• Clinical and Experimental Pediatrics
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• v.60 no.1
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• pp.1-9
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• 2017

Malformations of cortical development are rare congenital anomalies of the cerebral cortex, wherein patients present with intractable epilepsy and various degrees of developmental delay. Cases show a spectrum of anomalous cortical formations with diverse anatomic and morphological abnormalities, a variety of genetic causes, and different clinical presentations. Brain magnetic resonance imaging has been of great help in determining the exact morphologies of cortical malformations. The hypothetical mechanisms of malformation include interruptions during the formation of cerebral cortex in the form of viral infection, genetic causes, and vascular events. Recent remarkable developments in genetic analysis methods have improved our understanding of these pathological mechanisms. The present review will discuss normal cortical development, the current proposed malformation classifications, and the diagnostic approach for malformations of cortical development.

• Journal of Life Science
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• v.14 no.6 s.67
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• pp.975-985
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• 2004

This study attempts to investigate the developmental alterations of rat cerebral cortex, and the effects of EGEE on the developmental cerebral cortex in the prenatal, postnatal and adults were examined by morphological methods and H-E staining was used for the histological changes. In the case of injection of EGEE, at 14 day of fetal phase, parietal cortex was thickest $(95{\pm}12.7\;{\mu}m)$ but, it was thinner than in the control group $(102{\pm}14.0\;{\mu}m)$ and, occipital cortex $(57{\pm}10.5\;{\mu}m)$ compared with other cortexes was the thinnest in fetal phase. In the suckling phase, each cortex grew thick quickly but, after weanning phase, the growth of the cortex slowed and the thickness of cortex was similar to that of cortex in the adult phase. At 105 day after birth, the parietal cortex was thickest $(934{\pm}21.6\;{\mu}m)$ but, decreased compared with control group $(1113{\pm}19.0\;{\mu}m)$. When EGEE was injected in intraperitoneal of rat, the number of neuroblasts per unit area was largest $(207.7{\pm}11.4/10^{-2}\;mm$ at the mantle layer of parietal cortex at 14 day of fetal phase but, decreased compared with control group $(224.2{\pm}13.8/10^{-2}\;mm$ , and the size was largest $(7.5{\pm}1.3\;{\mu}m)$ at the ependymal cell layer of occipital cortex at 3 day after birth but, decreased compared with control group $(9.0{\pm}1.2\;{\mu}m)$. Simillar to control group, the number of granular cells and pyramidal cells were largest at the II and III layer of parietal cortex, but decreased during developmental phase. The size was largest at the IV and V layer of occipital cortex but it was decreased compared with control group. When EGEE was injected in intraperitoneal of rat, the cerebral cortex from fetal phase to 3 day after birth has differentiated into the 3 layers; ependymal, mantle and marginal layer, but empty cisternaes or vacoules in the cerebral cortexes and the condensed phases of neuroblasts were appeared. From 5 day after birth, it has differentiated into the 4 layers; molecular, external granular, mixed layer of internal granular, external and internal pyramidal cells and multiformal layer but, empty cisternaes or vacoules in the granular and pyramidal cell layers were appeared and the number per unit area of neuron was decreased. In the cerebral cortex of the weaning and adult phases, division of cell layers was not clear and empty cisternae was formed in the cortex with the cells in external granular and pyramidal cell layers, was magnified or condensed around blood vessels of neurons.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.6
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• pp.467-477
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• 2001

We examined astrocyte regional heterogeneity in their morphological changes in response to various stimuli. Astrocytes were cultured from six different neonatal rat brain regions including cerebral cortex, hippocampus, cerebellum, mid brain, brain stem and hypothalamus. Astrocyte stellation was induced by serum deprivation and the maximum stellation in different regional astrocytes was achieved after 2 h. After 24 h, in all astrocyte cultures, the level of stellation returned to their original level. Cerebellar or hypothalamic astrocytes were the most or the least sensitive, respectively, to serum deprivation. The order of maximum sensitivity to serum deprivation among different regional astrocytes was: cerebellum＞mid $brain{\ge}hippocampus,\;brain\;stem{\ge}cerebral$ cortex＞hypothalamus. Isoproterenol-induced astrocyte stellation was also examined in different regional astrocytes, and similar order of maximum sensitivity as in serum deprivation was observed. Next a possible developmental effect on astrocyte morphological changes was examined in cerebral cortex and cerebellum astrocytes cultured from postnatal day 1 (P1), P4 and P7 rat brains. A much higher sensitivity of cerebellum astrocytes to serum deprivation as well as isoproterenol treatment was consistently observed in P1, P4 and P7-derived astrocytes compared to cerebral cortex astrocytes. The present study demonstrates different regional astrocytes maintain different levels of morphological plasticity in vitro.

• Journal of Life Science
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• v.16 no.6
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• pp.1014-1028
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• 2006

This study attempted to investigate the developmental alterations of the cerebral cortex. The effects of EGEE on the developmental cerebral cortex in the prenatal, postnatal and adults were examined by lectin histochemical methods. To investigate the change of sugar residues of glycoconjugates, biotinylated lectins(DBA, SBA, PNA, BSL-1, RCA-1, sWGA, UEA-1, Con A and LCA) were detected with by IHC using ABC kit. In the case of injection of EGEE, the reactions to Con A and LCA were shown in binding phase in the cerebral cortex commonly, and the reactions to PNA, RCA-1 and LCA were shown partially, the number of lectins to be shown reaction were decreased, and there were no reactions to DBA, SBA, BSL-1, RCA-1 and UEA-1. The reaction to Con A was similar to control group during developmental phases. The reaction to LCA was increased in the fetal, suckling, and weanning phases compared with control group. But there were no reactions to SBA and sWGA, the reaction to PNA was decreased in the frontal and occipital cortex and no reaction to sWGA in the fetal phase. There were no reactions to sWGA and PNA in the suckling phase and, no reaction to PNA and sWGA. The reaction to Con A was decreased in the frontal, parietal and occipital cortexes and, the reaction to LCA was decreased in the frontal and occipital cortexes in adult phase. As the results, the effects of EGEE, environmental hormone on the each part of cerebral cortex have shown differences. But, It had deep effect on the differentiation and growth in the cerebral cortex pathologically. In particular, the effect was severe in suckling phase. $Galactosyl-({\beta}-1,3)-N-acetyl-D-galactosamine$,${\beta}-N-acetyl-D-galactosamine$ and ${\beta}-N-acetyl-D-glucosamine$ were decreased while ${\alpha}-D-mannose$ and ${\alpha}-D-glucose$ were increased. It affected the sugar metabloism, and it was severe in fetal and suckling phases.

• Development and Reproduction
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• v.14 no.3
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• pp.171-177
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• 2010

A recent report demonstrated that in human aging brain after menopause/andropause luteinizing hormone (LH) is localized in the cytoplasm of pyramidal neurons of hippocampus and a significant increase of LH is also detected in the cytoplasm of pyramidal neurons and neurofibrillary tangles of Alzheimer's disease brain compared to age-matched control brain. It was suggested that the decreased steroid hormone production and the resulting LH expression in the neurons vulnerable to Alzheimer's disease pathology may have some relevance to the development of Alzheimer's disease. It is, however, unclear whether the presence of LH in neurons of human aging and Alzheimer's disease brain is due to intracellular LH expression or to LH uptake from extracellular sources, since gonadotropins are known to cross the blood brain barrier. Moreover, there is no report by using the brain of experimental animal that LH is expressed in such neurons as found in the human brain. In the present study, we found that LH immunoreactivity is localized in the pyramidal neurons of cerebral cortex and hippocampus of 12 and 18 months old rats but can not detect any immunoreactivity for LH in the young adult (3-5 months old) rats. To confirm that these LH immunoreactivity results from de novo synthesis in the brain but not the uptake from extracellular space, we performed RT-PCR and found that mRNA for LH is detected in several regions of brain including cerebral cortex and hippocampus. These findings suggest us that LH expression in old rat brain may play an important role in aging process of rat brain.

• Toxicological Research
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• v.17
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• pp.11-16
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• 2001

The development of the central nervous system is a continuous process during the embryonic and fetal periods. For a better understanding of congenital anomalies of central nervous system, three major events of normal development, i.e., neurulation (3 to 4 weeks), brain vesicle formation (4 to 7 weeks) and mantle formation (over 8 weeks) should be kept in mind. The first category of anomalies is neural tube defect. Neural tube defects encompass all the anomalies arise in completion of neurulation. The second category of central nervous system anomalies is disorders of brain vesicle formation. This is anomaly that applies for "the face predicts the brain". Holoprosencephaly covers a spectrum of anomalies of intracranial and midfacial development which result from incomplete development and septation of midline structures within the forebrain or prosencephalon. The last category of central nervous system malformation is disorders involving the process of mantle formation. In the human, neurons are generated in two bursts, the first from 8 to 10 weeks and next from 12 to 14 weeks. By 16 weeks, most of the neurons have been generated and have started their migration into the cortex. Mechanism of migration disorders are multifactorial. Abnormal migration into the cortex, abnormal neurons, faulty neural growth within the cortex, unstable pial-glial border, degeneration of neurons, neural death by exogenous factors are some of the proposed mechanism. Agyria-pachygyria are characterized by a four-layerd cortex. Polymicrogyria is gyri that are too numerous and too small, and is morphologically heterogeneous. Cortical dysplasia is characterized by the presence Q[ abnormal neurons and glia arranged abnormally in focal areas of the cerebral cortex. Neuroglial malformative lesions associated with medically intractable epilepsy are hamartia or hamartoma, focal cortical dysplasia and microdysgenesis.ysgenesis.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.57-58
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• 2005

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.2
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• pp.256-265
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• 1997

Objectives：The purpose of this study was to investigate the characteristics and differences of brain function in pervasive developmental disorder and developmental language disorder. Method：The subjects were composed of 14 cases of pervasive developmental disorder and 13 cases developmental language disorder. They were investigated by technitium-99m-EDC SPECT. All SPECT were visually assessed by two nuclear medicine specialists, and then quantified by region of interest including temporal, parietal cortex, thalamus, basal ganglia and cerebellum. Result：In both groups, cerebral blood flow was decreased in the temporal, parietal cortex, basal ganglia, thalamus, cerebellum by visual assessment. There was no significant difference between the 2 groups by quantitative and qualitative assessment. Conclusion：These results suggest that pervasive developmental disorder and developmental language disorder are caused by defects in the interneural connection and that both disorders are spectrum disorders.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.16 no.2
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• pp.153-159
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• 2005

Autistic disorder and other PDD are currently viewed as a largely genetically determined neurodevelopmental disorder, although its underlying biological causes remain to be established. In this review, we examine the available neurodevelopmental literature on autistic disorder and discuss the findings that have emerged. Typical neuropathological observations are rather consistent with respect to the limbic system (increased cell packing density and smaller neuronal size), the cerebellum (decreased number of Purkinje cells) and the cerebral cortex ($>50\%$ of the cases showed features of cortical dysgenesis). However, most of the reported studies had to contend with the problem of small sample sizes, the use of quantification techniques, not free of bias and assumptions, and high percentages of autistic subjects with comorbid mental retardation or epilepsy. Furthermore, data from the limbic system and on age-related changes lack replication by independent groups. It is anticipated that future neuropathological studies held great promise, especially as new techniques such as design-based stereology and gene expression are increasingly implemented and combined, larger samples are analysed, and younger subjects free of comorbidities are investigated.

• Molecules and Cells
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• v.20 no.2
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• pp.189-195
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• 2005

Ethanol has long been implicated in triggering apoptotic neurodegeneration. We examined the effects of ethanol on the rat brain during synaptogenesis when a spurt in brain growth occurs. This period corresponds to the first 2 postnatal weeks in rats and is very sensitive to ethanol exposure. Ethanol was administered subcutaneously to 7-day- postnatal rat pups by a dosing regimen of 3 g/kg at 0 h and again at 2 h. Blood ethanol levels peaked ($677{\pm}16.4mg/dl$) at 4 h after the first ethanol administration. The cerebral cortexes of the ethanol-treated group showed several typical symptoms of apoptosis such as chromosome condensation and disintegration of cell bodies. Activated caspase-3 positive cells were found in the cortex within 2 h of the first injection, and reached a peak at 12 h. In addition, TUNEL staining revealed DNA fragmentation in the same regions. These results demonstrate that acute ethanol administration causes neuronal cell death via a caspase-3-dependent pathway within 24 h, suggesting that activation of caspase-3 is a marker of the developmental neurotoxicity of ethanol.