• 제목/요약/키워드: Thalamus

검색결과 199건 처리시간 0.022초

모듈라 신경망을 이용한 대뇌피질의 모델링 (Model for Cerebral Cortex Using Modular Neural Network)

  • 김성주;연정흠;조현찬;전홍태
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2002년도 하계종합학술대회 논문집(3)
    • /
    • pp.139-142
    • /
    • 2002
  • The brain of the human is the best model for the artificial intelligence and is studied by many natural, medical scientists and engineers. In the engineering department, the brain model becomes a main subject in the area of development of a system that can represent and think like human. In this paper, we approach and define the function of the brain biologically and especially, make a model for the function of cerebral cortex, known as a part that performs behavior inference and decision for sensitive information from the thalamus. Therefore, we try to make a model for the transfer process of the brain. The brain takes the sensory information from sensory organ, proceeds behavior inference and decision and finally, commands behavior to the motor nerves. We use the modular neural network in this model. finally, we would like to design the intelligent system that can sense, recognize, think and decide like the brain by learning the information process in the brain with the modular neural network.

  • PDF

확산텐서영상에서 확산경사자장의 방향수에 따른 FA값 및 FA의 표준편차와의 상관 관계

  • 이영주;황문정;배성진;장용민;우성구;서수지
    • 대한자기공명의과학회:학술대회논문집
    • /
    • 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
    • /
    • pp.33-33
    • /
    • 2003
  • 목적: 확산텐서영상 획득시 확산경사자장의 방향수와 FA값, 그리고 FA값의 표준편차와의 상관관계를 조사해 보고자 하였다. 대상 및 방법: 3T MR scanner에서 정상성인 10명(남자 5명, 여자 5명)을 대상으로 걸어주는 확산강조 경사자장의 수(N = 6, 11, 23, 35, 47)를 증가시키며 확산텐서영상을 획득하였다. 획득된 영상들로부터 FA map을 만들고 주요 뇌구조물(frontal GM, putamen, posterior limb of internal capsule, thalamus 등)에 관심영역을 설정하여 FA값을 측정하였으며 그 FA값의 표준편차(sd) 를 계산하였다. 이때 사용한 펄스열은 Stejskal-Tanner type의 확산강조 경사자장이 포함된 single-shot SE EPI를 사용하였으며 영상획득시 사용한 피라미터는 다음과 같다. TR/TE=8000ms/71ms, Thickness/spacing=5/2mm, FOV=240mm, Matrix=$128{\times}128$, NEX= 1, b value=1000s/$\textrm{mm}^2$.

  • PDF

Proton MR Spectroscopic Changes in Parkinson′s Disease

  • 백현만;최보영;손병철;정성택;이형구;서태석
    • 대한자기공명의과학회:학술대회논문집
    • /
    • 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
    • /
    • pp.88-88
    • /
    • 2003
  • Purpose: To investigate whether there are significant changes in regional brain metabolism in patients with Parkinson's disease after thalamotomy using proton magnetic resonance spectroscopy (1H MRS). Materials and methods: Fifteen patients with Parkinson's disease of mean age 56.5 years (7 males and 8 females; mean age, 56.5 years) that have treated with levodopa were included. All patients with tremor experienced amelioration of their symptoms on the side contralateral to the thalamotomy. As a single-voxel technique, 1H MR spectra were obtained from the volume of interested regions in thalamus and primary motor cortex. Spectral parameters were: 20 ms TE, 2000 ms TR, 128 averages, 2500 Hz spectral width, and 2048 data points.

  • PDF

Massive Calcified Cerebellar Pilocytic Astrocytoma with Rapid Recurrence : A Rare Case

  • Aydemir, Fatih;Kardes, Ozgur;Kayaselcuk, Fazilet;Tufan, Kadir
    • Journal of Korean Neurosurgical Society
    • /
    • 제59권5호
    • /
    • pp.533-536
    • /
    • 2016
  • Pilocytic astrocytomas (PAs) are World Heath Organization Grade I tumors and are most common in children. PA calcification is not a common finding and has been reported more frequently in the optic nerve, hypothalamic/thalamus and superficially located cerebral tumors. We present a cerebellar PA in a 3-year-old male patient with cystic components and massive calcification areas. The residual tumor grew rapidly after the first operation, and the patient was operated on again. A histopathological examination revealed polar spongioblastoma-like cells. Massive calcification is not a common feature in PAs and can lead to difficulties in radiological and pathological differential diagnoses.

시상부 뇌농양의 뇌실내로의 파열 - 증례보고 - (Intraventricular Rupture of a Thalamic Abscess - A Case Report -)

  • 정득채;장석정;안태형
    • Journal of Korean Neurosurgical Society
    • /
    • 제30권9호
    • /
    • pp.1140-1143
    • /
    • 2001
  • The mortality of patients with brain abscess has decreased significaltly. This has been attributed to improved diagnostic imaging, the evolution of neurosurgical techniques and understanding of intracranial pressure pathophysiology, greater critical care understanding, and newer antibiotics. However, the mortality associated with intraventricular rupture of brain abscess remained consistently high at or above 80% once identified. A case of intraventicular rupture of thalamic abscess with good quality of survival is presented based on aggressive 4-component therapeutic plan used. The four components are 1) extraventricular drainage for 6 weeks, 2) lavage of the ventricular system using closed irrigation system, 3) intravenous antibiotics, 4) intraventricular gentamicin and vancomycin, twice and once daily, respectively.

  • PDF

Neuroprotection of Lithium is Associated with Inhibition of Bax Expression and Caspase 8 Activation

  • Kwon, Gee-Youn;Kim, Soo-Kyung
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제5권5호
    • /
    • pp.389-396
    • /
    • 2001
  • Neuroprotective properties of lithium were investigated by using in vivo NMDA excitotoxicity model. The appearance of TUNEL positive cells was prominent within 24 h of NMDA (70 mg/kg, i.p.) injection in the regions of the cortex, hippocampal formation, and thalamus of mouse cerebrum. NMDA treatment resulted in the extensive enhancement of Bax immunoreactivity in the cortical and hippocampal regions. NMDA also increased the immunoreactivity of caspase 8 in the similar regions of the mouse cerebrum. However, the increased immunoreactivity of Bax and caspase 8 were dramatically attenuated by chronic lithium pretreatment (lithium chloride, 300 mg/kg/d, i.p. for $7{\sim}10$ days). At the same time, lithium ion blocked the appearance of TUNEL positive cells, and the morphological assessment indicated an effective neuroprotection by lithium against NMDA excitotoxicity. Although the exact action mechanism of lithium is not straightforward at this time, we propose that the inhibition of Bax and caspase cascade is involved in the neuroprotective action of lithium.

  • PDF

효과적인 뇌기능 영상 분석을 위한 유효 연결성을 이용한 대규모 네트워크 분석 (Large-Scale Network Analysis using Effective Connectivity for Effective Brain Functional Imaging Analysis)

  • 박기희;이성환
    • 한국정보과학회:학술대회논문집
    • /
    • 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(C)
    • /
    • pp.377-378
    • /
    • 2011
  • 본 논문은 뇌기능 연구에 크게 기여하는 기능적 자기공명영상을 효과적으로 분석하기 위한 유효 연결성(Effective Connectivity, EC)을 이용한 대규모 네트워크(Large-Scale Network, LSN) 분석(LSN-EC)을 제안한다. 유효 연결성은 뇌영역간의 시공간적 인과관계를 표현한 연결성이며, 뇌의 기능적 연결성 및 구조탐색 사용된다. LSN-EC는 뇌영역간의 EC를 표현하고 그룹간의 차이분석을 통하여 뇌질환 분석 및 진단 연구로의 응용이 가능하다. 실험결과에서 알츠하이머병과 관련이 높다고 알려진 후대상피질(Posterior Cingulate Cortex)과 해마(Hippocampus)가 포함된 변연엽(Limbic Lobe), 기저핵 및 시상(Basal Ganglion and Thalamus) 주변 영역에서 감소된 EC를 확인하였다.

HPLC-ECD에 의한 흰쥐 뇌 부위별 Catecholamine 및 대사산물의 신속정량법 (Determination of Catecholamines and Their Metabolites in Rat Brain by High Performance Liquid Chromatography with Electrochemical Detector)

  • 노일협
    • 약학회지
    • /
    • 제32권1호
    • /
    • pp.50-54
    • /
    • 1988
  • A simple and sensitive method was studied for the simultaneous determination of catecholamine, indoleamine and their related metabolites by high performance liquid chromatography with electrochemical detector. Norepinephrine, dopamine, serotonin and their metabolites of 3,4-dihydroxyphenylacetic acid, homovanillic acid, 5-indoleacetic acid were resolved from rat brain tissue homogenates by separation on reversed phase $C_{18}$ column with mobile phase consisting of monochloroacetate buffer (pH2.47), 1.42mM sodium octyl sulfonate and 7% acetonitrile. Both catechols and indoles can be eluted in 15min. The sensitivities of this method are sufficient for determination of at least 100 pg of neurochemical amines in brain samples, for example, frontal cortex, olfactory bulb, striatum, septum, hippocampus, thalamus, hypothalamus, medulla & pons and cerebellum. The highest level of dopamine was observed in striatum whereas norepinephrine and serotonin were in hypothalamus.

  • PDF

치매가 동반된 특발성 기저핵 석회화 1례 (A Case of Idiopathic Basal Ganglia Calcification with Dementia)

  • 신희영;신일선
    • 생물정신의학
    • /
    • 제13권1호
    • /
    • pp.38-42
    • /
    • 2006
  • The case of a 66- year-old woman with coexisting idiopathic basal ganglia calcification(IBGC) and dementia was presented. The calcification was detected in bilateral basal ganglia, dentate nucleus, and thalamus by brain imaging. Serum calcium and phosphorus levels were normal. The underlying diseases of calcification of basal ganglia such as parathyroid dysfunction and other infectious, toxic, or metabolic illness were excluded. The patient had memory impairment and frontal executive dysfunction without aphasia, agnosia, apraxia, and visuospatial impairment in neuropsychological test. It suggested that the cognitive impairment might be due to the dysfunction of frontal-subcortical circuit.

  • PDF

정신분열증의 신경 해부학 (Neuroanatomy in Schizophrenia)

  • 민성길
    • 생물정신의학
    • /
    • 제3권1호
    • /
    • pp.3-13
    • /
    • 1996
  • Many studies have been conducted to search for the anatomical abnormalities in the brain which ore etiologically related with schizophrenia. Generally schizophrenia in known to be related with decreased brain tissue, hypofrontality and abnormalities in the temporal lobe including the hippocamypus, the agmygdala and the entorhinal cortex. Other areas related with the disorder ore basal ganglia, thalamus, brain stem, pons and nucleus accumbens. Abnormality in brain asymmetry is one of the new areas of interest which needs further study. The results so for ore inconsistent and it is unlikely that the abnormality in one structure is the only cause of the disorder. Rather, schizophrenia develops from the impairment of the parallel processing of integrated and reciprocal information which is distributed to the multiple structures. Histopathologic studies in the postmortem brain suggest that schizophrenia is related with neurodevelopmental abnormality rather than neurodegenerative abnormality.

  • PDF