Search

MIDIキーボードと機能的磁気共鳴画像法(fMRI)を用い，聴覚フィードバックによって指先の力を調整するときの脳活動を検討した．本研究は，指の力のコントロールにおける聴覚フィードバックの効果と，その時の脳活動について明らかにすることを目的として行った．実験の結果，指先の力を制御する際に音圧と力が対応する聴覚フィードバックが返ってくる場合(Normal条件)の方が，対応していない場合(Reverse条件)よりうまく指先を制御できることが示された．また，力の補正に関わると考えられる脳活動が左角回と右上頭頂小葉で確認された．さらに，左背側前運動皮質や両側の一次聴覚皮質が聴覚フィードバックの音の違いにそれぞれ特異的な応答を示すことが示唆された．この研究は，聴覚と運動の統合メカニズムについて議論する一助となることが期待される．, We conducted an experiment using a keyboard instrument. The purpose of this study was to reveal what kind of auditory feedback is helpful for controlling finger force. Participans were asked to control the force of fingertips depending on auditory feedback, and the brain activities related to the force control were measured with functional magnetic resonance imaging. As a result, it was shown that "Normal condition," in which the intensity of feedback sound increased as the finger force was strengthened, is more effective in controlling the fingertip force than "Reverse condition." Furthermore, we found brain activity associated with adjustment of force control in the left angular gyrus and right superior parietal lobule. In addition, we observed activation patterns specific to feedback sound in the left dorsal premotor cortex and bilateral primary auditory cortex. This study will give an insight into adaptive mechanisms of auditory-motor integration.

Background In these days, the occurrence of neuropsychological complications during perioperative period has become the subject of discussion. Diabetes is indicated as one of the metabolic risk factors. Although the number of patients with diabetes mellitus (DM) has been increasing, the pathophysiology of postoperative neuropsychological dysfunction in DM patient is still unclear. Recently, a deficiency of neurotransmitters, such as monoamines, was reported to be associated with mental disorders. Therefore, we investigated the effects of surgical stress on behavioral activity and the hippocampal noradrenaline (NA) level in type 2 diabetes mellitus model (T2DM) mice.Methods Eighty-four 6-week-old male C57BL/6J mice were divided into four groups (control, surgery control, T2DM, and surgery T2DM groups). T2DM mice were established by feeding a high fat diet (HFD) for 8 weeks. At 14 weeks of age, fifteen mice in every group underwent a series of behavioral tests including an open field (OF) test, a novel objective recognition (NOR) test and a light-dark box (LD) test. In the surgery groups, open abdominal surgery with manipulation of intestine was performed 24 hours before the behavioral tests as a surgical stress. Hippocampal NA level was examined in six mice in each group by high-performance liquid chromatography. The data were analyzed by Mann-Whitney U test and P values less than 0.05 were considered significant.Results The T2DM group showed significantly increased explorative activity in the NOR test (P = 0.0016) and significantly increased transition in the LD test (P = 0.043) compared with those in the control group before surgery. In T2DM mice, surgical stress resulted in decreased total distance in the OF test, decreased explorative activity in the NOR test, and decreased transition in the LD test (OF: P = 0.015, NOR: P = 0.009, LD: P = 0.007) and decreased hippocampal NA (P = 0.015), although they were not revealed in control mice.Conclusion T2DM mice by feeding a HFD showed increased behavioral activities, and surgical stress in T2DM mice caused postoperative hypoactivity and reduction of hippocampal NA level.

Background There has been much discussion recently about the occurrence of neuropsychological complications during the perioperative period. Diabetes is known to be one of the metabolic risk factors. Although the number of patients with diabetes mellitus (DM) has been increasing, the pathophysiology of postoperative neuropsychological dysfunction in DM patients is still unclear. Recently, a deficiency of neurotransmitters, such as monoamines, was reported to be associated with mental disorders. Therefore, we investigated the effects of surgical stress on behavioral activity and hippocampal noradrenaline (NA) level in type 2 diabetes mellitus model (T2DM) mice. Methods Eighty-four 6-week-old male C57BL/6J mice were divided into four groups (non-diabetes, non-diabetes with surgery, T2DM, and T2DM with surgery groups). T2DM mice were established by feeding a high-fat diet (HFD) for 8 weeks. At 14 weeks of age, fifteen mice in each group underwent a series of behavioral tests including an open field (OF) test, a novel object recognition (NOR) test and a light–dark (LD) test. In the surgery groups, open abdominal surgery with manipulation of the intestine was performed 24 h before the behavioral tests as a surgical stress. Hippocampal noradrenaline (NA) concentration was examined in six mice in each group by high-performance liquid chromatography. The data were analyzed by the Mann–Whitney U test, and p values less than 0.05 were considered significant. Results The T2DM group showed significantly increased explorative activity in the NOR test (P = 0.0016) and significantly increased frequency of transition in the LD test (P = 0.043) compared with those in the non-diabetic group before surgery. In T2DM mice, surgical stress resulted in decreased total distance in the OF test, decreased explorative activity in the NOR test, and decreased frequency of transition in the LD test (OF: P = 0.015, NOR: P = 0.009, LD: P = 0.007) and decreased hippocampal NA (P = 0.015), but such differences were not observed in the non-diabetic mice. Conclusions Mice with T2DM induced by feeding an HFD showed increased behavioral activities, and surgical stress in T2DM mice caused postoperative hypoactivity and reduction of the hippocampal NA level.