Recruitment pattern of sympathetic neurons during breath-holding at different lung volumes in apnea divers and controls
Recruitment pattern of sympathetic neurons during breath-holding at different lung volumes in apnea divers and controls
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DOI：
10.1016/j.autneu.2011.05.003
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发表时间：
2011-10-28
影响因子：
2.7
通讯作者：
Dujic, Zeljko
中科院分区：
文献类型：
--
作者：
Breskovic, Toni;Steinback, Craig D.;Dujic, Zeljko
我们测试了一个假设，即屏气潜水员（BHD）比对照组获得更高水平的交感神经激活，这是由于屏气的持续时间，而不是不同的招募策略。在6名对照组和8名BHD患者中，我们测量了在功能剩余容量（FRC）和总肺活量（TLC）屏气之前和期间的肌肉交感神经活动（MSNA）。在一部分受试者中，我们应用了一种新的技术来检测多单元MSNA中的动作电位（ap）。与对照组相比，BHD组在基线时爆发AP含量（13 +/- 7比6 +/- 3 AP/burst， P = 0.05）和活动簇数（5 +/- 1比3 +/- 1簇/burst， P = 0.05）较低。然而，由于BHD组的猝发频率（20 +/- 4次/分钟）高于对照组（13 +/- 3次/分钟）（P = 0.039），各组间的整体交感AP/单位时间具有可比性（131 +/- 105对173 +/- 152 AP/分钟，P = 0.62）。潜水员在FRC屏气期间达到的总MSNA水平更高（2298 +/- 780 vs. 1484 +/- 575 a.u./min; P = 0.039）。TLC屏气结束时的总MSNA在两组之间具有可比性（157 +/- 50（对照组）vs 214 +/- 41 (BHD)）；P = 0.61)。在两组中，FRC和TLC屏气均增加了AP频率、突发AP含量和活动簇/突发，但反应幅度由屏气类型决定。潜水员使用的ap /burst和活动簇/burst数量较少。在两组中，屏气导致了相似的MSNA的增加，这是通过刺激频率的增加和先前沉默的、更大的（传导更快的）交感神经元的招募，可能是通过在同一次爆发中重复刺激来实现的。(C) 2011 Elsevier B.V.版权所有
We tested the hypothesis that breath-hold divers (BHD) attain higher level of sympathetic activation than controls due to the duration of breath-hold rather than a different recruitment strategy. In 6 control subjects and 8 BHD we measured muscle sympathetic neural activity (MSNA) prior to and during functional residual capacity (FRC) and total lung capacity (TLC) breath-holding. On a subset of subjects we applied a new technique for the detection of action potentials (APs) in multiunit MSNA. Compared with controls, BHD group had lower burst AP content (13 +/- 7 vs. 6 +/- 3 AP/burst; P = 0.05) and number of active clusters (5 +/- 1 vs. 3 +/- 1 clusters/burst; P = 0.05) at baseline. However, the overall sympathetic AP/unit-time was comparable between the groups (131 +/- 105 vs. 173 +/- 152 AP/min; P = 0.62) due to increased burst frequency in BHD group (20 +/- 4 bursts/min) vs. controls (13 +/- 3 bursts/min) (P = 0.039). The achieved level in total MSNA during FRC breath-holds was higher in divers (2298 +/- 780 vs. 1484 +/- 575 a.u./min; P = 0.039). Total MSNA at the end of TLC breath-hold was comparable between the groups (157 +/- 50 (controls) vs. 214 +/- 41 s (BHD); P = 0.61). FRC and TLC breath-holds increased AP frequency, burst AP content and active clusters/bursts in both groups but the response magnitude was determined by the type of the breath-hold. The divers used fewer number of APs/burst and active clusters/burst. In both groups breath-holds resulted in similar increases in MSNA which were reached both by an increase in firing frequency and by recruitment of previously silent, larger (faster conducting) sympathetic neurons, and possibly by repeated firing within the same burst. (C) 2011 Elsevier B.V. All rights reserved.