quantal analysis による海馬でのエンケファリンの作用機序の研究

金沢大学医学部研究課題/領域番号60770110, 研究期間(年度):1985出典：研究課題「quantal analysis による海馬でのエンケファリンの作用機序の研究」課題番号60770110（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-60770110/）を加工して作

Inhibitory processes in development of seizure activity in hippocampal slices

取得学位 : 博士（医学）, 学位授与番号 : 医博乙第1074号, 学位授与年月日：平成1年11月15日,学位授与年：198

ラット歯状回のシナプス伝達とてんかん波発生に対するソマトスタチンの効果

金沢大学医学部・附属病院電気生理学的実験を開始する2日前に成熟ラットにCysteamine(100mg/kg)を腹空内投与した群と生理食塩水を投与した対照群を用意し、それぞれのラットの海馬スライスを作成した。歯状回の顆粒細胞層に記録電極を刺入し、場の電位を記録した。分子層を単一パルスで通電し、単シナプス性の場の電位変化を誘発した。対照群では、いくら刺激強度を強めても、単発の集合活動電位しか誘発されないが、Cysteamine投与群では、電気刺激により、2〜5発の集合活動電位がバースト状に誘発された。また、100Hz、1秒間の高頻度刺激を10分間隔で繰り返し刺激すると後発射の発展を観察することができる。対照群では15スライスのうち、8スライスで後発射の発展を観察することができるが、Cysteamine投与群では、16スライス中15スライスで後発射の発展を観察することができた。第5回目の高頻度刺激によって誘発される後発射数を2群間で比較すると、後発射の発生を観察した対照群8スライスで7.5±5.2(平均±標準偏差)、後発射の発生を観察したCysteamine投与群15スライスで18.5±8.3であり、Cysteamine投与群ではてんかん様異常波の発生が促進されることが証明された。Cysteamineは脳内ソマトスタチンを涸渇する物質として知られており、以上の結果はソマトスタチン濃度の減少がてんかんの誘発に関与するを示している。てんかん患者の歯状回のソマトスタチン濃度が減少しているとする従来の報告に一致する興味深い結果が得られた。研究課題/領域番号:06770750, 研究期間(年度):1994出典：研究課題「ラット歯状回のシナプス伝達とてんかん波発生に対するソマトスタチンの効果」課題番号06770750（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-06770750/）を加工して作

海馬苔状線維終末の単離標本からのイオン電流の記録

金沢大学医学部研究課題/領域番号:02770059, 研究期間(年度):1990出典：研究課題「海馬苔状線維終末の単離標本からのイオン電流の記録」課題番号02770059（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-02770059/）を加工して作

The relationship between auditory ERP and neuropsychological assessments in schizophrenia

金沢大学附属病院To clarify the cognitive significance of event-related potential (ERP) abnormalities in schizophrenia, we examined the relationships of amplitudes and latencies of ERP components with performance on neuropsychological tests in schizophrenic patients. Twenty patients underwent the Trail Making B Test (TM-B), which is sensitive to frontal lobe dysfunction, and the logical memory, verbal paired-association, and visual reproduction subtests of the Wechsler Memory Scale (WMS), which are sensitive to temporal lobe dysfunctions, and ERP recordings during performance of an oddball auditory discrimination task. Pearson product–moment correlations indicated that an increased P200 amplitude was correlated with poor performance on the TM-B, whereas a decreased P300 amplitude was correlated with poor performance on the verbal paired-association subtest of the WMS. These findings suggest that a P200 abnormality represents the frontal lobe dysfunction, and a P300 abnormality represents the left temporal lobe dysfunction in schizophrenia

Hub structure in functional network of EEG signals supporting high cognitive functions in older individuals

IntroductionMaintaining high cognitive functions is desirable for “wellbeing” in old age and is particularly relevant to a super-aging society. According to their individual cognitive functions, optimal intervention for older individuals facilitates the maintenance of cognitive functions. Cognitive function is a result of whole-brain interactions. These interactions are reflected in several measures in graph theory analysis for the topological characteristics of functional connectivity. Betweenness centrality (BC), which can identify the “hub” node, i.e., the most important node affecting whole-brain network activity, may be appropriate for capturing whole-brain interactions. During the past decade, BC has been applied to capture changes in brain networks related to cognitive deficits arising from pathological conditions. In this study, we hypothesized that the hub structure of functional networks would reflect cognitive function, even in healthy elderly individuals.MethodTo test this hypothesis, based on the BC value of the functional connectivity obtained using the phase lag index from the electroencephalogram under the eyes closed resting state, we examined the relationship between the BC value and cognitive function measured using the Five Cognitive Functions test total score.ResultsWe found a significant positive correlation of BC with cognitive functioning and a significant enhancement in the BC value of individuals with high cognitive functioning, particularly in the frontal theta network.DiscussionThe hub structure may reflect the sophisticated integration and transmission of information in whole-brain networks to support high-level cognitive function. Our findings may contribute to the development of biomarkers for assessing cognitive function, enabling optimal interventions for maintaining cognitive function in older individuals

A comparative study on long-term evoked auditory and visual potential responses between Schizophrenic patients and normal subjects

<p>Abstract</p> <p>Background</p> <p>The electrical signals measuring method is recommended to examine the relationship between neuronal activities and measure with the event related potentials (ERPs) during an auditory and a visual oddball paradigm between schizophrenic patients and normal subjects. The aim of this study is to discriminate the activation changes of different stimulations evoked by auditory and visual ERPs between schizophrenic patients and normal subjects.</p> <p>Methods</p> <p>Forty-three schizophrenic patients were selected as experimental group patients, and 40 healthy subjects with no medical history of any kind of psychiatric diseases, neurological diseases, or drug abuse, were recruited as a control group. Auditory and visual ERPs were studied with an oddball paradigm. All the data were analyzed by SPSS statistical software version 10.0.</p> <p>Results</p> <p>In the comparative study of auditory and visual ERPs between the schizophrenic and healthy patients, P300 amplitude at Fz, Cz, and Pz and N100, N200, and P200 latencies at Fz, Cz, and Pz were shown significantly different. The cognitive processing reflected by the auditory and the visual P300 latency to rare target stimuli was probably an indicator of the cognitive function in schizophrenic patients.</p> <p>Conclusions</p> <p>This study shows the methodology of application of auditory and visual oddball paradigm identifies task-relevant sources of activity and allows separation of regions that have different response properties. Our study indicates that there may be slowness of automatic cognitive processing and controlled cognitive processing of visual ERPs compared to auditory ERPs in schizophrenic patients. The activation changes of visual evoked potentials are more regionally specific than auditory evoked potentials.</p

Effects of etizolam and ethyl loflazepate on the P300 event-related potential in healthy subjects

<p>Abstract</p> <p>Background</p> <p>Benzodiazepines carry the risk of inducing cognitive impairments, which may go unnoticed while profoundly disturbing social activity. Furthermore, these impairments are partly associated with the elimination half-life (EH) of the substance from the body. The object of the present study was to examine the effects of etizolam and ethyl loflazepate, with EHs of 6 h and 122 h, respectively, on information processing in healthy subjects.</p> <p>Methods</p> <p>Healthy people were administered etizolam and ethyl loflazepate acutely and subchronically (14 days). The auditory P300 event-related potential and the neuropsychological batteries described below were employed to assess the effects of drugs on cognition. The P300 event-related potential was recorded before and after drug treatments. The digit symbol test, trail making test, digit span test and verbal paired associates test were administered to examine mental slowing and memory functioning.</p> <p>Results</p> <p>Acute administration of drugs caused prolongation in P300 latency and reduction in P300 amplitude. Etizolam caused a statistically significant prolongation in P300 latency compared to ethyl loflazepate. Furthermore, subchronic administration of etizolam, but not ethyl loflazepate, still caused a weak prolongation in P300 latency. In contrast, neuropsychological tests showed no difference.</p> <p>Conclusions</p> <p>The results indicate that acute administration of ethyl loflazepate induces less effect on P300 latency than etizolam.</p

Effects of Aging Stereotype Threat on Working Self-Concepts: An Event-Related Potentials Approach

Although the influence of stereotype threat (ST) on working self-concepts has been highlighted in recent years, its neural underpinnings are unclear. Notably, the aging ST, which largely influences older adults’ cognitive ability, mental and physical health, did not receive much attention. In order to investigate these issues, electroencephalogram (EEG) data were obtained from older adults during a modified Stroop task using neutral words, positive and negative self-concept words in aging ST vs. neutral control conditions. Results showed longer reaction times (RTs) for identifying colors of words under the aging ST compared to the neutral condition. More importantly, the negative self-concept elicited more positive late P300 amplitudes and enhanced theta band activities compared to the positive self-concept or neutral words under the aging ST condition, whereas no difference was found between these self-concepts and neutral words in the control condition. Furthermore, the aging ST induced smaller theta band synchronization and enhanced alpha band synchronization compared to the control condition. Moreover, we also observed valence differences in self-concepts where the negative self-concept words reduced early P150/N170 complex relative to neutral words. These findings suggest that priming ST could activate negative self-concepts as current working self-concept, and that this influence occurred during a late neural time course