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Stress in pregnancy hits offspring's emotional brain

Tue, 2006-12-19 12:50 - Kerry

Stress experienced by a pregnant female can alter the structure of her offspring's brain, particularly regions vital for emotional  development, scientists have discovered. Furthermore, in rodents at least, the effects differ in male and female offspring. That might help explain the different susceptibilities of men and women to emotional and psychiatric disorders, says Katharina Braun, from the University of Magdeburg,Germany. Braun presented the work at the Federation of European Neuroscience Societies' annual meeting in Vienna, Austria, on Tuesday. Braun and colleagues at the University of Jerusalem in Israel studied the effects of stress on pregnant rats. If they become stressed in last trimester of pregnancy, their offspring developed fewer nerve connections in two brain regions that control emotions - the cingulate cortex and orbitofrontal cortex. In addition, the nerve cells in several other regions show different branching patterns to normal, with different effects on males and females. In the hippocampus, an important region that controls memory and emotion, males show an increase in branching while females show a decrease. In the prefrontal cortex, the males develop shorter nerve branches, while the females do not. Braun has not yet tested the behavioural effects of these changes on adult rats, but the results could reveal a possible mechanism for the development of emotional disorders seen in humans.

"Early experiences, especially emotional experiences, shape brain circuits for later life," says Braun. The susceptibility to stress continues after birth, with different types of stress and trauma leading to different brain effects, she adds.


For example, daily painful stimuli given to young rodent pups, separation from their mother, each led to changes in the prefrontal cortex. But while separation led to more nerve connections, stimuli led to fewer.

Further experiments on brush tail rats - which are unusual in that the father helps care for the offspring - showed that removal of the father early in the pups' life also leads to fewer neuron connections in the brain's emotion centres.
The pups grow up underactive and do not respond to the voices of their mothers.  Animals that were emotionally deprived seem to develop  emotional and social deficits.

Frozen emotions
Braun compared the results to the sad experiences of Romanian orphans. "Like the animal brain, the human brain needs to learn the grammar of emotions," she says. "Children after they are adopted catch up nicely on cognitive level, but the emotional side looks like it has been somehow frozen." (See Orphaned boys and girls react differently to care.)
"We are now collaborating with psychiatrists, asking questions such as 'Can these effects be reversed?'," says Braun. Knowing when the adult brain loses the flexibility of the young brain will be important.
Some evidence for hope came from work by Igor Branchi, at the University of Rome in Italy. He reported that when rodents were allowed extra social stimulation - the mouse equivalent of kindergarten - a lot of early emotional deficits could be improved.

Boys and Girls
Boys are more likely to develop attention deficit hyperactivity disorder (ADHD) than girls - a disorder that seems to be related to the brain's prefrontal attention systems, while women are more likely to develop depression, which is known to be related to shrinkage in the hippocampus.

12:02 12 July 2006
NewScientist.com news service
Helen Philips, Vienna
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Weblinks
Federation of Neurosciences Annual Meeting
http://fens2006.neurosciences.asso.fr/
University of Magdeburg
http://www.uni-magdeburg.de/unv_eng.html
 From issue of New Scientist magazine, 12 July 2006, page

Comments

Sat, 2007-08-18 16:58 — neophyte

Here's a question:

I'm not a doctor, or pretend to be one, but simple logic dictates this simple question:  If stress hurts a developing baby, did it ever occur to people that maybe mothers don't want to give-up their babies, but are doing so because adoption agencies and/or parents are making them choose that option because they have the mothers convinced they have no choice but give their children up for adoption?

Isn't that a stress that can be prevented?

Sat, 2008-05-31 15:22 — Kerry

More than one source of stress

Clearly, it makes sense stress during pregnancy is not healthy for the mother or baby.  This is the very reason why a pregnant woman needs support from family, friends, and quality health-care providers -- all teaching, explaining and showing the new-mother what she eats and how she behaves affects her baby inside, and will also help determine the future development of that child, once he is born.  This is why parenthood for the woman begins at conception, not birth.

It must be remembered, too, birth itself is a major stress for a newborn.  Penelope Leach wrote a wonderful book describing the birth-process, and it's stunning to read how birth, and the removal of all that was familiar creates new stress for a newborn.  For instance, imagine being the  newborn being removed from all the sounds and smells and tastes that were familiar.  Imagine the loss of mommy's heartbeat and muffled-voice... and having all the "comforts of home" suddenly replaced by the sounds, taste and feel of a foreign room, with unfamiliar voices and strange sounds. Imagine all the basic needs (like food and physical comfort) which were once constantly provided, suddenly becoming needs with a priority.  This is why mother-child bonding is so crucial to the baby and the mother, because both need to know neither has been hurt or damaged, and this is why all parents need to know how stress affects child development.

With that in mind, consider how the stress of institutional care, or multiple care-givers can confuse and unsettle a child because life has become inconsistent, abrupt, and harsh.  Inconsitency and constant change causes stress and panic, even in adults.  [What ADULT can endure constant change without some comforts of 'the familiar", and what child can rationalize like an adult?]

Below is the article about orphanages, but I believe it's safe to say infant neglect can happen anywhere, by anyone, even adoptive and foster parents:

Growing up in an orphanage can substantially stunt early cognitive and physical development – but being placed in foster care may reverse this to some degree, a study of abandoned Romanian children suggests.

However, the researchers observing the youngsters found that boys do not show the same initial improvements as girls when placed in foster care: "The girls placed in foster care do much better in terms of their IQ scores compared with boys," says Nathan Fox of the University of Maryland, US, one of the team.

The study involved comprehensive assessments of 136 children placed in institutional care as part of the Bucharest Early Intervention Project. Sixty-nine of the originally institutionalised children were selected at random and placed in foster care, while the remaining 67 youngsters stayed in the orphanage.

There are not enough resources in Bucharest to place all of the children in foster care, the researchers say.

Verbal skills

At about 4.5 years of age, girls in foster care scored an average of 79 on the IQ test given to them, while those who remained in institutional care scored an average of 59. But the mean score of boys in both groups was in the 60s. Even with foster care intervention, most of the children still scored in the low IQ range. Average IQ scores are around 100.

"It's a very interesting finding. One wouldn't expect it [the sex difference] at all," says Seth Pollak, a developmental psychopathologist at the University of Wisconsin, Madison, US.

Fox says his team does not know why girls seem to respond better to foster care, in terms of cognitive development. He speculates that foster parents may be more talkative with the girls in their care, boosting these children's verbal skills. Fox and other scientists stress they must find out more about the differences in foster care versus institutional care to understand what gives girls the advantage.

Emotional and behavioural

Another researcher, Charles Zeanah of Tulane University in New Orleans, US, analysing data from the same project, found that psychiatric disorders were 3.5 times more common among institutionalised children than among children in normal family care. He also found that foster care could help the psychiatric condition of orphaned, institutionalised children.

His group determined that children in foster homes had a reduced risk of emotional disorders, including anxiety and depression. But they found no difference in the frequency of behavioural disorders such as hyperactivity and aggression between children in foster care or institutional care.

Zeanah notes that girls are more likely to suffer from emotional disorders – so may gain more psychiatric benefit from foster care – while boys more commonly have behavioural problems. "Girls are much more responsive to placement in foster care and have their [psychiatric] symptoms ameliorated more than boys," he notes.

Delayed puberty

However, girls may also be more vulnerable to delayed physical development while in institutional care. Dana Johnson at the University of Minnesota described how the orphaned Romanian children he and his colleagues studied had markedly lower levels of natural growth hormones.

According to their latest analysis, puberty appears delayed by an average two years among girls in institutional care in comparison with girls in normal family environments. Boys, on the other hand, have a puberty delay of about 1.5 years when they remain in orphanages.

The studies were presented on Wednesday at the American Association for the Advancement of Science meeting in St. Louis, Missouri.

http://www.newscientist.com/article.ns?id=dn8736