• Toxicological Research
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• 제17권2호
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• pp.73-82
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• 2001

The incidence and distribution of necrotic and apoptotic neural cells, and activated astrocytes in the brain of rats intoxicated intra peritoneally with diisopropylfluorophosphate were investigated. Pyridostigmine bromide (0.1 mg/kg) and atropine methylnitrate (20 mg/kg) were pretreated intramuscularly 30 min and 10 min, respectively, prior to diisopropylfluorophosphate (4-10 mg/kg) administration. Diisopropylfluorophosphate induced severe limbic seizures, early necrotic and delayed apoptotic brain injuries, and rapid astrocytic responses. The necrosis, which was closely related to seizure intensity, was observed as early as 1 hr after intoxication predominently in hippocampal pyramidal cells, cerebellar Purkinje cells and neurons in pyriform/entorhinal cortices, showing malacia of neurophils. In contrast, apoptosis started to appear 12 hr after intoxication in neurons in thalamus, amygdala and neocortex, and ephendymal cells surrounding the 4th ventricle. Since marked apoptosis was induced in rats exhibiting relatively-low seizure intensity, the degree of necrosis and apoptosis was shifted to each type of injury according to the seizure intensity. Activated astrocytes, observed within 1 hr along the limbic system, were suggested to affect the neural injury patterns by producing high level of nitric oxide. However, the distribution of activated astrocytes was not in parallel with those of necrotic or apoptotic injuries, implying that the astrocytic responses resulted from seizure activity rather than neural injuries. Furthermore, astrocytes in malacic tissues disappeared during the severe limbic seizures. Therefore, it would be one of the cautionary notes on the expression of glial fibrillary acidic protein in astrocytes as a biochemical marker of brain injuries following acute exposure to organophosphates.

• The Korean Journal of Physiology and Pharmacology
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• 제9권5호
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• pp.263-268
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• 2005

Striatum has important roles in motor control, habitual learning and memory. It receives glutamatergic inputs from neocortex and thalamus, and dopaminergic inputs from substantia nigra. We examined effects of dopamine (DA) on the corticostriatal synaptic transmission using in vitro extracellular recording technique in rat brain corticostriatal slices. Synaptic responses were elicited by stimulation of cortical glutamatergic inputs on the corpus callosum and recorded in the dorsal striatum. Corticostriatal population spike (PS) amplitudes were decreased ($39.4{\pm}7.9$%) by the application of $100{\mu}M$ DA. We applied receptor subtype specific agonists and antagonists and characterized the modulation of corticostriatal synaptic transmission by different DA receptor subtypes. $D_2$ receptor agonist (quinpirole), antagonist (sulpiride), and $D_1$ receptor antagonist (SKF 83566), but not $D_1$ receptor agonist (SKF 38393), induced significantly the reduction of striatal PS. Pretreatment neither with SKF 83566 nor sulpiride significantly affected corticostriatal synaptic inhibition by DA. However, the inhibition of DA was completely blocked by pretreatment with mixed solution of both SKF 83566 and sulpiride. These results suggest that DA inhibits corticostriatal synaptic transmission through both $D_1$ and $D_2$ receptors in concert with each other.

• The Korean Journal of Physiology and Pharmacology
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• 제13권3호
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• pp.209-214
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• 2009

The striatum receives glutamatergic afferents from the cortex and thalamus, and these synaptic transmissions are mediated by ${\alpha}$-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and N-methyl D-aspartate (NMDA) receptors. The purpose of this study was to characterize glutamate receptors by analyzing NMDA/AMPA ratio and rectification of AMPA and NMDA excitatory postsynaptic currents (EPSCs) using a whole-cell voltage-clamp method in the dorsal striatum. Receptor antagonists were used to isolate receptor or subunit specific EPSC, such as (DL)-2-amino-5-phosphonovaleric acid (APV), an NMDA receptor antagonist, ifenprodil, an NR2B antagonist, CNQX, an AMPA receptor antagonist and IEM-1460, a GluR2-lacking AMPA receptor blocker. AMPA and NMDA EPSCs were recorded at - 70 and + 40 mV, respectively. Rectification index was calculated by current ratio of EPSCs between + 50 and - 50 mV. NMDA/AMPA ratio was 0.20${\pm}$0.05, AMPA receptor ratio of GluR2-lacking/GluR2-containing subunit was 0.26${\pm}$0.05 and NMDA receptor ratio of NR2B/NR2A subunit was 0.32${\pm}$0.03. The rectification index (control 2.39${\pm}$0.27) was decreased in the presence of both APV and combination of APV and IEM-1460 (1.02${\pm}$0.11 and 0.93${\pm}$0.09, respectively). These results suggest that the major components of the striatal glutamate receptors are GluR2-containing AMPA receptors and NR2A-containing NMDA receptors. Our results may provide useful information for corticostriatal synaptic transmission and plasticity studies.

• Journal of Korean Neurosurgical Society
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• 제41권4호
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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.

• 인지과학
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• 제21권3호
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• pp.429-446
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• 2010

본 연구는 경기장에서 스포츠 팬들이 자신이 응원하는 팀의 경기 승패에 따라 경험하는 긍정, 부정 정서가 정서의 편측화를 보이는 지를 fMRI 실험을 통하여 살펴보는 것이다. 이를 위해 S 프로야구 구단 팬 12명을 대상으로 S구단이 승리한 장면과 패배한 장면을 보여주었다. 측정결과, 승리장면을 지켜본 피험자들의 좌우 쐐기소엽, 우하후두이랑, 우하전두이랑, 좌편도체, 우해마옆이랑, 좌갈고리, 좌대상이랑, 좌하측두이랑, 우중측두이랑, 좌소뇌비탈, 좌소뇌정상 영역에서 활성화 반응이 나타났다. 반면에 패배장면을 지켜본 피험자들의 우중간전두이랑, 좌전대상회, 좌소이랑, 좌조가비핵, 좌창백핵, 좌배쪽전핵, 좌시상, 좌전장, 좌뇌섬엽 영역에서 활성화 반응이 나타났다. 본 연구결과 정서가의 반구비대칭 증거가 뚜렷하게 나타나지 않았으며 승리자극에서는 나타난 편도체의 활성이 패배자극에서는 나타나지 않아 패배정서 유발에 보다 심층적인 연구가 필요할 것으로 보아졌다.

• 대한본초학회지
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• 제21권4호
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• pp.197-205
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• 2006

Objectives: Anti-oxidants are known to prevent neuronal diseases with pathological and physiological changes such as the brain atrophy and cognitive impairment. This study was designed to investigate the protective effects of Korean ginseng on the oxidative stress induced pathologic changes, and develop new animal model for the brain atrophy. Korean ginseng has anti-oxidant, anti-aging, and protective effects on the brain ischemia. Methods : The intracerebroventricular (ICV) hydrogen peroxide ($H_2O_2$) injection into mice was conducted to generate oxidative stress. Results : The ICV $H_2O_2$ (1 M, $5\;{\mu}l$ injection did not induce either convulsion or death in the acute phase. At the end of second week, cognitive impairment and pathologic change of the brain were observed. The massive brain atrophy was found in the $H_2O_2-injected$ mice, especially in the hippocampus and thalamus. Treatment with Korean ginseng showed a protective effect against the brain atrophy. The $H_2O_2$ injected mice revealed cognitive impairment in the passive avoidance test, and Korean ginseng alleviated cognitive impairment. Conclusion : The results indicate that Korean ginseng has a protective effect on the oxidative stress-induced neuronal damages.

• The Journal of Korean Physical Therapy
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• 제29권3호
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• pp.109-114
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• 2017

Purpose: The ascending reticular activating system (ARAS) is responsible for regulation of consciousness. In this study, using diffusion tensor imaging (DTI), we attempted to reconstruct the thalamocortical projections between the intralaminar thalamic nuclei and the frontoparietal cortex in normal subjects. Methods: DTI data were acquired in 24 healthy subjects and eight kinds of thalamocortical projections were reconstructed: the seed region of interest (ROI) - the intralaminar thalamic nuclei and the eight target ROIs - the medial prefrontal cortex, dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, orbitofrontal cortex, premotor cortex, primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. Results: The eight thalamocortical projections were reconstructed in each hemisphere and the pathways were visualized: projections to the prefrontal cortex ascended through the anterior limb and genu of the internal capsule and anterior corona radiata. Projections to the premotor cortex passed through the genu and posterior limb of the internal capsule and middle corona radiata; in contrast, projections to the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex ascended through the posterior limb of the internal capsule. No significant difference in fractional anisotropy, mean diffusivity, and fiber volume of all reconstructed thalamocortical projections was observed between the right and left hemispheres (p>0.05). Conclusion: We reconstructed the thalamocortical projections between the intralaminar thalamic nuclei and the frontoparietal cortex in normal subjects. We believe that our findings would be useful to clinicians involved in the care of patients with impaired consciousness and for researchers in studies of the ARAS.

• Journal of Yeungnam Medical Science
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• 제15권2호
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• pp.306-315
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• 1998

1994년 1월에서 1998년 8월까지의 영남대학교 의과대학 부속병원에서 신경베체트병으로 진단받은 9명의 환자를 대상으로 전신적인 임상증상과 자기공명영상소견을 분석한 결과 주된 전신적인 증상은 구강궤양, 안질환, 음부궤양이었으며, 자기공명영상소견에서 병소부위는 중뇌, 내포, 뇌교, 시상, 대뇌기저핵, 중소뇌각, 연수, 그리고 피질하백질 순으로 호발되었다. 이들 병소는 T2강조영상에서 불균질의 고신호강도, T1강조영상에서 저신호 강도로 보였으며, 국소적인 조영증강이 비교적 흔하게 관찰되었다. 추적영상에서 병변의 호전 및 재발이 관찰되었으나 1년이상 추적검사에서 병변이 있던 부위에 뇌조직의 위축이 관찰되었다. 결론적으로 신경베체트병의 전신적인 임상증상과 특징적인 자기공명영상소견을 앎으로서 신경베체트병의 진단에 도움이 되리라 생각한다.

• Clinical and Experimental Pediatrics
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• 제59권sup1호
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• pp.139-144
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• 2016

Encephalocraniocutaneous lipomatosis (ECCL) is a rare neurocutaneous syndrome that affects ectomesodermal tissues (skin, eyes, adipose tissue, and brain). The neurologic manifestations associated with ECCL are various including seizures. However, ECCL patients very rarely develop brain tumors that originate from the neuroepithelium. This is the first described case of ECCL in combination with dysembryoplastic neuroepithelial tumor (DNET) that presented with intractable seizures. A 7-year-old girl was admitted to our center because of ECCL and associated uncontrolled seizures. She was born with right anophthalmia and lipomatosis in the right temporal area and endured right temporal lipoma excision at 3 years of age. Seizures began when she was 3 years old, but did not respond to multiple antiepileptic drugs. Brain magnetic resonance (MR) imaging performed at 8 and 10 years of age revealed an interval increase of multifocal hyperintense lesions in the basal ganglia, thalamus, cerebellum, periventricular white matter, and, especially, the right temporal area. A nodular mass near the right hippocampus demonstrated the absence of N-acetylaspartate decrease on brain MR spectroscopy and mildly increased methionine uptake on brain positron emission tomography, suggesting low-grade tumor. Twenty-four-hour video electroencephalographic monitoring also indicated seizures originating from the right temporal area. Right temporal lobectomy was performed without complications, and the nodular lesion was pathologically identified as DNET. The patient has been seizure-free for 14 months since surgery. Although ECCL-associated brain tumors are very rare, careful follow-up imaging and surgical resection is recommended for patients with intractable seizures.

• 인지과학
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• 제17권1호
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• pp.1-13
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• 2006

본 연구에서는 지향성을 탐지하는 과제를 하는 동안 활성화되는 뇌 영역을 검토하기 위하여 기능적 자기공명영상 기법을 이용하였다. 마음이론의 기본적 기제로 알려진 지향성 탐지에 관여하는 뇌의 활성화 영역이 사전 지시가 주어지는가에 따라 다른지를 알아보는 것이 연구의 주된 목적이었다. 과제에 대한 사전 지시가 주어진 경우에는 좌반구에서는 구부와 상측두회가 활성화되었고 우반구에서는 하후두회, 변연상회, 하두정소엽, 시상의 내배측핵, 설전소엽이 활성화되었다. 사전 지시가 주어지지 않았던 경우에는 우반구의 하두정소엽과 상두정소엽만이 활성화되었다. 두 경우에 공통적인 영역으로 하두정소엽이 관찰되었다. 이런 결과는 사전 지시가 지향성 탐지 관련 뇌 영역들을 더 분명하게 활성화시켰음을 시사한다. 지향성 탐지 기제의 자발적 작동과 참가자의 특성에 대한 추후 연구의 필요성을 논의하였다.