Washington (PTI): Scientists are on track to block your worst fears after identifying the most prominent neurotransmitter in the brain that plays a key role in the process of "unlearning."

It could eventually help develop therapies to treat a variety of Post-traumatic stress disorder (PTSD), including phobias and anxiety.

PTSD is an anxiety disorder that can develop after exposure to a terrifying event or ordeal in which grave physical harm occurred or was threatened.

According to researchers at California's Salk Institute for Biological Studies, a receptor for glutamate, the most prominent neurotransmitter in the brain, plays a crucial role in the process of "unlearning".

"Most people agree that failure to 'unlearn' is a hallmark of post-traumatic stress disorders and if we had a drug that affects this gene it could help soldiers returning from war to 'unlearn' their fear memories," said Stephen F. Heinemann, a professor at Molecular Neurobiology Laboratory, who led the study, published in the current issue of the Journal of Neuroscience.

Mr. Heinemann and his team were particularly interested in whether mGluR5, short for metabotropic glutamate receptor 5, which had been shown to be involved in several forms of behavioral learning, also plays a role in inhibitory learning.