大鼠腦電波及心臟自主神經功能於運動過程中之變化：老化及高血壓之影響

Abstract

若能偵測運動過程中之生理訊號，將有許多重要應用，故運動過程中生理訊號向來是許多研究者致力研究的議題，而往往難以排除因運動造成的雜訊干擾。長期運動會調節心臟自主神經系統以及其他生理訊號，更可以降低血壓以及減緩老化。若干擾自主神經系統活性後，會進而影響大腦功能，本論文成功建立記錄大鼠運動過程中之腦波及心電訊號之模式，可藉此了解運動過程中大腦皮質與心臟間之互動。目的：利用大鼠生理訊息同時紀錄及分析系統，探討運動過程中大腦與心臟自主神經之間的互動，並嘗試觀察高血壓以及老化是否有其特異表現。方法：以8及60週齡Wistar-Kyoto (WKY) 及8週齡 spontanouesly hypertensive rat (SHR) 為實驗對象，植入頭電極7天後，對大鼠進行跑步機運動，並同時紀錄其腦波和心電訊號。統計方法以雙因子變異數分析來檢定差異性，並以 Fisher’s 法進行事後比較，統計水準至少達p＜0.05，數據以mean ± SEM 表示。結果：各組相比，大鼠進行運動時腦波平均功率 (F=22.412)、alpha (F=113.260)、 beta (F=34.732)、delta (F=23.049) 及 theta波 (F=22.521)，各頻帶腦波平均功率百分比均達顯著差異 (p<0.05) ;心電訊號部份，心跳RR間距 (F=45.721) 以及心率變異性中HF (F=56.503)、LF (F=139.613) 及LF/HF (F=56.500) 均達顯著差異(p<0.05)，進行事後比較。發現年老使運動過程中的腦波變化較不明顯但心臟自主神經功能明顯降低;高血壓大鼠於運動過程中theta波顯著低於正常血壓大鼠。結論：大鼠於運動過程中，處於較專注且警覺的狀態，且睡意下降，其心臟自主神經功能亦在運動過程中下降。於開始運動進行時，大腦皮質活性增加快於心臟反應，而年老大鼠於運動狀態下其自主神經功能明顯衰退，高血壓大鼠於運動過程中theta波有其特異表現，進一步求證後可作為評估罹患高血壓之指標。There will be numerous important applications to record physiological signals during strenuous exercise. Many researchers aim for that but it’s still difficult to exclude exercise-induced interference. Long-term exercise will regulate cardiac autonomic system and other physiological signals, reduce blood pressure and retard aging. Further, it will affect cerebral function after interrupting autonomic system activity. This discourse successfully established animal model of recording electroencephalogram and electrocardiogram during exercise. The developed technique will offer a way to study the interaction of cerebral cortex and heart during exercise in rats. Purpose: With continuous recording and analyzing the system of rats, we could explore the interaction of brain and cardiac autonomic system during exercise; also, we could attempt to observe distinction of hypertension and aging. Methods: All experiments were carried out on 8 and 60 weeks Wistar-Kyoto and spontaneously hypertension rats. After seven days from the electrodes and electrocardiogram were implanted, continuous electroencephalogram (EEG) and electrocardiogram (ECG) were recorded during treadmill exercise in rats. Effects of the exercise on the physiological parameters were assessed using two-way analysis of variance (ANOVA) and t-test with repeated measures. When indicated by a significant F statistic, regional differences were isolated using post hoc comparisons by the Fisher’s least-significant difference test. Statistical significance was assumed for p< 0.05. Values are expressed as means  SEM. Results: Compared with each groups, treadmill exercise resulted significant difference in mean power frequency (F=22.412), alpha (F=113.260), beta (F=34.732), delta (F=23.049) and theta power (F=22.521) of the EEG, and R-R interval (F=45.721), HF (F=56.503), LF (F=139.613) and LF/HF (F=56.500) of EEG. Such changes quickly reversed when the treadmill exercise was stopped. Conclusion: Rats were more attention and alertness and lower sleepiness and cardiac autonomic function during exercise. At beginning of exercise, the increase of cortical activity was faster than heart response. Autonomic function of elderly rat declined appreciably during exercise. There was outstanding expression of theta power during exercise in hypertension rats. After further attestation it may be the predictor of affecting hypertension.