• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.22-29
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• 2015

Objective : Perinatal hypoxic-ischemic encephalopathy (HIE) and prolonged febrile seizures (pFS) are common neurologic problems that occur during childhood. However, there is insufficient evidence from experimental studies to conclude that pFS directly induces hippocampal injury. We studied cognitive function and histological changes in a rat model and investigated which among pFS, HIE, or a dual pathologic effect is most detrimental to the health of children. Methods : A rat model of HIE at postnatal day (PD) 7 and a pFS model at PD10 were used. Behavioral and cognitive functions were investigated by means of weekly open field tests from postnatal week (PW) 3 to PW7, and by daily testing with the Morris water maze test at PW8. Pathological changes in the hippocampus were observed in the control, pFS, HIE, and HIE+pFS groups at PW9. Results : The HIE priming group showed a seizure-prone state. The Morris water maze test revealed a decline in cognitive function in the HIE and HIE+pFS groups compared with the pFS and control groups. Additionally, the HIE and HIE+pFS groups showed significant hippocampal neuronal damage, astrogliosis, and volume loss, after maturation. The pFS alone induced minimal hippocampal neuronal damage without astrogliosis or volume loss. Conclusion : Our findings suggest that pFS alone causes no considerable memory or behavioral impairment, or cellular change. In contrast, HIE results in lasting memory impairment and neuronal damage, gliosis, and tissue loss. These findings may contribute to the understanding of the developing brain concerning conditions caused by HIE or pFS.

• Biomedical Science Letters
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• v.10 no.4
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• pp.385-389
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• 2004

A novel gene Jpk, originally isolated as a trans-acting factor associating with the position-specific regulatory element of murine Hox gene has been reported to be expressed differentially in the liver of diabetic animals. Therefore, in an attempt to develop a possible diagnostic marker and/or new therapeutic agent for the Diabetes Mellitus, we analysed the expression pattern of Jpk among organs of normal and diabetic Sprague-Dawley (SD) rats. Total RNAs were isolated from each organs (brain, lung, heart, liver, spleen, kidney, muscle, blood, and testis) of diabetic and normal rats in both normal feeding and after fasting condition. And then RT (reverse transcription) PCR has been performed using Jpk­specific primers. The Jpk gene turned out to be expressed in all organs tested, with some different expression profiles among normal and diabetes, though. Upon fasting, Jpk expressions were reduced in all organs tested except kidney, muscle and brain of normal rat. Whereas in diabetes, Jpk expressions were increased in all organs except heart, muscle and testis when fasted. Compared to the normal rat, the Jpk expression level in blood was remarkably upregulated (about 15-30times) in diabetic rat whether in normal feeding or fasting conditon, suggesting that the Jpk could be a candidate gene for the possible blood diagnostic marker for the Diabetes Mellitus.

• 한국전자현미경학회:학술대회논문집
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• 2004.05a
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• pp.50-52
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• 2004

• BMB Reports
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• v.48 no.3
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• pp.139-146
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• 2015

Adaptive brain function and synaptic plasticity rely on dynamic regulation of local proteome. One way for the neuron to introduce new proteins to the axon terminal is to transport those from the cell body, which had long been thought as the only source of axonal proteins. Another way, which is the topic of this review, is synthesizing proteins on site by local mRNA translation. Recent evidence indicates that the axon stores a reservoir of translationally silent mRNAs and regulates their expression solely by translational control. Different stimuli to axons, such as guidance cues, growth factors, and nerve injury, promote translation of selective mRNAs, a process required for the axon's ability to respond to these cues. One of the critical questions in the field of axonal protein synthesis is how mRNA-specific local translation is regulated by extracellular cues. Here, we review current experimental techniques that can be used to answer this question. Furthermore, we discuss how new technologies can help us understand what biological processes are regulated by axonal protein synthesis in vivo.

• Journal of Korean Neurosurgical Society
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• v.62 no.3
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• pp.265-271
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• 2019

The expansion and folding of the cerebral cortex occur during brain development and are critical factors that influence cognitive ability and sensorimotor skills. The disruption of cortical growth and folding may cause neurological disorders, resulting in severe intellectual disability and intractable epilepsy in humans. Therefore, understanding the mechanism that regulates cortical growth and folding will be crucial in deciphering the key steps of brain development and finding new therapeutic targets for the congenital anomalies of the cerebral cortex. This review will start with a brief introduction describing the anatomy of the brain cortex, followed by a description of our understanding of the proliferation, differentiation, and migration of neural progenitors and important genes and molecules that are involved in these processes. Finally, various types of disorders that develop due to malformation of the cerebral cortex will be discussed.

• Molecules and Cells
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• v.45 no.2
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• pp.53-64
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• 2022

Three-dimensional cultures of human neural tissue/organlike structures in vitro can be achieved by mimicking the developmental processes occurring in vivo. Rapid progress in the field of neural organoids has fueled the hope (and hype) for improved understanding of brain development and functions, modeling of neural diseases, discovery of new drugs, and supply of surrogate sources of transplantation. In this short review, we summarize the state-of-the-art applications of this fascinating tool in various research fields and discuss the reality of the technique hoping that the current limitations will soon be overcome by the efforts of ingenious researchers.

• Applied Microscopy
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• v.46 no.4
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• pp.179-183
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• 2016

Mapping brain structural and functional connections through the whole brain is essential for understanding brain mechanisms and the physiological bases of brain diseases. Although region specific structural or functional deficits cause brain diseases, the changes of interregional connections could also be important factors of brain diseases. This review will introduce common neuroimaging modalities, including structural magnetic resonance imaging (MRI), functional MRI (fMRI), diffusion tensor imaging, and other recent neuroimaging analyses methods, such as voxel-based morphometry, cortical thickness analysis, local gyrification index, and shape analysis for structural imaging. Tract-Based Spatial Statistics, TRActs Constrained by UnderLying Anatomy for diffusion MRI, and independent component analysis for fMRI also will also be introduced.

• 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.

• Development and Reproduction
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• v.13 no.2
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• pp.89-95
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• 2009

p63 has been demonstrated to localize in stem cells and precursor cells of various epithelial tissues previously, but the localization of p63 throughout tooth formation, particularly during the enamel and root formation stages, remains to be adequately characterized. Therefore, in this study, we have demonstrated, via immunohistochemical methods, that p63 is ubiquitously expressed in the dental epithelium during tooth development. p63 was detected in the basal and suprabasal layers of the epithelia, including the skin, hair follicles, oral mucosa, and submandibular ducts. However, in the tooth region, all cells of the dental lamina, enamel organ, Hertwig's epithelial root sheath (HERS), and epithelial cell rests of Malassez (ERM) evidenced immunoreactivity for p63. These results indicate that p63 may perform different roles, other than stem cell maintenance, in tooth development.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.21-30
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• 1998

Ginseng root has been considered to prevent neuronal degeneration associated with brain ischemia, but experimental proof in support of this speculation is limited. Moreover, few studies have compared the neuroprotective actions of ginseng ingredients with those of peptide growth factors and cytokines isf vivo. Using a gerbil forebrain ischemia model, we demonstrated that the oral administration of red ginseng powder before an ischemic insult prevents delayed neuronal death in the hippocampal CAI field and that a neuroprotective molecule within red ginseng powder is ginsenoside Rbl. The neurotrophic effect of ginsenoside Rbl, when examined in the gerbil ischemia model and in neuronal cultures was as potent as or more potent than the effects of epidermal growth factor, ciliary neurotrophic factor, erythropoietin, prosaposin, interleukin-6 and interleukin-3. Besides the protection of hippocampal CAI neurons against brain ischemia/repercussion injuries, ginsenoside Rbl was shown to prevent place navigation disability, cortical infarction and secondary thalamic degeneration in stroke-prone spontaneous hypertensive rats with permanent occlusion of the unilateral middle cerebral artery distal to the striate branches. These findings may validate the empirical use of ginseng root for the treatment of cerebrovascular diseases