Long-term facilitation of phrenic nerve activity in cats: responses and short time scale correlations of medullary neurones.
Long-term facilitation of phrenic nerve activity in cats: responses and short time scale correlations of medullary neurones.
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猫膈神经活动的长期促进：髓质神经元的反应和短时间尺度相关性。
DOI：
10.1113/jphysiol.1996.sp021158
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Lindsey,BG
中科院分区：
文献类型：
--
作者：
Morris,KF;Arata,A;Shannon,R;Lindsey,BG
1. 外周化学感受器或中缝隐核的刺激都会导致膈运动神经元活动的长期促进。这项工作的第一个目的是测量在诱导长期促进过程中，中缝隐核、孤束核以及面后核、歧义核和歧义后核区域的神经元的同步反应。第二个目标是评估化学反应性raphe神经元与其他监测位置的神经元和膈运动神经元的功能关系。2. 在15只麻醉、麻痹、迷走神经切断、人工通气的成年猫中，同时记录了多达30个单髓神经元和膈神经传出活动。颈动脉化学感受器通过动脉注射200微升CO2饱和盐溶液刺激。用周期触发直方图和两次呼吸调节统计检验分析尖峰序列。使用刺激前后时间直方图和累积和直方图来评估刺激反应。交叉相关被用来检验尖峰列车之间的非随机时间关系。峰值触发的平均直方图提供了与膈运动神经元功能关联的证据。3. 对348个中缝暗核神经元中的113个进行了监测。29个中缝神经元的放电频率在刺激过程中增加；十八岁下降。在21对同时被监测的中缝神经元中，一个神经元的放电率在刺激期间增加，然后下降，而另一个神经元的放电率则随着前者的放电率下降而开始增加。18个化学反应性中缝神经元的膈峰触发平均值具有短时间尺度特征。在1407对神经元中的184对的交叉相关图中发现了短时间尺度特征。4. 这些数据提示了颈动脉化学感受器影响髓质中缝神经元的平行途径，并支持了中线呼吸相关神经元集合转换来自这些感受器的信息并调节呼吸运动输出增益的假设。
1. Stimulation of either peripheral chemoreceptors or nucleus raphe obscurus results in long‐term facilitation of phrenic motoneurone activity. The first objective of this work was to measure the concurrent responses of neurones in the nucleus raphe obscurus, the nucleus tractus solitarii, and the regions of the retrofacial nucleus, nucleus ambiguus and nucleus retroambigualis during induction of long‐term facilitation. A second goal was to assess functional relationships of the chemoresponsive raphe neurones with neurones in the other monitored locations and with phrenic motoneurones. 2. Up to thirty single medullary neurones and phrenic nerve efferent activity were recorded simultaneously in fifteen anaesthetized, paralysed, vagotomized, artificially ventilated adult cats. Carotid chemoreceptors were stimulated by close arterial injection of 200 microliters of CO2‐saturated saline solution. Spike trains were analysed with cycle‐triggered histograms and two statistical tests for respiratory modulation. Peristimulus‐time histograms and cumulative sum histograms were used to assess responses to stimulation. Cross‐correlation was used to test for non‐random temporal relationships between spike trains. Spike‐triggered average histograms provided evidence for functional associations with phrenic motoneurones. 3. One hundred and thirteen of 348 neurones were monitored in the nucleus raphe obscurus. The firing rates of twenty‐nine raphe neurones increased during stimulation; eighteen decreased. In twenty‐one pairs of concurrently monitored raphe neurones, the firing rate of one increased its activity during stimulation then decreased, while the other showed an increase that began as the rate of the former declined. Eighteen chemoresponsive raphe neurones had short time scale features in their phrenic spike‐triggered averages. Short time scale features were found in cross‐correlograms from 184 of 1407 neurone pairs. 4. The data suggest parallel routes by which carotid chemoreceptors influence medullary raphe neurones and support the hypotheses that mid‐line respiratory‐related neuronal assemblies transform information from those receptors and regulate the gain of respiratory motor output.