Leacy Jack K, Burns David P, Jendzjowsky Nicholas G, Braun Connor, Herrington Brittney A, Wilson Richard Ja, Vermeulen Tyler D, Foster Glen E, Rosenberg Alexander J, Anderson Garen K, Rickards Caroline A, Lucking Eric F, O'Halloran Ken D, Day Trevor A
Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland.
Hotchkiss Brain institute, University of Calgary, Calgary, Alberta, Canada.
J Cereb Blood Flow Metab. 2025 Mar 13:271678X251322348. doi: 10.1177/0271678X251322348.
Neurovascular coupling (NVC) is the link between local neuronal activity and regional cerebral blood flow. High altitude (HA) ascent induces acute hypoxic vasodilation of the cerebral vasculature, with associated changes in CO and acid-base status. We aimed to characterise the effects of (a) acute removal of the HA-induced vasodilation and (b) rapid ascent to and residency at HA on NVC responses. In twelve healthy participants (7 M/5F), arterial blood gases and NVC were measured at baseline (1130 m) and on days two (<24 h at HA) and nine (post-acclimatisation) at 3800 m. Acute gas challenges were performed using end-tidal forcing, with (a) normoxia and isocapnic hypoxia at 1130 m and (b) poikilocapnic hypoxia and isocapnic hyperoxia on days two and nine at 3800 m. Posterior cerebral artery velocity (PCAv) was measured using transcranial Doppler ultrasound in each condition and time-point. NVC was assessed via a standardized 30 s intermittent strobe light visual stimulus (VS), and quantified as the peak and mean change from baseline in PCAv. No significant differences were observed for any NVC metric across all conditions and time points. Our results reveal remarkable stability of the NVC response following (a) acute removal of HA-induced hypoxic vasodilation and (b) rapid ascent to and residency at 3800 m.
神经血管耦合（NVC）是局部神经元活动与局部脑血流之间的联系。高原（HA）攀登会诱发脑血管的急性缺氧性血管舒张，并伴有一氧化碳和酸碱状态的相关变化。我们旨在描述（a）急性消除HA诱导的血管舒张以及（b）快速攀登至HA并在HA停留对NVC反应的影响。在12名健康参与者（7名男性/5名女性）中，于基线（1130米）以及在海拔3800米处的第2天（在HA处<24小时）和第9天（适应后）测量动脉血气和NVC。使用呼气末强制进行急性气体激发，（a）在1130米处进行常氧和等碳酸性缺氧，（b）在海拔3800米处的第2天和第9天进行异碳酸性缺氧和等碳酸性高氧。在每种情况和时间点使用经颅多普勒超声测量大脑后动脉速度（PCAv）。通过标准化的30秒间歇性频闪视觉刺激（VS）评估NVC，并将其量化为PCAv相对于基线的峰值和平均变化。在所有情况和时间点，未观察到任何NVC指标有显著差异。我们的结果显示，在（a）急性消除HA诱导的缺氧性血管舒张以及（b）快速攀登至3800米并在该处停留后，NVC反应具有显著的稳定性。
