• The Korean Journal of Physiology and Pharmacology
• /
• 제12권5호
• /
• pp.245-251
• /
• 2008

Single-channel recordings of TASK-1 and TASK-3, members of two-pore domain $K^+$ channel family, have not yet been reported in dorsal root ganglion (DRG) neurons, even though their mRNA and activity in whole-cell currents have been detected in these neurons. Here, we report single-channel kinetics of the TASK-3-like $K^+$ channel in DRG neurons and up-regulation of TASK-3 mRNA expression in tissues isolated from animals with spinal cord injury (SCI). In DRG neurons, the single-channel conductance of TASK-3-like $K^+$ channel was $33.0{\pm}0.1$ pS at - 60 mV, and TASK-3 activity fell by $65{\pm}5%$ when the extracellular pH was changed from 7.3 to 6.3, indicating that the DRG $K^+$ channel is similar to cloned TASK-3 channel. TASK-3 mRNA and protein levels in brain, spinal cord, and DRG were significantly higher in injured animals than in sham-operated ones. These results indicate that TASK-3 channels are expressed and functional in DRG neurons and the expression level is up-regulated following SCI, and suggest that TASK-3 channel could act as a potential background $K^+$ channel under SCI-induced acidic condition.

• The Korean Journal of Physiology
• /
• 제30권1호
• /
• pp.117-124
• /
• 1996

This study evaluated the hypothesis that motoneuron collaterals modulate the excitability of ventral spinocerebellar tract neurons. In acute cats, 128 ventral cerebellar tract cells were studied extracellularly to determine the effects of ventral root stimuli. The majority of the cells responded to ventral root stimulation with either short or long latency increases in spike discharge. In many cells with sufficient spontaneous activity ventral root stimulation also evoked a long lasting reduction in activity. In preparations with the dorsal root ganglion removed VSCT neurons had similar response properties. In some cells contralateral ventral root stimulation also evoked excitatory responses. These findings indicate the VSCT can provide the cerebellum with information regarding activity in the final output neurons of the motor system, the alpha motoneurons.

• Archives of Pharmacal Research
• /
• 제20권1호
• /
• pp.93-95
• /
• 1997

The aim of the present study was to elucidate the mechanism of action of DA-5018 and to compare it with those of capasaicin, resiniferatoxin (ultrapotent capasaicin analog), and olvanil (systemic antinociceptive agent equipotent with capasaicin developed by Proctor & Gamble) (fig.1).

• Rapid Communication in Photoscience
• /
• 제5권1호
• /
• pp.11-12
• /
• 2016

Schwann cells and neuronal cells from dorsal root ganglion (DRG) in embryos of rat were cultured in vitro respectively. The purified neuronal cells with anti-mitotic agents and purified Schwann cells were co-cultured and then accomplished myelination processing. Infection of Semliki forest virus into this myelinated co-culture system was performed and then accomplished demyelination. We identified myelination and demyelination processing using antibody of neuropeptide Y.

• Annals of Clinical Neurophysiology
• /
• 제4권1호
• /
• pp.85-88
• /
• 2002

Ramsay-Hunt syndrome is a viral disease associated with peripheral facial nerve paralysis accompany by erythematous vesicular rashs on the ear(zoster oticus) or in the mouth. Based on clinical presentations that indicated involvement of more than one ganglion, the gasserian, geniculate, petrous, accessory, jugular and second and third dorsal root ganglia comprised a chain in which inflammation of a single ganglion could extend to nearby ganglia. A 71-year-old man presented with left. peripheral facial palsy with otalgia, vesicular eruption in $V_2$, $V_3$, C2, C3 dermatome, tinnitus, and hearing loss.

• The Korean Journal of Physiology and Pharmacology
• /
• 제2권2호
• /
• pp.165-172
• /
• 1998

Under certain pathophysiological conditions, such as inflammation and ischemia, the concentration of H^+$ ion in the tissue surrounding neurons is changed. Variations in H^+$ concentration are known to alter the conduction and/of the gating properties of several types of ion channels. Several types of K^+$ channels are modulated by pH. In this study, the whole cell configuration of the patch clamp technique has been applied to the recording of the responses of change of external pH on the delayed rectifier K^+$ current of cultured DRG neurons of rat. Outward K^+$ currents were examined in DRG cells, and the Charybdotoxin and Mn^{2+}$ could eliminate Ca^{2+}-dependent$ K^+$ currents from outward K^+$ currents. This outward K^+$ current was activated around -60 mV by step depolarizing pulses from holding potential -70 mV. Outward K^+$ currents were decreased by low external pH. Activation and steady-state inactivation curve were shifted to the right by acidification, while there was small change by alkalization. These results suggest that H^+$ could be alter the sensory modality by changing and modifying voltage-dependent K^+$ currents, which participated in repolarization.

• Journal of Korean Neurosurgical Society
• /
• 제39권5호
• /
• pp.340-346
• /
• 2006

Objective : The lack of anatomical knowledge for the anterior cervical microforaminotomy is liable to injure the neurovascular structures. The surgical anatomy is examined with special attention to the ventral aspect exposed in anterior cervical microforaminotomy. Methods : In 16adult formalin fixed cadaveric cervical spine, the author measured the distances from the medical margin of the longus colli to the medical wall of the ipsilateral vertebral artery and the angle for the ipsilateral vertebral artery. The distances from the lateral margin of the posterior longitudinal ligament to the medial margin of the ipsilateral medial wall of the vertebral artery, to the ipsilateral dorsal root ganglion was measured too. Results : The distance from the medial margin of the longus colli to the ipsilateral vertebral artery was $13.3{\sim}14.7mm$ and the angle for the ipsilateral vertebral artery was $41{\sim}42.5\;degrees$. The range of distance from the lateral margin of the posterior longitudinal ligament to the ipsilateral vertebral artery was $11.9{\sim}16.1mm$, to the ipsilateral dorsal root ganglion was $11.6{\sim}12.9mm$. Conclusion : These data will aid in reducing neurovascular injury during anterior cervical approaches.

• Advances in Traditional Medicine
• /
• 제2권1호
• /
• pp.36-40
• /
• 2002

Effects of hydrogen peroxide $(H_2O_2)-induced$ neurotoxicity were investigated in cultured newborn rat spinal dorsal root ganglion (DRG) neurons after DRG neurons were treated in the media containning various concentrations of $H_2O_2$. In addition, the protective effect of Herba Epimedii (HE) extract against $H_2O_2-induced$ neurotoxicity was examined. Cytotoxic values were determined by the cell viability of living cells using 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay. In the present study, exposure of neurons to $H_2O_2$ resulted in a significant cell death in a dose- and time-dependent manners in cultured DRG neurons. The decrement of cell viability by $H_2O_2$ was blocked by HE. These results suggest that the neuroprotective effect of HE against $H_2O_2-induced$ cytotoxicity may result from the prevention of injury induced by $H_2O_2$.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2018년도 추계학술대회
• /
• pp.448-451
• /
• 2018

본 연구는 뉴런 세포와 슈반 세포의 공동 배양에 의한 수초화 발생 과정과 herpes simplex virus-1 감염에 의한 탈수초화 발생과정을 전자 현미경과 분자생물학적 분석에 의하여 확인하고자 하였다. 쥐의 배아로부터 후근신경절(dorsal root ganglion, DRG)을 분리하여 슈반(Schwann) 세포와 뉴런 세포(neuronal cell)를 in vitro에서 각각 배양하였다. 유사 분열 억제인자로 처리한 뉴런세포와 정제된 슈반세포를 함께 공동 배양을 하여 수초화를 발생시켰다. 이렇게 수초화된 공동 배양 세포에 herpes simplex virus-1를 감염시켜 탈수초화를 진행시켰다. 수초 형성의 존재를 의미하는 myelin protein zero(MPZ) 항체를 사용하고 전자 현미경을 이용하여 수초 발생 및 탈수초화 과정을 관찰하였다.

• The Korean Journal of Pain
• /
• 제26권2호
• /
• pp.135-141
• /
• 2013

Background: Although paclitaxel is a widely used chemotherapeutic agent for the treatment of solid cancers, side effects such as neuropathic pain lead to poor compliance and discontinuation of the therapy. Ethyl pyruvate (EP) is known to have analgesic effects in several pain models and may inhibit apoptosis. The present study was designed to investigate the analgesic effects of EP on mechanical allodynia and apoptosis in dorsal root ganglion (DRG) cells after paclitaxel administration. Methods: Rats were randomly divided into 3 groups: 1) a control group, which received only vehicle; 2) a paclitaxel group, which received paclitaxel; and 3) an EP group, which received EP after paclitaxel administration. Mechanical allodynia was tested before and at 7 and 14 days after final paclitaxel administration. Fourteen days after paclitaxel treatment, DRG apoptosis was determined by activated caspase-3 immunoreactivity (IR). Results: Post-treatment with EP did not significantly affect paclitaxel-induced allodynia, although it tended to slightly reduce sensitivities to mechanical stimuli after paclitaxel administration. After paclitaxel administration, an increase in caspase-3 IR in DRG cells was observed, which was co-localized with NF200-positive myelinated neurons. Post-treatment with EP decreased the paclitaxel-induced caspase-3 IR. Paclitaxel administration or post-treatment with EP did not alter the glial fibrillary acidic protein IRs in DRG cells. Conclusions: Inhibition of apoptosis in DRG neurons by EP may not be critical in paclitaxel-induced mechanical allodynia.