• The Journal of Korean Medicine
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• v.18 no.1
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• pp.58-71
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• 1997

In order to the location and local arrangement of nerve cell bodies and nerve fibers projecting to the meridian points related to facial nerve paralysis in the rat using the neural tracers, CTB and WGA-HRP, labeled neurons the were investigated by immunohistochemical and HRP histochemical methods following injection of 2.5% WGA-HRP and 1% CTB into Hyopko$(S_6)$. Chichang$(S_4)$, Sugu$(GV_{26})$, Sajukkong$(TE_{23})$ and Yangbaek$(G_{14})$. Following injection of Hyopko$(S_6)$, Chichang$(S_4)$, labeled motor neurons were founded in facial nucleus, trigeminal motor nucleus, reticular nucleus and hypoglossal nucleus. labeled sensory neurons were founded in trigeminal ganglia and $C_{1-2}$ spinal ganglia. sympathetic motor neurons were found in superior cervical ganglia. Sensory fibers labeled in brainstem were found in mesencephalic trigeminal tract, sensory root of trigeminal nerve, oral, interpolar and caudal part of trigeminal nucleus, area postrema, nucleus tractus solitarius, lateral reticular nucleus and $C_{1-2}$ spinal ganglia. Following injection of Sugu$(GV_{26})$, labeled motor neurons were founded in facial nucleus. Labeled sensory neurons were founded in trigeminal ganglia and $C_{1-2}$ spinal ganglia. Sympathetic motor neurons were found in superior cervical ganglia. Sensory fibers labeled in brainstem were found in spinal trigeminal tract, trigeminal motor nucleus, mesencephalic trigeminal tract, oral. interpolar and caudal parts of trigeminal nucleus, area postrema, nucleus tractus solitarius, lateral reticular nucleus, dorsal part of reticular part and $C_{1-2}$ spinal ganglia. Following injection of Sajukkong$(TE_{23})$ and Yangbaek$(G_{14})$, labeled motor neurons were founded in facial nucleus, trigeminal motor nucleus. Labeled sensory neurons were founded in trigeminal ganglia and $C_{1-2}$ spinal ganglia. sympathetic motor neurons were found in superior cervical ganglia. Sensory fibers labeled in brainstem were found in oral, interpolar and caudal parts of trigeminal nucleus, area postrema, nucleus tractus solitarius, inferior olovary nucleus, medullary reticular field and lamina I-IV of $C_{1-2}$ spinal cord. Location of nerve cell body and nerve fibers projecting to the meridian points related to the facial nerve paralysis in the rats were found in facial nucleus and trigeminal motor nucleus. Sensory neurone were found in trigeminal ganglia and $C_{1-2}$ spinal ganglia. Sympathetic motor neurons were found in superior cervical ganglia. Sensory fibers labeled in brainstem were found in mesencephalic trigeminal tract, oral, interpolar and caudal parts of trigeminal nucleus, area postrema, nucleus tractus solitarius. lateral reticular nucleus, medullary reticular field.

• BMB Reports
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• v.51 no.1
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• pp.3-4
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• 2018

Parkinson's disease (PD) is a debilitating disorder resulting from loss of dopamine neurons. In dopamine deficient state, the basal ganglia increases inhibitory synaptic outputs to the thalamus. This increased inhibition by the basal ganglia output is known to reduce firing rate of thalamic neurons that relay motor signals to the motor cortex. This 'rate model' suggests that the reduced excitability of thalamic neurons is the key for inducing motor abnormalities in PD patients. We reveal that in response to inhibition, thalamic neurons generate rebound firing at the end of inhibition. This rebound firing increases motor cortical activity and induces muscular responses that triggers Parkinsonian motor dysfunction. Genetic and optogenetic intervention of the rebound firing prevent motor dysfunction in a mouse model of PD. Our results suggest that inhibitory synaptic mechanism mediates motor dysfunction by generating rebound excitability in the thalamocortical pathway.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.385-398
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• 1997

The location and local arrangement of motor, sensory neurons within brain stem, nodose ganglia, spinal ganglia and sympathetic ganglia projecting to rat's kidney and meridian point BL 23, GB 25 were investigated by HRP immunohistochemical methods following injection of 5% WGA-HRP into left kidney and meridian point BL 23, GB 25. Following injection of WGA-HRP into left kidney, anterogradely labelled sensory neurons were founded within either nodose ganglia and spinal ganglia. The sensory neurons innervating rat's left kidney were observed within spinal ganglia $T_{7}{\sim}L_3$. Sympathetic motor neurons innervating rat's left kidney were labelled within left suprarenal ganglia, either celiac ganglia, superior mesenteric ganglia, and sympathetic chain ganglia $T_{1}{\sim}L_3$. Sympathetic chain ganglia were concentrated in $T_{12}{\sim}L_1$. The sensory neurons innervating rat's meridian point BL 23 were founded within spinal ganglia $T_{2}{\sim}L_2$. They were numerous in spinal in ganglia $T_{10}{\sim}T_{12}$. Sympathetic motor neurons innervating rat's meridian point BL 23 were observed in suprarenal ganglia and greater splanchnic trunk, sympathetic chain ganglia from $T_1$ to $L_3$. They were concentrated in $T_{12}{\sim}L_3$. The sensory neurons innervating rat's meridian point GB 25 were labelled within spinal ganglia $T_{6}{\sim}T_{13}$. They were numerous in from T10 to $T_{12}$. Sympathetic motor neurons innervating rat's meridian point GB 25 were labelled within greater splanchnic trunk and sympathetic chain ganglia $T_{12}{\sim}L_3$. They were concentrated in $T_{13}{\sim}L_1$. This results neuroanatomically imply that the location of rat's motor and sensory neurons innervating meridian point BL 23 and GB 25 were closely related that of innervating kidney.

• Journal of Korean Neurosurgical Society
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• v.46 no.1
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• pp.1-4
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• 2009

Objective: To report an unsuspected adaptive plasticity of single upper motor neurons and of primary motor cortex found after microsurgical connection of the spinal cord with peripheral nerve via grafts in paraplegics and focussed discussion of the reviewed literature. Methods: The research aimed at making paraplegics walk again, after 20 years of experimental surgery in animals. Amongst other things, animal experiments demonstrated the alteration of the motor endplates receptors from cholinergic to glutamatergic induced by connection with upper motor neurons. The same paradigm was successfully performed in paraplegic humans. The nerve grafts were put into the ventral-lateral spinal tract randomly, with out possibility of choosing the axons coming from different areas of the motor cortex. Results: The patient became able to selectively activate the re-innervated muscles she wanted without concurrent activities of other muscles connected with the same cortical areas. Conclusion: Authors believe that unlike in nerve or tendon transfers, where the whole cortical area corresponding to the transfer changes its function a phenomenon that we call "brain plasticity by areas". in our paradigm due to the direct connection of upper motor neurons with different peripheral nerves and muscles via nerve grafts motor learning occurs based on adaptive neuronal plasticity so that simultaneous contractions of other muscles are prevented. We propose to call it adaptive functional "plasticity by single neurons". We speculate that this phenomenon is due to the simultaneous activation of neurons spread in different cortical areas for a given specific movement, whilst the other neurons of the same areas connected with peripheral nerves of different muscles are not activated at the same time. Why different neurons of the same area fire at different times according to different voluntary demands remains to be discovered. We are committed to solve this enigma hereafter.

• PNF and Movement
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• v.7 no.4
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• pp.45-53
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• 2009

Purpose : The purpose of this article was to review the literature on mirror neuron system with reference to its functional diversity in stroke rehabilitation.. Method : This review outlines scientific findings regarding different neurophysiological properties in mirror neurons, and discusses their involvement in process of stroke rehabilitation. Result & Conclusions : Mirror neurons were first discovered in macaque monkey. These neurons, like most neurons in F5 areas in premotor cortex, fired when an individual performs an action, as well as when he/she observes a similar action done by another individual, although originally fired only during action execution. Mirror neurons form a network for motor planning and initiating of motor action. Thus, in stroke rehabilitation based on the mirror neuron-action observation, motor imagery, observation with intent to imitate and imitation-may help activate mirror neuron system for improved outcome of physical therapy. These studies provide a scientific theoretical basis and discuss for the use of mirror neuron system as a complement to clinical physical therapy in stroke rehabilitation.

• Korean Journal of Acupuncture
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• v.32 no.3
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• pp.136-143
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• 2015

This study was performed to comparative investigate the distribution of primary sensory and motor neurons associated with Cheonji(PC1) acupoint by using neural tracing technique. A total 4 SD rats were used in the present study. After anesthesia, the rats received microinjection of $6{\mu}l$ of cholera toxin B subunit(CTB) into the corresponding sites of the acupoints Cheonji(PC1) in the human body for observing the distribution of the related primary sensory neurons in dorsal root ganglia(DRGs) and motor neurons in the spinal cord(C3~T4) and sympathetic ganglia. Three days after the microinjection, the rats were anesthetized and transcardially perfused saline and 4% paraformaldehyde, followed by routine section of the DRGs, sympathetic chain ganglia(SCGs) and spinal cord. Labeled neurons and nerve fibers were detected by immunohistochemical method and observed by light microscope equipped with a digital camera. The labeled neurons were recorded and counted. From this research, the distribution of primary sensory and motor neurons associated with Cheonji(PC1) acupoints were concluded as follows. Muscle meridian related Cheonji(PC1) are controlled by spinal segments of C5~T1, C6~T4, respectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1202-1207
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• 2003

In order to clarify the neuroprotective effect of Cornu Saigae Tataricae(CST) water extract on cultured mouse spinal motor neuron damaged by hydrogen peroxide (H₂O₂), MTT [3-(4,5-dimethylthiazole-2-yl)- 2,5-diphenyltetrazolium bromide] assay, LDH (Lactate Dehydrogenase) activity assay and SRB (Sulforhodamine B) assay were carried out after the cultured mouse spinal motor neuron were preincubated with various concentrations of CST water extract for 3 hours prior to exposure of hydrogen peroxide Cell viability of cultured mouse spinal motor neurons exposed to various concentrations of hydrogen peroxide for 6 hours was decreased in a dose-dependent manner. MTT50 values were 40 uM hydrogen peroxide. Cultured mouse spinal motor neurons in the medium containing various concentration of hydrogen peroxide for 6 hours showed increasing of LDH activity and decreasing of total protein synthesis. We know that hydrogen peroxide was toxic on cultured spinal motor neurons. Pretreatment of CST water extract for 3 hours following hydrogen peroxide prevented the hydrogen peroxide-induced neurotoxicity such as increasing of LDH activity and decreasing of total protein synthesis. These results suggest that hydrogen peroxide shows toxic effect on cultured spinal motor neurons and CST water extract is highly effective in protecting the neurotoxicity induced by hydrogen peroxide.

• The Korean Journal of Pain
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• v.35 no.2
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• pp.160-172
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• 2022

Background: The authors established an in vitro model of diabetic neuropathy based on the culture system of primary neurons and Schwann cells (SCs) to mimic similar symptoms observed in in vivo models of this complication, such as impaired neurite extension and impaired myelination. The model was then utilized to investigate the effects of insulin on enhancing neurite extension and myelination of diabetic neurons. Methods: SCs and primary neurons were cultured under conditions mimicking hyperglycemia prepared by adding glucose to the basal culture medium. In a single culture, the proliferation and maturation of SCs and the neurite extension of neurons were evaluated. In a co-culture, the percentage of myelination of diabetic neurons was investigated. Insulin at different concentrations was supplemented to culture media to examine its effects on neurite extension and myelination. Results: The cells showed similar symptoms observed in in vivo models of this complication. In a single culture, hyperglycemia attenuated the proliferation and maturation of SCs, induced apoptosis, and impaired neurite extension of both sensory and motor neurons. In a co-culture of SCs and neurons, the percentage of myelinated neurites in the hyperglycemia-treated group was significantly lower than that in the control group. This impaired neurite extension and myelination was reversed by the introduction of insulin to the hyperglycemic culture media. Conclusions: Insulin may be a potential candidate for improving diabetic neuropathy. Insulin can function as a neurotrophic factor to support both neurons and SCs. Further research is needed to discover the potential of insulin in improving diabetic neuropathy.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.738-741
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• 2003

In order to evaluate the cytotoxicity of methylmercuric chloride(MMC) in cultured spinal motor neurons of neonatal mouse, cell viability was measured by MTT assay in spinal motor neurons treated with 1-30 μM MMC for 48 hours. And also, the protective effect of Radix Polygoni Multiflori(RPM) was examined by cell viability in these cultures. Cell viability was significantly decreased in dose-dependent manner after cultured cells were exposured to 20 μM MMC for 48 hours. Protective effect of RPM on MMC-mediated toxicity was very effective in these cultures. From above the results, it suggests that MMC has toxic effect in cultured mouse spinal motor neurons and herb extract such as RPM is very effective in blocking the neurotoxicity induced by MMC.

• BMB Reports
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• v.28 no.4
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• pp.323-330
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• 1995

Recent studies have shown that dopamine applied to cultured swimming motor neurons of Polyorchis penicillatus produces an inhibitory action by opening potassium channels through $D_2$-like receptors. In this study, it was demonstrated that dopamine found in the hydromedusa was not from exogenous sources and the content of dopamine depended on the $Ca^{2+}$ content of the dissecting media. In addition, a combination of thin layer chromatography and high performance liquid chromatography showed the presence of DOPA and DO PAC-like compounds in the jellyfish. The glyoxylic acid method for catecholamines suggested that a population of small cells, neither swimming motor neurons nor B-like neurons, had dopaminergic systems. From all these results, it is suggested here that DA synthesized from DOPA in some cells is released. being dependent on calcium concentrations, into a synaptic cleft and degraded into DOPAC after acting as an inhibitory transmitter to swimming motor neurons.