Researchers in the United Kingdom make an important discovery

Oct 4, 2011 15:13 GMT  ·  By
Exposure to stressful experiences triggers the release of a protein that helps the brain counteract the negative consequences of these stimuli
   Exposure to stressful experiences triggers the release of a protein that helps the brain counteract the negative consequences of these stimuli

Scientists with the University of Leicester, in the United Kingdom, say they've made an important discovery while analyzing the code on which the human brain operates – a new, key actor involved in determining how the cortex deals with, and mitigates for, daily stress.

In modern societies, stress is ever-present and widespread. There are very few people who have jobs, for example, who never felt stressed at work. Studies have already shown that stressed people are at increased risks of developing a wide variety of diseases.

Past researches have also documented a few mechanisms that the human brain uses in order to protect itself from the negative effects of chemicals released when people are under stress. The Leicester team proposes that yet another mechanism is available to the cortex for fulfilling this complex task.

One of the most puzzling and interesting aspects of the study was the discovery of “thin, mushroom-like” regions on the surface of neurons. These structures are believed to play an important role in learning and remembering.

When a person undergoes a stressful experiences, painful memories are immediately inscribed in their neural circuits. But when the intensity of the stimuli are too great, the newly-discovered neural structures come into play, suppressing the stress associated with painful memories.

The modifications were triggered by the release of a particular protein, called lipocalin-2, which is generated in the hippocampus during and immediately after stressful events. Under normal circumstances, this molecule is not produced.

In a series of studies conducted on unsuspecting lab rats, Leicester investigators determined that knocking off the gene coding for this protein made mice exposed to stress cower in fear and hide in their cage. Other mice subjected to the same treatment snapped out of it shortly after, and carried on.

Details of the new research effort are published in this week's issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS). A Marie Curie Excellence Grant from the European Commission provided the team with the funds they needed for the study.

“Identification of lipocalin-2 as a new player the brain uses to help us cope with stress is an important step forward. We are getting closer to deciphering molecular mechanisms of stress that, if not functioning properly, may lead to stress-related psychiatric diseases,” Dr. Robert Pawlak explains.

“Stress-related psychological and mental disturbances are extremely common and affect more than 30% of the population. We are keen to investigate whether the mechanisms discovered by us apply to humans and could help inform clinical strategies to deal with anxiety disorders and depression,” he adds.

The expert holds an appointment as a lecturer in neuroscience at the University of Leicester Department of Cell Physiology and Pharmacology. He was the leader of the research team, and the author of the PNAS paper.