Prolonged oxygen exposure as a newborn could impair later cognitive development

31 July 2018
mum and preterm baby

New research finds that prolonged oxygen exposure in newborn mice can impair the signalling pathways required for long-term learning and memory.

The University of Alabama at Birmingham research has been published in the Nature Scientific Reports and suggests that preterm infants needing prolonged periods of oxygen supplementation are at a higher risk for developing neurodevelopment impairment.

Researchers say preterm infants require oxygen supplementation in order to survive and it’s not yet clear why it may lead to deficits in long-term cognitive function.

To understand the long-term effect early oxygen exposure on the brain development, Assistant Professor Dr Manimaran Ramani and his team developed a mouse model in which they could assess the long-term effects of oxygen exposure on newborn mice.

The researchers say the brain development in the newborn mice pups corresponds to that of human infants of 24- to 28-weeks gestation which means the mouse model allowed the team to understand and develop therapies for early oxygen induced long-term cognitive dysfunction.

In this model, adolescent mice that had oxygen exposure as neonates had spatial navigation memory deficits and hippocampal shrinkage — findings that are consistent with children born preterm. 

“We are trying to identify therapeutic strategies to prevent and treat cognitive deficits seen in children born preterm and to understand the long-term effects of early oxygen exposure on brain development and function,” says Dr Ramani.

“This study shows that, in mice, oxygen exposure during a critical developmental period may have a deleterious effect on the hippocampal signalling pathway and mitochondrial function — critical needs for the memory formation and maintenance.”

Dr Ramani says additional studies will be needed to determine the mechanisms by which early oxygen exposure leads to mitochondrial dysfunction in the hippocampus, a brain region that plays an essential role in the formation and maintenance of memory.

“What this tells us is that oxygen supplementation during the newborn period may have a negative impact long-term brain function.  Since reducing oxygen supplementation is shown to increase mortality among the preterm infants who require oxygen supplementation, we need to identify the therapies that can mitigate toxic effects of oxygen on brain development and function.”

You can read more about this research here.