Effect of Acute Nitrate Supplementation on Neurovascular Coupling and Cognitive Performance in Hypoxia

The matching of oxygen supply to neural demand (i.e. neurovascular coupling [NVC]) is an important determinant of cognitive performance. The impact of hypoxia on NVC remains poorly characterized. NVC is partially modulated by nitric oxide (NO) which may initially decrease in hypoxia. This study investigated the effect of acute NO-donor (nitrate) supplementation on NVC and cognitive function in hypoxia. Twenty healthy men participated in this randomized, double-blind, crossover design study. Following normoxic cognitive/NVC testing, participants consumed either nitrate (NIT) or a NIT-depleted placebo (PLA). Participants then underwent 120 min of hypoxia (11.6±0.1% O2) and all cognitive/NVC testing was repeated. NVC was assessed as change in middle cerebral artery (MCA) blood flow during a cognitive task (incongruent Stroop) using Transcranial Doppler. Additional computerized cognitive testing assessed separately targeted memory, executive function, attention, sensorimotor and social cognition domains. Salivary nitrite significantly increased following supplementation in hypoxia for NIT (+2.6±1.0 AU) compared to PLA (+0.2±0.3 AU; pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author