Effect of acute intermittent hypoxia on cortico-diaphragmatic conduction in healthy humans.

Effect of acute intermittent hypoxia on cortico-diaphragmatic conduction in healthy humans.
Exp Neurol. 2021 Feb 16;:113651
Authors: Welch JF, Perim RR, Argento PJ, Sutor TW, Vose AK, Nair J, Mitchell GS, Fox EJ
Abstract
Acute intermittent hypoxia (AIH) is a strategy to improve motor output in humans with neuromotor impairment. A single AIH session increases the amplitude of motor evoked potentials (MEP) in a finger muscle (first dorsal interosseous), demonstrating enhanced corticospinal neurotransmission. Since AIH elicits phrenic/diaphragm long-term facilitation (LTF) in rodent models, we tested the hypothesis that AIH augments diaphragm MEPs in humans. Eleven healthy adults (7 males, age = 29 ± 6 years) were tested. Transcranial and cervical magnetic stimulation were used to induce diaphragm MEPs and compound muscle action potentials (CMAP) recorded by surface EMG, respectively. Stimulus-response curves were generated prior to and 30-60 min after AIH. Diaphragm LTF was assessed by measurement of integrated EMG burst amplitude and frequency during eupnoeic breathing before and after AIH. Following baseline measurements, AIH was delivered from an oxygen generator connected to a facemask under poikilocapnic conditions (15 one minute episodes of 9% inspired oxygen with one minute room air intervals). There were no detectable changes in MEP (-1.5 ± 12.1%, p = 0.96) or CMAP (+0.1 ± 7.8%, p = 0.97) amplitud...

Source: Experimental Neurology - February 16, 2021 Category: Neurology Authors: Welch JF, Perim RR, Argento PJ, Sutor TW, Vose AK, Nair J, Mitchell GS, Fox EJ Tags: Exp Neurol Source Type: research