'Fear factor' tweaked in gene study
Italian team sees altered fight-or-flight mechanism in mice
30 August, 14:56
(ANSA) - Rome - Italian scientists say they have managed to tweak the 'fear factor' that sparks the fight-or-flight mechanism in the human brain.
The discovery, in genetically modified mice, could lead to drug treatment to help individuals whose daily lives are hampered when they are frozen by the competing emotions, researchers said.
A team led by Cornelius Gross at the European Molecular Biology Laboratory at Monterotondo near Rome and the GlaxoSmithKline lab at Verona genetically altered a nerve cell in mice so that it contained a chemical receptor that responded to a new drug.
When they injected the drug, they found that the classic fight-or-flight mechanism was altered, according to a study published in the journal Neuron.
"When we inhibited these neurons," Gross said, "we noted to our surprise that the mice exhibited different risk evaluation behaviour, such as raising their hind legs".
"It appears that we didn't actually block the fear but modified their response from passive acceptance to an active coping strategy".
He said that these functions had "never been found" in the part of the brain that acts as a sort of command centre, the amigdala.
Gross said a new generation of drugs might be able to better control emotions in people whose fight-or-flight response "immobilizes" them.
Most people choose either one or the other action but some are effectively inhibited from doing anything until the stimulus passes.
