Sica A L, Gandhi M R, Steele A M
Department of Pediatrics, Schneider Children's Hospital, New Hyde Park, NY 11042.
Brain Res Dev Brain Res. 1991 Dec 17;64(1-2):77-86. doi: 10.1016/0165-3806(91)90211-z.
We hypothesized that synchronization of neonatal inspiratory motoneurons is achieved by common inputs from one or more central pattern generators. Such inputs are manifested in neural discharges as medium-frequency (less than 50 Hz) and/or high-frequency (greater than or equal to 50 Hz) oscillations. Furthermore, if both oscillations appeared, one or both might be gated, i.e. present only in the first or second half of inspiration. The spontaneous discharges of phrenic (C5 and C6) roots and hypoglossal nerves were recorded in anesthetized or decerebrated, vagotomized, paralyzed and artificially ventilated neonatal swine. Autopower spectral analyses showed that phrenic discharges had peaks in the medium- and/or the high-frequency band. Phrenic spectra, derived from either half of inspiration, demonstrated that, while both types of oscillation were present throughout inspiration, their amplitudes were larger during the second half of inspiration. However, comparisons of the relative distributions of power in each half of inspiration showed that the increase of high-frequency power was much larger than that of medium-frequency power during the second half of inspiration. In contrast to phrenic spectra, hypoglossal spectra had peaks only at medium-frequencies; consequently, correlated frequencies (indicative of common inputs) in phrenic-hypoglossal coherence spectra were present at those frequencies. The presence of highly correlated frequencies provided strong evidence of a medium-frequency pattern generator which may remain operative beyond the neonatal period.
我们假设，新生儿吸气运动神经元的同步是由来自一个或多个中枢模式发生器的共同输入实现的。这种输入在神经放电中表现为中频（小于50Hz）和/或高频（大于或等于50Hz）振荡。此外，如果两种振荡都出现，其中一种或两种可能会被门控，即仅出现在吸气的前半段或后半段。在麻醉或去大脑、切断迷走神经、麻痹并人工通气的新生猪中记录膈神经（C5和C6）根和舌下神经的自发放电。自功率谱分析表明，膈神经放电在中频和/或高频带出现峰值。来自吸气任何半段的膈神经频谱表明，虽然两种振荡在整个吸气过程中都存在，但它们的振幅在吸气后半段更大。然而，对吸气各半段功率相对分布的比较表明，在吸气后半段高频功率的增加远大于中频功率的增加。与膈神经频谱相反，舌下神经频谱仅在中频出现峰值；因此，膈神经-舌下神经相干频谱中的相关频率（表明共同输入）在这些频率处出现。高度相关频率的存在为中频模式发生器的存在提供了有力证据，该发生器可能在新生儿期之后仍然起作用。
