• 제목/요약/키워드: Nerve fiber

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Near-Infrared Laser Stimulation of the Auditory Nerve in Guinea Pigs

  • Guan, Tian;Wang, Jian;Yang, Muqun;Zhu, Kai;Wang, Yong;Nie, Guohui
    • Journal of the Optical Society of Korea
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    • v.20 no.2
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    • pp.269-275
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    • 2016
  • This study has investigated the feasibility of 980-nm low-energy pulsed near-infrared laser stimulation to evoke auditory responses, as well as the effects of radiant exposure and pulse duration on auditory responses. In the experiments, a hole was drilled in the basal turn of the cochlea in guinea pigs. An optical fiber with a 980-nm pulsed infrared laser was inserted into the hole, orientating the spiral ganglion cells in the cochlea. To model deafness, the tympanic membrane was mechanically damaged. Acoustically evoked compound action potentials (ACAPs) were recorded before and after deafness, and optically evoked compound action potentials (OCAPs) were recorded after deafness. Similar spatial selectivity between optical and acoustical stimulation was found. In addition, OCAP amplitudes increased with radiant exposure, indicating a photothermal mechanism induced by optical stimulation. Furthermore, at a fixed radiant exposure, OCAP amplitudes decreased as pulse duration increased, suggesting that optical stimulation might be governed by the time duration over which the energy is delivered. Thus, the current experiments have demonstrated that a 980-nm pulsed near-infrared laser with low energy can evoke auditory neural responses similar to those evoked by acoustical stimulation. This approach could be used to develop optical cochlear implants.

Heat Acclimatization in Hot Summer for Ten Weeks Suppress the Sensitivity of Sweating in Response to Iontophoretically-administered Acetylcholine

  • Lee, Jeong-Beom
    • The Korean Journal of Physiology and Pharmacology
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    • v.12 no.6
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    • pp.349-355
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    • 2008
  • To determine the peripheral mechanisms involved in thermal sweating during the hot summers in July before acclimatization and after acclimatization in September, we evaluated the sweating response of healthy subjects (n=10) to acetylcholine (ACh), a primary neurotransmitter involved in peripheral sudomotor sensitivity. The quantitative sudomotor axon reflex test (QSART) measures sympathetic C fiber function after iontophoresed ACh evokes a measurable reliable sweat response. The QSART, at 2 mA for 5 min with 10% ACh, was applied to determine the directly activated (DIR) and axon reflex-mediated (AXR) sweating responses during ACh iontophoresis. The AXR sweat onset-time by the axon reflex was $1.50{\pm}0.32$ min and $1.84{\pm}0.46$ min before acclimatization in July and after acclimatization in September, respectively (p<0.01). The sweat volume of the AXR(l) [during 5 min 10% iontophoresis] by the axon reflex was $1.45{\pm}0.53\;mg/cm^2$ and $0.98{\pm}0.24\;mg/cm^2$ before acclimatization in July and after acclimatization in September, respectively (p<0.001). The sweat volume of the AXR(2) [during 5 min post-iontophoresis] by the axon reflex was $2.06{\pm}0.24\;mg/cm^2$ and $1.39{\pm}0.32\;mg/cm^2$ before and after acclimatization in July and September, respectively (p<0.001). The sweat volume of the DIR was $5.88{\pm}1.33\;mg/cm^2$ and $4.98{\pm}0.94\;mg/cm^2$ before and after acclimatization in July and September, respectively (p<0.01). These findings suggest that lower peripheral sudomotor responses of the ACh receptors are indicative of a blunted sympathetic nerve response to ACh during exposure to hot summer weather conditions.

A Clinical and Electrophysiologic Study of Carpal Tunnel Syndrome (수근관 증후군의 임상 및 전기신경생리 소견)

  • Baek Su-Jeong;Kim Dong-Hyun;Kim Jin-Sang
    • The Journal of Korean Physical Therapy
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    • v.14 no.4
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    • pp.266-273
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    • 2002
  • Carpal Tunnel Syndrome(CTS) is a common entrapment neuropathy of the median nerve at the wrist. An Electrophysiologic study has been widely used for the diagnosis of carpal tunnel syndrome. The subjects of this study were 48 cases (88 hands) with clinically suspected carpal tunnel syndrome who underwent electrodiagnostic examination from Jan 1, 2001 to Sep 30, 2001, The results were as follows: 1. Among 48 persons with a clinically suspected carpal tunnel syndrome, 40 patients were female 83.33$\%$ and the patients who are above 60 years old were 37.50$\%$. 2. Electrodiagnostic results were 22 cases (45.84$\%$) with bilateral carpal tunnel syndrome and 10 cases (20.83$\%$) with normal. 3. Physical findings consisted of tingling sensation in 48.86$\%$ of the involved hands, positive Phalen's Sign in 20.46$\%$ of them, thenar atrophy in 15.91$\%$ of them, and weakness in 14.77$\%$ of them. 4. Electrophysiologic studies showed a decreased sensory conduction velocity in 20 cases (22.73$\%$) of total hands, a prolonged latency in 3 cases (3.41$\%$) of them, abnormal sensory and motor fiber in 33 cases (37.50$\%$) of them, and normal in 27 cases (30.68$\%$) of them. Considering above results, we had better make a diagnosis precisely the patients with clinically suspected carpal tunnel syndrome through subjective symtoms, physical examinations, and electrophysiologic studies.

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Cimicifugoside Inhibits Catecholamine secretion by blocking Nicotinic Acetylcholine Receptor in Bovine Adrenal Chromaffin cell.

  • Woo, Kyung-Chul;Park, Yong-Su;Suh, Byung-Sun;Kim, Kyong-Tai
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.51-51
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    • 2003
  • The medicinal plant Cimicifuga Racemosa (Black cohosh) has been used to treat many kinds of neuronal and menopausal symptoms, such as arthritis, menopausal depression, nerve pain, etc. Here, we examined the effect of Cimicifugoside (CF), one of triterpene glycosides which have been known as pharmacologically active ingredients of C. Racemosa, on nicotinic acetylcholine receptor (nAChR)-mediated catecholamine (CA) secretion in bovine adrenal chromaffin cell. Cimicifugoside inhibited calcium increase induced by 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP), a nAChR agonist with a half maximal inhibitory concentration (IC50) of 18${\pm}$2${\mu}$M. In contrast, cimicifugoside did not affect the calcium increases evoked by high K$\^$+/, veratridine, and bradykinin. The DMPP-induced sodium increase was also inhibited by cimicifugoside with IC50 of 2${\pm}$0.3${\mu}$M, suggesting that the activity of nAChRs is inhibited by cimicifugoside. Cimicifugoside did not effect on the KCl-induced secretion but markedly inhibited the DMPP-induced catecholamine secretion which was monitored by carbon-fiber amperometry in real time, and by high performance liquid chromatography (HPLC) through electrochemical detection. The results suggest that cimicifugoside selectively inhibits nAChR-mediated response in bovine chromaffin cells.

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Ultrastructure of Substance P Immunopositive Axons in the Human Dental Pulp

  • Moon, Byung Hee;Ha, Jung Hong;Han, Hye Min;Kim, Tae Heon;Park, Sook Kyung;Bae, Yong Chul
    • International Journal of Oral Biology
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    • v.43 no.3
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    • pp.155-160
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    • 2018
  • There exists very little information on the ultrastructure of substance P immunopositive (+) fibers in the human dental pulp, which may help in understanding the mechanism for substance P associated pulpal inflammatory pain. To address this issue, we investigated the presence of substance P+ fibers in the human dental pulp by light- and electron-microscopic immunohistochemistry. Light microscopy revealed that substance P+ fibers ran within neurovascular bundles in the radicular pulp and in the core of coronal pulp. They were also frequently present in the peripheral pulp. Substance P+ fibers showed beads like swellings interconnected by thin axonal strand, in a manner similar to bouton en passants and interconnecting axonal strand in the spinal cord. Electron microscopy revealed that almost all the substance P+ axons were unmyelinated. The axonal swellings of the substance P+ contained numerous clear round vesicles (40-50 nm in diameter) and many large dense-cored vesicles (80-110 nm in diameter) as well as many mitochondria. The vesicles and mitochondria were rarely observed in the thin axonal strand interconnecting the swellings. Intimate interrelationship or synaptic structure between the swellings of substance P+ axon and nearby pulpal cells or axons was not found. These findings suggest co-release of substance P and glutamate from the substance P+ pulpal axons and its action on nearby structures in a paracrine manner.

Neonatal influenza virus infection affects myelination in influenza-recovered mouse brain

  • Kim, Jin Hee;Yu, Ji Eun;Chang, Byung-Joon;Nahm, Sang-Soep
    • Journal of Veterinary Science
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    • v.19 no.6
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    • pp.750-758
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    • 2018
  • Influenza virus infection is a zoonosis that has great socioeconomic effects worldwide. Influenza infection induces respiratory symptoms, while the influenza virus can infect brain and leave central nervous system sequelae. As children are more vulnerable to infection, they are at risk of long-term neurological effects once their brains are infected. We previously demonstrated that functional changes in hippocampal neurons were observed in mice recovered from neonatal influenza infection. In this study, we investigated changes in myelination properties that could affect neural dysfunction. Mice were infected with the influenza virus on postnatal day 5. Tissues were harvested from recovered mice 21-days post-infection. The expression levels for myelin basic protein (MBP) were determined, and immunohistochemical staining and transmission electron microscopy were performed. Real-time polymerase chain reaction and Western blot analyses showed that mRNA and protein expressions increased in the hippocampus and cerebellum of recovered mice. Increased MBP-staining signal was observed in the recovered mouse brain. By calculating the relative thickness of myelin sheath in relation to nerve fiber diameter (G-ratio) from electron photomicrographs, an increased G-ratio was observed in both the hippocampus and cerebellum of recovered mice. Influenza infection in oligodendrocyte-enriched primary brain cell cultures showed that proinflammatory cytokines may induce MBP upregulation. These results suggested that increased MBP expression could be a compensatory change related to hypomyelination, which may underlie neural dysfunction in recovered mice. In summary, the present results demonstrate that influenza infection during the neonatal period affects myelination and further induces functional changes in influenza-recovered mouse brain.

Effect of Massages on The Skeletal Muscles of Sciatic Nerve Neurectomized ddY Mice (마사지가 좌골신경 절단 마우스의 골격근에 미치는 영향)

  • Kim Chul-Yong;Kim Seong-Hak;Park sang-Ock;Bae Sung-Soo;Park Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.15 no.2
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    • pp.19-51
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    • 2003
  • To demonstrate the effect of massages on the skeletal muscles of immobilization ddY mice models induced by right side sciatic nerve neurectomy, the cross sectional histological profiles of the muscularis (M) gastrocnemius, M. tibialis cranialis and M. tibialis caudalis were observed after 28 days of treatment of massages with the changes of body weight, thickness of hind limb and individual muscle weights. In addition, changes of serum aspartate amino- transferase (AST) and creatine phosphokinase (CK) levels were also demonstrated with diameter of individual muscle fiber and muscle fasciculata, and number of muscle fiber in each of three types of muscles located in the calf. The experimental groups were divided into five groups, 1) Sham-operated group (Sham), 2) Neurectomized but not massage control group (Control), 3) Neurectomized and massage at knee joint regions (T1), 4) Neurectomized and massage at calf regions (T2), and 5) Neurectomized and massages at achilles tendon regions (T3). The experimental animals were used 5 per groups. The results are as follow: 1. No significant changes of body weight were demonstrated in this groups during whole experimental periods compared to that of Sham group. In addition, no significant changes of body weight gains during experimental periods (Day 0 - Day 27: 28 days of treatment) were also observed. 2. The thickness of intact left side hind limb was not changes in all tested groups compared to that of Sham group. However, the thickness of right side hind limb were remarkedly decreased in Control, T1, T2 and T3 groups compared to that of Sham group. In addition, the differences of thickness of hind limb between right and left sides were also significantly increased in Control and massage groups (T1, T2 and T3) compared to that of Sham group. However, the thickness of right side of hind limb were significantly increased and the differences of thickness between both sides of hind limb were dramatically decreased in massage groups compared to that of Control group in followed order: T1 > T3 > T2. 3. Absolute and relative weight of M. gastrocnemius in the intact left side of hind limb was not changes in all tested groups compared to that of Sham group. However, the weight of right side M. gastrocnemius were remarkedly decreased in Control, T1, T2 and T3 groups compared to that of Sham group. In addition, the differences of weight of M. gastrocnemius between right and left sides were also significantly increased in Control and massage groups compared to that of Sham group. However, the weight of right side M. gastrocnemius were significantly increased and the differences of weight between both sides of M. gastrocnemius were dramatically decreased in massage groups compared to that of Control group in followed order: T3 > T1 >. 4. Absolute and relative weight of M. tibialis cranialis in the intact left side was not changes in all tested groups compared to that of Sham group. However, the weight of right side M. tibialis cranialis were remarkedly decreased in Control, T1, T2 and T3 groups compared to that of Sham group. In addition, the differences of weight of M. tibialis cranialis between right and left sides were also significantly increased in Control and massage groups compared to that of Sham group. However, the weight of right side M. tibialis cranialis were significantly increased and . the differences of weight between both sides of M. tibialis cranialis were dramatically decreased in massage groups compared to that of Control group in followed order: T3 > T1 > T2. 5. Absolute and relative weight of M. tibialis caudalis in the intact left side was not changes in all tested groups compared to that of Sham group. However, the weight of right side M. tibialis caudalis were remarkedly decreased in Control, T1, T2 and T3 groups compared to that of Sham group. In addition, the differences of weight of M. tibialis caudalis between right and left sides were also significantly increased in Control and massage groups compared to that of Sham group. However, the weight of right side M. tibialis caudalis were significantly increased and the differences of weight between both sides of M. tibialis caudalis were dramatically decreased in massage groups compared to that of Control group in followed order: T3 > T1 > T2. 6. A significant increase of serum AST levels were demonstrated in Control group. However, serum AST levels of massage groups were significantly decreased compared to that of Control group in followed order: T3 > T1 > T2. In case of 73 group, the values decreased into similar levels compared to that of Sham group. 7. A significant increase of serum CK levels were demonstrated in Control group. However, serum CK levels of massage groups were significantly decreased compared to that of Control group in followed order: T3 > T1 > T2.

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Enhanced Transdermal Delivery of Procaine Hydrochloride by lontophoresis -Comparison of Synergic Effect of High Voltage Current and Ultrasound- (이온도입에 의한 염산프로카인의 경피전달 증대 -고전압전류 및 초음파 병행의 상승효과 비교-)

  • Lee, Jong-Sook;Kim, Kyoung-Won;Lee, Jae-Hyoung;Choi, Yeong-Wook;Lee, Jae-Hwi
    • Journal of Pharmaceutical Investigation
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    • v.36 no.3
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    • pp.185-192
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    • 2006
  • The purpose of this study was to determine the effects of iontophoresis on transdermal delivery of procaine hydrochloride in healthy volunteers, as well as to the synergic effect of high voltage current or ultrasound on the efficacy of transdermal delivery of iontophoresis. Forty healthy volunteers were randomly assigned to four groups topical application group (TA), iontophoresis group (IT), pre-treatment of high voltage current stimulation with iontophoresis (HVS + IT), and pre-treatment of ultrasound application with iontophoresis (US + IT). All subjects received procaine iontophoresis on the forearm using direct current with 4 mA f3r 15 minutes. All subject was measured the duration of local anesthesia, pressure pain threshold, pain perception threshold using rectangular wave at 0.2 ms, 1 ms, 50 ms of rectangular current stimulation after procaine iontophoresis. For comparisons of the sensory characteristics and efficacy of iontophoresis between the groups, an one-way ANOVA and Kruskal-Wallis were used. The significant difference the duration of local anesthesia were found between the groups (p<0.001). The local anesthetic duration of IT, HVS+IT were significantly longer than TA. Meanwhile, the local anesthetic duration of US+IT was significantly longer than HVS+IT, IT and TA group (p<0.05). Also, the pressure pain threshold, pain perception threshold at 0.2 ms, 1 ms, 50 ms were significant difference between the groups (p<0.001). All sensory characteristics including pressure pain threshold, pain perception threshold of IT, HVS+IT was significantly increased than TA, whereas, US+1T was significantly increased HVS+1T, IT and TA (p<0.05). This study showed that the procaine iontophoresis have increase the duration of local anesthesia concomitantly pressure pain threshold and pain perception threshold of sensory nerve fibers such as $A-{\beta}$, $A-{\delta}$ and C fiber. This findings suggest that the iontophoresis enhanced the transdermal delivery of drug ions in vivo. The combination of ultrasound application and iontophoresis synergized the transdermal delivery of drug ions. It is suggests that an electric field, mechanical and heating property of ultrasound may contribute to synergic effect due to temporary changes of structure in the stratum corneum.

Distribution of Parvalbumin-Immunoreactive Retinal Ganglion Cells in the Greater Horseshoe Bat, Rhinolophus ferrumequinum (한국관박쥐 망막에서 파브알부민 면역반응성 망막신경절세포의 분포 양상)

  • Jeon, Young-Ki;Kim, Tae-Jin;Lee, Eun-Shil;Joo, Young-Rak;Jeon, Chang-Jin
    • Journal of Life Science
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    • v.17 no.8 s.88
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    • pp.1068-1074
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    • 2007
  • Parvalbumin occurs in various types of cells in the retina. We previously reported parvalbumin distribution in the inner nuclear layer of bat retina. In the present study, we identified the parvalbumin-immunoreactive neurons in the ganglion cell layer of the retina of a bat, Rhinolophus ferrumequinum, and investigated the distribution pattern of the labeled neurons. Parvalbumin immunoreactivity was found in numerous cell bodies in the ganglion cell layer. Quantitative analysis showed that these cells had medium to large-sized somas. The soma diameter of the parvalbumin-immunoreactive cells in the ganglion cell layer ranged from 12.35 to 19.12 ${\mu}m$ (n=166). As the fibers in the nerve fiber layer were also stained, the majority of parvalbumin-immunoreactive cells in the ganglion cell layer should be medium to large-sized retinal ganglion cells. The mean nearest neighbor distance of the parvalbumin-immunoreactive cells in the ganglion cell layer of the bat retina ranged from 59.57 to 62.45 ${\mu}m$ and the average regularity index was 2.95 ${\pm}$ 0.3 (n=4). The present results demonstrate that parvalbu-min is expressed in medium to large-sized retinal ganglion cells in bat retina, and they have a well-or-ganized distributional pattern with regular mosaics. These results should be important as they are applicable to a better understanding of the unsolved issue of a bat vision. This data will help to provide fundamental knowledge for the better understanding of the unique behavioral aspects of bat flight maneuverability.

Early Growth and Development of Eye in Dotted Gizzard Shad, Konosirus punctatus (전어, Konosirus punctatus의 초기 성장 및 눈 발달)

  • Park, In-Seok;Im, Soo-Yeon;Seol, Dong-Won;Lee, Jin-Hwan;Hur, Jun-Wook;Jeong, Gwan-Sik
    • Development and Reproduction
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    • v.10 no.2
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    • pp.93-96
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    • 2006
  • The total length, head length, head height, eye diameter, retina thickness, and lens diameter of the dotted gizzard shad, Konosirus punctatus, showed positive allometric relationships between hatching and 30 days post-hatching (dph). The increase in total length relative to head length and head height, head length growth relative to eye and lens diameter, head height growth relative to eye diameter and lens diameter, and thickness of the retina relative to eye diameter, lens diameter, head length, and head height were showed allometric relationships. The eyes were formed completely at 9 dph. At this age, the eye has a lens, an optic nerve fiber layer, a ganglion cell layer, an inner plexiform layer, an inner nuclear layer, an outer plexiform layer, an outer nuclear layer, an outer limiting membrane, a rod and cone layer, and an epithelial layer. The essential demands that must be met by the retina in this species pertain to light sensitivity and spatial resolution.

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