Risk of brain injury is genetic

University researchers have identified a link between injury to the developing brain and common variation in genes associated with schizophrenia and the metabolism of fat.

The study builds on previous research, which has shown that being born prematurely - before 37 weeks - is a leading cause of learning and behavioural difficulties in childhood.

Around half of infants weighing less than 1500g at birth go on to experience difficulties in learning and attention at school age.

Unique collaboration

Scientists at Edinburgh, Imperial College London and King’s College London studied genetic samples and MRI scans of more than 80 premature infants at the time of discharge from hospital.

The tests and scans revealed that variation in the genetic code of genes known as ARVCF and FADS2 influenced the risk of brain injury on MRI in the babies.

Global challenge

Premature births account for 10 per cent of all births worldwide, according to experts.

Earlier research has shown that being born preterm is closely related to abnormal brain development and poor neurodevelopmental outcome.

However, scientists say that they do not fully understand the processes that lead to these problems in some infants.

Researchers add that future studies could look at how changes in these genes may bring about this risk of - or resilience - to brain injury.

Environmental factors such as degree of prematurity at birth and infection play a part, but, as our study has found, they are not the whole story and genetic factors have a role in conferring risk or resilience. We hope that our findings will lead to new understanding about the mechanisms that lead to brain injury and ultimately new neuroprotective treatment strategies for preterm babies.-Dr James Boardman (Scientific director of the Jennifer Brown Research Laboratory at the MRC Centre for Reproductive Health at the University of Edinburgh)

(Image: Thinkstock)

Research Finds Pain In Infancy Alters Response To Stress, Anxiety Later In Life

Early life pain alters neural circuits in the brain that regulate stress, suggesting pain experienced by infants who often do not receive analgesics while undergoing tests and treatment in neonatal intensive care may permanently alter future responses to anxiety, stress and pain in adulthood, a research team led by Dr. Anne Murphy, associate director of the Neuroscience Institute at Georgia State University, has discovered.

An estimated 12 percent of live births in the U.S. are considered premature, researchers said. These infants often spend an average of 25 days in neonatal intensive care, where they endure 10-to-18 painful and inflammatory procedures each day, including insertion of feeding tubes and intravenous lines, intubation and repeated heel lance. Despite evidence that pain and stress circuitry in the brain are established and functional in preterm infants, about 65 percent of these procedures are performed without benefit of analgesia. Some clinical studies suggest early life pain has an immediate and long-term impact on responses to stress- and anxiety-provoking events.

The Georgia State study examined whether a single painful inflammatory procedure performed on male and female rat pups on the day of birth alters specific brain receptors that affect behavioral sensitivity to stress, anxiety and pain in adulthood. The findings demonstrated that such an experience is associated with site-specific changes in the brain that regulate how the pups responded to stressful situations. Alterations in how these receptors function have also been associated with mood disorders.

The study findings mirror what is now being reported clinically. Children who experienced unresolved pain following birth show reduced responsiveness to pain and stress.

“While a dampened response to painful and stressful situations may seem advantageous at first, the ability to respond appropriately to a potentially harmful stimulus is necessary in the long term,” Dr. Murphy said.

“The fact that less than 35 percent of infants undergoing painful and invasive procedures receive any sort of pre- or post-operative pain relief needs to be re-evaluated in order to reduce physical and mental health complications associated with preterm birth.”

Study shows human brain able to discriminate syllables three months prior to birth

A team of French researchers has discovered that the human brain is capable of distinguishing between different types of syllables as early as three months prior to full term birth. As they describe in their paper published in the Proceedings of the National Academy of Sciences, the team found via brain scans that babies born up to three months premature are capable of some language processing.

Many studies have been conducted on full term babies to try to understand the degree of mental capabilities at birth. Results from such studies have shown that babies are able to distinguish their mother’s voice from others, for example, and can even recognize the elements of short stories. Still puzzling however, is whether some of what newborns are able to demonstrate is innate, or learned immediately after birth. To learn more, the researchers enlisted the assistance of several parents of premature babies and their offspring. Babies born as early as 28 weeks (full term is 37 weeks) had their brains scanned using bedside functional optical imaging, while sounds (soft voices) were played for them.

Three months prior to full term, the team notes, neurons in the brain are still migrating to what will be their final destination locations and initial connections between the upper brain regions are still forming—also neural linkages between the ears and brain are still being created. All of this indicates a brain that is still very much in flux and in the process of becoming the phenomenally complicated mass that humans are known for, which would seem to suggest that very limited if any communication skills would have developed.

The researchers found, however, that even at a time when the brain hasn’t fully developed, the premature infants were able to tell the difference between female versus male voices, and to distinguish between the syllables “ba” and “ga”. They noted also that the same parts of the brain were used by the infants to process sounds as adults. This, the researchers conclude, shows that linguistic connections in the brain develop before birth and because of that do not need to be acquired afterwards, suggesting that at least some abilities are innate.