Washington: Worms may help shed light on what causes some people to suffer from life-threatening anxiety disorders while others are better able to cope with stress, scientists say.
Maureen Barr, a professor in the Department of Genetics at Rutgers University in US and colleagues, found that the architectural structure of the six sensory brain cells in the roundworm, responsible for receiving information, undergo major changes and become much more elaborate when the worm is put into a high stress environment.
Scientists have known for some time that changes in the tree-like dendrite structures that connect neurons in the human brain and enable our thought processes to work properly can occur under extreme stress, alter brain cell development and result in anxiety disorders like depression and Post Traumatic Stress Disorder.
However, the cause behind these molecular changes in the brain is not known.
"This type of research provides us necessary clues that ultimately could lead to the development of drugs to help those suffering with severe anxiety disorders," Barr said.
In the study published in Current Biology, scientists identified six sensory nerve cells in the tiny, transparent roundworm, known as the C elegans and an enzyme called KPC-1/furin which triggers a chemical reaction in humans that is needed for essential life functions like blood-clotting.
While the enzyme also appears to play a role in the growth of tumours and the activation of several types of virus and diseases in humans, in the roundworm the enzyme enables its simple neurons to morph into new elaborately branched shapes when placed under adverse conditions.
Normally, this one-millimetre long worm develops from an embryo through four larval stages before molting into a reproductive adult.
When put under stressful conditions of overcrowding, starvation and high temperature, the worm transforms into an alternative larval stage known as the dauer that becomes so stress-resistant it can survive almost anything - including the Space Shuttle Columbia disaster in 2003 of which they were the only living things to survive, researchers said.
When a perceived threat is over, these tiny creatures and their IL2 neurons transform back to a normal lifespan and reproductive state like nothing had ever happened.
Under a microscope, the complicated looking tree-like connectors that receive information are pruned back and the worm appears as it did before the trauma occurred.
This type of neural reaction differs in humans who can suffer from extreme anxiety months or even years after the traumatic event even though they are no longer in a threatening situation.
The ultimate goal, Barr said, is to determine how and why the nervous system responds to stress.