匂いと味が一致しない刺激が与えられた場合の脳波活動に見られるシータ帯域の増加

This study aimed to investigate how odor stimulation affects taste perception. Electroencephalogram (EEG) signals were measured from the frontal region of the head in normal subjects, and frequency analyses were performed. Each odor stimulation was delivered while the subject tasted chocolate, using chocolate paste as the odorant for ‘matched odor stimulation’, and garlic paste for ‘unmatched odor stimulation’. Differences appeared in EEG signals. Comparing frequencies of EEGs under ‘unmatched odor stimulation’ with those under ‘matched odor stimulation’ showed that the occupancy rate of the theta-frequency band under ‘unmatched odor stimulation’ was higher than that under ‘matched odor stimulation’. Interestingly, a negative correlation existed between the occupancy rate of the theta-frequency band and the subjective feeling of chocolate sweetness. The present findings suggest that when we receive unmatched smell against the foods, subjective feelings are disturbed, and theta-band brain activity is increased while cross-checking the unmatched information

Influence of Active Fingertip Contact with a Stable Surface on Postural Sway and Electromyographic Activities of the Lower Extremity Muscles Immediately after Descending a Step

Recent studies have shown that active contact cues from a fingertip provide information that leads to reduced postural sway during static standing. Although the falling risk increases immediately after descending a step, little is known about the influence of active fingertip contact with a stable surface. The purpose of this study was to investigate the influence of fingertip contact on the sway and the EMG (Electromyographic) activities of lower extremity muscles immediately after descending a step. Nine healthy male volunteers participated in this study. Sway was measured by the center of pressure (COP) and compared under three conditions: (1) standing without touching, (2) standing with the right index fingertip lightly touching (<1N), and (3) standing forcefully touching (5~10N). EMG activities were measured associated with sway and compared. More areas of COP were observed while standing without touching than while standing with light or forceful touching, but there was no significant difference between the two touching conditions. No significant differences in the length of COP and the EMG activities were observed among the three conditions. The results suggested that the fingertip touch contact with a stable surface decreased sway immediately after descending a step by finely controlling the lower extremity muscles

チュウスウ シンケイケイ NMDA ジュヨウタイ ノ カツドウ ガ ヒキオコス ケイケン イゾンテキ シナプス カソセイ ノ セイリガクテキ オヨビ ビョウタイ セイリガクテキ ヨウソウ

N-methyl-D-aspartate (NMDA) receptors play an important role in neural plasticity in the central nervous systems (CNSs). We can change our behaviors according to storing things in memory and learning, and the ability is necessary for survival in the daily life. The “learning and memory” is based on experience-dependent neural plasticity in the CNSs. NMDA receptor activation is essential for inducing plastic changes in the structural and functional refinement of synapses and circuits. “Hebbian learning” is an important form of learning and memory. Mg2+ block is a fine equipment of NMDA receptor, and is required to establish“ Hebbian learning”. NMDA receptor activation, however, does not always induce preferred conditions. There are cases that, in particular situations, NMDA receptor activation-dependent plasticity causes pathological conditions. In this review, I will overview the roles of the NMDA receptors in physiological and pathophysiological conditions