• Title/Summary/Keyword: nerve fiber

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Effects of Morphine on Somatosyrnpathetic Reflex and Arterial Blood Pressure Response Evoked by Stimulation of Peripheral Nerves

  • Huh, Min-Gang;Yan, Hai-Dun;Lim, Won-Il;Kim, Jun
    • The Korean Journal of Physiology
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    • v.29 no.2
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    • pp.309-321
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    • 1995
  • In the present study, the relationship between the somatosympathetic reflexes and arterial blood pressure responses to electrical stimulation of the peripheral nerve was investigated in cats anesthetized with ${\alpha}-chloralose$. Single sympathetic postganglionic fiber activities were recorded from the hindlimb muscle and skin nerves and also from the cervical and abdominal sympathetic chains. Effects of the morphine on responses of the sympathetic nerve and arterial blood pressure to activation of the peripheral $A{\delta}-$ and C-afferent nerves were analyzed. The following results were obtained. 1) Arterial blood pressure was depressed by peripheral AS-afferent stimulation (A-response) and was elevated during C-afferent activation (C-response). 2) Intravenously administered morphine enhanced the C-response while the A-response decreased insignificantly, Only the C-response was decreased by intrathecal morphine. 3) All the ten recorded cutaneous sympathetic fibers showed periodic discharge pattern similar to respiratory rhythm and five of them also showed cardiac-related rhythm. However, most of the muscular sympathetic fibers had cardiac-related rhythm and only four fibers showed respiratory rhythm. 4) Morphine decreased the sympathetic C-reflex elicited by the peripheral C-afferent activation and the abdominal sympathetic A-reflex was also decreased by morphine. From the above results, it was concluded that supraspinal mechanisms were involved in the enhanced arterial pressor response to peripheral C-afferent activation by intravenous morphine.

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Distribution of the neuropeptide Y immunoreactive neurons in the olfactory bulb of striped field mouse(Apodemus agrarius) (야생등줄쥐(Apodemus agrarius) 후각망울의 neuropeptide Y 면역반응세포의 분포)

  • Jeong, Young-gil;Kim, Kil-soo;Jung, Ju-young;Lee, Nam-seob;Lee, Kyeng-youl;Kim, Moo-kang
    • Korean Journal of Veterinary Research
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    • v.39 no.3
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    • pp.407-416
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    • 1999
  • This study was carried out to investigate the NPY-immunohistochemical characteristics of the olfactory bulb in the striped field mouse(Apodemus agrarius). The animals were anesthesized with thiopental sodium and perfused with 4% paraformaldehyde through left ventricle and aorta. Brains were removed and tranfered 10%, 20% and 30% sucrose. Sections were then cut on a cryostat into $40{\mu}m$-thick. The tissue immunostained with avidin-biotinylated complex method. The main olfactory bulb consisted of seven circumferential laminae : an olfactory nerve fiber layer, a glomerular layer with glomeruli surrounding by periglomerular cells, an external plexiform layer having granule and tufted cells, a mitral cell layer, a narrow internal plexiform layer, a granule cell layer forming several cell rows and a layer of white matter. The accessory olfactory bulb had four layers : an olfactory or vomeronasal nerve fiber layer, a glomerular layer consisting of small glomeruli, a mixed layer not distinguishing the external plexiform/mitral cell/granule cell layers and a granule cell layer. Most of NPY-immunoreactive(NPY-IR) neurons in main olfactory bulb were localized in the deeper portion of granule cell layer, white matter and anterior olfactory nucleus. In addition, some NPY-IR neurons were identified in the external plexiform layer. The shape of NPY-IR neurons of all olfactory bulb were predominant round or oval, sometime multipolar in shape. And most NPY-IR processes were parallel to long axis of white matter. In accessory olfactory bulb, NPY-IR neurons were not found in all region.

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Classification of Fiber Tracts Changed by Nerve Injury and Electrical Brain Stimulation Using Machine Learning Algorithm in the Rat Brain (신경 손상과 전기 뇌 자극에 의한 흰쥐의 뇌 섬유 경로 변화에 대한 기계학습 판별)

  • Sohn, Jin-Hun;Eum, Young-Ji;Cheong, Chaejoon;Cha, Myeounghoon;Lee, Bae Hwan
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2021.07a
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    • pp.701-702
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    • 2021
  • The purpose of the study was to identify fiber changes induced by electrical stimulation of a certain neural substrate in the rat brain. In the stimulation group, the peripheral nerve was injured and the brain area associated to inhibit sensory information was electrically stimulated. There were sham and sham stimulation groups as controls. Then high-field diffusion tensor imaging (DTI) was acquired. 35 features were taken from the DTI measures from 7 different brain pathways. To compare the efficacy of the classification for 3 animal groups, the linear regression analysis (LDA) and the machine learning technique (MLP) were applied. It was found that the testing accuracy by MLP was about 77%, but that of accuracy by LDA was much higher than MLP. In conclusion, machine learning algorithm could be used to identify and predict the changes of the brain white matter in some situations. The limits of this study will be discussed.

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Effects of Somatostatin on the Responses of Rostrally Projecting Spinal Dorsal Horn Neurons to Noxious Stimuli in Cats

  • Jung, Sung-Jun;Jo, Su-Hyun;Lee, Sang-Hyuck;Oh, Eun-Hui;Kim, Min-Seok;Nam, Woo-Dong;Oh, Seog-Bae
    • The Korean Journal of Physiology and Pharmacology
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    • v.12 no.5
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    • pp.253-258
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    • 2008
  • Somatostatin (SOM) is a widely distributed peptide in the central nervous system and exerts a variety of hormonal and neural actions. Although SOM is assumed to play an important role in spinal nociceptive processing, its exact function remains unclear. In fact, earlier pharmacological studies have provided results that support either a facilitatory or inhibitory role for SOM in nociception. In the current study, the effects of SOM were investigated using anesthetized cats. Specifically, the responses of rostrally projecting spinal dorsal horn neurons (RPSDH neurons) to different kinds of noxious stimuli (i.e., heat, mechanical and cold stimuli) and to the $A{\delta}$ -and C-fiber activation of the sciatic nerve were studied. Iontophoretically applied SOM suppressed the responses of RPSDH neurons to noxious heat and mechanical stimuli as well as to C-fiber activation. Conversely, it enhanced these responses to noxious cold stimulus and $A{\delta}$-fiber activation. In addition, SOM suppressed glutamate-evoked activities of RPSDH neurons. The effects of SOM were blocked by the SOM receptor antagonist cyclo-SOM. These findings suggest that SOM has a dual effect on the activities of RPSDH neurons; that is, facilitation and inhibition, depending on the modality of pain signaled through them and its action site.

The Effect of Laser Irridation on the Ultrastructure of Retina (Laser 조사가 망막의 미세구조에 미치는 영향)

  • Kim, Douk Hoon;Mun, Jung Hak
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.1
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    • pp.15-22
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    • 1996
  • The fine structure of retinal tissue was studied to investigate on effect of Laser irridation on the ICR mouse with electron microscope. The results obtained were as follows: 1. At the normal groups, the most retinal layers were a complex structure, consisting of several specific cells and nerve fiver. 2. In the increasing time of Laser irridation, each cell layer of retina was not uniform of the structure and band. The visual cells were severely heterochromatin swelling of cytoplasm, irregular shape & heterochromatin of nuclear, and disappear of some cytoplasm. The nucleus and nerve fiber of retinal layer was a very irregular shape, formation of vesicle, not identify of each intercellular boundary. The pigment epithelial cells were not an uniform, a large vesicle formation of cytoplasm, and a condensation & very irregular shape of nucleus.

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Study on Electric Stimulus Pattern in Cochlear Implant Using a Computer Model (신경모델링을 이용한 인공와우 전기자극 패턴 연구)

  • Yang, Hyejin;Woo, Jihwan
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.12
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    • pp.249-255
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    • 2012
  • A cochlear implant system uses charge-balanced biphasic pulses that are known to reduce tissue damage than monophasic pulses. In this study, we investigated effect of pulse pattern on neural responses using a computer model, based on the Hodgkin-Huxley equation. Electric pulse phase, pulse duration, and phase gap have been systematically varied to characterize auditory nerve responses. The results show that neural responses, dynamic range and threshold are represented as a function of stimulus patterns and duration. The results could greatly extend to develop more efficient cochlear implant stimulation.

Measurements of Temperature Characteristics of The Lung Inflation and Deflation Reflexes Using Automated Vagal Cooling System in Anesthetized Dogs (자동신경 냉각장치를 이용한 흡식반사와 호식반사의 온도특성 측정)

  • 송영진;차은종
    • Journal of Biomedical Engineering Research
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    • v.12 no.3
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    • pp.177-184
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    • 1991
  • Characteristics of the lung inflation and deflation reflexes were measured at various temperatrues on the cervical vagi in five anesthetized mongrel dogs. Nerve temperature was maintained at the body temperature, and $2-14^{\circ}C$ with $2^{\circ}C$ apart using a specially designed automated vagal cooling apparatus with an accuracy to within ${\pm}0.1^{\circ}C$ at each temperature. The inflation reflex was blocked abruptly at $8-10^{\circ}C$. The deflation reflex started weakened at $14^{\circ}C$, thereafter showed a gradual blockade with the temperature decreased with a substantial variance among the animals. It was approximately 75% blocked at $2-6^{\circ}C$. These differences in temperature characteristics made it hard to differentiate the deflation reflex from the inflation reflex. In one animal, however, the inflation reflex was completely blocked with the deflation reflex almost alive at $6-8^{\circ}C$. This suegests that differential cold blockade of the vagal reflexes can be done only in selected subjects. Fur- thermore, the fact that these two reflexes were blocked at different temperatures may be due to the differences in the nerve fiber size and the changes in the conduction velocity with temperature.

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Analysis of Fractional Anisotropy Measurements of Diffusion Tensor Images in the Gyrus of the Brain by AUDIT-K Scale (AUDIT-K 척도에 따른 뇌 이랑 부위의 확산텐서 비등방도 측정값 분석)

  • Kwak, Jong-Hyeok;Kim, Gyeong-Rip;Cho, Hee-Jung;Lee, Eun-Sook;Sung, Soon-Ki
    • The Journal of the Korea Contents Association
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    • v.19 no.7
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    • pp.176-185
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    • 2019
  • Diffusion tensor images were obtained for middle-aged men according to the AUDIT-K scale. As a result of the fractional anisotropy (FA) value of the gyrus nerve fibers in the brain region measured and analyzed by the Tract-Based Spatial Statics, FA values of general drinkers were measured lower than those of estimated alcohol use disabled people. This was statistically significant. In other words, the use of alcohol significantly affects the anatomic microstructural changes measured in the Gyrus of the brain region, and it may damage the nerve fiber tract and affect the functional abnormalities associated with it.

Detecting of Periodic Fasciculations of Avian Muscles Using Magnetic and Other Multimedia Devices

  • Nakajima, Isao;Tanaka, Sachie;Mitsuhashi, Kokuryo;Hata, Jun-ichi;Nakajima, Tomo
    • Journal of Multimedia Information System
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    • v.6 no.4
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    • pp.293-302
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    • 2019
  • In the past, there was a theory that influenza wasn't transmitted directly from birds but was infected to humans via swains. Recently, molecular level research has progressed, and it was confirmed that the avian influenza virus can directly infected to human lung and intestinal epithelial cells. Three pandemicsin the past 100 years were also infected to humans directly from birds. In view of such scientific background, we are developing a method for screening sick birds by monitoring the physiological characteristics of birds in a contactless manner with sensors. Here, the movement of respiratory muscles and abdominal muscles under autonomic innervation was monitored using a magnet and Hall sensor sewn on the thoracic wall, and other multimedia devices. This paper presents and discusses the results of experiments involving continuous periodic noise discovered during flight experiments with a data logger mounted on a Japanese pheasant from 2012 to 2015. A brief summary is given as the below: 1. Magnet and Hall sensor sewn to the left and right chest walls, bipolar electrocardiograms between the thoracic walls, posterior thoracic air sac pressure, angular velocity sensors sewn on the back and hips, and optical reflection of LEDs (blue and green) from the skin of the hips allow observation of periodic vibrations(fasciculations) in the waves. No such analysis has been reported before. 2. These fasciculations are presumed to be derived from muscle to maintain and control air sac pressure. 3. Since each muscle fiber is spatially Gaussian distributed from the sympathetic nerve, the envelope is assumed to plot a Gaussian curve. 4. Since avian trunk muscles contract periodically at all time, we assume that the sympathetic nerve dominates in their control. 5. The technique of sewing a magnet to the thoracic wall and measuring the strength of the magnetic field with a Hall sensor can be applied to screen for early stage of avian influenza, with a sensor attached to the chicken enclosure.