Modest spontaneous recovery of ventilation following chronic high cervical hemisection in rats
Modest spontaneous recovery of ventilation following chronic high cervical hemisection in rats
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DOI：
10.1016/j.expneurol.2008.01.013
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发表时间：
2008-05-01
影响因子：
5.3
通讯作者：
Reier, P. J.
中科院分区：
文献类型：
--
作者：
Fuller, D. D.;Doperalski, N. J.;Reier, P. J.
在成年大鼠C2脊髓半切（C2 HS）后，同侧膈运动神经元（PhMN）通过潜伏的交叉脊髓侧支（即，自发性横膈现象; sCPP）。在C2 HS后安静呼吸期间维持通气，但在呼吸刺激（例如高碳酸血症）期间增加通气的能力受损。我们假设sCPP的长期表达将对应于呼吸挑战期间呼吸模式的逐步正常化。通过体积描记法在未麻醉的动物中评估呼吸，并在麻醉、麻痹和迷走神经切断的大鼠中测量膈运动输出。在C2 HS后2周，每分钟通气量（VE）在基线（室内空气）条件下如预期保持不变，但在高碳酸血症激发期间基本上变钝（未受伤的体重匹配大鼠中VE为68 ± 3%）。然而，到12周时，脊髓损伤大鼠达到了高碳酸VE反应，为对照组的85 +/- 7%（p = 0.017 vs. 2 wks）。这些大鼠也表现出更频繁的呼吸增强（AB's）或“叹气”（p
Following C2 spinal hemisection (C2HS) in adult rats, ipsilateral phrenic motoneuron (PhMN) recovery occurs through a time-dependent activation of latent, crossed-spinal collaterals (i.e., spontaneous crossed phrenic phenomenon; sCPP) from contralateral bulbospinal axons. Ventilation is maintained during quiet breathing after C2HS, but the ability to increase ventilation during a respiratory stimulation (e.g. hypercapnia) is impaired. We hypothesized that long-term expression of the sCPP would correspond to a progressive normalization in ventilatory patterns during respiratory challenge. Breathing was assessed via plethsymography in unanesthetized animals and phrenic motor output was measured in urethane-anesthetized, paralyzed and vagotomized rats. At 2-week post-C2HS, minute ventilation (VE) was maintained during baseline (room air) conditions as expected but was substantially blunted during hypercapnic challenge (68 +/- 3% of VE in uninjured, weight-matched rats). However, by 12 weeks the spinal-lesioned rats achieved a hypercapnic VE response that was 85 +/- 7% of control (p = 0.017 vs. 2 wks). These rats also exhibited augmented breaths (AB's) or "sighs" more frequently (p