• Applied Microscopy
• /
• v.36 no.2
• /
• pp.119-130
• /
• 2006

To investigate the role of myelin-associated glycoprotein (MAG) in the normal aging process, aging-related morphometric and ultrastructural analyses of the MAG-positive (MAG-(+)) oligodendrocytes were carried out in the cerebral cortex of the Sprague-Dawley rats. In the aged rats, the density of MAG-(+) oligodendrocytes was significantly decreased in the cortical layer (IV-VI) compared with that of the adult rats. However, the percentage of medium and dark types of oligodendrocytes was significantly increased by aging. In the aged rats, the mean nuclear area of the MAG-(-) oligodendrocytes was interestingly reduced compared with that of MAG-(+) oligodendrocytes. In addition, MAG immunoreactive products were markedly decreased in the medium-dark type of oligodendroglial cytoplasm and processes, and were scarcely localized in the dark type of oligodendrocytes of the aged rats. These results suggest that degeneration of oligodendrocytes-myelin system by aging is associated with down regulation of MAG, and that may contribute to further understanding of the biology of MAG in the oligodendrocytes-myelin system.

• Journal of Life Science
• /
• v.14 no.6 s.67
• /
• pp.975-985
• /
• 2004

This study attempts to investigate the developmental alterations of rat cerebral cortex, and the effects of EGEE on the developmental cerebral cortex in the prenatal, postnatal and adults were examined by morphological methods and H-E staining was used for the histological changes. In the case of injection of EGEE, at 14 day of fetal phase, parietal cortex was thickest $(95{\pm}12.7\;{\mu}m)$ but, it was thinner than in the control group $(102{\pm}14.0\;{\mu}m)$ and, occipital cortex $(57{\pm}10.5\;{\mu}m)$ compared with other cortexes was the thinnest in fetal phase. In the suckling phase, each cortex grew thick quickly but, after weanning phase, the growth of the cortex slowed and the thickness of cortex was similar to that of cortex in the adult phase. At 105 day after birth, the parietal cortex was thickest $(934{\pm}21.6\;{\mu}m)$ but, decreased compared with control group $(1113{\pm}19.0\;{\mu}m)$. When EGEE was injected in intraperitoneal of rat, the number of neuroblasts per unit area was largest $(207.7{\pm}11.4/10^{-2}\;mm$ at the mantle layer of parietal cortex at 14 day of fetal phase but, decreased compared with control group $(224.2{\pm}13.8/10^{-2}\;mm$ , and the size was largest $(7.5{\pm}1.3\;{\mu}m)$ at the ependymal cell layer of occipital cortex at 3 day after birth but, decreased compared with control group $(9.0{\pm}1.2\;{\mu}m)$. Simillar to control group, the number of granular cells and pyramidal cells were largest at the II and III layer of parietal cortex, but decreased during developmental phase. The size was largest at the IV and V layer of occipital cortex but it was decreased compared with control group. When EGEE was injected in intraperitoneal of rat, the cerebral cortex from fetal phase to 3 day after birth has differentiated into the 3 layers; ependymal, mantle and marginal layer, but empty cisternaes or vacoules in the cerebral cortexes and the condensed phases of neuroblasts were appeared. From 5 day after birth, it has differentiated into the 4 layers; molecular, external granular, mixed layer of internal granular, external and internal pyramidal cells and multiformal layer but, empty cisternaes or vacoules in the granular and pyramidal cell layers were appeared and the number per unit area of neuron was decreased. In the cerebral cortex of the weaning and adult phases, division of cell layers was not clear and empty cisternae was formed in the cortex with the cells in external granular and pyramidal cell layers, was magnified or condensed around blood vessels of neurons.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.12
• /
• pp.1555-1562
• /
• 2000

Objects : Surgical management of the distal anterior cerebral artery(DACA) aneurysms presents several unique problems to surgeons, such as difficulty in early identification of parent arteries, high incidence of rebleeding and premature rupture, and requirement of unfamiliar approach other than conventional frontotemporal craniotomy. Therefore, preoperative anatomical knowledge of anterior interhemispheric fissure and entry point of dissection is prerequisite. Authors utilized a frontobasal approach for DACA aneurysms by using consistent external landmark for guidance to the deep structure. Materials and Methods : From Nov. 1995 to Jun. 1999, a surgical clipping of DACA aneurysms was carried out in 9 patients among a total 131 patients with intracranial aneurysms. In each case, the clinical and aneurysmal features were carefully reviewed through the angiograms, medical records, and intraoperative findings. Results : The incidence of DACA aneurysms was 6.9% from our series. All cases were arisen from juxtacallosal por-tion ; 6 cases from pericallosal-callosomarginal(PC-CM) junction and 3 from pericallosal-frontopolar(PC-FP) junction. Associated vascular anomalies were noted in 3 cases and multiple aneurysms in 3 cases, respectively. The preoperative clinical grades were generally poor. An early surgery was performed in 7 cases and frontobasal interhemispheric approaches in 7 cases. Postoperatively, two patients died of complications ; one delayed ischemic vasospasm and one aspiration pneumonia but remaining patients recovered well. Conclusion : The frontobasal interhemispheric approach was useful for DACA aneurysms in early surgery. Division of superior sagittal sinus(SSS) enabled a minimal retraction of brain on both sides, and prevention of intraoperative rupture was possible. Authors suggest the frontopolar(first frontal bridging) vein as a constant external landmark for approaching the genu of the corpus callosum and juxtacallosal DACA aneurysms.

• Journal of the Korean Society of Radiology
• /
• v.18 no.2
• /
• pp.73-81
• /
• 2024

This study compared the cortical thickness of patients with mood disorders and a control group to assess structural abnormalities. A retrospective study was conducted from September 2020 to August 2022 at the Department of Psychiatry, P Hospital in Yangsan, Gyeongsangnam-do. The study included 44 individuals diagnosed with mood disorders and 59 healthy individuals without any pathological lesions. The 3D-T1 MPRAGE images obtained from magnetic resonance imaging examinations were utilized, and FreeSurfer software was employed to measure cortical thickness. Statistical analysis involved independent samples t-tests to measure the differences in means between the two groups, and Cohen's d test was used to compare the effect sizes of the differences. Furthermore, the correlation between the measured average cortical thickness and Positive and Negative Syndrome Scale scores was analyzed. The research results revealed that patients with mood disorders exhibited decreased cortical thickness compared to the normal control group in both superior frontal regions, both rostral middle frontal regions, both caudal middle frontal regions, both pars opercularis, pars orbitals, pars triangularis regions, both superior temporal regions, both inferior temporal regions, both lateral orbitofrontal regions, both medial orbitofrontal regions, both fusiform regions, both posterior cingulate regions, both isthmus cingulate regions, both superior parietal regions, both inferior parietal regions, both supramarginal regions, left postcentral region, right bank of the superior temporal sulcus region, right middle temporal region, right rostral anterior cingulate region, and right insula region. Among them, regions that showed differences with effect sizes of 0.8 or higher were left fusiform (d=0.82), pars opercularis (d=0.94), superior frontal (d=0.88), right lateral orbitofrontal (d=0.85), and pars orbitalis (d=0.89). Additionally, there was a weak negative correlation between PANSS scores and average cortical thickness in both the left hemisphere (r=-0.234) and right hemisphere (r=-0.230). These findings are expected to be helpful in identifying areas of cortical thickness reduction in patients with mood disorders compared to healthy individuals and understanding the relationship between symptom severity and cortical thickness changes.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.16 no.2
• /
• pp.160-172
• /
• 2005

Attention-Deficit/Hyperactivity Disorder(ADHD) is the most common neurodevelopmental disorder in child psychiatry. The etiology or ADHD is not completely understood, but involved in genetical and/or neurocognitive deficits. This article reviews the current state of the literature pertaining to the neurodevelopmental aspects of ADHD. Although the neurodevelopment of ADHD remains unclear, emerging evidence documents its genetic and neurobiologic underpinnings. A pathophysiology of ADHD has not been fully characterized, although genetic, neurobiologic, neuroimaging, and neuropsychological studies of ADHD consistently implicates dysfunction in the fronto-subcortical network and abnormality in the dopaminergic and noradnergic systems. Furthermore some suggests that the timing of aberrant brain development in ADHD could be in early gestation and genetic and/or early environmental influences on brain development in ADHD are fixed, nonprogressive. Although many studies provide evidences for the important or psychosocial or environmental adversities in ADHD, they may be not specific predictors of ADHD but nonspecific triggers of an underlying predisposition or modifiers of the course of disorder.

• The Korean Journal of Zoology
• /
• v.33 no.2
• /
• pp.141-151
• /
• 1990

Raf protein kinases and protein kinase C belong to serine/threonine-specific proteins in the cytoplasin, and are similar to each other in functional structure and the aspect of the distribution of celI. The distribution of raf protein kinase in the cerebrum of Geoclemys reevesfi as studied by using the antibodies against a-raf and c-raf protein kinase which induce the expression of raf fainily oncogenes. In general, raf protein kinases were distributed in such restricted regions as the general pallium, hippocampal formation, pdmordiuin hippocampi,nucleus of lateral olfactory tract, basal amygdaloid nucleus, and bed of stria terminalis. Immunological labeling of c-raf protein kinase was more widespread than that of a-raf. However, the intensity of the labeling of c-raf was lower than that of a-raf. The spherical cells of basal amygdaloid nucleus is a ring-like form, because only the cytoplasm was imunolabeled. Especially, c-raf protein kinase occurred in the cells which contained protein kinase C abundandy such as pyramidal cells and Purkinje cells. This suggests that a- and e-raf protein kinases may synegistically induce carclnoma with myc gene which is activated by protein kinase C.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.8 no.1
• /
• pp.113-122
• /
• 1997

The purpose of this study was to examine brain structural abnormalities in autistic children. Magnetic resonance imaging(MRI) findings in 22 male children with a DSM-Ⅲ-R diagnosis of autistic disorder and 17 non-autistic male control children were investigated. The ratio measures by lineometry was used to examine the cerebrum, midbrain, cerebellum, brain stem and ventricular system. The left to right ratio of the lateral ventricle was larger in autistic children than in controls. The pons was significantly larger in autistic children than in controls, and the cerebellum was smaller in autistic children. There were no significant differences between autistic children and controls in the symmetricity of the fontral lobe, parietal lobe, occipital lobe and temporal lobe, and in the size of the midbrain and 4th ventricle. These findings suggest that autistic disorder may be related to structural impairment of the brain.

• Journal of Biomedical Engineering Research
• /
• v.25 no.5
• /
• pp.323-328
• /
• 2004

The development of group-specific tissue probability maps (TPM) provides a priori knowledge for better result of cerebral tissue classification with regard to the inter-ethnic differences of inter-subject variability. We present sequential procedures of group-specific TPM and evaluate the age effects in the structural differences of TPM. We investigated 100 healthy volunteers with high resolution MRI scalming. The subjects were classified into young (60, 25.92+4.58) and old groups (40, 58.83${\pm}$8.10) according to the age. To avoid any bias from random selected single subject and improve registration robustness, average atlas as target for TPM was constructed from skull-stripped whole data using linear and nonlinear registration of AIR. Each subject was segmented into binary images of gray matter, white matter, and cerebrospinal fluid using fuzzy clustering and normalized into the space of average atlas. The probability images were the means of these binary images, and contained values in the range of zero to one. A TPM of a given tissue is a spatial probability distribution representing a certain subject population. In the spatial distribution of tissue probability according to the threshold of probability, the old group exhibited enlarged ventricles and overall GM atrophy as age-specific changes, compared to the young group. Our results are generally consistent with the few published studies on age differences in the brain morphology. The more similar the morphology of the subject is to the average of the population represented by the TPM, the better the entire classification procedure should work. Therefore, we suggest that group-specific TPM should be used as a priori information for the cerebral tissue classification.

• Journal of the Korea Computer Graphics Society
• /
• v.10 no.4
• /
• pp.1-5
• /
• 2004

본 논문에서는 인체의 머리 부분을 촬영한 자기 공명 촬영 영상(MRI: Magnetic Resonance Imaging)에서 뇌 영역의 대뇌 피질 만을 분할하는 방법에 대해 제시하고자 한다. 뇌의 해부학적 구조를 파악할 경우에 영상 내에 함께 보여지는 두개골과 뇌척수액 등을 제외한 대뇌피질 영역을 분할하면 보다 효과적인 정보 분석 및 진단이 가능하게 된다. 본 논문에서는 3단계 알고리즘을 제시한다. 첫번째 단계에서는 Speckle reducing anisotropic diffusion (SRAD)를 이용하여 영상 내에 존재하는 잡음을 제거하기 위한 필터링이다. 두번째 단계에서는 필터링된 결과를 이용하여 추출된 임계값과 사용자의 인터렉션인 씨드 포인트를 통해 영상분할을 수행하고, 세 번째 단계에서는 후 처리를 통해 분할 결과를 보완한다. 영상분할 결과의 정확성을 측정하기 위하여 현재 병원의 의료진들이 사용하고 있는 Mayo clinic사의 Analyze를 이용하여 분할된 결과와의 오류를 측정하였다. 또한 최종 결과에 대해 ultravis를 이용한 볼륨 렌더링으로 영상분할의 최종 결과를 제시하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2002.12a
• /
• pp.175-178
• /
• 2002

인간은 두뇌의 일부를 이용하여 감각 정보를 수집하고 이에 대한 분석 및 판단을 행한 후에 행동을 취하는 일반적인 과정에 의해, 느끼고 생각하고 말한다. 이런 일련의 과정은 신경생리학적으로 밝혀진 바에 의하면, 대뇌의 시상에 분포한 일차 감각영역에서 감각 정보를 수집한다. 수집된 감각 정보는 과거 기억과의 비교를 통해 인식되고 인식된 정보는 일차 운동영역으로 전달되어 행동으로 나타난다. 수집된 감각 정보를 판단하는 기관은 감각 연합 영역으로 알려져 있으며, 과거 정보를 통해 비교하여 판단하는 방식이고, 과거 정보에 없는 새로운 정보의 경우 파페즈회로를 통해 새로운 정보로 기억하게 된다. 본 논문에서는 신경회로망의 적응적 학습 기법을 통해 파페즈회로의 기능을 구현하고자 한다. 기존 학습의 내용에 의해 알고 있는 감각 입력에 대해서는 인식 결과를 출력하고 그렇지 않은 입력에 대해서는 학습을 통해 이후 과정에 대응하도록 적응적인 구조와 학습 방법을 지닌 신경회로망을 이용하여 구현하고자 한다.