Premature birth can alter the
connectivity between key areas of the brain, according to a new
study led by King's College London.
The findings should help
researchers to better understand why premature birth is linked to a
greater risk of neurodevelopmental problems, including autistic
spectrum disorders and attention deficit disorders.
The study used functional magnetic
resonance imaging (fMRI) to look at specific connections in the
brains of 66 infants, 47 of whom were born before 33 weeks and were
therefore at high risk of neurological impairment, and 19 born at
term. The brain connections investigated were between the thalamus
and the cortex, connections which develop rapidly during the period
a preterm infant is cared for on a neonatal unit.
Researchers found that those born
in the normal window of birth (37-42 weeks) showed a remarkably
similar structure to adults in these brain regions, strengthening
existing evidence that the brain's network of connections is quite
mature at the time of birth.
However, infants born prematurely
(before 33 weeks gestation) were found to have less connectivity
between areas of the thalamus and particular areas of the brain's
cortex known to support higher cognitive functions, but greater
connectivity between the thalamus and an area of primary sensory
cortex which is involved in processing signals from the face, lips,
jaw, tongue, and throat.
The greater the extent of
prematurity, the more marked were the differences in the pattern of
brain connectivity.
The authors suggest that the
stronger connections involving face and lips in babies born preterm
may reflect their early exposure to breastfeeding and
bottlefeeding, while the reduced connectivity in other brain
regions may be linked to the higher incidence of difficulties seen
in later childhood.
Dr Hilary Toulmin of King's College
London said: "The next stage of our work will be to understand how
these findings relate to the learning, concentration and social
difficulties which many of these children experience as they grow
older."
Professor David Edwards, also from
King's, added: "The ability of modern science to image the
connections in the brain would have been inconceivable just a few
years ago, but we are now able to observe brain development in
babies as they grow, and this is likely to produce remarkable
benefits for medicine."
The paper, Specialization
and integration of functional thalamocortical connectivity in the
human infant, is published in theProceedings of the National Academy of Sciences.