• Title/Summary/Keyword: neuron

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Metformin ameliorates olanzapine-induced disturbances in POMC neuron number, axonal projection, and hypothalamic leptin resistance

  • Kim, Jaedeok;Lee, Nayoung;Suh, Sang Bum;Jang, Sooyeon;Kim, Saeha;Kim, Dong-Gyu;Park, Jong Kook;Lee, Keun-Wook;Choi, Soo Young;Lee, Chan Hee
    • BMB Reports
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    • v.55 no.6
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    • pp.293-298
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    • 2022
  • Antipsychotics have been widely accepted as a treatment of choice for psychiatric illnesses such as schizophrenia. While atypical antipsychotics such as aripiprazole are not associated with obesity and diabetes, olanzapine is still widely used based on the anticipation that it is more effective in treating severe schizophrenia than aripiprazole, despite its metabolic side effects. To address metabolic problems, metformin is widely prescribed. Hypothalamic proopiomelanocortin (POMC) neurons have been identified as the main regulator of metabolism and energy expenditure. Although the relation between POMC neurons and metabolic disorders is well established, little is known about the effects of olanzapine and metformin on hypothalamic POMC neurons. In the present study, we investigated the effect of olanzapine and metformin on the hypothalamic POMC neurons in female mice. Olanzapine administration for 5 days significantly decreased Pomc mRNA expression, POMC neuron numbers, POMC projections, and induced leptin resistance before the onset of obesity. It was also observed that coadministration of metformin with olanzapine not only increased POMC neuron numbers and projections but also improved the leptin response of POMC neurons in the olanzapine-treated female mice. These findings suggest that olanzapine-induced hypothalamic POMC neuron abnormality and leptin resistance, which can be ameliorated by metformin administration, are the possible causes of subsequent hyperphagia.

Design of a Digital Neuron Processor Using the Residue Number System (잉여수 체계를 이용한 디지털 뉴론 프로세서의 설계)

  • 윤현식;조원경
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.10
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    • pp.69-76
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    • 1993
  • In this paper we propose a design of a digital neuron processor using the residue number system for efficient matrix.vector multiplication involved in neural processing. Since the residue number system needs no carry propagation for modulus operations, the neuron processor can perform multiplication considerably fast. We also propose a high speed algorithm for computing the sigmoid function using the specially designed look-up table. Our method can be implemented area-effectively using the current technology of digital VLSI and siumlation results positively demonstrate the feasibility of our method. The proposed method would expected to adopt for application field of digital neural network, because it could be realized to currently developed digital VLSI Technology.

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Network of hypothalamic neurons that control appetite

  • Sohn, Jong-Woo
    • BMB Reports
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    • v.48 no.4
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    • pp.229-233
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    • 2015
  • The central nervous system (CNS) controls food intake and energy expenditure via tight coordinations between multiple neuronal populations. Specifically, two distinct neuronal populations exist in the arcuate nucleus of hypothalamus (ARH): the anorexigenic (appetite-suppressing) pro-opiomelanocortin (POMC) neurons and the orexigenic (appetite-increasing) neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons. The coordinated regulation of neuronal circuit involving these neurons is essential in properly maintaining energy balance, and any disturbance therein may result in hyperphagia/obesity or hypophagia/starvation. Thus, adequate knowledge of the POMC and NPY/AgRP neuron physiology is mandatory to understand the pathophysiology of obesity and related metabolic diseases. This review will discuss the history and recent updates on the POMC and NPY/AgRP neuronal circuits, as well as the general anorexigenic and orexigenic circuits in the CNS. [BMB Reports 2015; 48(4): 229-233]

Differential actions of intracerebroventricular (ICV) opioid receptor agonists on the activity of dorsal horn neurons (DHN) in the cat spinal cord

  • 오우택;문태상;하태길;고광호
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.303-303
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    • 1994
  • ICV infusion of morphine (MOR) produces strong analgesia in man and animals. The analgesic effect is thought to be mediated by the centrifugal inhibtory control, But neural mechanisms of the analgesic effect of ICV morphine are not well understood. For example, in the previous studies, ICV morphine does not inhibit nociceptive transmission in the spinal cord. On the contrary, ICV MOR often excites activity of dorsal horn neuron in the spinal cord. In the present study, we found that ICV MOR had dust actions on activity of dorsal horn neuron that it produced both inhibition and excitation of dorsal horn neurons. Since MOR exerts i Is action via three different types of opioid receptors, we further sought to investigate if there are differential effects of opioid receptor agonists on dorsal horn neurons when administered ICV.

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A Study on Adaptive Filter Bank using Neural Networks in Time Domain (신경망을 이용한 적응 다중 대역 필터 설계)

  • 이건기;이주원;김광열;방만식;이병로;김영일
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.4
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    • pp.673-677
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    • 2003
  • In this study, we propose the new filter bank that is adaptive filter bank using neural networks in time domain. Also, we proposed a new filter neuron as neuron with filter window, the structure and algorithm for filter banks. The performance of neural filter banks is shown from two examples. It show characteristics the simple structure and higher speed processing than traditional methods (filter banks in frequency domain, etc.). In many applications, the proposed method will provide the high performance to features detection of signals in time domain.

Neuron-on-a-Chip technology: Microelectrode Array System and Neuronal Patterning (뉴런온칩 기술: 미세전극칩시스템과 신경세포 패터닝 기술)

  • Nam, Yoon-Key
    • Journal of Biomedical Engineering Research
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    • v.30 no.2
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    • pp.103-112
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    • 2009
  • Neuron-on-a-Chip technology is based on advanced neuronal culture technique, surface micropatterning, microelectrode array technology, and multi-dimensional data analysis techniques. The combination of these techniques allowed us to design and analyze live biological neural networks in vitro using real neurons. In this review article, two underlying technologies are reviewed: Microelectrode array technology and Neuronal patterning technology. There are new opportunities in the fusion of these technologies to apply them in neurobiology, neuroscience, neural prostheses, and cell-based biosensor areas.

Motor Neuron Disease and Stem Cell Approach for Its Remediation

  • Kim, Jong Deog;Bhardwaj, Jyoti;Chaudhary, Narendra;Seo, Hyo Jin
    • KSBB Journal
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    • v.28 no.5
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    • pp.269-274
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    • 2013
  • Motor neuron disease (MND) is a fatal neurodegenerative disorder caused by progressive and selective degeneration of motor neurons (MNs). Because of the versatile nature, stem cells have the potential to repair or replace the degenerated cells. In this review, we discussed stem cell based therapies including the use of embryonic stem cells (ESCs), neural stem cells (NSCs), induced pluripotent stem cells (iPSCs) and genetically engineered cells to produce the neurotrophic factors for the treatment of MND. To achieve this goal, the knowledge of specificity of the cell target, homing and special markers are required.

Competitive Learning Neural Network with Dynamic Output Neuron Generation (동적으로 출력 뉴런을 생성하는 경쟁 학습 신경회로망)

  • 김종완;안제성;김종상;이흥호;조성원
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.9
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    • pp.133-141
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    • 1994
  • Conventional competitive learning algorithms compute the Euclidien distance to determine the winner neuron out of all predetermined output neurons. In such cases, there is a drawback that the performence of the learning algorithm depends on the initial reference(=weight) vectors. In this paper, we propose a new competitive learning algorithm that dynamically generates output neurons. The proposed method generates output neurons by dynamically changing the class thresholds for all output neurons. We compute the similarity between the input vector and the reference vector of each output neuron generated. If the two are similar, the reference vector is adjusted to make it still more like the input vector. Otherwise, the input vector is designated as the reference vector of a new outputneuron. Since the reference vectors of output neurons are dynamically assigned according to input pattern distribution, the proposed method gets around the phenomenon that learning is early determined due to redundant output neurons. Experiments using speech data have shown the proposed method to be superior to existint methods.

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