• 제목/요약/키워드: hippocampus

검색결과 840건 처리시간 0.021초

Reduction of long-term potentiation at Schaffer collateral-CA1 synapses in the rat hippocampus at the acute stage of vestibular compensation

  • Lee, Gyoung Wan;Kim, Jae Hyo;Kim, Min Sun
    • The Korean Journal of Physiology and Pharmacology
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    • 제21권4호
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    • pp.423-428
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    • 2017
  • Vestibular compensation is a recovery process from vestibular symptoms over time after unilateral loss of peripheral vestibular end organs. The aim of the present study was to observe time-dependent changes in long-term potentiation (LTP) at Schaffer collateral-CA1 synapses in the CA1 area of the hippocampus during vestibular compensation. The input-output (I/O) relationships of fEPSP amplitudes and LTP induced by theta burst stimulation to Schaffer's collateral commissural fibers were evaluated from the CA1 area of hippocampal slices at 1 day, 1 week, and 1 month after unilateral labyrinthectomy (UL). The I/O relationships of fEPSPs in the CA1 area was significantly reduced within 1 week post-op and then showed a non-significant reduction at 1 month after UL. Compared with sham-operated animals, there was a significant reduction of LTP induction in the hippocampus at 1 day and 1 week after UL. However, LTP induction levels in the CA1 area of the hippocampus also returned to those of sham-operated animals 1 month following UL. These data suggest that unilateral injury of the peripheral vestibular end organs results in a transient deficit in synaptic plasticity in the CA1 hippocampal area at acute stages of vestibular compensation.

영역확장법과 동적외곽선모델을 이용한 해마(hippocampus)의 외곽선 검출 (Contour detection of hippocampus using Dynamic Contour Model and Region Growing)

  • 장동표;김효대;이두수;김선일
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 춘계학술대회
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    • pp.116-118
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    • 1997
  • In hippocampal morphology Abnormalities, including unilateral or bilateral volume loss, are known to occur in epilepsy, Alzheimer's disease, and in certain amnestic syndromes. To detect such abnormalities in hippocampal morphology, we present a method that combines region growing and dynamic contour model to detect hippocampus from MRI brain data. The segmentation process is performed two steps. First region growing with a seed point is performed in the region of hippocampus and the initial contour of dynamic contour model is obtained. Second, the initial contour is modified on the basis of criteria that integrate energy with contour smoothness and the image gradient along the contour. As a result, this method improves fairly sensitivity to the choice of the initial seed point, which is often seen by conventional contour model. The power and practicality of this method have been tested on two brain datasets. Thus, we have developed an effective algorithm to extract hippocampus from MRI brain data.

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갈근약침(葛根藥鍼)이 알콜 중독(中毒) 백서(白鼠) 해마(海馬)의 Nitric Oxide Synthase에 미치는 영향(影響) (Effects of Puerariae radix herb-acupuncture on nitric oxide synthase expression in the hippocampus of alcohol-intoxicated Sprague-Dawley rats)

  • 정재훈;김호현;이은용
    • Journal of Acupuncture Research
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    • 제20권4호
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    • pp.1-10
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    • 2003
  • Objective: The purpose of this study was to determine the effects of Puerariae radix(PR) herb-acupuncture on nitric oxide synthase(NOS) expression in hippocampus of alcohol-intoxicated Sprague-Dawley(SD) rats. Methods: SD rats were randomly assigned into 6 groups; normal group, control group, alcohol with herb-acupuncture group(0.3, 3, 30 and 300mg/kg PR). Normal groups were received with NaCl, while alcohol intoxication groups were injected intraperitoneally with alcohol(2g/kg) twice per day for 3 days. Herb-acupuncture groups were injected on Zhongwan(CV12) for 5 consecutive days. For the detection of NADPH-d-positive cells in hippocampus, immunohistochemistry was performed. Results: n control group, a significant decrease in NADPH-d-positive cells was observed compared to normal group. In alcohol with herb-acupuncture group, NADPH-d-positive cells increased significantly compared to control group. Conclusions: The present results revealed that NOS expression is enhanced in the hippocampus of SD rats through PR herb-acupuncture in an acute alcoholic intoxication condition.

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Contrast-enhanced Bias-corrected Distance-regularized Level Set Method Applied to Hippocampus Segmentation

  • Selma, Tisa;Madusanka, Nuwan;Kim, Tae-Hyung;Kim, Young-Hoon;Mun, Chi-Woong;Choi, Heung-Kook
    • 한국멀티미디어학회논문지
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    • 제19권8호
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    • pp.1236-1247
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    • 2016
  • Recently, the level set has become a popular method in many research fields. The main reason is that it can be modified into many variants. One such case is our proposed method. We describe a contrast-enhancement method to segment the hippocampal region from the background. However, the hippocampus region has quite similar intensities to the neighboring pixel intensities. In addition, to handle the inhomogeneous intensities of the hippocampus, we used a bias correction before hippocampal segmentation. Thus, we developed a contrast-enhanced bias-corrected distance-regularized level set (CBDLS) to segment the hippocampus in magnetic resonance imaging (MRI). It shows better performance than the distance-regularized level set evolution (DLS) and bias-corrected distance-regularized level set (BDLS) methods in 33 MRI images of one normal patient. Segmentation after contrast enhancement and bias correction can be done more accurately than segmentation while not using a bias-correction method and without contrast enhancement.

Swimming During Pregnancy Increases the Expression c-Fos and c-Jun in the Hippocampus of Rat Offspring

  • Sim, Young-Je;Kim, Jee-Youn;Kim, Chang-Ju
    • 운동영양학회지
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    • 제13권1호
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    • pp.23-28
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    • 2009
  • The expression of c-Fos and c-Jun represents neuronal activity and plays a crucial role in the shaping of the development of brain. During the late pregnancy, exercise is known to influence neuronal activity of offspring. In the present study, the effect of swimming during pregnancy on the expression of c-Fos and c-Jun in the CA1, CA2, CA3 regions, and the dentate gyrus of the hippocampus of rat offspring was investigated using immunohistochemistry. Pregnant rats in the swimming group were forced to swim for 10 min once a day from 15 days after pregnancy until delivery. The expression of c-Fos and c-Jun in the CA1, CA2, CA3 regions, and the dentate gyrus of the hippocampus of pups was significantly increased by maternal swimming during late pregnant period. The present results show that prenatal swimming may enhance the neuronal activity of pups and affect the neonatal brain development.

Serial Expression of Hypoxia Inducible Factor-$1{\alpha}$ and Neuronal Apoptosis in Hippocampus of Rats with Chronic Ischemic Brain

  • Yu, Chi-Ho;Moon, Chang-Taek;Sur, Jung-Hyang;Chun, Young-Il;Choi, Won-Ho;Yhee, Ji-Young
    • Journal of Korean Neurosurgical Society
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    • 제50권6호
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    • pp.481-485
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    • 2011
  • Objective : The purpose of this study is to investigate serial changes of hypoxia-inducible factor $1{\alpha}$ (HIF-$1{\alpha}$), as a key regulator of hypoxic ischemia, and apoptosis of hippocampus induced by bilateral carotid arteries occlusion (BCAO) in rats. Methods : Adult male Wistar rats were subjected to the permanent BCAO. The time points studied were 1, 2, 4, 8, and 12 weeks after occlusions, with n=6 animals subjected to BCAO, and n=2 to sham operation at each time point, and brains were fixed by intracardiac perfusion fixation with 4% neutral-buffered praraformaldehyde for brain section preparation. Immunohistochemistry (IHC), western blot and terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay were performed to evaluate HIF-$1{\alpha}$ expression and apoptosis. Results : In IHC and western blot, HIF-$1{\alpha}$ levels were found to reach the peak at the 2nd week in the hippocampus, while apoptotic neurons, in TUNEL assay, were maximal at the 4th week in the hippocampus, especially in the cornu ammonis 1 (CA1) region. HIF-$1{\alpha}$ levels and apoptosis were found to fluctuate during the time course. Conclusion : This study showed that BCAO induces acute ischemic responses for about 4 weeks then chronic ischemia in the hippocampus. These in vivo data are the first to show the temporal sequence of apoptosis and HIF-$1{\alpha}$ expression.

죽력지출환(竹瀝枳朮丸)의 메탄올추출 엑기스가 흰쥐의 전뇌허혈에 미치는 영향 (Effects of Methanol Extract of Jukryukjichul-hwan on Global Cerebral Ischemia of Rats)

  • 류지철;김영균;권정남
    • 대한한의학회지
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    • 제27권2호
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    • pp.1-13
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    • 2006
  • Objectives : Ischemic brain injury is a worldwide problem that often causes irreversible brain damage. Moreover, prevention of ischemic brain injury is more important than anything else, since after-effects of stroke significantly threat the quality of life. Jukryukjichul-hwan (JRH) is an oriental medicinal formula for stroke patients in Korea. This study evaluated neuroprotective effects of methanol extract of JRH on global cerebral ischemia in rats. Changes of the pyramidal neurons, Bax and TUNEL immuno-positive neurons in CA1 hippocampus were observed using immunohistochemistry. Methods : Sprague-Dawley Rats were induced with temporal global cerebral ischemia (TGI) by occluding the bilateral common carotid artery with hypotension, The rats were divided into 3 groups. We treated one group with methanol extract of JRH after operation, another group before and after the operation. We observed Bax expressions inducing apoptosis of neurons and TUNEL-positive Pyramidal Neurons as an index of survival and apoptosis of pyramidal neurons in CA1 Hippocampus. Results : JRH treatment before and after TGI inhibited Bax expression in CA1 hippocampus. JRH treatment before and after TGI reduced the cell death of pyramidal neurons in CA1 hippocampus. JRH treatment after TGI reduced the cell death of pyramidal neurons in CA1 hippocampus. JRH treatment before and after TGI reduced TUNEL-positive cells in CA1 hippocampus. Conclusion : These results suggest that JRH has a neuroprotective effect (by anti-apoptosis) against cerebral ischemia.

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방기복령탕(防己茯苓湯)이 백서에서 LPS로 유도된 우울증에서 면역 조직학적 변화에 미치는 효과 (Effect of Banggibongnyeongtang on the immunohistological change in LPS-induced depression rats)

  • 박성준;이태희
    • 대한한의학방제학회지
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    • 제28권1호
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    • pp.53-62
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    • 2020
  • Objective : This study is accomplished in order to investigate the effect of banggibongnyeongtang on the immunohistological change in LPS-induced depression rats to confirm the histological result of the previous behavioral and biochemical effect. Methods : LPS 5 ㎍ was injected to lateral ventricle and experimental groups were administered BBT intraperitoneally. The concentration of 5-HT in the Medial Prefrontal Cortex, Striatum, Hippocampus, Amygdala was measured by ELISA. IL-1β, TNF-α mRNA and BDNF mRNA expression in the hippocampus was examined by RT-PCR. Result : BBT enhanced 5-HT concentration at all part of brain but no significantly difference at medial prefrontal cortex and striatum. LPS+BBT400 group increased 5-HT concentration significantly than LPS group at hippocampus and amygdala (p<0.05). BBT decreased IL-1β mRNA expression dose dependently but only with significantly decrease in LPS+BBT400 group than LPS group's in Hippocampus (p<0.05). But BBT did not decrease TNF-α mRNA expression significantly in Hippocampus. BBT increased the expression of BDNF mRNA at hippocampus and LPS+BBT400 group significantly increased comparing with LPS group does (p<0.05). Conclusion : It is postulated that the anti-depressant effect of BBT can be validated through the anti-inflammatory effect, 5-HT concentration increase, and the neuro-protective effect mediated by BDNF by combining the results of the previous report about the behavioral and biochemical effect.

천마가미방이 Scopolamine으로 유발된 흰쥐의 해마 손상에 미치는 영향 (Protective Effect of the Gastrodiae Rhizoma-gamibang on the Scopolamine-induced Hippocampal Damage in Sprague-Dawley Rats)

  • 박은혜;이숭인;정종길;김경옥;김정상
    • 대한본초학회지
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    • 제30권3호
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    • pp.49-54
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    • 2015
  • Objectives : This study investigated the neuroprotective effect of Gastodia Rhizoma-gamibang (GG) water extracts against scopolamine-induced neurotoxicity in the hippocampus of male Sprague-Dawley rats. Methods : The animals were divided into five different groups with six animals per each group. The normal group (Nor) was administered with saline, while the control group (Con) was administered with saline after scopolamine treatment. The experimental group (Exp) was administered orally GG extracts at doses of 200 mg/kg (GG1 group), 400 mg/kg (GG2 group), 1000 mg/kg (GG5 group) for 30 day after scopolamine treatment. Results : From a light microscopy study, the nuclei of neurons and glial cells in the hippocampus were more shrunken or condensed in the 30 day control group compared with normal group. In the experimental groups, proportional to the dose, recovered from neurotoxicity induced by scopolamine. The control group, the density of hippocampal neurons were reduced 17-20% compared to normal group. The densities of neurons from the CA1, and CA3 area of the hippocampus in the GG1, GG2 and GG5 groups significantly increased compared with the Con. In the experimental group, neuronal cells are recovered from scopolamine-induced damage. A number of glial cells are observed increase from GG2 and GG5 groups. The PAS-positive materials in the tissues hippocampus), was lower in the Exp than the Con. Conclusions : The present study demonstrates that Gastodia Rhizoma-gamibang extract reduces neuronal damage in the hippocampus of scopolamin-induced impairment mice.

두충(杜沖)이 수컷 노화쥐의 우울증에 미치는 효과 (Effects of Eucomiae Cortex on the Depression of Male Aged Mice)

  • 김호현;안상현;박선영
    • 동의생리병리학회지
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    • 제33권1호
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    • pp.10-16
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    • 2019
  • In order to investigate the effects of Eucomiae Cortex extracts on the depression caused by aging, histochemistry and immunohistochemistry were performed on the hippocampus of aged rats and the following results were obtained. Experimental animals were divided into three groups as follows: 8 week old ICR male mice, Aging-elicited group (AE group) and Eucomiae Cortex treatment group (EC group) 50 week old male ICR mice were used. The control group and AE group did not take any treatment and did not restrict diets and negatives. In the EC group, 0.51g/kg of Eucomiae Cortex extract was dissolved in distilled water once a day for 6 months. The Eucomiae Cortex extract reduced pyramidal neuronal damage in C3 hippocampus and dentate gyrus, increased DJ-1, SHH positive responses in aged mouse hippocampus, and 8-OHdG positivity was reduced, ${\beta}$-endorphin positivity was reduced in aged mouse substantia nigra. Therefore, based on the above results, Eucomiae Cortex extract reduces damage of pyramidal neurons in the hippocampus caused by aging, inhibits neuronal cell death, induces proliferation and differentiation of stem cells in the hippocampus, reduces DNA damage-induced oxidative stress, so improves the reduction of hippocampus volume. It is also thought to improves depression due to aging through ${\beta}$-endorphin which enhances mood through the inhibition of pain.