Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Improved recipe for magnetic brain stimulation

20.01.2005


Transcranial magnetic stimulation (TMS), in which the brain is stimulated using a magnetic coil held outside the skull, has shown some promise in both studying the brain and in treating mental disorders such as depression, epilepsy, and Parkinson’s disease. Such magnetic fields induce tiny electrical currents inside the skull that alter the activity of neural pathways.



While TMS offers the advantages of relative safety and noninvasiveness, the results of its use in both research and treatment have been disappointing. In human studies, neurological effects of TMS have been transient, rarely lasting longer than 30 minutes.

Now, researchers led by John Rothwell of the Institute of Neurology at University College London have devised a new TMS method that produces rapid, consistent, and controllable changes in the motor cortex of humans that last more than an hour. Their findings offer the potential for both more useful research studies using TMS as well as greater therapeutic application.


In their studies, the researchers applied various patterns of repetitive magnetic pulses to the scalps of volunteer subjects. They aimed the pulses at the motor cortex that controls muscle response, because effects on the motor cortex can be objectively measured by recording the amount of electrical muscle response to stimulation. Specifically, the researchers positioned the magnetic coil over the motor cortex area that controls hand movement, and they measured response by determining the amount of muscle response in a small muscle in the subjects’ hands.

The researchers recognized the ethical issue of experimenting on healthy human subjects who had nothing to gain from such experiments. So, they began their studies with stimulations of smaller intensities and lower frequencies than they ultimately used in the experiments. Those initial tests showed that there were no long-lasting or side effects from such stimulations.

In their experiments, the researchers found that they could produce controllable, consistent, and long-lasting effects using short bursts of low-intensity pulses over a period of 20 to 190 seconds. Significantly, the researchers found they could overcome the shortcomings of previous stimulation approaches that produced a mix of both excitation and inhibition of transmission of signals between neurons in the brain. The researchers discovered that the excitatory effect of TMS builds up rapidly, within about a second, while the inhibitory effect builds up within several seconds. Thus, by adjusting the length of stimulation, they could favor excitatory or suppressive effects on the brain.

"We have found these stimulation paradigms to be safe in normal subjects and capable of producing consistent, rapid, and controllable electrophysiological and behavioral changes in the function of the human motor system that outlast the period of stimulation by more than 60 minutes" concluded the scientists.

"The method may prove useful not only in the motor cortex but also in other regions of the brain for both the study of normal human physiology and for therapeutic manipulation of brain plasticity," they concluded.

Heidi Hardman | EurekAlert!
Further information:
http://www.cell.com

More articles from Studies and Analyses:

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

nachricht Urbanization to convert 300,000 km2 of prime croplands
27.12.2016 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH

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: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>