Life stressors trigger neurological disorders in unborns

Previous research has shown that when mothers are exposed to certain traumas or life stressors it can activate a single molecular trigger in brain cells. This can often activate conditions such as schizophrenia, post-traumatic stress disorder and some forms of autism. However, little was understood about the impact this could have on a mother's unborn child.

A new study, published in Neuron, has identified a molecular mechanism in the prenatal brain that may help explain how cells change when exposed to certain environmental conditions. 

It was found, during the research, that embryos in mice that had been exposed to alcohol, methyl-mercury, or maternal seizures saw a single gene, HSF1 become activated in the cerebral cortex. This gene plays "a crucial role in the response of brain cells to prenatal environmental insults", according to the team.

They added that HSF1 is able to protect and enable brain cells to survive prenatal assaults and mice that lack this gene demonstrated "structural brain abnormalities" and were prone to seizures after birth due to their exposure to very low levels of toxins.

Even in mice where the HSF1 gene was properly activated to combat severe changes to their environment, the molecular mechanism alone could permanently change how brain cells respond. This could be the reason why so people become more vulnerable to neuropsychiatric disorders later in life.

Dr Kazue Hasimoto-Torii, principal investigator of the Center for Neuroscience, Children’s National Health System and lead author of the paper, said that, although it is generally accepted that exposure to harmful environmental factors increase the susceptibility of the brain to neurological and psychiatric disorders, new types of environmental agents are continuously added to the mix, requiring evolving studies.

Stem cells also played a key role in the study, with the team using them to support their theory that stress causes vulnerable cells to malfunction. During the research, stem cells were taken from people diagnosed with schizophrenia and found that they responded more dramatically when exposed to environmental insults than stem cells from non-schizophrenic individuals.