Molecular x-ray method sheds light on brain disorders
A new 3D x-ray method, SAXS-CT, offers detailed images of brain cells and maps the myelin sheaths of nerve cells, which are key to understanding conditions such as multiple sclerosis and Alzheimer's disease, according to Danish research published in the July issue of NeuroImage.
The myelin sheaths of nerve cells are lamellar membranes surrounding the neuronal axons. The myelin layers are important to the central nervous system as they ensure the rapid and uninterrupted communication of signals along the neuronal axons. Changes in the myelin layers are associated with a number of neurodegenerative disorders such as cerebral malaria, multiple sclerosis and Alzheimer's disease.
Although the development of these diseases is not fully understood, they are thought to be related to the damage of the myelin layers, so that messages from the brain reach the various parts of the body poorly or not at all.
"We have combined two well-known medical exam methods: SAXS (small-angle x-ray scattering) and CT. Combined with a specially-developed program for data processing, we have been able to examine the variations of the myelin sheaths in a rat brain all the way down to the molecular level without surgery,” Torben Haugaard Jensen, PhD, of Niels Bohr Institute at the University of Copenhagen, explained in an interview.
Jensen said, “The method will be more suitable for researching the development and pathways of the diseases [rather than diagnosing the diseases]. A lot of this is still not known today.”
The experiments took place at the Paul Scherrer Institute in Switzerland, which is equipped with an x-ray source that can measure SAXS at a high resolution. By incorporating methods from CT scanning researchers produced 3D x-ray images. “The method,” said Jensen, “builds on methods and principles used in radiology today, but combines them in new ways to obtain new information.”
The method produces detailed measurements of cross sections from different angles, which are based on analysis of 800,000 images.
"We can see the myelin sheaths of the neuronal axons and we can distinguish the layers which have a thickness of 17.6 nanometers,” wrote Jensen and colleagues. "Up until now, you had to cut out a little sample in order to examine the layers in one area and get a single measuring point. With the new method, we can examine 250,000 points at once without cutting into the sample. We can get a complete overview over the concentration and thickness of the myelin and this gives the ability to determine whether the destruction of the myelin is occurring in spots or across the entire sample.”
“Through this improved insight into the diseases, it may be possible to develop new approaches for prevention, treatment and possibly diagnosis,” Jensen concluded.
The myelin sheaths of nerve cells are lamellar membranes surrounding the neuronal axons. The myelin layers are important to the central nervous system as they ensure the rapid and uninterrupted communication of signals along the neuronal axons. Changes in the myelin layers are associated with a number of neurodegenerative disorders such as cerebral malaria, multiple sclerosis and Alzheimer's disease.
Although the development of these diseases is not fully understood, they are thought to be related to the damage of the myelin layers, so that messages from the brain reach the various parts of the body poorly or not at all.
"We have combined two well-known medical exam methods: SAXS (small-angle x-ray scattering) and CT. Combined with a specially-developed program for data processing, we have been able to examine the variations of the myelin sheaths in a rat brain all the way down to the molecular level without surgery,” Torben Haugaard Jensen, PhD, of Niels Bohr Institute at the University of Copenhagen, explained in an interview.
Jensen said, “The method will be more suitable for researching the development and pathways of the diseases [rather than diagnosing the diseases]. A lot of this is still not known today.”
The experiments took place at the Paul Scherrer Institute in Switzerland, which is equipped with an x-ray source that can measure SAXS at a high resolution. By incorporating methods from CT scanning researchers produced 3D x-ray images. “The method,” said Jensen, “builds on methods and principles used in radiology today, but combines them in new ways to obtain new information.”
The method produces detailed measurements of cross sections from different angles, which are based on analysis of 800,000 images.
"We can see the myelin sheaths of the neuronal axons and we can distinguish the layers which have a thickness of 17.6 nanometers,” wrote Jensen and colleagues. "Up until now, you had to cut out a little sample in order to examine the layers in one area and get a single measuring point. With the new method, we can examine 250,000 points at once without cutting into the sample. We can get a complete overview over the concentration and thickness of the myelin and this gives the ability to determine whether the destruction of the myelin is occurring in spots or across the entire sample.”
“Through this improved insight into the diseases, it may be possible to develop new approaches for prevention, treatment and possibly diagnosis,” Jensen concluded.