French researchers develop imaging technique for neurological disease analysis


Researchers at the Institut Fresnel, CNRS, Aix-Marseille University in France have developed the new high-speed polarisation molecular-scale imaging technique to facilitate the view of biological processes that occur during neurodegenerative disorders such as Alzheimer’s disease and multiple sclerosis.

The technique has the capacity to acquire information on chemical makeup and orientation of molecules within seconds to provide insights into their behaviour.

Initially, the new method is expected to enable the study of disease progression at the molecular level and upon further development in the detection of early signs of neurodegenerative diseases.

Led by Sophie Brasselet, the research team used artificial lipid membranes to evaluate the technique.

The method uses coherent Raman scattering and provides chemical makeup of a molecule according to its molecular vibrations, eliminating the need for fluorescent labels or chemicals.

An electro-optical device Pockels cell was used to regulate the laser’s polarisation for obtaining information on molecular orientation.

"The technique was found to be sensitive to measure the organisation of lipids that are present around red blood cells and reveal deformation."

Brasselet said: “We took the concept of intensity modulation used for stimulated Raman scattering and transposed it to polarisation modulation using an off-the-shelf device.

“The signal detection for our technique is very similar to what is done with stimulated Raman scattering, except that instead of detecting only the intensity of the light, we detect polarisation information that tells us if molecules are highly oriented or totally disorganised.”

During the evaluation, the technique was found to be sensitive to measure the organisation of lipids that are present around red blood cells and reveal deformation.

Translatable to biological tissue, the technique is believed to have the potential to allow a better understanding of disease progression involving myelin sheath breakdown.

Brasselet further added: “Ultimately, we would like to develop coherent Raman imaging so that it could be used in the body to detect diseases in their early stages.

“To do this, the technique would have to be adapted to work with endoscopes or other tools in development that allow light-based imaging inside the body.”