Pain is a negative feeling that we want to get rid of as soon as possible. In order to protect our bodies, we react for example by withdrawing the hand. This action is usually understood as the consequence of the perception of pain. A team from the Technical University of Munich (TUM) has now shown that perception, the impulse to act and provision of energy to do so take place in the brain simultaneously and not, as was expected, one after the other.
Led by Markus Ploner, Heisenberg Professor for Human Pain Research, scientists from the Department of Neurology of the university hospital TUM Klinikum rechts der Isar investigated in detail how a painful event is processed in the brain.
For the first time they were able to show that the brain yields at least three different responses to a painful stimulus, and that these responses are simultaneous and independent of one another. The results may have fundamental repercussions for the understanding of pain and treatment of pain patients.
Pain embodies at least three factors: Perception of pain, an action such as withdrawing the hand from a hot stove, and a response of the autonomic nervous system which provides the necessary energy for the action. The autonomic nervous system controls essential functions such as heart rate, breathing, digestion and metabolism.
Combination of behavioral and EEG measurements
In their experiments, the researchers applied short pain stimuli of varying strengths to the back of the hand of healthy volunteers. The perception of pain was determined based on the participants evaluation of the stimulus on a rating scale.
The team, led by Markus Ploner, investigated the action component based on the reaction time the subjects needed to withdraw their fingers in response to the stimulus. Moreover, to determine the response of the autonomic nervous system, the team measured the sweat production at the interior surface of the hand.
For the entire duration of the experiment, brain activity was measured using electroencephalography (EEG). This method provides highly precise information on when and how nerve cells react to pain stimuli.
Pain components arise independently of one another
Ploner and his team applied a statistical method known as mediation analysis to the data. The method has been well established in the social sciences for some time now; however, this was its first application to EEG data. The team was thus able to find out which brain responses serve the three pain components, and when exactly they take place.
The results of the evaluations surprised the researchers: "For the first time we were able to see that the brain responses to the pain components did not take place one after the other, but rather in part simultaneously.
This means that the preparation for action and the provision of energy are not entirely dependent on the perception of pain; instead they are in part triggered independently of one another," explains Laura Tiemann, the study's lead author.
Comprehensive pain therapy for chronic pain patients
Although at first rather abstract, these findings could be of great importance to patients suffering from chronic pain. Ploner recommends considering all three components of pain in comprehensive pain therapy: "For chronic pain patients, it is possible that not only the perception of pain, but also the preparation and performance of actions against pain and the provision of the energy to do so are changed. Our findings are thus a biological argument for holistic pain therapy approaches that take different pain components into account. Such approaches would include psychotherapy and drug therapy as well as physiotherapy," Ploner says. This kind of therapy, referred to as Multimodal Pain Therapy, is already being offered at the TUM Interdisciplinary Center for Pain Medicine.
Prof. Dr. Markus Ploner
Department of Neurology of the university hospital
Klinikum rechts der Isar of the Technical University of Munich
Tel.: 089 4140-4608
Laura Tiemann, Vanessa D. Hohn, Son Ta Dinh, Elisabeth S. May, Moritz M. Nickel, Joachim Gross and Markus Ploner: Distinct patterns of brain activity mediate perceptual and motor and autonomic responses to noxious stimuli, Nature Communications, October 2018, DOI: 10.1038/s41467-018-06875-x (Open Access).
http://www.professoren.tum.de/en/ploner-markus/ - Profile of Prof. Markus Ploner
https://www.painlabmunich.de/ - Research group of Markus Ploner
https://mediatum.ub.tum.de/1468890 - Download High Resolution Image
Dr. Ulrich Marsch | Technische Universität München
Inselspital: Fewer CT scans needed after cerebral bleeding
20.03.2019 | Universitätsspital Bern
Building blocks for new medications: the University of Graz is seeking a technology partner
19.03.2019 | Karl-Franzens-Universität Graz
DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.
The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...
Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.
The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...
Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.
Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...
The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.
A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...
Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.
"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...
11.03.2019 | Event News
01.03.2019 | Event News
28.02.2019 | Event News
22.03.2019 | Life Sciences
22.03.2019 | Life Sciences
22.03.2019 | Information Technology