• Journal of Korean Physical Therapy Science
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• v.3 no.1
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• pp.907-918
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• 1996

Evoked potentials(EP) are defined as electric responses of the nerves system to sensory stimulation. EPs are used mainly to test conduction in the visual, auditory, and somatosensory systems, especially in the central parts of these systems. Somatosensory evoked potentials (SEP) are the potentials elicited by stimulation of peripheral nerves and recorded at various sites along the sensory pathway. SEPs types consist mainly of SEPs to electric stimulation of arm or leg nerves. SEPs to arm stimulation are usually recorded simultaneously from clavicular, cervical, and scalp electrodes; SEPs to leg stimulation are recorded from lumbar, low thoracic, and scalp electrodes. Subject variables that have practical impotance are age, limb length, body height, and temperature. General clinical interpretation of abnormal SEPs wave decreases of peripheral conduction time, and abolition of SEPs recorded from different levels to identify lesions of peripheral nerves, plexus, nerve root, spinal cord, cauda equina, hemispheric brainstem, and cerebral parts of the somatosensory pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.6
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• pp.661-670
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• 1998

Dopamine has been generally known to exert antinociceptive action in behavioral pain test, such as tail flick and hot plate test, but there appears to be a great variance in the reports on the antinociceptive effect of dopamine depending on the dosage and route of drug administration and type of animal preparation. In the present study, the effects of dopamine on the responses of wide dynamic range (WDR) cells to mechanical, thermal and graded electrical stimuli were investigated, and the dopamine-induced changes in WDR cell responses were compared between animals with an intact spinal cord and the spinal animals. Spinal application of dopamine (1.3 & 2.6 mM) produced a dose-dependent inhibiton of WDR cell responses to afferent inputs, the pinch-induced or the C-fiber evoked responses being more strongly depressed than the brush-induced or the A-fiber evoked responses. The dopamine-induced inhibition was more pronounced in the spinal cat than in the cat with intact spinal cord. The responses of WDR cell to thermal stimulation were also strongly inhibited. Dopamine $D_2$ receptor antagonist, sulpiride, but not $D_1$ receptor antagonist, significantly blocked the inhibitory action of dopamine on the C-fiber and thermal responses of dorsal horn cells. These findings suggest that dopamine strongly suppresses the responses of WDR cells to afferent signals mainly through spinal dopamine $D_2$ receptors and that spinal dopaminergic processes are under the tonic inhibitory action of the descending supraspinal pathways.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.1
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• pp.9-19
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• 1998

The present study was primarily carried out to characterize the properties of the spinomesencephalic tract (SMT) neurons that project from the upper cervical spinal segments to the midbrain. It was also investigated whether these neurons received convergent afferent inputs from other sources in addition to cervical inputs. Extracellular single unit recordings were made from neurons antidromically activated by stimulation of midbrain. Recording sites were located in lamina $I{\sim}VIII\;of\;C1{\sim}C3$ segments of spinal cord. Receptive field (RF) and response properties to mechanical stimulation were studied in 71 SMT neurons. Response profiles were classified into six groups: complex (Comp, n=9), wide dynamic range (WDR, n=16), low threshold (LT, n=5), high threshold (HT, n=6), deep/tap (Deep, n=10), and non- responsive (NR, n=25). Distributions of stimulation and recording sites were not significantly different between SMT groups classified upon their locations and/or response profiles. Mean conduction velocity of SMT neurons was $16.7{\pm}1.28\;m/sec$. Conduction velocities of SMTs recorded in superficial dorsal horn (SDH, n=15) were significantly slower than those of SMTs recorded in deep dorsal horn (DDH, n=18), lateral reticulated area (LRA, n=21), and intermediate zone and ventral horn (IZ/VH, n=15). Somatic RFs for SMTs in LRA and IZ/VH were significantly larger than those in SDH and DDH. Five SMT units (4 Comps and 1 HT) had inhibitory somatic RFs. About half (25/46) of SMT units have their RFs over trigeminal dermatome. Excitabilities of 5/12 cells and 9/13 cells were modulated by stimulation of ipsilateral phrenic nerve and vagus nerve, respectively. These results suggest that upper cervical SMT neurons are heterogenous in their function by showing a wide range of variety in location within the spinal gray matter, in response profile, and in convergent afferent input.

• Journal of Acupuncture Research
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• v.20 no.3
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• pp.15-23
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• 2003

Objective : The role of high frequency 120 Hz electroacupuncture(EA) in carrageenan-induced pain was studied by examining the alnalgesic effects, and prostaglandin $E_2(PGE_2)$ levels measurement and spinal N-methyl-D-aspartate(NMDA) receptor expression. Inflammation was induced by an intraplantar injection of 1% carrageenan into the right hind paw. Method : Bilateral EA stimulation with 120 Hz were delivered at those acupoints corresponding to Zusanli and Sanyinjiao in man via the needles for a total of 30 min duration in carrageenan-injected rats. Results : EA stimulation showed significant analgesic effects as measured by analgesy-meter at all time points tested compared with controls. Three hours after carrageenan injection, PGE2 levels were measured by commercial kit. EA significantly inhibited PGE2 production in the right paw. The number of NR1 and NR2A, NMDA receptor, immunoreactive neurons was significantly increased in the superficial dorsal horn(laminae I-II) and nucleus proprius(laminae III-IV) of ipsilateral spinal cord at L4-5. But the number of carrageenan-induced NR1 and NR2A immunoreactive neuron, especially NR1 immunoreaction in the superficial dorsal horn, was reduced by 120 Hz EA stimulation. Conclusions : These results indicate that NMDA receptors may mediate transmission of nociceptive information originating in tissue inflammation of hind paw and high frequency 120 Hz EA stimulation have an alleviating action against local inflammatory pain.

• The Korean Journal of Physiology
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• v.24 no.2
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• pp.403-411
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• 1990

The present investigation was performed to see a possible influence of the dorsal raphe nucleus (DRN) on pancreatic exocrine secretion in anesthetized rats since the DRN had been known to exert a regulatory mechanism on sympathetic activity which was known to be very important for pancreatic exocrine secretion, particularly in rats. Twenty-nine Sprague-Dawley rats fasted for 24 hours were anesthetized by i.p. injection of 1 g/kg of urethane. The pancreatic duct was cannulated to collect pancreatic juice while bile juice was diverted into the jejunum. The duodenopyloric junction was tightly ligated. After surgery for collection of pancreatic exocrine secretion and recording of carotid blood pressure, a coaxial electrode was stereotaxically inserted in the DRN with a guide of a brain atlas. And then, electrical stimulus of biphasic square wave with 2 v, 2 msec, 40 Hz was applied on the electrode for 10 minutes. Pancreatic volume flow and protein output secreted in 10 min were measured. Either bilateral cervical vagotomy or spinal cord transection at the level of $C4{\sim}C5$ was performed 20 min prior to stimulation of the DRN. 1) Electrical stimulation of the DRN resulted in significant (p<0.05) increase in pancreatic volume flow and protein output. These stimulatory effects were not affected by cervical vagotomy but completely abolished by cervical cord transection. 2) Electrical stimulation of the DRN also resulted in significant (p<0.05) rise of blood pressure of the carotid artery. The hypertensive effect was not affected by cervical vagotomy but completely abolished by cervical cord transection. The results strongly suggest that the DRN, a part of the central serotonergic system, could exert a stimulatory influence on pancreatic exocrine secretion by increasing the sympathetic activity in anesthetized rats.

• International Journal of Oral Biology
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• v.32 no.4
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• pp.153-160
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• 2007

The superficial dorsal horn, particularly substantia gelatinosa (SG) in the spinal cord, receives inputs from small-diameter primary afferents that predominantly convey noxious sensation. Reactive oxygen species (ROS) are toxic agents that may be involved in various neurodegenerative diseases. Recent studies indicate that ROS are also involved in persistent pain through a spinal mechanism. In the present study, whole cell patch clamp recordings were carried out on SG neurons in spinal cord slice of young rats to investigate the effects of hydrogen peroxide on neuronal excitability and excitatory synaptic transmission. In current clamp condition, tert-buthyl hydroperoxide (t-BuOOH), an ROS donor, depolarized membrane potential of SG neurons and increased the neuronal firing frequencies evoked by depolarizing current pulses. When slices were pretreated with phenyl-N-tert-buthylnitrone (PBN) or ascorbate, ROS scavengers, t-BuOOH did not induce hyperexcitability. In voltage clamp condition, t-BuOOH increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs), and monosynaptically evoked excitatory postsynaptic currents (eEPSCs) by electrical stimulation of the ipsilateral dorsal root. These data suggest that ROS generated by peripheral nerve injury can modulate the excitability of the SG neurons via pre- and postsynaptic actions.

• The Korean Journal of Physiology
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• v.24 no.2
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• pp.389-402
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• 1990

The physiological characteristics of the neurons receiving the ventral root afferent inputs were investigated in the cat. A total of 70 cells were identified in the lumbosacral spinal cord. All these cells responded only to the C-strength stimulation of the distal stump of cut ventral root and the estimated conduction velocities of the VRA fibers were not faster than 4 m/sec. The majority of them were silent in resting state. For 49 cells, their peripheral receptive fields were characterized. Among them, 25 cells were exclusively excited by VRA inputs, 8 were inhibited and the remaining cells recevied both excitatory and inhibitory VRA inputs. According to the response pattern to the mechanical stimuli applied to their receptive fields, only a fourth of them were typical high threshold cell, a sixth, wide dynamic range cells, while remainings were a rather complex cells. Most of the cells receiving VRA inputs, received only the A ${\delta}-peripheral$ nerve inputs. Intravenous injection of morphine decreased the response of spinal cells to the VRA activation. The responses were abolished completely by counter irritation to the common peroneal nerve with C-strength-low frequency stimuli. These physiological properties of the spinal neurons receiving the VRA inputs are differ in some aspect from the spinal neurons receiving nociceptive inputs from the periphery, but still were consistent with the contention that VRA system might carry nociceptive informations arising from the spinal cord and/or neraby surrounding tissues.

• Journal of Korean Medicine Rehabilitation
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• v.34 no.3
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• pp.107-117
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• 2024

The objective of this study is to report the clinical effects of applying an integrated rehabilitation protocol to four patients with traumatic cervical spinal cord injuries. The treatments applied included acupuncture, cupping and moxibustion, chuna manual therapy, functional electrical stimulation, and other physical therapies. The evaluation methods included American Spinal Injury Association Impairment Scale, functional independence measure (FIM), modified Barthel index (MBI), numeric rating scale (NRS) and other scales. All patients presented marked improvements in FIM, MBI, NRS and other scales, along with increased muscle strength in the manual muscle test. The application of our protocol resulted in clear clinical benefits and enhanced the recovery and quality of life for the patients in this study.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.3
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• pp.237-244
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• 1999

Magnesium ion is known to selectively block the N-methyl-D-aspartate (NMDA)-induced responses and to have anticonvulsive action, neuroprotective effect and antinociceptive action in the behavioral test. In this study, we investigated the effect of $Mg^{2+}$ on the responses of dorsal horn neurons to cutaneous thermal stimulation and graded electrical stimulation of afferent nerves as well as to excitatory amino acids and also elucidated whether the actions of $Ca^{2+}$ and $Mg^{2+}$ are additive or antagonistic. $Mg^{2+}$ suppressed the thermal and C-fiber responses of wide dynamic range (WDR) cell without any effect on the A-fiber responses. When $Mg^{2+}$ was directly applied onto the spinal cord, its inhibitory effect was dependent on the concentration of $Mg^{2+}$ and duration of application. The NMDA- and kainate-induced responses of WDR cell were suppressed by $Mg^{2+}$, the NMDA-induced responses being inhibited more strongly. $Ca^{2+}$ also inhibited the NMDA-induced responses current-dependently. Both inhibitory actions of $Mg^{2+}$ and $Ca^{2+}$ were additive, while $Mg^{2+}$ suppressed the EGTA-induced augmentation of WDR cell responses to NMDA and C-fiber stimulation. Magnesium had dual effects on the spontaneous activities of WDR cell. These experimental findings suggest that $Mg^{2+}$ is implicated in the modulation of pain in the rat spinal cord by inhibiting the responses of WDR cell to noxious stimuli more strongly than innocuous stimuli.

• Korean Journal of Acupuncture
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• v.36 no.3
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• pp.162-170
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• 2019

Objectives : Increasing evidence suggests that parasympathetic vagus nerve activity plays a role in modulating acupuncture-induced anti-inflammatory reaction, but the function of sympathetic nerve is not known. Here, we investigated whether splanchnic sympathetic nerve activity was involved in the regulation of splenic expression of $TNF-{\alpha}$ mRNA by electroacupuncture (EA) in LPS-injected animals. Methods : DiI was injected into the stomach or celiac ganglion (CG) for retrograde labeling of the target tissues. EA was given at ST36 and the electrical stimulation on the sciatic nerve in LPS-injected mice. c-Fos signals in the tissues were analyzed by immunofluorescence staining, and $TNF-{\alpha}$ mRNA was analyzed by real-time PCR. Results : Application of EA at ST36 or electrical stimulation on the sciatic nerve induced c-Fos expression in neurons of the spinal cord and celiac ganglion (CG). Then, the vagotomy reduced c-Fos levels in CG neurons but not in the spinal cord in animals given EA. Expression of $TNF-{\alpha}$ mRNA which was induced in the spleen after LPS was significantly inhibited by EA, then the vagotomy elevated $TNF-{\alpha}$ mRNA level similar to that in LPS-injected animals. Splanchnectomy in animals given LPS and EA also increased $TNF-{\alpha}$ mRNA though it was less effective than vagotomy. Conclusions : Our data suggest that EA delivered to the spleen via the splanchnic sympathetic nerve may be involved in attenuating splenic inflammatory responses in LPS-injected animals.