The ultimate aim of the work is to understand how neuronal circuits are reorganised at this exact moment in time and to take advantage of anaesthesia to reconfigure them correctly following trauma. This would allow anaesthetic techniques to be used in the future to treat pain described by amputated patients in what are known as "phantom limbs".
Neuroscience research in recent years has shown that the brain is a dynamic structure. Phenomena such as learning, memorising or recovery from stroke are made possible by the brain's plastic properties. Brain plasticity does not, however, always have a beneficial effect.
For example, some amputated patients suffering from chronic pain (known as phantom limb pain) feel as though their missing limb were "still there". Such "phantom limb" illusions are related to the appearance in the brain of incorrect representations of the missing body part.
Persons under regional anaesthetic describe these very same false images.
Based on these observations, Inserm's researchers wished to discover whether anaesthesia could, in addition to fulfilling its primary function, induce comparable phenomena in the brain. If this were so, anaesthetics could be used as new therapeutic tools capable of modulating brain activity.
With this in mind, a team headed by Dr Stein Silva monitored 20 patients who were to have one of their arms anaesthetised before surgery. The patients were shown 3D images of the hand, shot from different angles, and their ability to distinguish the right hand from the left was assessed. Results showed how anaesthesia affected the patients' ability to perceive their body correctly.
The researchers observed three phenomena based on these tests:
All the patients described false sensations in their arm (swelling, difference in size and shape, imagined posture).
In general, patients under anaesthetic took longer to distinguish between a left and right hand and made far more mistakes than persons not under anaesthetic.
The best results were obtained when the anaesthetised limb was visible.
In other words, anaesthetising the hand (peripheral deafferentation ) modifies brain activity and rapidly changes the way we perceive the outside world and our own body. The teams are now using functional brain imaging to characterise the regions concerned in the brain. They also hope that it will be possible to use anaesthesia for therapeutic purposes in the future by modulating post-lesional plasticity (chronic pain in amputated patients, improved recovery in those suffering from brain lesions).
Inserm researcher Stein Silva, an anaesthetist and the chief author of the study, believes that it will no doubt be necessary to develop new anaesthetic techniques to inhibit or directly stimulate the brain images associated with painful phenomena.
Impaired Visual Hand Recognition in Preoperative Patients during Brachial Plexus Anesthesia Importance of Peripheral Neural Input for Mental Representation of the Hand
Stein Silva, M.D.,* Isabelle Loubinoux, Ph.D.,† Michel Olivier, M.D.,‡ Benoît Bataille, M.D.,‡ Olivier Fourcade, M.D., Ph.D.,‡ Kamran Samii, M.D., Ph.D.,‡ Marc Jeannerod, M.D., Ph.D.,§ Jean-Francois Démonet, M.D., Ph.D.
Anesthesiology, January 2011 - http://dx.doi.org/10.1097/ALN.0b013e31820164f1
Contact chercheur:Stein Silva
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy