Tarasiuk A, Sica A L
Department of Physiology, Faculty of Health Sciences, Ben Gurion University, Beer Sheva, Israel.
Brain Res Bull. 1997;42(2):105-10. doi: 10.1016/s0361-9230(96)00220-1.
In the present investigation, brain stem spinal cord preparations of 0-4-day-old rats were used to determine whether inspiratory-related discharges were modulated by a central pattern generator either during baseline conditions or during conditions of increased chemical drive. Spectral analyses were carried out on pairs of nerve activities during superfusion with normal solutions (pH = 7.4) and during superfusion with acidic solutions (pH = 6.8-7.0). Autopower spectra of nerve discharges in normal pH solution revealed the presence of two peaks: one in the 2-6 Hz band and the other in the 20-39 Hz band. Peaks occurring over both frequency ranges were highly correlated as revealed by coherence spectral analysis. Acidic stimulation produced no systematic changes in spectral features, for example, shifting peaks to other frequency regions, or increasing the values of coherence. The 2-6 Hz peak is most likely due to the arrival of depolarizing inputs from the brain stem that generate a ramp of activity at recording sites. On the other hand, activity in the 20-39 Hz region represents the discharge frequency of inspiratory motoneurons. The fact that coherence is present in this latter band provides evidence for short-time scale (ms) synchronization of functionally and anatomically distinct inspiratory motoneurons by a central pattern generator.
在本研究中，使用0至4日龄大鼠的脑干脊髓标本，以确定在基线条件下或化学驱动增加的条件下，吸气相关放电是否受中枢模式发生器的调节。在使用正常溶液（pH = 7.4）灌注期间和使用酸性溶液（pH = 6.8 - 7.0）灌注期间，对成对的神经活动进行了频谱分析。正常pH溶液中神经放电的自功率谱显示存在两个峰值：一个在2 - 6 Hz频段，另一个在20 - 39 Hz频段。如相干谱分析所示，在这两个频率范围内出现的峰值高度相关。酸性刺激未产生频谱特征的系统性变化，例如，将峰值转移到其他频率区域或增加相干值。2 - 6 Hz的峰值很可能是由于来自脑干的去极化输入到达，在记录部位产生了活动斜坡。另一方面，20 - 39 Hz区域的活动代表吸气运动神经元的放电频率。后一个频段中存在相干性这一事实，为中枢模式发生器在功能和解剖学上不同的吸气运动神经元的短时间尺度（毫秒）同步提供了证据。
