• 제목/요약/키워드: neocortex

검색결과 30건 처리시간 0.028초

EEG model by statistical mechanics of neocortical interaction

  • Park, J.M.;Whang, M.C.;Bae, B.H.;Kim, S.Y.;Kim, C.J.
    • 대한인간공학회지
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    • 제16권2호
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    • pp.15-27
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    • 1997
  • Brain potential is described using the mesocolumnar activity defined by averaged firings of excitatory and inhibitory neuron of neocortex. Lagrangian is constructed based on SMNI(Statistical Mechanics of Neocortical Interaction) and then Euler Lagrange equation is obtained. Excitatory neuron firing is assumed to be amplitude- modulated dominantly by the sum of two modes of frequency .omega. and 2 .omega. . Time series of this neuron firing is calculated numerically by Euler Lagrangian equation. I .omega. L related to low frequency distribution of power spectrum, I .omega. H hight frequency, and Sd(standard deviation) were introduced for the effective extraction of the dynamic property in the simulated brain potential. The relative behavior of I .omega. L, I .omega. H, and Sd was found by parameters .epsilon. and .gamma. related to nonlinearity and harmonics respectively. Experimental I .omega L, I .omega. H, and Sd were obtained from EEG of human in rest state and of canine in deep sleep state and were compared with theoretical ones.

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시각자극과 삼음교 자침으로 유발된 성적 흥분의 대뇌 활성화 영상의 비교 : 3 테슬라 기능적 자기공명영상법 (Comparison of Brain Activation Images Associated with Sexual Arousal Induced by Visual Stimulation and SP6 Acupuncture : fMRI at 3 Tesla)

  • 최남길;한재복;장성주
    • 대한방사선기술학회지:방사선기술과학
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    • 제32권2호
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    • pp.183-194
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    • 2009
  • 목 적 : 정상인 여성을 대상으로 기능적 자기공명영상법(functional magnetic resonance imaging : fMRI)을 이용하여 성적 흥분반응과 관련되는 시각자극과 삼음교(SP6, 三陰交) 경혈자극 의한 대뇌 활성화 영역의 차이점을 밝히고, 나아가서는 성적흥분의 기전을 신경해부학적인 측면에서 규명하고자 하였다. 대상 및 방법 : 성기능이 정상적인 오른손잡이 여자 21명(19$\sim$32세 : 평균 22세)을 대상으로 3.0 Tesla MR scanner를 이용하여 fMRI 영상을 얻었다. 성적 흥분을 유도하기 위한 패러다임은 3분간의 에로틱 비디오 시청과 삼음교(SP6)자침에 의한 자극을 주었으며, 자극 전 후에는 각각 1분간의 휴지기를 두었다. 또한 광명혈(GB37) 후방으로 3 cm 위치에 있는 비경혈점에 자극을 주어 경혈(acupoint)과 비경혈(shampoint) 자침에 의한 대뇌의 활성화 양상을 비교하였다. 기능적 자기공명영상의 획득은 AC-PC line을 기준으로 20개의 횡단면으로부터 총 2,000개의 기초영상을 얻었으며, SPM99 프로그램을 이용하여 평균 활성화 영상을 얻었다. 결 과 : 삼음교 경혈과 비경혈의 침자극에 의한 비교실험에서 경혈은 비경혈에 비하여 대뇌 신피질에서 평균 5배, 변연계에서 2배 높은 활성화도를 보였다. 비경혈 자극시에 간뇌의 HTHL, 기저핵의 GLO, AMYG, 그리고 두정엽의 SMG 등에서는 활성화 신호가 관찰되지 않았다. 성적흥분과 관련된 대뇌의 해부학적인 영역을 시각자극과 삼음교 경혈자극 별로 비교 분석한 결과, 두 자극간의 평균 활성화율(activation ratio)은 신피질과 변연계 모두에서 유의한 차이가 없었다(p < 0.05). 반면 평균 활성화도(activity)는 신피질의 경우에는 두 자극간에 유의한 차이를 보이지 않았으나, 변연계의 경우에는 경혈 자극시에 유의하게 더 높은 활성화도를 보였다(p < 0.05). 결 론 : 기능적 자기공명영상법을 이용하여 성적흥분과 관련된 시각자극과 경혈 침술자극에 의하여 유발된 대뇌 활성화 양상의 차이점과 신경해부학적 기전의 차이점을 규명할 수 있었으며, 이러한 결과를 바탕으로 향후 한방의 경혈, 경락 이론을 과학적인 측면에서 입증할 수 있을 것으로 기대한다.

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일차 수술후 재발한 난치성 간질환자에 대한 수술 (Surgery in Patients with Previous Resection of the Epileptogenic Zone Due to Intractable Epilepsy)

  • 김재엽;최하영;김영현
    • Journal of Korean Neurosurgical Society
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    • 제30권11호
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    • pp.1300-1307
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    • 2001
  • Purposes : This study reports the possible causes of seizure recurrence in patients underwent previous epilepsy surgery, and surgical strategy for resection of the additional epileptogenic zone locating at the distant area to the site of first resection. Methods : A total of 10 patients with previous surgery due to intractable epilepsy were studied. Five of these underwent standard temporal lobectomy, four extratemporal resection, and one corticoamygdalectomy. Seizure outcome of these were class III-IV. Evaluation methods for reoperation included MRI, 3D-surface rendering of MRI, PET, prologned video-EEG recording with surface electrodes and subdural grid electrodes. Additional resection was done in the frontal lobe in two, in the temporal lobe in three, in the parietal lobe in two, and in the supplementary sensori-motor area in two. Tumor in the superior frontal gyrus in the left hemisphere was removed in one patient. Extent of resection was decided based on the results of ictal subdural grid EEGs and MRI findings. Awake anesthesia and electrocortical stimulation were performed in the two patients for defining the eloquent area. Results : Histopathologic findings revealed extratemporal cortical dysplasia in six, hippocampal sclerosis and cortical dysplasia of the temporal neocortex in one, neuronal gliosis in two, and meningioma in one. Previous pathology of the five patients with cortical dysplasia in the second operation was hippocampal sclerosis plus cortical dysplasia of the temporal neocortex. After reoperation, seizure outcomes were class I in six, class II in three, class III in one at the mean follow-up period of 17.5 months. Characteristically, patients in class II-III after reoperation showed histopathologic findings of hippocampal sclerosis plus temporal neocortical cortical dysplasia plus extratemporal cortical dysplasia. Conclusions : Seizure recurrence after epilepsy surgery was related with the presence of an additional epileptogenic zone distant to the site of first operation, and the majority of the histopathology of the surgical specimens was cortical dysplasia. In particular, hippocampal sclerosis plus temporal neocortical cortical dysplasia was highly related with seizure recurrence in patients with previous operation. In these patients, multimodal evaluation methods were necessary in defining the additional epileptogenic zone.

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뇌신경교세포(腦神經膠細胞) 집단(集團)의 발생(發生)과 이동(移動)에 대한 방사선(放射線) 자기법적(自記法的) 관찰 II. 뇌(腦) 외배엽성(外胚葉性) 신경교세포(神經膠細胞)의 분열(分裂)과 이동(移動)에 대하여 (Radioautographical observations of development and appearance of glia cells in brain II. Division and migration of ectodermal glial cell in the brain)

  • 곽수동
    • 대한수의학회지
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    • 제32권4호
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    • pp.489-496
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    • 1992
  • The division, distribution and migration of the macroglial cells in the juvenile mouse brain were investigated with the radioautography. Forty mice (ICR) were randomly subdivided into two groups. The twenty mice from group 1 were weighing initially 5 to 6g, aged 10 to 12 days and were sacrificied at 2 hrs, 2, 3, 5, 7, 10, 15 and 20 days after a single intraperitoneal injection of $^3H$-thymichine ($4{\mu}$ Ci/g of body weight). Twenty mice from group 2 were weighing intially 2.5 to 5g, aged 3 to 8 days and were sacrificed at 2 hrs, 2, 3, 5. 7, 10, 15 and 20 days after a single($4{\mu}$ Ci/g of body weight) and/or after intraperitoneal repeated injections($2{\mu}$ Ci/g of body weight/interval) at 2, 3 and 5 days after the first injection. The brain preparations were processed for autoradiogrouphy using Kodak NTB-3 emulsion following development in Kodak D-19, fixation in Kodak fixer, and then stained with cresyl echt violet or hematoxylin counterstain. The labeling index of the ectodermal glial cells in the subependymal layers of the lateral ventricles (SLLV), corpus callosum (CC), molecular layer of the neocortex (MLN ), inner layer except the molecular layer in the neocortex (ILN) and medulla of the cerebrum (MC) were invested. 1. Labeling cells appeared from 2 hour and some of them sustained in the 20 day after injection. In the single injection group, the peak of the labeling index reached a 7.6% at 3 day, 3.6% at 7 day, 3.3% at 2 day, 5.0% at 3 day and 2.3% at 2 day from the SLLV. CC, MLN, ILN and MC, respectively. In the repeated injecton group, the peak of the labeling index reached a 32.0 at 7 day, 11.0% at 10 day, 89% at 7 day, 16.0% at 10 day and 10.8% at 15 day from the SLLV, CC, MLN, ILM and MC, respectively. 2 The glial cells of the SLLV were recognized as to be migrated into the CC and to be not or less to be into the MC and ILN but to be not into the MLN. Glial cell aggregates in the neocotex and MC were recognized as to be proliferated and then disappeared in the itself regions.

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뇌 해마를 제거한 흰쥐의 일반활동 및 음식물섭취 (General Activity and Food Intake Following Removal of the Hippocampus in Rats)

  • 이종수;강일영
    • The Korean Journal of Physiology
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    • 제1권1호
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    • pp.43-49
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    • 1967
  • Nine male rats in which 90% or more of the hippocampal tissue was removed through a small hole made in the neocortex at the boundary between the parietal and the occipital lobes (hippocampal group), 3 male rats with similar neocortical damage alone (operated control group), and 9 normal control male rats (normal control group) were prepared. Their general activity was measured for 48 hours in an activity cage by recording the number of beams they interrupted. The amount of food and water intake was also checked simultaneously. Results obtained were as follows: 1. The general activity of the hippocampal group was 2 to 3 times as great as that of the operated control or the normal control group. 2. All of the 3 groups demonstrated clear-cut circadian variation of activity, the diurnal and the nocturnal activity being in the ratio 22 : 78. 3. The amount of food and water consumed by the hippocampal group did not differ significantly from that by the opperated control or the normal control group. In the course of the experiment which continued for 3 months the hippocampal group gained weight least among the 3 groups.

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방사선조사에 의해 피질이형성증 백서의 전기행동학적, 병리조직학적 특징 (Electrobehavioral and Pathological Characteristics in Cerebral Cortical Dysplasia Induced by External Irradiation in the Rat)

  • 최하영
    • Journal of Korean Neurosurgical Society
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    • 제29권7호
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    • pp.861-867
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    • 2000
  • Purpose : Neuronal migration disorder(NMD) is a major underlying pathology of patients with intractable epilepsy. The role of NMD on seizure susceptibility or epileptogenecity, however, has not been documented. Methods : External irradiation of total amount of 250 cGY was performed to the fetal rats on days 16(E16) and 17(E17) of gestation. After delivery, the rats of 230-260g were decapitated for the histopathologic study. Epileptog-enecity of the NMD was studied by observing electroclinical events after intraperitoneal kainic acid(KA) injection in the control rats and NMD rats. Results : Histopathologic findings revealed focal and/or diffuse cortical dysplasia consisting of dyslamination of the cerebral cortex and appearance of the cytomegalic neurons, neuronal heterotopia in the periventricular white matter, dispersion of the pyramidal layer and the dentate gyrus of the hippocampus, and agenesis of the corpus callosum. Abnormal expression of neurofilaments protein(NF-M/H) was characteristically observed in the dysplastic neurons of the neocortex and hippocampus. Early ictal onset and prolonged ictal activity on EEG and clinical seizures were observed from the NMD rats unlike with the control rats. Conclusions : Exteranl irradiation on the fetal rats produced NMD. And the rats with NMD were highly susceptible to kainic acid provoked seizures. This animal model would be useful to study the pathophysiology of clinically relevant NMDs.

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Seizure-related Encephalopathy in Rats Intoxicated with Diisopropylfluorophosphate

  • Kim, Yun-Bae;Hur, Gyeung-Haeng
    • 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.

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Dopamine Modulates Corticostriatal Synaptic Transmission through Both $D_1$ and $D_2$ Receptor Subtypes in Rat Brain

  • Lee, Hyun-Ho;Choi, Se-Joon;Kim, Ki-Jung;Cho, Hyeong-Seok;Kim, Seong-Yun;Sung, Ki-Wug
    • 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.

학습과 기억의 생물학적 기초(I):신경심리학적 개관 (The Biological Base of Learing and Memory(I):A Neuropsychological Review)

  • 김문수
    • 인지과학
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    • 제7권3호
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    • pp.7-36
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    • 1996
  • 본 논문에서는 인간을 대상으로 한 신경심리학적 연구결과들을 중심으로 기억의 뇌생리적 기초에 관하여 지금까지 알려진 바를 개관하고자 하였다. 현재 인지심리학자들은 기억이 하나의 단일한 체계가 아니라 여러가지 독자적인 하위체계들로 구분된다고 생각한다. 이러한 다중기억체계의 관점을 따라 본 논문에서는 뇌의 어느부위가 손상될때 어떤 종류의 기억에 장애가 생기는가,그리고 뇌영상 기법을 사용하요 특정 기억과제를 수행하는 도중에 뇌의 어느 부위가 그 제시방식에 따라 약간씩 다르지만 대개 후두염,두정엽,그리고 측두엽의 경계선을 중심으로 한 비교적 넓은 부위가 중요한 것으로 보인다. 장기기억의 경우,그 한 하위체계인 암묵기억은 하나의 단일한 기억체계가 아니어서 어떤 학습과제가 사용되는가에 다라 관련되는 부위가 많이 달라진다. 반면에 외현기억의 형성(즉,응고화)에는 내측측두엽이 결정적인 역할을 한다는 사실을 잘 알려져 있다. 일화기억과 의미기억의 저장 그리고/또는 인출에는 측두피질과 전두전피질이 중요한 역할을 하는것으로 보인다. 끝으로,장기기억의 저장장소에 관한 최근의 견해가 소개되었다.

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Identification of 1,531 cSNPs from Full-length Enriched cDNA Libraries of the Korean Native Pig Using in Silico Analysis

  • Oh, Youn-Shin;Nguyen, Dinh Truong;Park, Kwang-Ha;Dirisala, Vijaya R.;Choi, Ho-Jun;Park, Chan-Kyu
    • Genomics & Informatics
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    • 제7권2호
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    • pp.65-84
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    • 2009
  • Sequences from the clones of full-length enriched cDNA libraries serve as valuable resources for functional genomics related studies, genome annotation and SNP discovery. We analyzed 7,392 high-quality chromatograms (Phred value ${\geq}$30) obtained from sequencing the 5' ends of clones derived from full-length enriched cDNA libraries of Korean native pigs including brainstem, liver, cerebellum, neocortex and spleen libraries. In addition, 50,000 EST sequence trace files obtained from GenBank were combined with our sequences to identify cSNPs in silico. The process generated 11,324 contigs, of which 2,895 contigs contained at least one SNP and among them 610 contigs had a minimum of one sequence from Korean native pigs. Of 610 contigs, we randomly selected 262 contigs and performed in silico analysis for the identification of cSNPs. From the results, we identified 1,531 putative coding single nucleotide polymorphisms (cSNPs) and the SNP detection frequency was one SNP per 465 bp. A large-scale sequencing result of clones from full-length enriched cDNA libraries and identified cSNPs will serve as a useful resource to functional genomics related projects such as a pig HapMap project in the near future.