Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brain scans show how placebo eases pain

20.02.2004


New studies are the first to document changes induced by placebo in the brain’s pain pathways



Researchers have produced the strongest evidence yet that placebo--or the mere expectation of relief, with no real treatment--causes physical changes in how the brain responds to pain. Their report appears in the Feb. 20 issue of Science.

In two related studies at the Ann Arbor Veterans Affairs (VA) Health Care System, University of Michigan and Princeton University, researchers used functional magnetic resonance imaging (fMRI) to map changes in blood flow in the brains of volunteers. The volunteers were subjected to harmless but occasionally painful electric shocks or heat. When they believed an anti-pain cream had been applied to their arm, they rated the pain as less intense--and the pain circuits in their brain showed less activity.


Doctors have long recognized the power of placebo to make patients feel better. But scientists are unsure why it works, and whether nerve pathways are actually affected. The new studies provide the first scans documenting the changes induced by placebo in the brain’s pain pathways.

"We’ve shown what the old family doctor knew very well--that his interaction with the patient made a great difference in the effectiveness of whatever treatment he was giving," said one of the researchers, Kenneth L. Casey, MD, who has studied pain for three decades. Casey is a neurology consultant for VA and a professor at the University of Michigan. Lead author was Tor D. Wager, MD, a graduate student at the University of Michigan when the research was conducted.

Researchers have performed brain experiments with fMRI since the early 1990s. It uses the technology of MRI--radio waves and a strong magnetic field--to show regions of the brain where blood vessels are widening, extra oxygen is being delivered, or other chemical changes are occurring. These are signs that an area of the brain is busy at work. By taking fMRI images as patients perform different tasks, researchers learn which areas of the brain control which functions.

The Michigan and Princeton pain studies, each involving about two dozen volunteers, show the prefrontal cortex as the area of the brain active in the placebo response. Scientists have developed intriguing models of how this area of the brain guides thought and action based on internal goals and expectations. In support of those theories, the new research by Casey and Wager’s group provides the first images of how the prefrontal cortex is activated by the expectation of pain relief, and how this in turn triggers a reduction of activity in pain-sensing areas of the brain: the thalamus, somatosensory cortex, and other parts of the cerebral cortex.

According to Casey, this clearer knowledge of the brain’s pain pathways may lead to new therapies for those with chronic or acute pain. "One could imagine compounds that would activate these control systems specifically," he said.

Casey also said the research sheds new light on the tangible benefits of the placebo effect in medicine. "If you’re providing a treatment to a patient, it’s important that you realistically provide them with the expectation that it would work, so you enhance the effect. If you gave them a drug or any kind of treatment with the attitude, either explicit or implicit, that this might not be effective, it would be much less likely to be effective."

Working with Wager and Casey on the study were James K. Rilling and Jonathan D. Cohen of Princeton University; Edward E. Smith and Alex Sokolik, University of Michigan; Richard J. Davidson, University of Wisconsin; Stephen M. Kosslyn, Harvard University; and Robert M. Rose, University of Texas Medical Branch.

Bonnie Johnson | EurekAlert!

More articles from Studies and Analyses:

nachricht First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf

nachricht Do microplastics harbour additional risks by colonization with harmful bacteria?
05.04.2018 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Why we need erasable MRI scans

New technology could allow an MRI contrast agent to 'blink off,' helping doctors diagnose disease

Magnetic resonance imaging, or MRI, is a widely used medical tool for taking pictures of the insides of our body. One way to make MRI scans easier to read is...

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

World's smallest optical implantable biodevice

26.04.2018 | Power and Electrical Engineering

Molecular evolution: How the building blocks of life may form in space

26.04.2018 | Life Sciences

First Li-Fi-product with technology from Fraunhofer HHI launched in Japan

26.04.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>