May 21, 2013
Premature Birth Disrupts Crucial Brain Development Processes
April Flowers for redOrbit.com - Your Universe Online
For the first time, researchers have employed a novel form of MRI to identify crucial developmental processes in the brain that are vulnerable to the effects of premature birth. The study, led by researchers at King´s College London´s Center for the Developing Brain, reveals that the disruption of these specific processes can have an impact on cognitive function in infants.
The new techniques developed for this study will allow the researchers to explore how the disruption of key processes can also cause conditions such as autism. The findings, published in the Proceedings of the National Academy of Sciences, will be used along with the new techniques to test possible treatments to prevent brain damage.
Professor David Edwards, Director of the Centre for the Developing Brain at King´s College London, said, “The number of babies born prematurely is increasing, so it has never been more important to improve our understanding of how preterm birth affects brain development and causes brain damage. We know that prematurity is extremely stressful for an infant, but by using a new technique we are able to track brain maturation in babies to pinpoint the exact processes that might be affected by premature birth. Here we have used innovative ways to understand how the development of the cerebral cortex is affected.”
The research team, which also included scientists from Imperial College London, used diffusion MRI — a type of imaging that looks at the natural diffusion of water in biological tissue — to observe the maturation of the cerebral cortex, where most of the brain´s computing power is found. The team analyzed the diffusion of water in the cerebral cortex of 55 premature infants being cared for in the Neonatal Intensive Care Unit at Queen Charlotte´s and Chelsea Hospital. Ten full-term babies were also examined. The researchers mapped the growing complexity and density of nerve cells across the whole of the cortex in the months leading up to the full-term expected date of birth.
During this period, they found that the most rapid maturation was in areas of the brain related to social and emotional processing, decision making, working memory and visual-spatial processing — functions which are often impaired after premature birth. The team also found that cortical development was reduced in preterm compared to full-term infants, with the greatest effect in the most premature infants. The infants were re-examined at two years of age. The researchers found that the preterm infants with the slowest cortical development performed less well on neurodevelopmental testing, demonstrating the longer-term impact of prematurity on cortical maturation.
“These findings highlight a key stage of brain development where the neurons branch out to create a complex, mature structure. We can now see that this happens in the latter stages of development that would usually take place in healthy babies when they are still in the womb. This suggests that premature birth can interrupt this vital developmental process. It may explain why we sometimes see adverse effects on brain development in those born only slightly prematurely as we now know that this process is happening right up to the normal time of birth. With this study we found that the earlier a baby is born, the less mature the cortex structure. The weeks a baby loses in the womb really matter,” said Edwards.
“These new techniques we´ve developed to identify these crucial processes will allow us to examine how disruption caused by premature birth can lead to conditions such as autism and learning difficulties. We will also use the technique in future studies to test new treatments to prevent brain damage. It´s an extremely exciting step forward.”