Scientists at Mainz and Innsbruck explore new treatment approach to overcome fear
A drug used to treat Parkinson's disease could also help people with phobias or post-traumatic stress disorder (PTSD). Scientists of the Translational Neurosciences (FTN) Research Center at Johannes Gutenberg University Mainz (JGU) are currently exploring the effects of psychotherapy to extinguish fears in combination with L-dopa. This drug does not only help movement disorders, but might also be used to override negative memories.
Professor Raffael Kalisch, head of the Neuroimaging Center (NIC) of the JGU Translational Neurosciences Research Center, and his collaborators at the University of Innsbruck are conducting research in mice and in humans into the psychological and neurobiological mechanisms of anxiety and fear.
"Fear reactions are essential to health and survival, but the memories of angst-inducing situations may cause long-term anxiety or phobias," explained Kalisch. In psychotherapy, the 'fear extinction' method is used in exposing people to a threat but without the adverse consequences. Latest research has proven that extinguishing fear also predicts mental health after trauma, suggesting extinction may be an important resilience mechanism.
Fear extinction involves a person being presented with a neutral stimulus, such as a circle on a screen, together with a painful sensation. Soon the person predicts pain in response to the circle on the screen and fear becomes conditioned. Then the person is shown the circle again, but this time without the painful stimulus, so that the person can disassociate the two factors. A person who is afraid of spiders, for example, will in psychotherapy be confronted with spiders in a way that reassures them that the spider is harmless.
In another research program, Belgian scientists tested the ability to extinguish fear in soldiers later deployed to a war zone and found differences in the soldiers' resilience to traumatic memories. Some experienced post-traumatic stress symptoms following their deployment, whereas those who were able to extinguish fear in the laboratory maintained a good state of mental health.
"If you are mentally flexible enough to change the associations that your mind has created, you might be better able to avoid lasting damage," explained Kalisch. In cooperation with other scientists, Kalisch has found first evidence that this process of changing negative associations might involve the brain's systems for reward and pleasure and depend on release of the neurotransmitter dopamine that helps control them.
However, even after successful extinction, old fear associations can return under other stressful circumstances. This might involve the development of PTSD or a relapse after successful psychotherapy. Kalisch has found that L-dopa, a drug to treat Parkinson's disease, can prevent this effect and could therefore possibly be used to prevent relapse in treated PTSD or phobia patients. L-dopa is taken up by the brain and transformed into dopamine that not only controls the brain's reward and pleasure centers and helps regulate movement, but also affects memory formation.
The person receiving L-dopa after extinction will thus create a stronger secondary positive memory of the extinction experience and will thus be able to more easily replace the negative memory. This raises new questions about the role of primary fear memories and secondary prevention by L-dopa. "We would like to be able to enhance the long-term effects of psychotherapy by combining it with L-dopa," said Professor Raffael Kalisch. To this end, he is about to start a clinical study of people with a spider phobia to determine the effects of L-dopa on therapy outcome. "Manipulating the dopamine system in the brain is a promising avenue to boost primary and secondary preventive strategies based on the extinction procedure," he continued.
Abstract Reference R10221: Fear extinction as a key human resilience mechanism: dopaminergic contributions.
Symposia S30: Ramping up resilience: from (epi) genetics, to optogenetics and imaging
Single dose of L-dopa makes extinction memories context-independent and prevents the return of fear. J Haaker, S Gaburro, A Sah, N Gartmann, TB Lonsdorf, K Meier, N Singewald, H-C Pape, F Morellini, R Kalisch. PNAS Plus - Biological Sciences - Psychological and Cognitive Sciences. 2013; 110 (26): E2428-36.
Empirical support for an involvement of the mesostriatal dopamine system in human fear extinction. K A Raczka, A Reif; J Deckert, N Gartmann, M-L Mechias, M Pessiglione, R Kalisch. Translational Psychiatry. 2011; 1: e12.
Professor Raffael Kalisch
Neuroimaging Center (NIC) at the Research Center Translational Neurosciences (FTN)
Johannes Gutenberg University Mainz
phone +49 6131 17-4588
http://www.uni-mainz.de/presse/17457_ENG_HTML.php - press release
Petra Giegerich | idw - Informationsdienst Wissenschaft
ARTORG and Inselspital develop artificial pancreas
26.11.2015 | Universitätsspital Bern
Laboratory study: Scientists from Cologne explore a new approach to prevent newborn epilepsies
24.11.2015 | Deutsches Zentrum für Neurodegenerative Erkrankungen e.V. (DZNE)
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...
25.11.2015 | Event News
17.11.2015 | Event News
21.10.2015 | Event News
27.11.2015 | Press release
27.11.2015 | Life Sciences
27.11.2015 | Materials Sciences