Yang C C, Kuo T B, Chan S H
Department of Physiology, Tzu Chi College of Medicine, Taiwan, Republic of China.
Neuroscience. 1997 Apr;77(3):813-27. doi: 10.1016/s0306-4522(96)00515-5.
This study evaluated the spectral characteristics of neuronal discharges in the caudal hypoglossal nucleus and their physiological relevance in adult, male Sprague Dawley rats which were anaesthetized and maintained with pentobarbital sodium. Based on auto-spectral analysis of extracellular single-neuron activity, three spectral patterns were identified in the spontaneous discharges of hypoglossal neurons. Neurons that exhibited a rhythmic pattern manifested a concentrated peak in the auto-spectrogram that corresponded to the mean discharge rate. A majority of hypoglossal neurons displayed the modulated pattern, which was manifested either as scattered power densities (wide-band modulated pattern) or with a peak frequency component that was different from the mean discharge rate (narrow-band modulated pattern). Neurons that exhibited a mixed pattern displayed both rhythmic and modulated spectral patterns. Cross-spectral analysis further revealed that respiratory modulation constituted a major physiological influence on caudal hypoglossal neurons. The respiratory modulated pattern, however, could be converted to a mixed pattern in the presence of a central dipsogen, angiotensin III. The results suggest that the spectral patterns of neuronal discharges in caudal hypoglossal neurons represent manifestations of multiple physiological information, including that regarding respiration and dipsogenesis, which is encoded in these neurons. It was also shown that this information may only be revealed by auto-spectral and cross-spectral analysis of neuronal discharge signals.
本研究评估了成年雄性Sprague Dawley大鼠尾侧舌下神经核中神经元放电的频谱特性及其生理相关性，这些大鼠用戊巴比妥钠麻醉并维持麻醉状态。基于细胞外单神经元活动的自谱分析，在舌下神经元的自发放电中确定了三种频谱模式。表现出节律性模式的神经元在自谱图中表现出一个与平均放电率相对应的集中峰值。大多数舌下神经元表现出调制模式，其表现为分散的功率密度（宽带调制模式）或具有与平均放电率不同的峰值频率成分（窄带调制模式）。表现出混合模式的神经元同时呈现节律性和调制性频谱模式。互谱分析进一步表明，呼吸调制对尾侧舌下神经元构成主要的生理影响。然而，在存在中枢性饮水素血管紧张素III的情况下，呼吸调制模式可转变为混合模式。结果表明，尾侧舌下神经元放电的频谱模式代表了多种生理信息的表现，包括与呼吸和饮水生成有关的信息，这些信息在这些神经元中进行编码。研究还表明，这些信息可能只能通过对神经元放电信号的自谱和互谱分析来揭示。
