`Low level cortisol in pre-term babies retards learning`

Sydney: Teenagers born prematurely may suffer from brain development problems due to low levels of cortisol - a hormone that plays a critical role in memory and learning abilities, according to an Australian study.

University of Adelaide researchers have demonstrated that teenagers born prematurely, that is before the 37th week, may suffer from such deficiencies.

The research, conducted by Julia Pitcher and Michael Ridding from the University of Adelaide`s Robinson Institute, shows reduced `plasticity`, the brain`s ability to change and adapt when it learns or experiences something new, in teen-agers born premature, the Journal of Neuroscience reports.

"Pre-term teens also had low levels of cortisol in their saliva, which was highly predictive of this reduced brain responsiveness," says Pitcher, according to an Adelaide statement.

"People often associate increased cortisol with stress but cortisol fluctuates up and down normally over each 24-hour period and this plays a critical role in learning, the consolidation of new knowledge into memory and the later retrieval of those memories," adds Pitcher.

"The growth of the brain is rapid between 20 and 37 weeks gestation and being born even mildly pre-term appears to subtly but significantly alter brain microstructure, neural connectivity and neurochemistry," says Pitcher.

Researchers used a non-invasive magnetic brain stimulation technique, inducing responses from the brain to obtain a measure of its plasticity.

"This might be important for the development of a possible therapy to overcome the neuroplasticity problem," Pitcher says.