To this effect, we examined whether transgenic neuroglobin overexpressing (Ngb-TG) mice displayed improved cognitive function in a spatial task and reduced anxiety in the elevated plus maze (EPM) following prolonged exposures to IH during the rest period, since anxiety, depression and memory deficits are readily apparent in a significant proportion of patients with sleep apnea (17–19). This evidence concerns the gene NGB and major depressive disorder.