• The Korean Journal of Zoology
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• v.36 no.1
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• pp.6-13
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• 1993

연두금파리 유충의 뇌와 복신경절에 분포하는 세로토닌 면역반응성 세포를 면역조직화학적 방법을 이용하여 동정하였다. 세로토인세포는 뇌에 28개, 제1식도하신경절의 첫째마디에 6개, 둘째마디에 10개 그리고 세째마디에 6개가 각각 존재하였다. 그리고 앞가슴신경절에 6개, 가운데가슴신경절에 4개 그리고 됫가슴신경절에 4개가 각각 위치하였다. 또한 복부신경절에서는 첫새 마디부터 일곱째 마디까지 각각 4개가 존재하였고 마지막마디인 여덟째마디에서는 단지 두개의 세포만이 관찰되었다. 결국 연두금파리 유충의 중추신경계에는 모두 94개의 세로토닌 면역반응성 세포들이 분포하였다. 이들 세포로부터 뻗어나온 축색들은 뉴로파일내에서 분지하거나 횡연합섬유를 이루었다.

• Progress in Medical Physics
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• v.15 no.4
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• pp.228-236
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• 2004

Retinal ganglion cells transmit visual scene as an action potential to visual cortex through optic nerve. Conventional recording method using single intra- or extra-cellular electrode enables us to understand the response of specific neuron on specific time. Therefore, it is not possible to determine how the nerve impulses in the population of retinal ganglion cells collectively encode the visual stimulus with conventional recording. This requires recording the simultaneous electrical signals of many neurons. Recent advances in multi-electrode recording have brought us closer to understanding how visual information is encoded by population of retinal ganglion cells. We examined how ganglion cells act together to encode a visual scene with multi-electrode array (MEA). With light stimulation (on duration: 2 sec, off duration: 5 sec) generated on a color monitor driven by custom-made software, we isolated three functional types of ganglion cell activities; ON (35.0$\pm$4.4%), OFF (31.4$\pm$1.9%), and ON/OFF cells (34.6$\pm$5.3%) (Total number of retinal pieces = 8). We observed that nearby neurons often fire action potential near synchrony (< 1 ms). And this narrow correlation is seen among cells within a cluster which is made of 6～8 cells. As there are many more synchronized firing patterns than ganglion cells, such a distributed code might allow the retina to compress a large number of distinct visual messages into a small number of ganglion cells.

• The Korean Journal of Zoology
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• v.30 no.1
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• pp.29-43
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• 1987

Incilaria fruhstorferi daiseninana의 뇌는 쌍을 이루고 있는 뇌(cerebral), 측(pleural), 노(parietal), 족(pedal)신경절과 단일 복부(abdominal)신경절로 구성되어 있으며, 이들은 융합된 신경고리를 이루고 있었다. 복부신경절로부터 나오는 내장신경은 생식, 장, 심장, 신장신경등으로 분지되어 이들 각 기관에 신경을 공급하고 있었다. 다음 3가지 방법, 즉, 내장신경을 Ni$^2$+로 역방향으로 충진하여 세포체를 염색하는 방법, 형광화합물 Lucifer yellow를 세포내로 주입하는 방법, 세포내활동전위와 내장신경의 세포외 활동전위를 동시에 측정하는 방법으로 적어도 12가지의 동정된 뉴우런이 내장신경과 관련되고 있음을 알았다. 알아낸 각 세포의 전기생리학적인 특성을 검지하고, 이것과 각 세포의 돌기 분지상태와의 관련 및 일부 세포간의 상호관계를 검사하였다. 이들중 8가지 세포가 내장신경에 축색돌기를 내보내는 효과신경세포라는 증거를 얻었다.

• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.1-9
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• 2000

The visceral ganglion and the right parietal ganglion of the African giant snail, Achatina fulica, consists of two hemispheres, each in left and right side, respectively, like a butterfly. The surface of cortex and medulla in the two ganglions are crowded with nerve cells, but nerve fibers form a network at the middle portion. The nerve cells in the cortex and medulla of the visceral ganglion and the right parietal ganglion are classified into the following four classes according to their sizes: giant (above 200 ${\mu}{\textrm}{m}$, in diameter), large (60-70 ${\mu}{\textrm}{m}$, in diameter), middle (30-40 ${\mu}{\textrm}{m}$, in diameter) and small (10-15 ${\mu}{\textrm}{m}$, in diameter) nerve cells, respectively. The giant and large nerve cells are rarely found(20-22 eas. in total) while the middle and small nerve cells are found in large quantities (middle: 400-500 eas., small: 700-800 eas.). In the AB/AY double staining, the giant nerve cell is identified as light yellow cells (LYC), while large and middle none cells as dark green cells (DGC) or yellow green cells (YGC), and small nerve cells as yellow cells (YC) or blue cells (BC), The DGC, which reacts positively to somatostatin immunostain reaction, inhibits the secretion of the growth control hormone. The giant and large nerve cells are identified to do the functions of phagocytosis as well as neurosecretion.

• Herbal Formula Science
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• v.7 no.1
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• pp.143-151
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• 1999

To evaluate the neurotoxic effect of oxygen radicals in cultured mouse spinal dorsal root ganglion(DRG) neurons, cytotoxicity was determined by MTT assay after cultured DRG neurons were grown in the media containing various concentrations of glucose oxidase(GO). In addition, neuroprotective effect of herb extract, Epimedium Koreanum Nakai was examined by MTT assay in cultured DRG neurons. Cell viability of cultured DRG neurons was remarkably decreased by GO in dose- and time-dependent manner, and Epimedium Koreanum Nakai protected remarkably GO-induced neurotoxicity in these cultures. From the above results, it is suggested that oxygen radicals is toxic in cultured mouse DRG neurons, and herb extracts such as Epimedium Koreanum Nakai are effective in prevention of the neurotoxicity induced by oxygen radicals in cultured mouse DRG neurons.

• Progress in Medical Physics
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• v.17 no.4
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• pp.260-267
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• 2006

A retinal ganglion cell's receptive field is defined as that region on the retinal surface In which a light stimulus will produce a response. A retinal ganglion cell peers out at a small patch of the visual scene through its receptive field and encodes local features with action potentials that pass through the optic nerve to higher centers. Therefore, defining the receptive field of a retinal ganglion cell is essential to understand the electrical characteristics of a ganglion cell. Distribution of receptive fields over retinal surface provides us an Insight how the retinal ganglion cell processes the visual scene. In this paper, we provide the details how to reconstruct the receptive field of a retinal ganglion cell. We recorded the ganglion cell's action potential with multielectrode array when the random checkerboard stimulus was applied. After classifying the retinal waveform Into ON-cell, OFF-cell, ON/OFF-cell, we reconstructed the receptive field of retinal ganglion cell with Matlab. Here, we show the receptive fields of ON-cell and OFF-cell.

• Applied Microscopy
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• v.39 no.3
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• pp.261-266
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• 2009

This study aim to disclose a possible mechanism for the neuronal cell death induced by peripheral nerve injury following a spinal nerve ligation (SNL) as a neuropathic pain model. Male Sprague-Dawley rats (270~290 g) were used for this study. Pain threshold was evaluated for their response to mechanical (von Frey hairs) stimuli 1, 3, and 7 days after a tight ligation of L5 ventral ramus. In control group, the small ganglion cells were strongly stained with routine toluidine blue (TB), whereas the large ganglion cells showed a little bit weak stainity. Each large ganglion cell is surrounded by perineuronal satellite cells. In experimental groups, small ganglion cells showing apparent degenerative changes increased on 1 day, and showed a peak in degenerative cell number at 3 days group, and decreased gradually at 7 days group. We also found a small number of large-sized ganglion cells showing mild degenerative changes. However their satellite cells ware relatively intact with no typical findings throughout this experiment. Under the electron microscope, small ganglion cells showed various stage and typical features of the dark degeneration including mitochondrial swelling.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.133-139
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• 2007

Although the physiological roles of calretinin have not been established, it may simply work as a calcium buffer or may actively work in calcium-mediated signal transduction. Calretinin plays a little role in the transport and physiological buffering of calcium in the adult photoreceptor cells, bipolar cells and horizontal cells of the human retina. We identified the calretinin-immunoreactive neurons in the inner nuclear cell layer and ganglion cell layer and the distribution pattern of the labeled neurons in the retina of a bat, Rhinolophus ferrumequinum, in this study. We observed the existence of calretinin-immunoreactive AII amacrine cell in the inner nuclear layer and ganglion cells in the ganglion cell layer of bat retina through this study. This observation must be significant along with our previous studies as we need to study for more understanding about the unsolved issue of a bat vision and the unique behavioral aspects of bat flight maneuverability.

• Applied Microscopy
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• v.40 no.1
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• pp.15-19
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• 2010

The present study was designed to demonstrate ionic zinc in the rat DRG by means of zinc selenium autometallography($ZnSe^{AMG}$). Ganglion cells varied in size from 15 to 100 ${\mu}m$. The smaller neurons were strongly stained with AMG, whereas the larger cells were weakly stained. Each large ganglion cell was surrounded by perineuronal satellite cells, showing apparent AMG staining. We demonstrated for the first time the existence of zinc-containing satellite cells in the rodent DRG. Using electron microscopy, fine AMG grains were observed scattered in the somata of the DRG neurons, especially small cells. However, much lower concentrations of the AMG grains occupied in the large cells, and these were mostly localized in lysosome-like organelles. These results indicate that zinc may be involved in sensory transmission in the DRG level.

• Progress in Medical Physics
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• v.16 no.3
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• pp.148-154
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• 2005

Since the output of retina for visual stimulus is carried by neurons of very diverse functional properties, it is not adequate to use conventional single electrode for recording the retinal action potential. For this purpose, we used newly developed multichannel recording system for monitoring the simultaneous electrical activities of many neurons in a functioning piece of retina. Retinal action potentials are recorded with an extra-cellular planar array of 60 microelectrodes. In studying the collective activity of the ganglion cell population it is essential to recognize basic functional distinctions between individual neurons. Therefore, it is necessary to detect and to classify the action potential of each ganglion cell out of mixed signal. We programmed M-files with MATLAB for this sorting process. This processing is mandatory for further analysis, e.g. poststimulus time histogram (PSTH), auto-correlogram, and cross-correlogram. We established MATLAB based protocol for waveform classification and verified that this approach was effective as an initial spike sorting method.