• 대한약리학회지
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• 제32권2호
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• pp.283-292
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• 1996

The spinal dorsal horn is the area where primary afferent fibers terminate and cutaneous sensory information is processed. A number of putative neurotransmitter substances, including excitatory and inhibitory amino acids and peptides, are present in this region. In this study, single neurons of the spinal dorsal horn were acutely isolated and the properties of whole cell current and responses to excitatory and inhibitory neurotransmitters were studied by patch clamp technique. Transverse slice ($(300{\mu}m$) of lumbar spinal cords from young rats$(7{\sim}14\;days)$ were sequentially treated with two pretenses(pronase 0.75 mg/ml and thermolysin 0.75 mg/ml), then single neurons were mechanically dissociated. These neurons showed near-intact morphology such as multipolar, ellipsoidal and bipolar, and pyramidal cells and we recorded the typical whole cell currents of $K^+$, $Ca^{2+}$ and ligand-operated channels from these neurons. Glutamate $(30{\mu}M)$ and N-methyl-D-aspartate(NMDA, $30{\mu}M)$ induced inward currents of $117{\pm}12.4$ pA(n=5) and $49{\pm}6.9$ pA(n=3), respectively. Glycine $(1{\mu}M)$ potentiated glutamate-induced currents $4{\sim}5$ times and NMDA-induced currents $8{\sim}10$ times. In addition, glycine $(30{\mu}M)$ induced Inward current ($31{\pm}6.1$ nA, n=2), which was rapidly desensitized after the peak to a new steady-state level. However, the inward currents induced by ${\gamma}-amino$ butyric acid(GABA, $1{\mu}M$) decreased continuously after the peak($226{\pm}41.6$ pA, n=3) under the similar experimental condition. The ionic currents and pharmacological responses of isolated neurons in this work were similar to those observed in vivo or in vitro spinal cord slice, indicating that acutely isolated neurons could be effectively used for further pharmacological studies.

• 한국동물학회지
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• 제26권2호
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• pp.107-123
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• 1983

The globus pallidus of normal cats were prepared for electron microscopic study following perfusion with a mixture of 1% paraformaldehyde and 1% glutaraldehyde solution. Neurons of two size categories were identified in 1 $\\mu$m araldite sections and their ultrastructural characteristics were studied in adjacent thin section. 1. Large neurons ($30 \\mum \\times 45 \\mum$ in diameter) had extensive areas of rough surfaced endoplasmic reticulm, abundant perinuclear Golgi complex, numerous mitochondria and lipofusin granule, and had a large spherical nucleus with shallow indentation of nuclear manbrane. Small neurons ($17 \\mum \\times 27 \\mum$ in diameter) had poorly rough surfaced endoplasmic reticulum, moderate number of mitochondria and randomly distributed Golgi complex. The nuclear envelope of this cell frequently showed multiple deep invagination. 2. Three types of axo-somatic synapses were identified on the basis of the size and shape of vesicle in the axon terminal and the symmetrical or asymmetrical thickening at the synaptic site. Type I synaptic terminal shows an even distribution of round and oval synaptic vesicles, and has a symmetrical synaptic thickening. Type II axon terminals reveal mostly round and pleomorphic vesicles and a few vesicles were localized near the presynaptic membrane in pale axoplasm and its synaptic thickening were symmetric. Type III axon terminals contain round vesicles, which were aggregated in the axoplasm, and has a asymmetrical synaptic thickening. 3. The majority of axo-somatic contact with the large and small neurons were type I, and type II and III synapes were rare.

• The Korean Journal of Pain
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• 제9권2호
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• pp.326-335
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• 1996

Background: Though a number of studies have described the distribution of substance P(SP)-like immunoreactivity in the spinal cord, they have been focused on lamina I and II of the dorsal horn and there are little morphological studies on the topographic distribution and ultrastructure of the SP immunoreactive neurons especially in the ventral horn of the spinal cord. this study was conducted to identify distribution pattern of SP immunoreactive neurons and to difine the synaptic organization of their processes in ventral horn of the thoracic cord of the cat by preembbeding immunocytochemical method using SP antiserum. Methods: Five adults cats of either sex were used and deeply anesthetized by intramuscular injection of ketamine. After removal of the spinal cord, samples of thoracic cord were taken and placed in fresh fixative at $4^{\circ}C$ for 2 hours. Transverse sections $50{\mu}m$ thick were processed using the preembbeding immunocytochemical method and incubated consecutively in the specific primary antibody and the 10% normal goat serum, the rabbit anti-substance P antiserum, the biotin-labelled goat anti-rabbit IgG and finally the avidin-biotin-peroxidase complex. The processed tissue sections were throughly washed and stained in the black with 1% uranyl acetate. Section were examined on a electron microscope. Results: 1) SP immunoreactive neurons were observed in the gray matter around central canal. 2) In lamina I and II SP immunoreactivity was observed in both myelinated and unmyelinated nerve fibers, but in ventral horn only in the unmyelinated nerve fibers. 3) SP immunoreactive axon terminals with small round and large dense core vesicles made chemical synapses onto the dendrites of motor neurons in the ventral horn. Conclusion: SP immunoreactive neurons might play an important role in modulation of motor neurons in the ventral horn of the thoracic cord of the cat.

• The Korean Journal of Physiology and Pharmacology
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• 제16권5호
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• pp.343-348
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• 2012

Blocking or regulating $K^+$ channels is important for investigating neuronal functions in mammalian brains, because voltage-dependent $K^+$ channels (Kv channels) play roles to regulate membrane excitabilities for synaptic and somatic processings in neurons. Although a number of toxins and chemicals are useful to change gating properties of Kv channels, specific effects of each toxin on a particular Kv subunit have not been sufficiently demonstrated in neurons yet. In this study, we tested electro-physiologically if heteropodatoxin2 ($HpTX_2$), known as one of Kv4-specific toxins, might be effective on various $K^+$ outward currents in CA1 neurons of organotypic hippocampal slices of rats. Using a nucleated-patch technique and a pre-pulse protocol in voltage-clamp mode, total $K^+$ outward currents recorded in the soma of CA1 neurons were separated into two components, transient and sustained currents. The extracellular application of $HpTX_2$ weakly but significantly reduced transient currents. However, when $HpTX_2$ was added to internal solution, the significant reduction of amplitudes were observed in sustained currents but not in transient currents. This indicates the non-specificity of $HpTX_2$ effects on Kv4 family. Compared with the effect of cytosolic 4-AP to block transient currents, it is possible that cytosolic $HpTX_2$ is pharmacologically specific to sustained currents in CA1 neurons. These results suggest that distinctive actions of $HpTX_2$ inside and outside of neurons are very efficient to selectively reduce specific $K^+$ outward currents.

• International journal of advanced smart convergence
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• 제7권4호
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• pp.57-65
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• 2018

Artificial neural network is inspired by the biological neural network. For simplicity, in computer science, it is represented as a set of layers. Many research has been made in evaluating the number of neurons in the hidden layer but still, none was accurate. Several methods are used until now which do not provide the exact formula for calculating the number of thehidden layer as well as the number of neurons in each hidden layer. In this paper model selection approach was presented. Proposed model is based on geographical analysis of decision boundary. Proposed model selection method is useful when we know the distribution of the training data set. To evaluate the performance of the proposed method we compare it to the traditional architecture on IRIS classification problem. According to the experimental result on Iris data proposed method is turned out to be a powerful one.

• KSBB Journal
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• 제18권3호
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• pp.207-210
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• 2003

Locus coeruleus (LC)에는 전체 노르아드레날린성 뉴런의 절반 가량이 모여 있는데, 여기서 노르아드레날린성 뉴런이 뇌의 거의 모든 부위로 신경자극을 보내게 된다. LC는 알츠하이머병, 파킨슨병, 헌팅턴병 같은 여러 가지 신경퇴행성 질환에서 공통적으로 타격을 받는 주요 부위이다. 뇌 유래 신경영양인자, BDNF가 LC 노르아드레날린성 뉴런을 포함한 중추신경계 뉴런들의 분화와 신경세포 생존에 중요한 조절자로 작용한다. 본 연구에서는 LC 노르아드레날린성 신경세포에서 여러 가지 작은 분자들과 성장인자들이 BDNF 생산을 촉진할 수 있는지를 조사하였다. 실험에 사용한 분자들로는 neuropeptides, cytokines, 성장인자, 신경전달물질들과 세포내 신호전달물질들이 포함되었다. 여러 가지 작은 분자들과 성장인자들 중에서 FGF8b, BMP-4, forskolin 그리고 dibutyrl cGMP가 LC 노르아드레날린성 뉴런에서 BDNF 분비를 뚜렷하게 증대시킨 것으로 판명되었다. 특히, BMP-4는 BDNF 생산을 2.5배 이상 증가시켰다. LC 노르아드레날린성 뉴런에서 BDNF를 증가시킨 물질들은 여러 가지 신경퇴행성 질환에서 신경세포가 손실되는 것을 막거나 지연시킬 수 있을 것이므로, 치료제나 증상완화제로서의 가능성이 높다.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2003년도 춘계학술대회
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• pp.52-56
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• 2003

In this paper, We evaluate the learning ability of non-monotonic DBM(Deterministic Boltzmann Machine) network through numerical simulations. The simulation results show that the proposed system has higher performance than monotonic DBM network model. Non-monotonic DBM network also show an interesting result that network itself adjusts the number of hidden layer neurons. DBM network can be realized with fewer components than other neural network models. These results enhance the utilization of non-monotonic neurons in the large scale integration of neuro-chips.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1553-1556
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• 2003

In this paper, We evaluate the learning ability of non-monotonic DBM(Deterministic Boltzmann Machine) network through numerical simulations. The simulation results show that the proposed system has higher performance than monotonic DBM network model. Non-monotonic DBM network also show an interesting result that network itself adjusts the number of hidden layer neurons. DBM network can be realized with fewer components than other neural network models. These results enhance the utilization of non-monotonic neurons in the large scale integration of neuro-chips.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 International Symposium of Silkworm/Insect Biotechnology and Annual Meeting of Korea Society of Sericultural Science
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• pp.99-99
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• 2003

Brain-derived neurotrophic factor (BDNF) induced a significant neurite extension of antennal lobe (AL) neurons from the silk moth Bombyx mori in culture on lamini/ concanavalin A-coated dishes, in comparison with smaller effect of 20-hydroxyecdy-sone (20-HE). But the effect fur neurite extension by 5-hydroxytryptamine (5-HT) could not be found. A significant increase in the number of new primary branches from the principal neurites of AL neurons was also shown in culture with BDNF and 5-HT, but not with 20-HE. (omitted)

• Journal of Biosystems Engineering
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• 제37권4호
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• pp.271-278
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• 2012

Worldwide trends in animal welfare have resulted in an increased interest in individual management of sows housed in groups within hog barns. Estrus detection has been shown to be one of the greatest determinants of sow productivity. Purpose: We conducted this study to develop a method that can automatically detect the estrus state of a sow by selecting optimal texture parameters from images of a sow's pudendum and by optimizing the number of neurons in the hidden layer of an artificial neural network. Methods: Texture parameters were analyzed according to changes in a sow's pudendum in estrus such as mucus secretion and expansion. Of the texture parameters, eight gray level co-occurrence matrix (GLCM) parameters were used for image analysis. The image states were classified into ten grades for each GLCM parameter, and an artificial neural network was formed using the values for each grade as inputs to discriminate the estrus state of sows. The number of hidden layer neurons in the artificial neural network is an important parameter in neural network design. Therefore, we determined the optimal number of hidden layer units using a trial and error method while increasing the number of neurons. Results: Fifteen hidden layers were determined to be optimal for use in the artificial neural network designed in this study. Thirty images of 10 sows were used for learning, and then 30 different images of 10 sows were used for verification. Conclusions: For learning, the back propagation neural network (BPN) algorithm was used to successful estimate six texture parameters (homogeneity, angular second moment, energy, maximum probability, entropy, and GLCM correlation). Based on the verification results, homogeneity was determined to be the most important texture parameter, and resulted in an estrus detection rate of 70%.