The organisation of the adult brain differs following preterm birth
29 May 2009
The UK has the highest number of preterm births in Western Europe, with one out of every 13 babies born before 37 completed weeks of gestation. Research is increasingly focusing on the quality of life of survivors, who are at greater risk of brain damage and consequent neurological disorders, cognitive and behavioural impairments in childhood and later in life.
Our group and others have previously reported developmental alterations in the structure of brain in response to early brain lesions using non-invasive magnetic resonance imaging (MRI) techniques. In Neuroimage this month we describe the results of two studies investigating the relationships between brain areas and complex cognitive functions using functional MRI, which allows us ‘to see’ which areas of the brain are active when an individual is completing a certain task. This allowed us to discover which parts of the brain were used for specific cognitive processes – memory (visual paired associates learning) and verbal fluency (the ease at which words beginning with a given letter of the alphabet can be generated) in young adults who were born very preterm (less than 33 weeks of gestation), who represent the oldest sample studied to date. The aim was to discover which long-term functional strategies the brain may use to overcome any changes in its structure due to preterm birth.
The main findings of the investigations were that preterm young adults performed as well as the full-term controls on the memory and verbal fluency tasks, however brain activation differences were observed between the two groups during cognitive processing. During completion of both tasks, the preterm group showed decreased activation in areas of the brain which are considered to be important for the performance of these types of task. At the same time, preterm born individuals showed increased activation in brain areas which were task-specific as well as non-specific, suggesting that the brain has the ability to ‘rewire’ and allow alternative regions to take over ’functions’ typically performed by other areas. Dr Nosarti, leading author, says: 'These two studies demonstrate that the human brain is remarkably resilient and can optimise its resources and adapt to early adverse circumstances'.
This work was funded by the March of Dimes (US) and by the The Health Foundation (UK). The full articles entitled 'Neural substrates of visual paired associates in young adults with a history of very preterm birth: alterations in fronto-parieto-occipital networks and caudate nucleus' and 'Neural substrates of letter fluency processing in young adults who were born very preterm: Alterations in frontal and striatal regions' were published in the April 17th issue of Neuroimage [Epub ahead of print] by the following authors: Chiara Nosarti, Ana Narberhaus, Robin Murray, Matthew Allin, Muriel Walshe, Emma Lawrence, Sukhi Shergill, Larry Rifkin and Philip McGuire.
Full articles:
Verbal fluency study: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WNP-4W38RH8-3&_user=121727&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000010000&_version=1&_urlVersion=0&_userid=121727&md5=6f2e74501f627029b880650eedc03bc6
Visual paired associates study: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WNP-4W38RH8-6&_user=121727&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000010000&_version=1&_urlVersion=0&_userid=121727&md5=e83cddcec9a09c317f61b36e37ccbfe4