A new drug tested on mice can reduce the fear caused by traumatic experiences

Catalan researchers from the Universitat Autònoma de Barcelona claim the new substance could be used to treat stress, phobias or depression. The drug development was done in cooperation with the Emory University in the US. The new drug still has to go through a long testing process.

CNA / N. Vidal

January 14, 2011 10:26 PM

Cerdanyola del Valles (CNA) .- 'Living a traumatic experience favours the persistence of fear associated with an aversive stimulus’, according to researchers from the Autonomous University of Barcelona (UAB) and the Emory University (USA). Together they have discovered a drug that can alleviate this fear. It is a compound that mimics the actions of the protein that activates TrkB receptors in the brain, essential for learning and emotional memory. The new substance could offer therapeutic measures for diseases like Alzheimer's, strokes, Parkinson's or depression and might even be effective for treating posttraumatic stress disorder, panic and phobias.

The drug is called 7.8-dihidroxiflavona and has been tested on mice that were firstly exposed to a traumatic situation. The mice showed a constant recollection of fear and a lack of ability to cover it up. ‘These specimens were frozen for some time and showed signs of having a trauma’, says the doctor responsible for the study Dr. Antonio Armario, a researcher at the Institute of Neuroscience and professor for the Cell Biology, Physiology and Immunology Department at the University of Barcelona. This indicates a similar phenomenon to what occurs to humans suffering from Post Traumatic Stress Disorder (PTSD) when they are exposed to a dramatic situation.

"We found that animals exposed to situations of intense stress were impaired in some learning tasks related to the hippocampus," the researcher said before mentioning how the administration of the new compound can eliminate this learning deficit. 'We feel that this molecule that we discovered is related to many of the consequences of stress and that it somehow favours the activity of the responsible receptor ', says Armario, who ensures that the 7.8-dihidroxiflavona ensured that the condition extinguished much faster. 'The 7.8-dihidroxiflavona activates TrkB receptors in the brain that are essential for learning and emotional memory, he says.

Possible usage

The results of the 7.8-dihidroxiflavona research suggests that as a drug it could be useful for the treatment of disorders based on fear, such as post-traumatic stress disorder, panic disorder or phobias. On top of that, it could have neuroprotective effects that could help develop structures for learning and memory- these potential therapeutic actions could be used for diseases like Alzheimer's, strokes, Parkinson's or depression.

The researchers recommend studying the usage of the substance with therapy, with sessions related to the extinction of fear for patients with anxiety disorders, or with people who are just after having a traumatic experience.

The study was led by Dr. Kerry Ressler from the Emory University (Atlanta) and by Dr. Antonio Armario from the University of Barcelona. Dr. Rudolph Anders, a researcher at the American University also participated. The article that was published in the American Journal of Psychiatry is part of the doctoral thesis of Dr Anders.

A natural compound

7.8-dihidroxiflavona is a flavonoid derivative. Flavonoids are present in foods like red wine, citrus fruits, cereals, tea and chocolate (70% of cocoa). The chronic administration of foods rich in flavonoids in laboratory animals has shown neuroprotective effects in rodent longevity, but the activation of TrkB receptors that is produced is low compared to the 7.8-dihidroxiflavona. TrkB receptors in the brain are activated in the mammalian by the protein BDNF. There are several pathologies such as depression or anxiety disorders, where the protein has altered their functions.

The administration of this protein as a drug is limited because most of the amount injected can not act on the central nervous system. Recent studies have shown that the 7.8-dihidroxiflavona is the first drug that mimics the actions of BDNF and enters the brain in a 'much more effective' way than the protein.