Does the motor cortical control of the diaphragm 'bypass' the brain stem respiratory centres in man?
Does the motor cortical control of the diaphragm 'bypass' the brain stem respiratory centres in man?
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DOI：
10.1016/s0034-5687(98)00083-8
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发表时间：
1998-11-01
期刊：
影响因子：
--
通讯作者：
Guz, A
中科院分区：
文献类型：
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作者：
Corfield, DR;Murphy, K;Guz, A
在人类中，横膈膜的皮质-运动兴奋可通过皮质-脊髓束“绕过”脑干呼吸中心（RC）直接作用于膈运动核；另外，这种控制可以通过RC和球脊髓路径间接进行。为了研究这一点，我们使用经颅磁刺激（TMS）刺激6名受试者在呼气末（膈肌放松）和自主吸气时的运动皮层。无论在正常碳酸血症或低碳酸血症（PETCO2=25 mmHg）期间（可能是呼吸“振荡器”沉默时）进行TMS，膈肌和拇指中诱发的复合动作电位的大小都没有不同。在另外六名受试者中，在呼吸周期的三个不同点进行放松的自发呼吸时进行经颅磁刺激。呼吸方式（潮气量或呼吸时间）未见异常。因此，我们无法证明横膈膜的皮质运动兴奋是通过脑干RC起作用的。(C) 1998 Elsevier Science B.V.版权所有
In humans, cortico-motor excitation of the diaphragm may act directly on the phrenic motor nucleus via the cortico-spinal tract 'bypassing' brain stem respiratory centres (RC); alternatively, or in addition, this control may be indirect via the RC and bulbo-spinal paths. To investigate this, we stimulated the motor cortex using transcranial magnetic stimulation (TMS) in six subjects at end-expiration (diaphragm relaxed) and during voluntary inspiration. The sizes of the evoked compound action potentials in the diaphragm and also, as a control, in the thumb were no different whether TMS was delivered during normocapnia or during hypocapnia (PETCO2=25 mmHg) when, presumably, the respiratory 'oscillator' was silent. In a further six subjects, TMS was performed during relaxed spontaneous breathing at three different points in the respiratory cycle. No perturbations in respiratory pattern (either tidal volume or respiratory timing) were seen. Thus we have been unable to demonstrate that the cortico-motor excitation of the diaphragm acts via the brain stem RC. (C) 1998 Elsevier Science B.V. All rights reserved.