• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.179-186
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• 2013

Neural stem cells are found in adult mammalian brain regions including the subgranular zone (SGZ) of the dentate gyrus (DG) and the subventricular zone (SVZ). In addition to these two regions, other neurogenic regions are often reported in many species. Recently, the subcallosal zone (SCZ) has been identified as a novel neurogenic region where new neuroblasts are spontaneously generated and then, by Bax-dependent apoptosis, eliminated. However, the development of SCZ in the postnatal brain is not yet fully explored. The present study investigated the precise location and amount of neuroblasts in the developing brain. To estimate the importance of programmed cell death (PCD) for SCZ histogenesis, SCZ development in the Bax-knockout (KO) mouse was examined. Interestingly, an accumulation of extra neurons with synaptic fibers in the SCZ of Bax-KO mice was observed. Indeed, Bax-KO mice exhibited enhanced startle response to loud acoustic stimuli and reduced anxiety level. Considering the prevention of PCD in the SCZ leads to sensory-motor gating dysfunction in the Bax-KO mice, active elimination of SCZ neuroblasts may promote optimal brain function.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2001년도 제2회 생물정보 워크샵 (DNA Chip Bioinformatics)
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• pp.45-60
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• 2001

. Mediator of transcriptional regulation is the evolutionary conserved coactivator complex that plays He central role in the integration and recruitment of diverse regulatory signals and transcription machinery to certain promoters. In yeast, each Mediator subunit is required for transcriptional regulation of a distinct group of genes. In order to decipher the mechanistic roles of Mediator proteins in regulating developmental specific gene expression, we isolated, and analyzed a multiprotein complex containing Drosophila Mediate. homologs (dMediato.). dMediato. interacts with several sequence-sperific transcription factors and basal transcription machinery, and is critical for activated transcription in response to diverse transcriptional activators. In order to elucidate the function of Mediator in metazoan development, we isolated mutants of a conserved Mediate. subunit, Drosophila Med6 (dMed6). dMed6 null homozygotes failed to pupate and died in the third larval instar. Larval mitotic cells and most imaginal discs showed severe defects in proliferation, but no apparent morphological defect was observed in other larval tissues. Clonal analysis of dMed6 mutant cells revealed that dMed6 is essential for cell viability and proliferation of most adult cell types. Drosophila cDNA microarray, quantitative RT-PCR, and in situ expression analyses of developmentally regulated genes in dMed6 mutants showed that transcriptional activation of a subset of genes involved in neuroblast proliferation in the larval brain were most affected. Our results suggest that dMed6 is required in most for transcriptional regulation of a subset of genes important for cell proliferation and metabolism.

• Molecules and Cells
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• 제26권6호
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• pp.576-582
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• 2008

Nervous system development takes place after positional information has been established along the dorsal-ventral (D/V) axis. The initial subdivision provided by a gradient of nuclear dorsal protein is maintained by the zygotic genes expressed along the D/V axis. In this study, an investigation was conducted to determine the range of Dpp function in repressing the expression of eagle (eg) that is present in intermediate neuroblasts defective (ind) and muscle specific homeobox (msh) gene domain. eg is expressed in neuroblast (NB) 2-4, 3-3 and 6-4 of the msh domain, and NB7-3 of the ind domain at the embryonic stage 11. In decapentaplegic (dpp) loss-of-function mutant embryos, eg was ectopically expressed in the dorsal region, while in dpp gain-of-function mutants produced by sog or sca-GAL4/UAS-dpp, eg was repressed by Dpp. It is worthy of note that Dpp produced from sim;;dpp embryos showed that Dpp could function at long range. However, Dpp produced from en-GAL4/UAS-dpp or wg-GAL4/UAS-dpp primarily acted at short-range. This result demonstrated that this discrepancy seems to be due to the repression of Dpp to EGFR signaling in sim;;dpp embryos. Taken together, these results suggest that Dpp signaling works at short-range, but can function indirectly at long-range by way of repression of EGFR signaling during embryonic neurogenesis.

• 대한한방내과학회지
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• 제24권1호
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• pp.104-112
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• 2003

Objectives : The purpose of this study is to evaluate the effects of Sohaphyang-won and is to study the mechanism for neuronal death protection in hypoxia with Embryonic day 20(E20) cortical cells of a guinea pig(Sprague Dawley). Methods : E20 cortical cells, used in this investigation were dissociated in Neurobasal media and grown for 14 days in vitro (DIV). On 14 DIV, Sohaphyang-won was added to the culture media for 72 hours. On 17 DIV, cells were given a hypoxic shock and further incubated in normoxia for another three days. On 20 DIV, Sohaphyang-won's effects for neuronal death protection were evaluated by LDH assay and the mechanism was studied by Bcl-2, Bak, Bax, caspase family. Results : This study indicates that Sohaphyang-won's effects for neuronal death protection in hypoxia is confirmed by LDH assay by the method of Embryonic day 20(E20) cortical neuroblast. Conclusions : Sohaphyang-won's mechanism for neuronal death protection in hypoxia restrains inflow of cytochrome C into cellularity caused by Bcl-2 increase and reduces the caspase cascade initiator caspase-10 and the effector caspase-3.

• 대한한방내과학회지
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• 제24권2호
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• pp.348-357
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• 2003

Objectives : The purpose of this investigation is to evaluate the effects of Aucklandiae Radix Moschus(木香 麝香)and to study the mechanism for neuronal death protection in hypoxia with Embryonic day 20 (E20) cortical cells of a rat (Sprague Dawley). Methods : E20 cortical cells used in this investigation were dissociated in Neurobasal media and grown for 14 days in vitro (DIV). On 14 DIV, Aucklandiae Radix Moschus(木香 麝香) was added to the culture media for 72 hrs. On 17 DIV, cells were given a hypoxic shock and further incubated in normoxia for another three days. On 20 DIV, Moschus(麝香)'s effects for neuronal death protection were evaluated by LDH assay and the mechanisms were studied by Bcl-2, Bak, Bax, caspase family. Results : This study indicate that Aucklandiae Radix(木香)'s effects for neuronal death protection in normoxia and Scutellariae Radix(麝香)'s effects for neuronal death protection in hypoxia were confirmed by LDH assay in culture method of Embryonic day 20(E20) cortical neuroblast. Moschus(麝香)'s mechanism for neuronal death protection in hypoxia is to increase the anti-apoptosis protein Bcl-2. Conclusions : It may be reasonable to propose that Moschus(麝香) protects delayed neuronal death in hypoxia by increasing Bcl-2, thereby reducing mitochondrial permeability transition(PT) pores, the cytochrome c channels.

• Anatomy and Cell Biology
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• 제56권1호
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• pp.69-85
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• 2023

Depression is one of the most common neuropsychiatric disorders and is associated with dysfunction of the neuroendocrine system and alterations in specific brain proteins. Boophone disticha (BD) is an indigenous psychoactive bulb that belongs to the Amaryllidacae family, which is widely used in Southern Africa to treat depression, with scientific evidence of potent antidepressant-like effects. The present study examined the antidepressant effects of BD and its mechanisms of action by measuring some behavioural parameters in the elevated plus maze, brain content of corticosterone, brain derived neurotropic factor (BDNF), and neuroblast differentiation in the hippocampus of Balb/c mice exposed to the five day repeated forced swim stress (5d-RFSS). Male Balb/c mice were subjected to the 5d-RFSS protocol to induce depressive-like behaviour (decreased swimming, increased floating, decreased open arm entry, decreased time spent in the open arms and decreased head dips in the elevated plus maze test) and treated with distilled water, fluoxetine and BD. BD treatment (10 mg/kg/p.o for 3 weeks) significantly attenuated the 5d-RFSS-induced behavioural abnormalities and the elevated serum corticosterone levels observed in stressed mice. Additionally, 5d-RFSS exposure significantly decreased the number of neuroblasts in the hippocampus and BDNF levels in the brain of Balb/c mice, while fluoxetine and BD treatment attenuated these changes. The antidepressant effects of BD were comparable to those of fluoxetine, but unlike fluoxetine, BD did not show any anxiogenic effects, suggesting better pharmacological functions. In conclusion, our study shows that BD exerted antidepressant-like effects in 5d-RFSS mice, mediated in part by normalizing brain corticosterone and BDNF levels.

• 생명과학회지
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• 제14권6호
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• pp.975-985
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• 2004

발생기 횐쥐 대뇌피질 발생의 형태적 변화와 이에 미치는 ECEE 영향을 구명하기 위해, 태생 14일, 태생 18일, 생후 수유기 및 이유기와 성체 대뇌를 각 부위로 나누어 H-E 염색으로 관찰하였다. EGEE 투여시 태생 14일에 대뇌피질의 두께는 두정엽피질이 제일 두꺼웠으나$(95{\pm}12.7\;{\mu}m)$, 대조군$(102{\pm}14.0\;{\mu}m)$에 비해 얇았고, 다른 피질에 비해 후두엽피질$(57{\pm}10.5\;{\mu}m)$이 제일 얇았다. 각 엽의 두께는 수유기 때에 급성장하는 경향을 나타내었으나, 이유기 이후 성장이 둔화되어 성체기 때와 유사했으며, 성체기 때는 두정엽피질$(93.4{\pm}21.6\;{\mu}m)$에서 가장 많이 성장하였다. EGEE 투여시 대뇌피질내 신경모세포의 수는 태생 14일 두정엽피질의 외투층에서 제일 많았으나$(207.7{\pm}11.4/10^{-2}\;mm$, 대조군에 비해 감소되었고$(224.2{\pm}13.8/10^{-2}\;mm$, 크기는 출생후 3일 후두엽피질의 뇌실막세포층에서 제일 크게 나타났으나$(7.5{\pm}1.3\;{\mu}m)$), 대조군$(9.0{\pm}1.2\;{\mu}m)$에 비해 감소되었다. 대조군과 같이 과립세포와 추체세포의 수는 두정엽피질의 II층과 III층에서 가장 많았으나, 대조군에 비해 감소되었고, 크기는 후두엽피질의 IV층과 V층에서 가장 컸으나, 대조군에 비해 감소되었다. EGEE 투여시 대조군과 같이 태생기와 출생후 3일까지의 대뇌피질은 뇌실막세포층, 외투층, 연변층의 3층으로 분화되나, 조직내 빈 강소와 공포가 나타나고, 신경모세포가 합착된 양상이 나타났다. 출생후 5일이후 수유기 때 대뇌피질층은 대조군과 동일하게 4층으로 나눌 수 있으나, 과립세포와 추체세포 내에 빈 강소나 공포가 나타났고, 신경세포의 수는 감소하였다. 이유기와 성체기 때는 대뇌피질의 세포층 구분이 뚜렷하지 않고, 외과립세포, 외추체세포들이 섞여 조직내 빈 강소나 공포가 형성되며, 신경세포 주위 혈관의 내강이 확대되거나 합착되어 나타났다.