Arousal increases baroreflex inhibition of muscle sympathetic activity.
Arousal increases baroreflex inhibition of muscle sympathetic activity.
复制标题
唤醒会增加肌肉交感神经活动的压力反射抑制。
DOI：
10.1046/j.1365-201x.2003.01071.x
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
M. Elam
中科院分区：
文献类型：
--
作者：
B. Wallin;V. Donadio;T. Karlsson;M. Kallio;M. Nordin;M. Elam
目的
已知引起唤醒的令人惊讶的感觉刺激会引起皮肤中人类交感神经活动的短暂激活，但不会引起肌肉神经的激活。事实上，轶事观察表明肌肉交感神经活动可能受到抑制。为了检验这一假设，我们在 36 名年龄在 19-71 岁的健康受试者中研究了令人惊讶的体感（皮肤电脉冲）或视觉（闪光）刺激对多单位肌肉交感神经活动的影响。
方法
在心电图 R 波后 200 或 400 毫秒给予刺激。虚拟刺激由没有感觉刺激的触发脉冲组成，用作对照。
结果
在群体基础上，任一类型的单一感觉刺激都会减弱一次或两次交感神经爆发的幅度，而在虚拟刺激后不会出现这种效应。就个体而言，在 16 名受试者中，至少一种刺激方式或延迟会引起抑制，而在 3 名受试者中，没有发生显着的抑制。所有受试者都存在皮肤交感神经激活的皮肤电信号。与一次相比，五次重复的皮肤电脉冲仅引起肌肉交感神经活动的轻微额外抑制，表明神经反应明显习惯化。在 9 名受试者中，实验重复一次，在 3 名受试者中重复两次（间隔 2-3 个月）；在 12 名受试者中，有 11 名受试者的交感神经效应是可重复的。在没有明显交感神经抑制的受试者组中，刺激引起平均血压小幅、短暂的升高，而在有交感神经抑制的受试者组中则不存在这种情况。
结论
研究发现，不同的感觉刺激会引起相似的效果，并且在重复时显着习惯，这表明肌肉交感神经活动的抑制是由于唤醒。交感神经和血压效应的个体差异可能是个体对压力的行为反应差异的一部分。
AIM
Surprising sensory stimuli causing arousal are known to evoke short-lasting activation of human sympathetic activity in skin but not in muscle nerves. In fact, anecdotal observations suggest that muscle sympathetic activity may be inhibited. To test this hypothesis, the effects of surprising somatosensory (electrical skin pulses) or visual (flash) stimuli on multiunit muscle sympathetic activity were studied in 36 healthy subjects, aged 19-71 years.
METHODS
The stimuli were given either 200 or 400 ms after the R-wave of the electrocardiogram. Dummy stimuli, consisting of trigger pulses without sensory stimuli, served as controls.
RESULTS
On a group basis, a single sensory stimulus of either type attenuated the amplitude of one or two sympathetic bursts, while no such effects occurred after dummy stimuli. Individually, the inhibition was evoked by at least one stimulus modality or delay in 16 subjects, whereas in three subjects no significant inhibition occurred. Electrodermal signs of skin sympathetic activation were present in all subjects. Compared with one, five repeated electrical skin pulses induced only minor additional inhibition of muscle sympathetic activity, indicating marked habituation of the neural response. In nine subjects, the experiments were repeated once and in three subjects twice (with intervals of 2-3 months); in 11 of the 12 subjects, the sympathetic effects were reproducible. In the group of subjects without significant sympathetic inhibition the stimuli induced a small, transient increase of mean blood pressure, which was not present in the group with sympathetic inhibition.
CONCLUSION
The finding that different sensory stimuli induce similar effects that habituate markedly on repetition suggests that the inhibition of muscle sympathetic activity is because of arousal. The interindividual differences in sympathetic and blood pressure effects may be part of interindividual differences in behavioural responses to stress.