The cooperative phenomenon of autonomic nervous system in urine storage for Wistar rats.

The fractal dimension (FD) and spectral frequencies of physiological signals are two important indices in the study of physiological functions and dynamical diseases. The first index can be used to characterize the intensity and the second the rhythms of signals embedded in seemingly random data. Recent studies using both indices verified that synergic co-activations of bladder and external urethral sphincter (EUS) of Wistar rats were present during the voiding of urine. In this study, the primary aims were to (1) examine if the involved muscles in the lower urinary tract would be under similar coactivations during the urine storage phase, and (2) characterize quantitatively the sympathetic and parasympathetic nerve activities simultaneously. Eighteen experiments were performed on six intact adult female Wistar rats and then the electromyogram of EUS and cystometrogram of bladder were analyzed. Results indicated that the EUS did not contain any significant spectral frequencies in the storage phase. Furthermore, its FDs (1.5918 +/- 0.0157) indicated that no appreciable amount of signal intensities was observed in the EUS. On the other hand, the bladder exhibited parasympathetic frequency of 8 Hz with signal-to-noise ratio (SNR) = 19.9001 decibel (dB) for group mean, and sympathetic frequency of 19 Hz with SNR = 22.8330 dB for group mean. In addition, its FDs (1.4796 +/- 0.0092) indicated relatively persistent intensities during storage, as compared to that of EUS (1.5918 +/- 0.0157) with statistical significance (P < 0.01). We concluded that the EUS was not activated during the phase of storage. The bladder was under the cooperative, not antagonistic, sympathetic and parasympathetic nerve activities with discernible rhythmic frequencies and persistent intensities.

Effects of acupuncture at Neiguan (PC 6) on electroencephalogram.

The aim of this study was to investigate if there were any effects on the electroencephalogram (EEG) of human brain by the manual stimulation of Neiguan (PC 6) acupuncture site. In this paper, two groups of six healthy male volunteers of ages 27.6 +/- 14.2 (mean +/- SD) and 28.5 +/- 13.0 (mean +/- SD) and no neurological disease participated in this study. A digital storage of 12-channel EEG recorder was used and spectral analyses of the data set of 18 trials were obtained before, during, and after sham/ manual acupuncture. To minimize artefacts, all data were collected with the subjects alert but eyes closed. No significant changes (P > 0.05) were obtained for the sham acupuncture group. As for the manual acupuncture group, the needle was inserted perpendicularly into the PC 6 acupuncture site and manually stimulated about 15 to 30 seconds to achieve De Qi sensation. Needles were left in place for 30 min and then removed. Analysis of the EEG data due to acupuncture was compared to the baseline data and changes were obtained. First, all trials had an increase in the amplitude and power of the alpha band during manual acupuncture (P < 0.05) when compared with the baseline data. Secondly, in the mean time, the frequency peaks in alpha band of 12-channels were all synchronized with much smaller standard deviation (P < 0.01). Thirdly, the manual acupuncture effects of higher power and synchronized frequencies persisted for at least 10 minutes after the experiment (P < 0.05) and did not disappear immediately for all 18 experiments. Finally, we hypothesized that the higher power and synchronized rhythms in brain oscillations may have to do with autonomic nervous system.

Effects of acupuncture at Neiguan (PC 6) of the pericardial meridian on blood pressure and heart rate variability.

The aims of this study were to investigate (i) if and when the blood pressure would rise or fall and (ii) the associated changes of human heart rate variability (HRV) by manual stimulation of the Neiguan (PC 6) acupuncture site. In this paper, two groups of six healthy male volunteers with ranges of ages 20-56 and 20-55 and with no neurological diseases participated in this study. In order to minimize artefacts, the electrocardiogram (ECG) and radial arterial pulse pressure wave were collected with the subjects alert but eyes closed before, during, and after sham/manual acupuncture. No statistically significant changes (P > 0.05) were found in the sham acupuncture group. As for the manual acupuncture group, the needle was inserted into the PC 6 acupoint and manually stimulated about 15 to 30 seconds to achieve De Qi sensation. Needles were left in place for 30 min and then removed. Analysis of the data due to acupuncture was then compared with the baseline values. Results indicate that the blood pressures of different subject can either rise (P < 0.01) or fall (P < 0.01). To further determine the indicator for one subject who exhibited both rise and fall of blood pressures, 7 more trials were given conducted with the same protocol until statistically significant results were obtained (P < 0.01). We found that his change of blood pressure was highly correlated (p = -0.94 and -0.99 for rise and fall, respectively) with the ratio of the magnitude of pulse pressure to that of the dicrotic notch in the local radial pulse wave (P < 0.01). As to the heart rate variability (HRV) spectra, significant changes in the low frequency (LF) and very low frequency (VLF) ranges were also detected. These results indicate that the autonomic innervations of heart have been modified. However, the information on the power of LF, high frequency (HF), and LF/HF of HRV are not conclusive to statistically differentiate the sympathetic contribution from that of the parasympathetic nervous systems at present stage.

Fractal dimension estimation via spectral distribution function and its application to physiological signals.

Rhythmic signals from physiological systems usually have memory and long-term correlation. They can be modeled as fractional Brownian motion or fractional Gaussian noise depending on if the signals are derived from cumulative effects of nerves and muscles. That is, they can be treated as signals with fractional dimension, and the value of its fractal dimension can be used to characterize the intensity of physiological signals. In this communication, a novel method of dimension estimation based on the calculation of spectral distribution function of discrete-time fractional Gaussian noise using Legendre polynomials as basis set is proposed. The effectiveness of this proposed method is demonstrated in the dynamic behavior of detrusor of the bladder and external urethral sphincter during micturition.