• Clinical and Experimental Pediatrics
• /
• 제49권5호
• /
• pp.558-564
• /
• 2006

목 적 : 경뇌 전자기 자극법은 변조 자기장을 이용하여 뇌세포에 대한 직접적인 영향을 주지 않으면서 중추 신경계를 자극할 수 있는 비침습적인 방법이다. 이전의 연구들은 대부분 생체 동물을 대상으로 수행되어져 왔으며 배양 조직에서의 연구는 별로 이루어진 바 없다. 이에 본 연구에서는 배양된 해마 절편에서 다른 주파수의 전자기 자극이 신경원에 미치는 영향과 약물에 의한 세포 손상 후 전자기 자극의 세포보호효과 여부에 대해 알아보고자 하였다. 방 법 : 생후 8일된 실험쥐의 대뇌를 적출하여 dissection microscope 하에서 양쪽 해마 부위를 분리하고 tissue chopper를 이용하여 $450{\mu}M$ 두께로 절편을 만든 후 Stoppini가 고안한 방법대로 배양을 시행하였다. 각각 5개의 건강한 해마 절편이 포함된 inserts를 선택하고, 전자기 자극군에 대해 0.67 Hz와 50 Hz의 주파수로 각각 배양 5일부터 3일 간격으로 6차례 전자기 자극을 가하였다. 또한, 배양 제 14일에 inserts 2개에 $100{\mu}M$ NMDA에 노출시키고 3일 후부터 3일 간격으로 insert 1개에 전자기 자극을 3차례 시행하였고 다른 1개의 insert와 대조군에는 자극을 가하지 않았다. 결 과 : 전자기 자극 후 신경원의 활성도를 알아보기 위해 NeuN 단백 발현을 western blotting을 이용하여 측정한 후 ${\beta}$-actin 단백 발현과의 비를 얻어 각 군에서 비교 분석하였다. 대조군($1.01{\pm}0.27$)에 비해 전자기 자극군에서 NeuN의 발현이 증가되어 있었으며, 특히 저주파 자극군($1.12{\pm}0.14$)에서보다 고주파 자극군($1.27{\pm}0.17$)에서 현저하였고 고주파 자극군에서는 대조군에 비해 통계적으로 유의한 증가를 보였다(P<0.05). 또한, NMDA 노출 후 실험군(전자기 자극군 : $1.15{\pm}0.27$, 전자기 비자극군 : $0.92{\pm}0.09$)에서 대조군($1.26{\pm}0.04$)에 비해 NeuN 발현이 감소되었으나 전자기 비자극군에서 더 많이 감소한 것을 알 수 있었다. 결 론 : 배양된 해마조직의 신경세포에 대한 전자기 자극은 저주파 자극군에 비해 고주파 자극군에서 대조군보다 통계적으로 유의한 수준의 NeuN 발현의 증가를 관찰할 수 있었고, NMDA 노출 후 전자기 자극을 가한 군에서 대조군보다 NeuN 발현 감소가 관찰되기는 하였으나 고주파 자극군에서는 통계적으로 유의하지 않은 정도였던 것으로 보아 전자기 자극이 신경원 활성을 증가시켜 신경세포의 발생 및 증식을 유도하며 세포 손상에 대한 신경보호효과도 보인다는 것을 알 수 있었다. 따라서 전자기 자극은 여러 신경 질환에 있어서 치료적 역할을 할 수 있는 가능성이 있다고 사료된다.

• Annals of Clinical Neurophysiology
• /
• 제1권2호
• /
• pp.147-153
• /
• 1999

Hippocampal slice models can be a powerful tool to study the mechanism of partial epilepsy. Despite the loss of connection with the rest of the brain, in vitro hippocampal slice preparations allow detailed physiological and pharmacological studies, which would be impossible, in vivo. There are several methods to induce electrographic seizures on hippocampal slice models. Those are electrical pulse train stimulation, 0 $Mg^{2+}$ artificial cerebrational fluid and high concentration of extracelluar $K^+$ on bath. Among them, the electrically triggered seizure may mimic the physiological communication between neuronal populations without any deterioration of normal physiologic and chemical status of the hippocampal slice models. Presumably, such communication from hyperexcitable areas to other neuronal populations is involved in the development of epilepsy. Electrographic seizures in hippocampal slice models occur in the network of neurons that are involved in epileptic seizures in the hippocampus in vivo. Because these models have many advantages and are very valuable to research of epileptogenesis on partial epilepsy, I would like to introduce the electrophysiological methods to induce electrographic seizure or epilepsy on hippocampal slice models briefly in this paper.

• Natural Product Sciences
• /
• 제11권3호
• /
• pp.179-182
• /
• 2005

We investigated that water extract of Acanthopanax sessiliflorus roots rescued the N-methyl-D-aspartate (NMDA), agonist of glutamate receptor, -induced toxicity in rat organotypic hippocampal slice culture. When the cell death in NMDA only-treated hippocampal slices was set 100%, A. sessiliflorus decreased the cell death to 75.4, 51.6, 48.9, and 40.6% at 1, 10, 50, and $100\;{\mu}g/ml$ treatment, respectively. On the basis of these results, the water extract of A. sessiliflorus roots may be a preventive agent against NMDA-induced cytotoxicity.

• Journal of Korean Neurosurgical Society
• /
• 제29권9호
• /
• pp.1161-1170
• /
• 2000

Objective : The transverse hippocampal slice is one of the most commonly studied in vitro models of mammalian brain physiology. However, despite its broad usage, there has been no standardization of slice preparation techniques or recording condition. It is well known that variations in recording conditions can result in profound different effects to neuronal responses. Evoked field potentials, recorded extracellularly, were used to investigate the effects of variations in hippocampal slice preparation protocol on hypoxia responses of CA1 neurones. Material & Methods : Before hypoxic injury, hippocampal slices were incubated for 4 hours. During incubation period, the slices were placed in a incubation chamber($21^{\circ}C$) for recovery from preparation injury and then transferred to recording chamber($34^{\circ}C$) for more recovery and baseline electric recording with current stimulation(0.1Hz). Various time periods in incubation chamber and recording chamber were applied to each experimental group(group 1=60min : 180min, group 2=90min : 150min, group 3=180min : 60min, time in incubation chamber : time in recording chamber) before 10 min hypoxia produced by replacing 95% $O_2$+5% $CO_2$ mixed gas to 95% $N_2$+5% $CO_2$ gas. Calcium, Magnesium ions and several drugs effecting on glutamate receptor also were studied. Recoveries from hypoxic injury of hippocampal slices were estimated by percent recovery of population spike(PS). Statistic analysis of study were performed using paired t-test. Results : The percent recovery of PS after 10min hypoxia was considerably enhanced by increasing the period of current stimulation during incubation period before hypoxic injury. Temperature effect on the result of this experiment was also studied(group 4) but the result from this showed no statistic significance. Low magnesium ion concentration of artificial CSF(Mg-free aCSF) during incubation period enhanced the recovery of PS but low calcium (calcium-free) and high magnesium ion concentration(2mM) reduced it after hypoxic injury. L-glutamate($100{\mu}M$) and AP-5($50{\mu}M$) had no effect on the recovery of PS but CNQX($10{\mu}M$) in artificial CSF during incubation period markedly enhanced the recovery of PS. Co-treatment of AP-5($50{\mu}M$), CNQX($10{\mu}M$) and high magnesium concentration(2mM) enhanced recovery of PS in immediate following period of hypoxic injury but the effect of cotreatment after then decayed rapidly and lost statistic significance. Conclusions : Judging from above results, the condition of baseline recording is important in observing the recovery of population spike after hypoxia, and the time and the condition should be controled more strictly to obtain reliable results.

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
• /
• pp.164.2-164
• /
• 1996

No Abstract, See Full Text

• 대한의용생체공학회:의공학회지
• /
• 제27권6호
• /
• pp.409-417
• /
• 2006

Research on neural circuit is a difficult area due to complexity and inaccessibility. Due to recent developments, the research using multi-electrode array of cells or tissues has become an important research area. However, there are some difficulties to decode the submerged meaning from huge and complex neural data. Moreover, it needs a harmonic collaboration between informatics and bioscience. In this paper, we have developed a custom-designed signal processing technique for multi-electrode array measured neural responses induced by electrical stimuli to the hippocampal tissue slices of the rat brain. The raw data from hippocampal slice using the multi-electrode array system were saved in a computer. Then we estimated characteristic points in each channel and calculated the total activity. To estimate the points, we used the Polynomial Fitting Approximation Method. Using the calculated total activity, we could provide the histogram or pseudo-image matrix to help interpretation of results.

• BMB Reports
• /
• 제31권2호
• /
• pp.117-122
• /
• 1998

Changes of lipocortin 1 (LC1) in the brain induced by immobilization stress were investigated in rats. Rats were immobilized for 0,1,2,3,4, and 5 h, and the brain slices were immunostained with anti-human LC1 antibodl (anti-LC1). Immunoreactivity of LCI (iLC1) was most prominent in neuronal cell bodies and processes of hippocampal CA regions and dentate gyrus. At rest without stress, most of the LC1 in the neuron located in the cytoplasm with the nuclei exhibiting relatively scarce immunoreactivity. Immobilization stress changed this intracellular distribution of LC1 by increasing nuclear LC1. The change was apparent in 1 h and reached the peak by 3 h. However, by 5 h of immobilization, the distribution pattern returned to that of the resting state. This transient nuclear translocation of LC1 was most prominent in $CA_1$ pyramidal neurons, and was not observed in areas other than the hippocampus. Adrenalectomy abolished this transient translocation of LC1. The roles of hippocampal LC1 as a mediator of glucocorticoid feedback signal and/or as an intracellar stress signaling protein could be suggested.

• Applied Microscopy
• /
• 제42권4호
• /
• pp.200-206
• /
• 2012

Induction of neurogenesis can occur in the hippocampus in response to various pathological conditions, such as Alzheimer's disease. The aim of this study was to investigate the changes that occur in endogenous neural stem cells in response to amyloid beta $(A{\beta})_{25-35}$-induced neuronal cell damage in organotypic hippocampal slice cultures. Cresyl violet staining and Fluoro-Jade B staining were used to detect neuronal cell damage and changes of mossy fiber terminals were observed by Timm's staining. The immunofl uorescence staining was used to detect the newly generated cells in the subgranular zone (SGZ) of the dentate gyrus with specific marker, 5-bromo-2'-deoxyuridine (BrdU), Ki-67, Nestin, and doublecortin (DCX). In compared to control slices, neuronal cell damage was observed and the mossy fibers were expanded to CA3 area by treatment with $A{\beta}_{25-35}$. Ki-67/Nestin- and BrdU/DCX-positive cells were detected in the SGZ. In conclusion, these results demonstrate that $A{\beta}$-induced neuronal damage results in an increase in endogenous neural stem cells in rat hippocampal slice cultures not only for gliosis but also for neurogenesis.

• 생명과학회지
• /
• 제27권3호
• /
• pp.355-360
• /
• 2017

다량의 에탄올을 섭취하면 기억 상실로 이어질 수 있으며, 종종 blackout으로 나타난다. Blackout의 불균형은 알코올 소비에 있어 다양한 사회 문제의 주요 원인이 될 수 있다. 그러나 이러한 알코올 유발 문제를 예방하는 치료법은 아직 존재하지 않는다. Hydrangeae dulcis folium은 Hydrangea serrata Seringe의 잎을 발효가공을 통해 만든 민간약 또는 차이다. 본 연구에서는 에탄올로 유도한 정신적 결핍에 대한 Hydrangeae dulcis folium의 에탄올 추출물(EHDF)의 효과를 평가하였다. 행동적 결핍 또는 장애를 테스트하기 위해 마우스에서 물체 인식 테스트가 수행하였다. 또한 시냅스 결손을 평가하기 위해, 마우스 해마 조각에서 에탄올에 취약한 것으로 알려져 있고 에탄올로 유발한 기억 상실과 관련이 있는 N-methyl-D-aspartate (NMDA) 수용체-매개 흥분성 시냅스 후 전위 및 long-term potentiation (LTP)을 측정하였다. 본 연구에서 에탄올(1 g/kg, i.p.)은 물체 인식 메모리를 손상 시켰지만, EHDF (10 또는 30 mg/kg)는 물체 인식 테스트에서 이러한 장애를 극복하였다. 흥미롭게도, EHDF ($30{\mu}g/ml$)는 해마 절편에서 에탄올 처리 후 억제되었던 LTP 및 NMDA 수용체 매개 시냅스 전달을 유의하게 개선시켰다. EHDF는 에탄올에 의해 유발된 물체 인식 기억력 결핍을 개선하였고, 또한 EHDF는 해마 절편에서 에탄올 유도성 LTP 및 NMDA 수용체 매개성 시냅스 전달을 상당히 개선시켰다.

• 한국독성학회:학술대회논문집
• /
• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
• /
• pp.89-89
• /
• 2002

It is well known that oxygen radicals induce neuronal cell damage by initiation of lipid peroxidation chain reaction. Recent work has been also demonstrated that enzymatically generated free radicals cause the release of glutamate and aspartate from cultured rat hippocampal slices.(omitted)