Tonic and phasic drive to medullary respiratory neurons during periodic breathing.
Tonic and phasic drive to medullary respiratory neurons during periodic breathing.
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DOI：
10.1016/j.resp.2012.03.012
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发表时间：
2012-05-31
影响因子：
2.3
通讯作者：
Orem JM
中科院分区：
文献类型：
--
作者：
Lovering AT;Fraigne JJ;Dunin-Barkowski WL;Vidruk EH;Orem JM
目前尚不清楚中枢神经活动如何导致周期性呼吸的重复终止和重新开始。我们假设吸气和呼气的神经活动在蜡质阶段最强，在衰弱阶段最少。我们分析了完整未麻醉成年猫在PB期间的横隔膜和延髓呼吸神经活动。横隔膜活动在蜡化期呈上升和时相变化，在衰退期呈下降和紧张期变化。呼气相(n=21)和吸气相(n=40)神经元的活动在蜡熟期普遍增加并呈时相变化，而在衰退期则逐渐减弱并趋于紧张期。在呼吸暂停伴PB期间，横隔膜活动是静默的，大多数(但不是全部)吸气细胞不活动，而大多数呼气细胞活动减少，但仍保持张力活动。我们认为，相互抑制的强度降低，继而呼吸驱动减弱，允许中枢模式发生器的吸气和呼气神经元同时紧张性活动，最终导致中枢性呼吸暂停。
It is unknown how central neural activity produces the repetitive termination and restart of periodic breathing (PB). We hypothesized that inspiratory and expiratory neural activities would be greatest during the waxing phase and least during the waning phase. We analyzed diaphragmatic and medullary respiratory neural activities during PB in intact unanesthetized adult cats. Diaphragmatic activity was increased and phasic during the waxing phase and was decreased and tonic during the waning phase. Activity of expiratory (n=21) and inspiratory (n=40) neurons was generally increased and phasic during the waxing phase and was decreased and more tonic during the waning phase. During apneas associated with PB, diaphragmatic activity was silent and most, but not all, inspiratory cells were inactive whereas most expiratory cells decreased activity but remained tonically active. We suggest that reduced strength of reciprocal inhibition, secondary to reduced respiratory drive, allows for simultaneous tonic activity of inspiratory and expiratory neurons of the central pattern generator, ultimately resulting in central apnea.