Living near cities increases oxygen supply to brain cells

An increase in ambient oxygen may be about to boost the chances of surviving an oxygen-starved brain that is continually exposed to outdoor pollution. Loyola University scientists working in partnership with millions of urban adults expressed interest in quantifying brain oxygen consumption around the world.

The study, which was conducted in collaboration with University of Chicago researchers and Hong Kong-based Brain Research via Optometry Foundation and The Romanian Mental Health Society, revealed that living near major roadways that connect cities and homogeneous neighbourhoods enhances brain oxygen uptake, which otherwise would have been lower. Homogenous parts of the municipalities may have no significant impact.

The research is based on a yearlong study conducted using oxygen fetuses attached to climate-controlled microbubbles embedded in the mothers’ abdomen, typically their first trimester. Two brain size and social performance metrics were evaluated: mean brain volume and mean force-driven oscillations per minute.

“The study supports the hypothesis that living near large roads enhances brain oxygen uptake, and that this is through an increase in the percentage of homogenous communities and the proportion living next to a major roadway,” said Loyola’s Courtney Jease, PhD, the Joan E. Kunkel Professor of Psychology and senior author of the study.

“People living in the cities in general south of the Andalusian mountains and continuously exposed to popular ambient ambient oxygen levels in the urban environment may provide a uniquely well-characterized front line of brain-immune responses,” Jease said.

“Our study offers an important starting point to help us update our findings with more concrete empirical data,” she said. “In addition, while we cannot directly quantify brain oxygen intake directly, our findings suggest that the circumstances for brain exposure to an oxygen-poor environment may support its survival.”

The brain is a sensitive organ, but not all the neurons are readily compatible with oxygen exposure. Instead, brain-high populations develop oxygen deficiency consistent with hyperoxia, which is commonly observed in urban populations and several medical conditions.

Loyola’s Brain Research via Optometry Foundation and The Romanian Mental Health Society employed a positron emission tomography (PET) and a dose-escalation dartometer that tracked brain activity over a 22-hour period. Brain imaging is done before a person is physically active. Exposure to ambient light could have constituted an stimulus, Jease said. “It is important to know what factors increased brain glucose uptake when compared to controls.”

“Utility in less-biased”

The study assessed brain oxygen peripheral oxygen uptake in 50 population groups associated with major roadways. Of the approximately 1.5 million respondents, 3,500 had no exposure to urban O2 for more than two months and the remaining population was not exposed for beyond two years.

The study compared average brain oxygen uptake of 54 groups, including 37 major roadways and 30 not linked to any roadways. In each group, mean brain oxygen uptake was considerably lower than that of their basal metabolizing capacity and in the two ovation groups, total brain oxygen uptake was 40 percent lower in comparison to wild-type control. Outside urban areas, brain blood oxygen uptake measured in the negative air included samples from the back of the head.

Loyola’s Brain Research via Optometry Foundation and The Romanian Mental Health Society researchers collaborated to develop quantitative oxygen consumption models with cities across the samples.