• Journal of Radiation Protection and Research
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• 제38권4호
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• pp.166-171
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• 2013

While high-dose ionizing radiation results in long term cellular cytotoxicity, chronic low-dose (<0.2 Gy) of X- or ${\gamma}$-ray irradiation can be beneficial to living organisms by inducing radiation hormesis, stimulating immune function, and adaptive responses. During chronic low-dose-rate radiation (LDR) exposure, whole body of mice is exposed to radiation, however, it remains unclear if LDR causes changes in gene expression of the whole brain. Therefore, we aim to investigate expressed genes (EGs) and signaling pathways specifically regulated by LDR-irradiation ($^{137}Cs$, a cumulative dose of 1.7 Gy for total 100 days) in the whole brain. Using microarray analysis of whole brain RNA extracts harvested from ICR and AKR/J mice after LDR-irradiation, we discovered that two mice strains displayed distinct gene regulation patterns upon LDR-irradiation. In ICR mice, genes involved in ion transport, transition metal ion transport, and developmental cell growth were turned on while, in AKR/J mice, genes involved in sensory perception, cognition, olfactory transduction, G-protein coupled receptor pathways, inflammatory response, proteolysis, and base excision repair were found to be affected by LDR. We validated LDR-sensitive EGs by qPCR and confirmed specific upregulation of S100a7a, Olfr624, and Gm4868 genes in AKR/J mice whole brain. Therefore, our data provide the first report of genetic changes regulated by LDR in the mouse whole brain, which may affect several aspects of brain function.

• Molecules and Cells
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• 제45권11호
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• pp.846-854
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• 2022

Neurons make long-distance connections via their axons, and the accuracy and stability of these connections are crucial for brain function. Research using various animal models showed that the molecular and cellular mechanisms underlying the assembly and maintenance of neuronal circuitry are highly conserved in vertebrates. Therefore, to gain a deeper understanding of brain development and maintenance, an efficient vertebrate model is required, where the axons of a defined neuronal cell type can be genetically manipulated and selectively visualized in vivo. Placental mammals pose an experimental challenge, as time-consuming breeding of genetically modified animals is required due to their in utero development. Xenopus laevis, the most commonly used amphibian model, offers comparative advantages, since their embryos ex utero during which embryological manipulations can be performed. However, the tetraploidy of the X. laevis genome makes them not ideal for genetic studies. Here, we use Xenopus tropicalis, a diploid amphibian species, to visualize axonal pathfinding and degeneration of a single central nervous system neuronal cell type, the retinal ganglion cell (RGC). First, we show that RGC axons follow the developmental trajectory previously described in X. laevis with a slightly different timeline. Second, we demonstrate that co-electroporation of DNA and/or oligonucleotides enables the visualization of gene function-altered RGC axons in an intact brain. Finally, using this method, we show that the axon-autonomous, Sarm1-dependent axon destruction program operates in X. tropicalis. Taken together, the present study demonstrates that the visual system of X. tropicalis is a highly efficient model to identify new molecular mechanisms underlying axon guidance and survival.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.224-229
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• 1993

The robot has spread remarkably, is used not only in manufacturing but also in various other fields, and is becoming more popular in everyday life. At the same time, the functional demands for all manner of robots have been diversified. Education regarding robots has been developing in the computer, mechanism, sensor and artificial intelligence fields. Technical education which integrates all of the above is necessary and in great demand. We have developed an educational robot so that it can be used in education in fields including structure, sensory and brain function and can also organically integrate those.

• 동의신경정신과학회지
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• 제8권2호
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• pp.25-37
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• 1997

The present experiment was designed to examine catecholamines, 5-hydroxytryptamine, amino acids. malondialdehyde(MDA) and free radical scavenging activity, by administering Chilbokyeum extracts of a variety of concentration to senile brain rats. The results were summarized as followings ; 1. Chilbokyeum significantly increased noradrenalin in the hippocampus and hypothalamus of the brain tissue of senile rats, ad even though Chilbokyeum increased noradrenalin also in other brain tissue, there was no significance. 2. Chilbokyeum had no effects on dopamine changes in all brain tissue of senile rats.3. Chilbokyeum significantly increased 5-hydroxy-tryptamine in cerebellum, but decreased in other brain tissue.4. Chilbokyeum increased amino in the brain tissue of senile rats. 5. Chilbokyeum significantly decreased MDA and free radical in the brain tissue of senile rats. According to the above results, Chilbokyeum is assumed to improve brain function by reaction by reacting on biochemical of the senile brain, and that Chilbokyeum can be used to treat regressive brain disease carrying symptoms of psychoactive disorders.

• 대한한방내과학회지
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• 제19권2호
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• pp.107-124
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• 1998

The present experiment was desined to examine catecholamines, 5-hydroxytryptamine, amino acids, malondialdehyde(MDA) and free radical scavening activity, by administering Cheonmagudeungyeum extract of a variety of concentraction to senile brain The results were summarized as followings: 1. Cheonmagudeungyeum significantly increased noradrenaline in the hippocampus and hypothalamus of the brain tissue of senile rats, and even though Cheonmagudeungyeum increased noradrenaline also in other brain tissue, there was no significance. 2. Cheonmagudeungyeum had no effects on dopamine changes in all brain tissue of senile rats. 3. Cheonmagudeungyeum significantly increased 5-hydrotryptamine in cerebellum, but decreased in other brain tissue. 4. Cheonmagudeungyeum increased amino acid in the brain tissue of senile rats. 5. Cheonmagudeungyeum significantly decresed MDA and free radical in the brain tissue of senile rats. According to the above results, Cheonmagudeungyeum is assumed to improve brain function by reacting on biochemical of the senile brain, and that Cheonmagudeungyeum can be used to treat regressive brain disease carrying symptoms of psychoactive disorders.

• 대한한방내과학회지
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• 제19권1호
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• pp.185-201
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• 1998

The present experiment was desined to examine catecholamines, 5-hydroxytryptamine, amino acids, malondialdehyde(MDA) and free radical scavening activity, by administering Samultang extract of a variety of concentraction to senile brain The results were summarized as followings: 1. Samultang significantly increased noradrenaline in the cortex, striatum, hippocampus and hypothalamus of the brain tissue of senile rats, and even though Samultang increased noradrenaline also in other brain tissue, there was no significance. 2. Samultang had effects on dopamine changes in hypothalamus of the brain tissue of senile rats. 3. Samultang significantly increased 5-hydrotryptamine in pons-medulla oblongota and cerebellum, but decreased in hypothalamus. 4. Samultang increased amino acid in the brain tissue of senile rats. 5. Samultang significantly decresed lipid peroxide production in the brain tissue of senile rats. 6. Samultang significantly decresed MDA and free radical in the brain tissue of senile rats. According to the above results, Samultang is assumed to improve brain function by reacting on biochemical of the senile brain, and that Samultang can be used to treat regressive brain disease carrying symptoms of psychoactive disorders.

• Advances in biomechanics and applications
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• 제1권4호
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• pp.253-267
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• 2014

The human head is identified as the body region most frequently involved in life-threatening injuries. Extensive research based on experimental, analytical and numerical methods has sought to quantify the response of the human head to blunt impact in an attempt to explain the likely injury process. Blunt head impact arising from vehicular collisions, sporting injuries, and falls leads to relative motion between the brain and skull and an increase in contact and shear stresses in the meningeal region, thereby leading to traumatic brain injuries. In this paper the properties and material modeling of the subarachnoid space (SAS) as it relates to Traumatic Brain Injuries (TBI) is investigated. This was accomplished using a simplified local model and a validated 3D finite element model. First the material modeling of the trabeculae in the Subarachnoid Space (SAS) was investigated and validated, then the validated material property was used in a 3D head model. In addition, the strain in the brain due to an impact was investigated. From this work it was determined that the material property of the SAS is approximately E = 1150 Pa and that the strain in the brain, and thus the severity of TBI, is proportional to the applied impact velocity and is approximately a quadratic function. This study reveals that the choice of material behavior and properties of the SAS are significant factors in determining the strain in the brain and therefore the understanding of different types of head/brain injuries.

• 수면정신생리
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• 제6권2호
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• pp.97-101
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• 1999

Sleep disorders are relatively common occurrence after traumatic brain injury. Sleep disturbances often resulted in difficulties in sleep onset and sleep maintenance, nonrestorative after sleep, poor daytime performances and poor individual sense of wellbeing. Unfortunately, there has been minimal attention paid to this common and disabling sequela of brain injury. Better undertanding about problem, pathophysiology and treatment of sleep disorder after traumatic brain injury will improve the cognitive function, social adjustment and rehabilitation for injured patients. Also it may be helpful to reduce traumatic brain injury in patients with sleep apnea.

• Journal of Pharmaceutical Investigation
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• 제23권1호
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• pp.1-9
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• 1993

The endothelial cell of brain capillary called the blood-brain barrier (BBB) has carrier-mediated transport systems for nutrients and drugs. The mechanism of the BBB transport of basic and acidic drugs has been reviewed and examined for endogenous transport systems in BBB in WKY and SHRSP. Acidic drugs such as salicylic acid and basic drugs such as eperisone are taken up in a carrier mediated manner through the BBB via the monocarboxylic acid and amine transport systems. The specific dysfunction for the choline transport at the BBB in SHRSP would affect the function of the brain endothelial cell and brain parenchymal cell. The utilization of the endogenous transport systems of monocarboxylic acid and amine could be promising strategy for the effective drug delivery to the brain.

• Kidney Research and Clinical Practice
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• 제37권4호
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• pp.315-322
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• 2018

The high mortality rates associated with acute kidney injury are mainly due to extra-renal complications that occur following distant-organ involvement. Damage to these organs, which is commonly referred to as multiple organ dysfunction syndrome, has more severe and persistent effects. The brain and its sub-structures, such as the hippocampus, are vulnerable organs that can be adversely affected. Acute kidney injury may be associated with numerous brain and hippocampal complications, as it may alter the permeability of the blood-brain barrier. Although the pathogenesis of acute uremic encephalopathy is poorly understood, some of the underlying mechanisms that may contribute to hippocampal involvement include the release of multiple inflammatory mediators that coincide with hippocampus inflammation and cytotoxicity, neurotransmitter derangement, transcriptional dysregulation, and changes in the expression of apoptotic genes. Impairment of brain function, especially of a structure that has vital activity in learning and memory and is very sensitive to renal ischemic injury, can ultimately lead to cognitive and functional complications in patients with acute kidney injury. The objective of this review was to assess these complications in the brain following acute kidney injury, with a focus on the hippocampus as a critical region for learning and memory.