• Journal of Biomedical Engineering Research
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• v.2 no.1
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• pp.47-54
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• 1981

This paper deals with a new approach to the modelling of neural interactions in the cerebellar cortex to construct a general purpose electronic simulation model. Since physiological data show that cerebellar neural activity changes in an approximately pulse manner in response to pulse stimulation, the differences in timing between excitation and inhibition of cerebellar cells will be treated as pure time delays and the transfer functions of the cells will be presented by pure gains. The parameters to be discussed in this paper are the coupling coefficients between a cell and its several inputs, the magnitude of a coupling coefficient which is presented as a measure of how much influnce a particular has on its target cell. And also this paper has been proposed that the cerrbellum engaged in improving the overall performance of the motor control system, i.e., the cerebellum is a compensator.

• The Korean Journal of Nuclear Medicine
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• v.32 no.5
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• pp.397-402
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• 1998

Purpose: The purpose of this study was to evaluate the phenomenon of diaschisis in the cerebellum and cerebral cortex in patients with pure basal ganglia hemorrhage using cerebral blood flow SPECT. Materials and Methods: Twelve patients with pure basal ganglia hemorrhage were studied with Tc-99m ECD brain SPECT. Asymmetric index (AI) was calculated in the cerebellum and cerebral cortical regions as |$C_R-C_L$/$(C_R-C_L){\times}200$, where $C_R$and $C_L$ are the mean reconstructed counts for the right and left ROIs, respectively. Hypoperfusion was considered to be present when AI was greater than mean +2 SD of 20 control subjects. Results: Mean AI of the cerebellum and cerebral cortical regions in patients with pure basal ganglia hemorrhage was significantly higher than normal controls (p<0.05): Cerebellum ($18.68{\pm}8.94$ vs $4.35{\pm}0.94$, $mean{\pm}SD$), thalamus ($31.91{\pm}10.61$ vs $2.57{\pm}1.45$), basal ganglia ($35.94{\pm}16.15$ vs $4.34{\pm}2.08$), parietal ($18.94{\pm}10.69$ vs $3.24{\pm}0.87$), frontal ($13.60{\pm}10.5$ vs $4.02{\pm}2.04$) and temporal cortex ($15.92{\pm}11.95$ vs $5.13{\pm}1.69$). Ten of the 12 patients had significant hypoperfusion in the contralateral cerebellum. Hypoperfusion was also shown in the ipsilateral thalamus (n=12), ipsilateral parietal (n=12), frontal (n=6) and temporal cortex (n=10). Conclusion: Crossed cerebellar diaschisis (CCD) and cortical diaschisis may frequently occur in patients with pure basal ganglia hemorrhage, suggesting that CCD can develop without the interruption of corticopontocerebellar pathway.

• Korean Journal of Biological Psychiatry
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• v.25 no.3
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• pp.60-71
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• 2018

Objectives A growing body of evidence has suggested that morphologic changes in cerebellum may be implicated with pathophysiology of major depressive disorder (MDD). The aim of this study is to investigate a difference in the volume and cortical thickness of the specific region of cerebellum between patients with MDD and healthy controls (HC). Methods A total of 127 patients with MDD and 105 HC participated in this study and underwent T1-weighted structural magnetic resonance imaging. We analyzed volume and cortical thickness of each twelve cerebellum regions divided by left and right and the volume and cortical thickness of the whole cerebellum from T1-weigted image of participants. One-way analysis of covariance was used to investigate the volume and cortical thickness difference of total and specific regions between two groups adjusting for age, gender, medication, and total intracranial cavity volume. Results We found that the patients with MDD had significantly greater volume in the left cerebellum lobule III region [false discovery rate (FDR)-corrected p = 0.034] compared to HC. Also, our findings indicate that cortical thickness of left lobule VIIB (FDR-corrected p = 0.032) and lobule VIIIB (FDR-corrected p = 0.032) are significantly thinner in the patients with MDD compared with the HC. No significant volume and cortical thickness differences were observed in other sub-regions of the cerebellum. The volumes and cortical thickness of whole cerebellum between patients with MDD and HC did not differ significantly. Conclusions We observed the region-specific volume and cortical thickness difference in cerebellum between the patients with MDD and HC. The results of our study implicate that the information about structural alterations in cerebellum with further replicative studies might provide a stepping stone toward a specific marker to diagnose MDD.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.10-21
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• 2000

Purpose: Episodic memory is described as an 'autobiographical' memory responsible for storing a record of the events in our lives. We performed functional brain activation study using ${H_2}^{15}O$ PET to reveal the neural basis of the encoding and the retrieval of episodic memory in human normal volunteers. Materials and Methods: Four repeated ${H_2}^{15}O$ PET scans with two reference and two activation tasks were performed on 6 normal volunteers to activate brain areas engaged in encoding and retrieval with verbal materials. Images from the same subject were spatially registered and normalized using linear and nonlinear transformation. Using the means and variances for every condition which were adjusted with analysis of covariance, t-statistic analysis were performed voxel-wise. Results: Encoding of episodic memory activated the opercular and triangular parts of left inferior frontal gyrus, right prefrontal cortex, medial frontal area, cingulate gyrus, posterior middle and inferior temporal gyri, and cerebellum, and both primary visual and visual association areas. Retrieval of episodic memory activated the triangular part of left inferior frontal gyrus and inferior temporal gyrus, right prefrontal cortex and medial temporal area, and both cerebellum and primary visual and visual association areas. The activations in the opercular part of left inferior frontal gyrus and the right prefrontal cortex meant the essential role of these areas in the encoding and retrieval of episodic memory. Conclusion: We could localize the neural basis of the encoding and retrieval of episodic memory using ${H_2}^{15}O$ PET, which was partly consistent with the hypothesis of hemispheric encoding/retrieval asymmetry.

• Progress in Medical Physics
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• v.16 no.1
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• pp.32-38
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• 2005

Impaired processing of facial information is one of the broad ranges of cognitive deficits seen in patients with schizophrenia. The purpose of this study was to elucidate the differences in brain activities involved in the process of facial working memory between schizophrenic patients and healthy comparison subjects. Ten patients with schizophrenia were recruited along with matched healthy volunteers as a comparison group. Functional magnetic resonance imaging (fMRI) was used to assess cortical activities during the performance of a 1-back working memory paradigm using images of neutral faces as mnemonic content. The patient group performed the tasks with reduced accuracy. Group analysis revealed that left fusiform gyrus, right superior frontal gyrus, bilateral middle frontal gyri/insula, left middle temporal gyrus, precuneus and vermis of cerebellum and showed decreased cortical activities in the patient group. On the other hand, an increased level of activation in lateral prefrontal cortex and parietal lobule was observed from the patient group, all in the right hemisphere. A decreased level of activity in the left fusiform gyrus among the patient group implicates inefficient processing of facial information. An increased level of activation in prefrontal and parietal neural networks from the patient group confirms earlier findings on the impaired working memory of patients with schizophrenia.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.2
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• pp.256-265
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• 1997

Objectives：The purpose of this study was to investigate the characteristics and differences of brain function in pervasive developmental disorder and developmental language disorder. Method：The subjects were composed of 14 cases of pervasive developmental disorder and 13 cases developmental language disorder. They were investigated by technitium-99m-EDC SPECT. All SPECT were visually assessed by two nuclear medicine specialists, and then quantified by region of interest including temporal, parietal cortex, thalamus, basal ganglia and cerebellum. Result：In both groups, cerebral blood flow was decreased in the temporal, parietal cortex, basal ganglia, thalamus, cerebellum by visual assessment. There was no significant difference between the 2 groups by quantitative and qualitative assessment. Conclusion：These results suggest that pervasive developmental disorder and developmental language disorder are caused by defects in the interneural connection and that both disorders are spectrum disorders.

• Journal of radiological science and technology
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• v.34 no.1
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• pp.17-25
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• 2011

In this study, we examined the impact caused by chronic exposure to Mn by investigating the degree of brain activation based on the data of recognition activities using fMRI (functional magnetic resonance imaging). A questionnaire survey, blood tests, and fMRI tests were carried out with respect to two groups. Group 1 was an exposure group consisting of 15 male workers who are 34 years old or older, and who worked for longer than 10 years in a shipbuilding factory as a welder. Group 2 was a control group consisting of 15 workers in manufacturing industries with the same gender and age. The results showed that blood Mn concentration of Group 1($1.3\;{\mu}g/dl$) was significantly higher than that of Group 2($0.8\;{\mu}g/dl$)(p < 0.001), and Pallidal Index (PI) of Group 1 was also significantly higher than that of Group 2 (p < 0.001). PI value of the group whose blood Mn concentration was $0.93\;{\mu}g/dl$ or higher was significantly higher than that of the group whose blood Mn concentration was less than $0.93 \;{\mu}g/dl$ (p < 0.001). As for brain activity area within the control group, the right and the left areas of occipital cortex showed significant activity and the left area of middle temporal cortex, the right area of superior inferior frontal cortex and inferior parietal cortex showed significant activity. Unlike the control group, the exposure group showed significant activity on the right area of superior inferior temporal cortex, the left of insula area. In the comparison of brain activity areas between the two groups, the exposure group showed significantly higher activation than the control group in such areas as the right inferior temporal cortex, the left area of superior parietal cortex and occipital cortex, and cerebellum including middle temporal cortex. However, in nowhere the control group showed more activated area than the exposure group. As the final outcome, chronic exposure to Mn increased brain activity during implementation of arithmetic task. In an identical task, activation increased in superior inferior temporal cortex, and insula area. And it was discovered that brain activity increase in temporal area and occipital area was more pronounced in the exposure group than in the control group. This result suggests that chronic exposure to Mn in the work environment affects brain activation neuro-network.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.546-551
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• 2007

The purpose of this investigation was to determine the effect of feeding dried mackerel as a means of increasing the intake of these n-3 polyunsaturated fatty acids on fatty acid compositions in liver and nervous tissue. Twenty male mice aged at 4 weeks were fed on the control (5% palm oil, control group) and 5% dried mackerel diets (mackerel group) for four weeks. In fatty acid compositions of liver and cortex, levels of total n-3 fatty acid, specially docosahexaenoic (22:6n-3, DHA) and eicosapentaenoic (20:5n-3, EPA) acids, were increased in the mackerel group compared to the control group, while docosapentaenoic acid (22:5n-6, DPAn-6) levels were decreased (p<0.05). In cerebellum and retina, levels of DHA were not significantly different between the control and mackerel groups, but levels of total n-6 fatty acids and arachidonic acid (20:4n-6, AA) were decreased in the mackerel group. These results indicated that intake of 5% dried mackerel increased levels of n-3 polyunsaturated fatty acids in cortex. Thus, we will investigate the relationship between brain function and cortex fatty acid compositions following intake of mackerel by assessing discrimination leaning ability.

• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.438-444
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• 2005

Purpose: Anhedonia has been proposed to be the result of a basic neurophysiologic dysfunction and a vulnerability marker that precede and contribute to the liability of developing schizophrenia. We hypothesized that anhedonia, as a construct reflecting the decreased capacity to experience pleasure, should be associated with decreased positive hedonic affect trait. This study examined the relationship between anhedonia and positive hedonic affect trait and searched for the brain legions which correlate with anhedonia in normal subjects. Materials and Methods: Using $^{18}F$-FDG PET scan, we investigated the brain activity of twenty one subjects during resting state. Questionnaires were administrated after the scan in order to assess the self-rated individual differences in physical/social anhedonia and positive/negative affect traits. Results: Negative correlation between physical anhedonia score and positive affect trait score was significant (Pearson coefficient =-0.440, p<0.05). The subjects physical and social anhedonia scores showed positive correlation with metabolic rates in the cerebellum and negative correlation with metabolic rates in the inferior temporal gyrus and middie frontal gyrus. In addition, the positive affect trait score positively correlated with various areas, most prominent with the inferior temporal gyrus. Conclusion: These results suggest that neural substrates, such as the inferior temporal gyrus and prefrontal-cerebellar circuit, which dysfunction has been proposed to be involved with the cognitive deficits of schizophrenia, may also play a significant role in the liability of affective deficits like anhedonia.

• Korean Journal of Acupuncture
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• v.31 no.1
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• pp.20-32
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• 2014

Objectives : There has been some controversy about the modulatory effects on brain function during acupuncture on each side of the same acupoint. This study was designed to investigate and compare the blood oxygen level-dependent(BOLD) responses of acupuncture on each side of ST36. Methods : Fourteen healthy subjects were recruited for imaging and received acupuncture or placebo stimulations either on the left or on the right acupoint of ST36 in each scan. For the voxel-wise statistical analysis, one sample T-test and the within-subject analysis of variance(ANOVA) test were performed using SPM8 software. Results : This study showed that acupuncture on each side of ST36 showed different BOLD signal patterns. Higher BOLD responses after acupuncture stimulations at the left ST36 compared to the right were observed mainly in the parahippocampal gyrus(BA 28), dorsolateral prefrontal cortex(DLPFC, BA 44), thalamus, culmen and claustrum. We investigated the different neural responses between rest and activation periods of placebo and acupuncture stimulations on each side of ST36. Acupuncture at the right ST36 elicited activation mainly in the insula, supplementary motor area(SMA) and anterior cingulate cortex(ACC), while acupuncture at the left ST36 elicited activation mainly in the insula, primary somatosensory cortex(SI, BA 2) and DLPFC(BA 44). Conclusions : To our knowledge, this is the first reported functional MRI study directly comparing when needling at the right and at the left side of ST36. This study's preliminary results proved to be evidence of acupuncture's different effects when performed on opposite sides of an acupoint.