manually segment the cortical plate. Thickness, area expansion, and curvature (i.e., folding) across the cortical plate regions were computed, and correlations of thickness values among different cortical plate regions were measured to analyze fetal cortico-cortical structural covariance throughout development of the early second trimester. The cortical plate displayed significant increases in thickness and expansions in area throughout all regions but changes of curvature in only certain major sulci. The topological architecture and network properties of fetal brain covariance presented immature and inefficient organizations with low degree of integration and high degree of segregation. Altogether, our results provide novel insight on the developmental patterning of cortical plate thickness and the developmental origin of brain network architecture throughout the early second trimester., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis plays an important role in normal brain development, and GH deficiency inevitably affects the growth of the cerebral cortex. This study was designed to analyze morphological differences in gray matter volume, cortical surface area, and gray matter thickness between children with isolated growth hormone deficiency (IGHD) and children with idiopathic short stature (ISS). Twenty-four children with IGHD (mean age 9.42 years, peak GH < 5 μg/l) and 24 controls with ISS (mean age 9.21 years, peak GH > 10 μg/l) were included. High-resolution three-dimensional T1-weighted MRIs were acquired at participants' first visit. Measurements of gray matter volume, cortical surface area and gray matter thickness were obtained using FreeSurfer. The total and regional differences between groups were statistically analyzed. Correlations between the FreeSurfer results and GH and IGF-I levels were also obtained. The gray matter volume, cortical surface area and gray matter thickness of the total brain and of the bilateral hemispheres of children with IGHD were significantly smaller than those of children with ISS (all P values < 0.05). All the measurements had similar cortical distributions between groups but varied across regions. Cortical regions with significant differences in the mean gray matter volume and surface area were mainly distributed around the bilateral central sulci and the lateral and basal parts of the temporal lobes (all P values < 0.05). There were negative correlations between gray matter volume, cortical surface area and GH levels, and the right hemispheric and total cortical surface area correlated significantly with GH levels (all P values < 0.05) in children with IGHD. There were significant positive correlations between gray matter volume, cortical surface area and IGF-I levels (all P values < 0.05) in both groups, except for in left hemispheric gray matter volume in children with ISS. Children with IGHD have significant morphological changes in the cerebral cortex, which were partially influenced by GH and IGF-I levels. These cortical changes may be related to deficits in their relatively slower development in intelligence, motor performance, and other functions., (Copyright © 2020 Elsevier B.V. All rights reserved.)

We hypothesized that the distinct maturational processes take place across different cortical areas from middle fetal stage to normal time of birth and these maturational processes are altered in late third trimester. Fractional anisotropies (FA) from diffusion tensor imaging (DTI) infer the microstructures of the early developing cortical plate. High-resolution DTI of 11 fetal brain specimens at postmenstrual age of 20 weeks (or simplified as 20 weeks), 19 in vivo brains at 35 weeks, and 17 in vivo brains at normal time of birth at term (40 weeks) were acquired. Population-averaged age-specific DTI templates were established with large deformation diffeomorphic metric mapping for subject groups at 20, 35, and 40 weeks. To alleviate partial volume effects, skeletonized FA values were used for mapping averaged cortical FA to the cortical surface and measuring FA at 12 functionally distinctive cortical regions. Significant and heterogeneous FA decreases take place in distinct cortical areas from 20 to 35 weeks and from 35 to 40 weeks, suggesting differentiated cortical development patterns. Temporally nonuniform FA decrease patterns during 35-40 weeks compared with those during 20-35 weeks were observed in higher-order association cortex. Measured skeletonized FA suggested dissociated changes between cerebral cortex and white matter during 35-40 weeks., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

In the previous studies, the criterion for deciding the occurrence time of the fetal central sulcus (CS) on magnetic resonance imaging (MRI) is based on the observation by the eyes. There have been no existing quantitative standards or numerical criteria in this field. In this study, we reconstructed the three-dimension (3D) images of the fetal brain based on the 7.0T MR images of 45 Chinese fetal specimens from the 11 to 22 weeks of gestational age (GA). Then we obtained data by measuring the maximum depth and length of the CS so as to analyze the early developmental pattern of it. These measures, especially CS depth, can be used to quantitatively determine the time of emergence of the fetal CS during the development. Statistics show that there are no gender or interhemispheric asymmetries of the CS from GA of 11 to 22 weeks., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

In this study, we clarified the gender and age-related asymmetries of the central sulcus (CS) in early adulthood using a parametric ribbon method. The CS was reconstructed and parameterized automatically from 3D MR images of 112 healthy right-handed subjects. The 3D anatomic morphology of the CS was presented using 5 sulcal parameters, including sulcal depth position-based profile (DPP), average depth (AD), average width (AW), top length (TL) and bottom length (BL). Asymmetry differences in DPPs were found in the medial and lateral part of the CS. In addition, significant gender differences were observed in the medial and middle parts of the right CS DPPs but scattered in the left side. We found leftward asymmetries of TL in males, but rightward asymmetries of AW in females. Males had a greater AW than females in the right hemisphere. Moreover, the females had bilateral longer TL and a longer left BL than did males. We also found significant age-related reductions in bilateral TL and increases in bilateral AW, with males presenting more obvious age-related change than females. There were sexual differences of the CS patterns, in which Type b was the most dominant sulcal pattern in males, whereas Type a was dominant in females. Three-way ANOVA revealed sexual and asymmetry changes of TL and BL among different CS patterns. Our findings indicate that the lateralization performances of the CS manifest as sexually and regionally different. In addition, it is suggested that males may undergo a faster progress of aging compared to females., (Copyright © 2015 ISDN. Published by Elsevier Ltd. All rights reserved.)

To investigate the fetal cerebral lobes development between 20 and 28 weeks gestational age, 36 fetus specimen without CNS abnormality, with 4 fetuses in each gestation week, were scanned with 3.0T MR. Lobular parameters were measured, including the parenchyma thickness of the frontoparietal and the temporal lobes, the margin length of frontoparietal, the insula and the temporal lobes, the Sylvian fissure and the perimeter of hippocampus, on the plane perpendicular to the longitudinal axis of hippocampus body across the base of cerebral peduncle. The relative value of parenchyma thickness and the lobes' length ratios to the same side hemisphere were calculated and their correlation with gestational weeks was analyzed. All measured parameters were positively correlated with gestational age. No significant tendency was found for relative value of the parenchyma thickness (P>0.05). The temporal lobe length ratio increased while the frontoparietal ratio decreased before 24 weeks GA and then the two reversed. The Sylvian fissure length ratio increased (P<0.001) and the hippocampus decreased (P<0.001) throughout this period. In conclusion, the early fetal cerebrum lobes developed asynchronously during this period, the 24 weeks GA could be a turning point for cerebrum development pattern changing from primitive to mature., (Copyright © 2013 ISDN. Published by Elsevier Ltd. All rights reserved.)

Introduction: The purpose of this study is to show the condition of laminar organization on 3.0T and 7.0T postmortem magnetic resonance imaging (MRI) and analyze developmental changes., Methods: Heads of 131 fetal specimens of 14-40 weeks gestational age (GA) were scanned by 3.0T MRI. Eleven fetal specimens of 14-27 weeks GA were scanned by 7.0T MRI. Clear images were chosen for analysis., Results: On T₁-weighted 3.0T MRI, layers could be visualized at 14 weeks GA and appeared clearer after 18 weeks GA. On 7.0T MRI, four zones could be recognized at 14 weeks GA. During 15-22 weeks GA, when laminar organization appeared typical, seven layers including the periventricular zone and external capsule fibers could be differentiated, which corresponded to seven zones in histological stained sections. At 23-28 weeks GA, laminar organization appeared less typical, and borderlines among them appeared obscured. After 30 weeks GA, it disappeared and turned into mature-like structures. The developing lamination appeared the most distinguishable at the parieto-occipital part of brain and peripheral regions of the hippocampus. The migrating thalamocortical afferents were probably delineated as a high signal layer located at the lower, middle, and upper part of the subplate zone at 16-28 weeks GA on T₁-weighted 3.0T MRI., Conclusions: T₁-weighted 3.0T MRI and T₂-weighted 7.0T MRI can well demonstrate the laminar organization. Development of the lamination follows a specific spatio-temporal regularity, and postmortem MRI of the parieto-occipital part of brain obtained with 3.0T or 7.0T is an effective way to show developmental changes.

Quantitative data of fetal cortical folding and its developmental changes supply important information in the estimation of fetal age and assessment of brain maturation, so the increasing tendencies of cortical growth and its folding conditions at the beginning of the second and third trimesters with post-mortem Magnetic Resonance Imaging (MRI) were analyzed. 131 fetal specimens of 14-40 weeks gestational age (GA) were selected and scanned with 3.0 T MR. Then the length of folded cortical margin (LFCM) and length of unfolded cortical margin (LUCM) were measured by Photoshop and ZoomMagic software. Degrees of cortical folding (DCF) were calculated by means of (LFCM-LUCM)/LFCM. Growth curves were obtained between the 3 above values and GA, and significant differences in age stages, hemispheres and genders were analyzed. The relationship between LFCM in centimeters, DCF and GA in weeks was described by two exponential growth curves [LFCM=5.325 exp(0.079GA); DCF=11.890 exp(0.043GA)]. The curves increased rapidly after 26 weeks GA, which could be recognized as a cut-off point of fetal cortical and sulcal development. LUCM and GA were described by a logarithmic growth curve which slowed down after 26 weeks GA [LUCM=30.580 Ln(GA)-72.490]. Significant differences of the 3 values before and after 26 weeks GA (p<0.01), but not any in hemispheres and genders were noticed. These results, which may be valuable in assessing normal brain development and can serve as a model in clinical settings, indicate that the cerebral volume first increases and is then followed by increases of the surface area., (Copyright 2010 ISDN. Published by Elsevier Ltd. All rights reserved.)

Asymmetry has been proved to exist in the human brain structure, function and behavior. Most of the existing brain asymmetry findings are originated from the western populations, while studies about the brain structural and functional asymmetries in East Asians are limited. Extensive evidence suggested that cultural differences, e.g. education and language, may lead to differences in brain structure and function between races. Therefore, we hypothesized that differences in brain structural asymmetries exist between East Asians and Westerners. In this study, we performed a comprehensive surface-based morphometric (SBM) analysis of brain asymmetries in cortical thickness, volume and surface area in two well-matched groups of right-handed, Chinese (n = 45) and Caucasian (n = 45) young male adults (age = 22-29 years). Our results showed consistent inter-hemispheric asymmetries in the three brain morphological measures in multiple brain regions in the Chinese young adults, including the temporal, frontal, parietal, occipital, insular cortices and the cingulate gyrus. Comparing with the Caucasians, the Chinese group showed greater structural asymmetry in the frontal, temporal, occipital and insular cortices, and smaller asymmetry in the parietal cortex and cingulate gyrus. These findings could provide a new neuroanatomical basis for understanding the distinctions between East Asian and Caucasian in brain functional lateralization. [ABSTRACT FROM AUTHOR]

This study aims to investigate metabolic changes in frontal and parietal cortices in the 6-OHDA induced Parkinson's rats. Ratios of N-acetyl-aspartic acid/creatine (NAA/Cr), choline/creatine (Cho/Cr), and glumatic acid and glutamine glutaminic acid/creatine (Glx/Cr) of regions of interests (ROIs) in the frontal and parietal cortices, and the substantia nigra were analyzed. NAA/Cr, Cho/Cr and Glx/Cr in the frontal and parietal cortices in the lesion side did not show any significant differences two weeks after operation compared with the contralateral side ( p > 0.05). NAA/Cr in the frontal cortex in the lesion side was significantly lower in the five weeks after operation; Cho/Cr remained normal; Glx/Cr increased ( p < 0.05), and all ratios of parietal cortex were normal. In the eight weeks after operation, NAA/Cr in the frontal cortex in the lesion side was lower than that of the five weeks ( p < 0.01), Cho/Cr still remained normal while Glx/Cr was higher than before ( p < 0.01). Regarding the parietal cortex, NAA/Cr increased significantly, while Cho/Cr and Glx/Cr remained normal. In the 12 weeks after operation, NAA/Cr, Cho/Cr and Glx/Cr in frontal cortex were consistent with that of the eight weeks, while they remained at the normal level in parietal cortex. The NAA/Cr in the substantia nigra decreased and Cho/Cr increased significantly during 2-8 weeks, and remained at the same level during 8-12 weeks. There are metabolic disturbances in PD rats. The transient hyperfunction in the parietal cortex can be considered as a compensation for the dysfunction of the frontal cortex and substantia nigra. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, investigations of the pathologic mechanism of Parkinson’s disease (PD) have mainly concentrated on the basal ganglia. However, recent studies have confirmed that pathological changes in PD are accompanied by functional motor changes of the cerebral cortex. Rats were injected with 6-hydroxydopamine and ascorbic acid in the right substantia nigra. In this rat model of PD, magnetic resonance spectroscopy showed the ratio of N-acetyl-aspartic acid to creatine in a lesion in the right frontal cortex was significantly lower than the same ratio in a control group of rats. The ratio of choline to creatine in a lesion in the right frontal cortex was not significantly different between the PD-model rats and control rats. In addition, the optical densities of neurofilament protein and synaptophysin positive sites decreased significantly on the side of the brain with the injury compared with the side without the injury, and with both sides in the control rats. The density of synapses in the frontal cortex on the lesioned side was decreased compared with the unlesioned side. There were abnormal changes in the presynaptic membrane, postsynaptic membrane and synaptic vesicles, and the typical synaptic structure was no longer apparent on the lesioned side. We hypothesized loss of neurons and synapses, abnormal synaptic structure and neuron and synaptic dysfunction of the frontal cortex with a lesion in the injury side of the frontal cortex in PD-model rats. These changes might have an important role in the pathologic mechanism of PD. [Copyright &y& Elsevier]