Interactions between Neural Oscillators and their Functional Hierarchical Structures

在氟烷麻醉下，动物在枕前-乳头后水平去脑。然后将动物固定在一个立体框架上，四肢放在一个移动的跑步机带上。将玻璃绝缘钨微电极插入中脑，识别中脑运动区（MLR），刺激该区域可诱导在跑步机上运动。对MLR进行强直电刺激（50脉冲/秒）。双极电极分别植入双侧腓肠肌和膈肌，记录肌电图，评估两组患者的步动节律和呼吸节律。通过记录心电图（ECG）评估心律。心跳周期被转换成另一个脉冲序列，其中脉冲以代表心跳周期的脉冲高度等间隔排列。将变换后的心跳信号命名为心跳波动。休息时，更多的iac节律受到呼吸节律的强烈调节（呼吸性窦性心律失常，RSA）。这种呼吸调节心跳的程度在跑步机上运动时变得很小。这表明在运动过程中，心脏和呼吸节律之间的耦合强度变弱。然后在氟烷麻醉下对动物进行双侧迷走神经切除。静息时，迷走神经切开术后心跳的呼吸调节程度明显减弱。然而，在运动时，心肺耦合的强度比静止时更大。然后用三碘化胆碱（4mg /Kg）麻醉动物，并进行人工通气。气胸也在麻醉下进行。在这样的准备中，强直性电刺激被传递到MLR以引起有效的运动。利用心率波动与后肢肌神经传出放电之间的一致性来评价mlr诱导的有效运动中心脏节律与运动节律的耦合性。心跳显然是由中央产生的步伐节奏调节的。这一结果表明存在中央起源的运动-心脏耦合。基于以上发现以及我们之前的发现，我们提出了一个关于生物振子层次结构的新模型。少

Animals were decerebrated at the precollicular-postmammillary level under halothane anesthesia. The animal was then fixed to a stereotaxic frame, and the limbs were placed on a moving treadmill belt. The glass-insulated tungsten microelectrode was inserted into the midbrain to identify the mesencephalic locomotor region (MLR), stimulation of which induces locomotion on a treadmill. Tonic electrical stimulation (50 pulses/s) was delivered to the MLR. Electromyograms were recorded by implantation of bipolar electrode into the bilateral gastrocnemius muscle and the diaphragm to evaluate the stepping rhythm and the respiratory rhythm, respectively. The cardiac rhythm was assessed by recording of electrocardiogram (ECG). The heart beat periods were transformed into another pulse train in which the pulses were arranged in equal intervals with the pulse height representing the heart beat periods. The transformed heart beat signal was designated as the heart beat fluctuation. At rest, the card … More iac rhythm was strongly modulated by the respiratory rhythm (Respiratory Sinus Arrhythmia, RSA). The extent of such respiratory modulation of heart beat became small during treadmill locomotion. This result suggested that the coupling strength between the cardiac and the respiratory rhythms became weak during locomotion. The animal was then vagotomized bilaterally under halothane anesthesia. At rest, the extent of the resiratory modulation of heart beat markedly reduced after vagotomy. However, the strength of the cardiorespiratory coupling became greater during locomotion than that at rest. The animal was then paralyzed with gallamine triethiodide (4 mg/Kg i.v.), and artificially ventilated. Pneumothorax was also performed under anesthesia. In such a preparation, tonic electrical stimulation was delivered to the MLR to elicit fictive locomotion. The coherence between the heart beat fluctuation and the efferent discharges of the hindlimb muscle nerve was used to evaluate the coupling between cardiac and locomotor rhythms during MLR-elicited fictive locomotion. Heart beat was apparently modulated by the centrally generated stepping rhythm. This result demonstrated that there was a locomotor-cardiac coupling of central origin. Based on the above findings as well as on our previous ones, we proposed a new model concerning the hierarchical structure of biological oscillators. Less