• BMB Reports
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• v.28 no.3
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• pp.221-226
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• 1995

Dopamine mediates inhibitory responses in Helix aspersa neurons from the right parietal lobe ("F-lobe") of the circumoesophageal ganglia. The effects appeared as a dose-dependent hyperpolarization of the plasma membrane and a decrease in the occurrence of spontaneous action potentials. The average hyperpolarization with 5 ${\mu}m$ dopamine was -12 mV (${\pm}1.5$mV, S.D., n=12). Dopamine also modulated the currents 'responsible for shaping the action potentials in these neurons. When dopamine was added and action potentials were triggered by an injection of current, the initial depolarization was slowed, the amplitude and the duration of action potentials were decreased, and the after-hyperpolarization was more pronounced. The amplitude and the duration of action potential were reduced about 15 mV and about 13% by 5 ${\mu}m$ dopamine, respectively. The effects of dopamine on the resting membrane potentials and the action potentials of Helix neurons were dose-dependent in the concentration range 0.1 ${\mu}m$ to 50 ${\mu}m$. In order to show 1) that the effects of dopamine were mediated by dopamine receptors rather than by direct action on ionic channels and 2) which type of dopamine receptor might be responsible for the various effects, we assayed the ability of mammalian dopamine receptor antagonists, SCH-23390 (antagonist of D1 receptor) and spiperone (antagonist of D2 receptor), to block the dopamine-dependent changes. The D1 and D2 antagonists partially inhibited the dopamine-dependent hyperpolarization and the decrease in action potential amplitude. They both completely blocked the decrease in action potential duration and the increase in action potential after-hyperpolarization. The dopamine-induced slowdown of the depolarization in the initial phase of the action potentials was less effected by SCH-23390 and spiperone. From the results we suggest 1) that Helix F-lobe neurons may have a single type of dopamine receptor that binds both SCH-23390 and spiperone and 2) that the dopamine receptor of Helix F-lobe neurons may be homologous with and primitive to the family of mammalian dopamine receptors.

• Biomedical Science Letters
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• v.14 no.2
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• pp.69-76
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• 2008

${\gamma}$-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system, and its actions are mediated by subtypes of GABA receptors named as $GABA_A$, $GABA_B,\;and\;GABA_C,\;GABA_A$, receptor consisting of ${\alpha},\;{\beta},\;{\gamma}\;and\;{\delta}$ subunits is a heterooligomeric ligand-gated chloride channel. This study was performed to investigate regulation of $GABA_A$ receptor by protein kinase C(PKC). Ion currents were recorded using gramicidine-perforated patch and whole cell patch clamp. mRNA encoding the subunits of PKC expressed in major pelvic ganglion (MPG) neurons was detected by using RT-PCR. The GABA-induced inward current was increased by PKC activators and decreased by PKC inhibitors, respectively. These effects were not associated with intracellular $Ca^{2+}$ and GAG (1-oleoyl-2-acetyl-sn-glycerol), a membrane permeable diacylglycerol (DAG) analogue. These results mean that the subfamily of PKC participating in activation of $GABA_A$ receptor would be an atypical PKC (aPKC). Among theses, ${\xi}$ isoform of aPKC was detected by RT-PCR. Taking together, we suggest that excitable $GABA_A$ receptor in sympathetic MPG neuron seemed to be regulated by aPKC, particular in ${\xi}$ isoform. The regulatory roles of PKC on excitatory $GABA_A$ receptors in sympathetic neurons of MPG may be an important factor to control the functional activity of various pelvic organs such as bowel movement, micturition and erection.

• Journal of Korean Neurosurgical Society
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• v.37 no.3
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• pp.207-212
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• 2005

Objective: Classically, single photon emission tomography is known to be the reference standard for evaluating the hemodynamic status of patients with moyamoya disease. Recently, T2-weighted perfusion magnetic resonance(MR) imaging has been found to be effective in estimating cerebral hemodynamics in moyamoya disease. We aim to assess the utility of perfusion-weighted MR imaging for evaluating hemodynamic status of moyamoya disease. Methods: The subjects were fourteen moyamoya patients(mean age: 7.21 yrs) who were admitted at our hospital between Sep. 2001 to Sep 2003. Four normal children were used for control group. Perfusion MR imaging was performed before any treatment by using a T2-weighted contrast material-enhanced technique. Relative cerebral blood volume(rCBV) and time to peak enhancement(TTP) maps were calculated. Relative ratios of rCBV and TTP in the anterior cerebral artery(ACA), middle cerebral artery(MCA) and basal ganglia were measured and compared with those of the posterior cerebral artery(PCA) in each cerebral hemispheres. Using this data, we analysed the hemodynamic aspect of pediatric moyamoya disease patients in regarding to the age, Suzuki stage, signal change in FLAIR MR imaging, and hemispheres inducing symptoms. Results: The mean rCBV ratio of ACA, MCA did not differ between normal children and moyamoya patients. However the significant TTP delay was observed at ACA, MCA territories (mean = 2.3071 sec, 1.2089 see, respectively, p < 0.0001). As the Suzuki stage of patients is advanced, rCBV ratio is decreased and TTP differences increased. Conclusion: Perfusion MR can be applied for evaluating preoperative cerebral hemodynamic status of moyamoya patients. Furthermore, perfusion MR imaging can be used for determine which hemisphere should be treated, first.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.877-885
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• 2000

Objective : The NOS inhibitors exhibit antinociceptive activity in rat model of neuropathic pain. NOS activity increases in the dorsal root ganglia(DRG) in neurop-athic pain. However, NOS activity decreases in the dorsal horn of spinal cord in the nerve injury models of neuropathic pain. To investigate whether the mechanism of decrease of NOS expression in the dorsal horn is related to a secondary effect resulting from increased NO production and likewise in the spinal DRG in the spinal nerve ligation model of neuropathic pain. Methods : We conducted behavioral tests for neuropathic pain, and nNOS immunohistochemistry and NADPH-diaphorase histochemistry after tight ligation of the 5th lumbar(L5) and 6th lumbar(L6) spinal nerves and L5 dorsal rhizotomy. Results : Typical neuropathic pain behaviors occurred 7 days after post-ligation in the neuropathic surgery group, but neuropathic pain behaviors in the dorsal rhizotomy group were absent or weak 7 days after post-operation. There was a decrease in the number of nNOS immunoreactive dorsal horn neurons on the both side(especially ipsilateral side) 7 days after post-ligation. The number of nNOS immunoreactive neurons in both side of the dorsal horn was not decreased 7 days after L5 dorsal rhizotomy. Conclusion : These data indicate that the changes in the injured DRG is essential for development and maintenance of neuropathic pain, and mechanism of decrease of nNOS expression in the dorsal horn is a secondary effect against the changes in the DRG including increased NO production in the spinal nerve ligation model of neuropathic pain.

• The Korean Journal of Nuclear Medicine
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• v.22 no.2
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• pp.163-170
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• 1988

8 patients of delayed CO sequelae were evaluated using Brain CT and $^{99m}Tc-HMPAO$ SPECT. The results were as follows; 1) CT findings of delayed CO sequleae were bilateral low density lesion in globus pallidus (l pt.), diffuse low density in white matter with bilateral low density in white matter (l pt.), diffuse low density in white matter with bilateral low density in globus pallidus (l pt.), diffuse low density in white matter with cortical atrophy (l pt.), bilateral low density in globus pallidus and diffuse low density in white matter with cortical atrophy (l pt.) and normal in 3 pts. 2) $^{99m}Tc-HMPAO$ Brain SPECT findings of delayed CO sequelae were decreased regional cerebral blood flow (rCBF) in frontal (1 among 8 pts.), frontal and basal ganglia (3 among 8 pts.), and diffuse patch decreased rCBF pattern (4 among 8 pts.) 3) $^{99m}Tc-HMPAO$ Brain SPECT study was well correlated with neurologic symptoms and signs in delayed CO sequelae. Our results may suggest that reduced cerebral blood flow contributes to the development of delayed CO sequelae.

• The Korean Journal of Pain
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• v.14 no.1
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• pp.12-18
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• 2001

Background: It is controversial whether the change in nitric oxide (NO) expression in the dorsal root ganglia (DRG) may be responsible for developtment and/or maintenance of painful diabetic neuropathy. The aim of this study was to clarify the role of NO in the pathogenesis of painful diabetic neuropathy. Methods: The effect of L-nitroargine methylester (L-NAME) or sodium nitroprusside (SNP) on allodynia was measured in streptozotocin (STZ)-induced diabetic rats. NO concentration was measured in the cerebrospinal fluid (CSF) and plasma of the diabetic rats. NADPH-diaphorase (NADPH-d) histochemistry was performed on the DRG and spinal cords of the STZ-induced diabetic rats. Results: L-NAME, an inhibitor of nitric oxide synthase, alleviated allodynia, while SNP, a nitric oxide donor, aggravated allodynia in diabetic rats. Plasma NO level in the diabetic rats was significantly decreased compared with control rats. NO level in the CSF of diabetic rats did not differ from that of the control rats. NADPH-d positive cells were decreased in the DRG of diabetic rats. However, NADPH-d histochemistry in the diabetic spinal cord was not different from that of the control rats. Conclusions: Downregulation of NO expression in the diabetic rats may not be causally related to the development and/or maintenance of painful diabetic neuropathy.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.171-175
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• 2005

Background: Hyperhidrosis is the troublesome disorder of excessive perspiration, which affects as much as 0.15-1% of the population. There are many methods for treating hyperhidrosis. In this report, we present our experience of dorsal percutaneous thoracic sympathetic ganglion block (TSGB) using 99.9% ethyl alcohol for treating palmar hyperhidrosis. Methods: Between March 1992 and July 2003, a total of 856 patients underwent TSGB for the treatment of palmar hyperhidrosis of which 625 were followed up for 2 years. There were 297 and 328 male and female patients, respectively, with a mean age of $23.9{\pm}7.7years$. TSGB was performed under fluoroscopic guidance using 99.9% ethyl alcohol at the T2 and T3 sympathetic ganglia. Results: In the 625 patients, the recurrence rates within the 1st and 2nd years were 29 and 8%, respectively. Compensatory sweating occurred in 42.1% of patients, which was severe in 7.5%. Of the 625 patients 21.0 and 36.9% were either very satisfied or relatively satisfied with the outcome, respectively. Conclusions: Our report confirms that TSGB may be a good alternative to endoscopic thoracic sympathectomy in the treatment of palmar hyperhidrosis.

• Clinical and Experimental Pediatrics
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• v.52 no.9
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• pp.1044-1047
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• 2009

A 13-year-old girl with psoriasis of the elbow, trunk, and face suddenly developed a severe headache followed by left hemiparesis and facial palsy. Brain magnetic resonance imaging showed an acute infarction of the right temporofrontal lobe and basal ganglia on the T2- and diffusion-weighted images. Cerebral angiography showed pre-occlusive irregular scalloped stenosis (99%) in the proximal M1 segment of the right middle cerebral artery and a web-like stenosis at the supraclinoid portion of the right internal carotid artery (ICA) suggestive of a spontaneous intracranial ICA dissection. The patient was administered a low dose of dipyridamole, and a rehabilitation program was initiated. Headache, left motor weakness, and facial droop improved within a week. However, mild left facial palsy and reduced fine motor function of the left hand were still present after 3 weeks. We report a rare case of spontaneous intracranial ICA dissection in a child with psoriasis.

• Clinical and Experimental Pediatrics
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• v.57 no.2
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• pp.75-78
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• 2014

Purpose: This study aimed to investigate the clinical features of macrocephaly at birth in Korea using ultrasonography. Methods: We retrospectively investigated the medical records of full-term birth neonates in Cheil General Hospital & Women's Healthcare Center from January 2000 to June 2012. The following parameters were recorded and analyzed: gestational age, sex, birth weight, height, occipitofrontal circumference (OFC), physical examination, perinatal problems, and ultrasonography results. Macrocephaly was diagnosed when the OFC was greater than two standard deviations, based on the 2007 Korean National Growth Charts. Results: There were 75 neonates with macrocephaly at birth (52 boys and 23 girls), with a mean OFC of $38.1{\pm}0.49cm$. A comparison of the birth weight and height with the OFC value showed that height was correlated with OFC (r=0.35) but birth weight was not correlated with OFC (r=0.06). There were no remarkable findings in 56 cases (75%). Germinal matrix hemorrhage was identified in 10 cases (13%). An enlarged cerebrospinal fluid space was found in 5 cases (6.7%). There were 3 cases of mega-cisterna magna (4%), 1 case of ventriculomegaly, and 1 case of an enlarged interhemispheric space (6 mm) among these patients. In addition, a choroid plexus cyst was seen in 1 case. Mineralizing vasculopathy in both basal ganglia with no evidence of congenital infection was found in 2 cases and an asymptomatic subarachnoid hemorrhage was found in 1 case. Conclusion: Our results indicate that macrocephaly at birth has benign ultrasonography findings and shows a pattern of male dominance.

• Journal of Korean Neurosurgical Society
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• v.41 no.4
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• pp.230-235
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• 2007

Objective : We investigated the incidence of the vascular abnormalities associated with spontaneous intracerebral hemorrhage [ICH] using three-dimensional computed tomographic angiography [3D-CTA]. Methods : We prospectively assessed consecutive 76 patients with spontaneous intracerebral hemorrhage [ICH] who underwent 3D-CTA between June 2003 and May 2005. The patients with a recent history of trauma or mainly subarachnoid hemorrhage were excluded. We investigated relationship between vascular abnormality and ICH location. The findings of 3D-CTA were classified as one of three patterns with ICH; type A [without evidence of vascular abnormality], type B [with no vascular abnormality as the source of hemorrhage, but with incidental vascular abnormality], and type C [presence of a vascular abnormality as the source of hemorrhage]. Results : Sites of ICH were lobar 26, basal ganglia 23, thalamus 17, posterior fossa 6 and dominant intraventricular hemorrhage [IVH] 4. Among 76 patients, sixteen [21.1%] vascular abnormalities were noted excluding 13 cases of stenoocclusive disease. Sixteen cases included 6 cases of cerebral aneurysms [7.9%], 5 moyamoya diseases [6.6%], 4 arteriovenous malformations [5.3%] and 1 dural sinus thrombosis [1.3%]. Lobar ICH [30.8%] had a higher vascular abnormalities than other types, and younger age [<40] group had a higher incidence of vascular abnormalities than old age group. The patterns of 3D-CTA include sixty cases [79.0%] of type A, 6 cases [7.8%] of type Band 10 cases [13.2%] of type C. The vascular abnormalities were found in 8 [13.5%] of 59 hypertensive patients and 8 [47.0%] of 17 non-hypertensive patients [p=0.006]. Conclusion : 3D-CT angiography is considered a useful screening tool for ICH patients with suspected cerebrovascular abnormalities and should be considered in such clinical settings, especially in lobar type and in non-hypertensive younger patients.