Akihiro Kawauchi

Acupuncture stimulation to the sacral segment affects state of vigilance in rats.

The effects of acupuncture stimulation to the sacral segment on electroencephalograms (EEGs) and activity of locus coeruleus (LC) neurons were examined in urethane-anesthetized rats. In 71 of 112 trials, when EEGs displayed small amplitude and high frequency, stimulation to the sacral segment-induced large amplitude and slow EEGs with a latency of <450s and duration ranged from 32s to >42 min. Stimulus-induced EEGs comprised significant increases in delta power and significant decreases in theta and beta powers. After intraperitoneal administration of bicuculline, stimulation to the sacral segment failed to induce changes in EEG pattern. Firing rate of noradrenergic LC neurons decreased significantly from 2.9+/-1.5 to 1.1+/-0.8 Hz (n=11, p<0.001). Decreased neuronal activity exhibited close relationships with increased EEG amplitude. These results suggest that acupuncture stimulation to the sacral segment changes the state of animals from light anesthesia to deep anesthesia, and that this change is mediated by GABAergic systems suppressing the activity of noradrenergic LC neurons.

Acupuncture to the sacral segment suppresses micturition through GABAergic system

The circadian rhythm of QT interval variability is still unclear, although it is known that QT interval prolongation is a predictor of sudden cardiac death. The aim of present study is to establish a dynamical model between RR interval variability and QT interval variability, and to identify its dynamical parameters in 24-hr circadian rhythms. A linear mathematical dynamical model is established between RR-interval variability and QT-interval variability. The model parameters can be identified using system identification technique. Simulated data show that the mathematical model fit well to the dynamics of QT-interval variability. Eight-young healthy subjects are recruited in the study. The results show that dynamics between RR variability and QT variability is individual-specific,and their dynamical parameters express distinct circadian rhythms. The results suggest that the circadian properties of QT interval dynamics may play a prominent role in sudden cardiac death prevention.