Study sheds light on why premature babies develop cognitive problems

Cognitive problems in some babies born prematurely may be linked to how the 'rich club' part of the brain develops.

The rich club is a set of regional hubs in the brain that are densely connected and enable different parts of the brain to communicate efficiently with one another. It is a common feature in all mammal brains.

In a new study published in the journal Proceedings of the National Academy of Sciences, scientists from Imperial College London and King's College London used magnetic resonance imaging to look at how the brain developed in 63 pre-term and full-term babies in the UK.

Their research reveals for the first time that the rich club structure is present from 30 weeks into the gestation period of pregnancy, and that it continues to develop its connections with the rest of the brain during the time leading up to the birth.

As the rich club organisation is present well before the time of full-term birth, which happens at around 39 weeks, the team believe that it may provide a fundamental structure for the emergence of complex neurological functions.

In pre-term babies, the researchers found that though rich club organisation remains intact, there are significant disruptions in the communication pathways interlinking the hubs, called the cortical-subcortical and short distance corticocortical connections.

This discovery may help explain why pre-term babies are more likely to go on to experience cognitive problems such as autism and attention deficit disorder.

Professor Daniel Rueckert, co-author of the study from the Department of Computing at Imperial, says, ''We think that this densely connected rich club organisation helps different parts of the brain to communicate with one another. Our study is helping us to see that any disruption to its development may impact later on in the growth of more complex brain functions.  Although more work needs to be done, our research is another piece in the jigsaw puzzle that is helping us to understand in more detail why some babies develop cognitive problems.''

To carry out their study, the scientists used a magnetic resonance imaging scanner, which creates a magnetic field and pulses of radio wave energy to make images of the brain. The team scanned the brains of 17 full term babies and 46 pre-term infants and compared data on the development of the rich club regions. They also scanned each brain at two different stages of the baby's growth in order to understand how the brain was developing.

The next step will see the team creating a comprehensive map of babies' brains as part of the Developing Human Connectome Project, which is funded by the European Research Council.