Years ago my friend Jim broke his neck surfing on his honeymoon in Mexico. Rushed back to the U.S., he was operated on as quickly as possible to save as much spinal cord as the surgeons could. Unfortunately, that turned out not to be very much.
Today researchers may have some good news for him. For many years, scientists have been doing their best to figure out why nerve cells refuse to regenerate, looking for ways to stimulate these cells to resume their growth, and thus, restore some spinal cord function, according to a story at medicaxpress.com.
Spinal cord injuries can come from car accidents, falls, or sports. In some cases, they can cause death.
To establish whether a single cell is growing, the cell must be visible in the first place, according to the story, and that’s been the problem. Up to now, researchers have had to cut the area of the spinal cord required for examination into ultra-thin slices, which are then examined under a microscope. The position and pathway of each cell is reconstructed.
In some cases, scientists have been able to first digitize each slice and then reassemble the images, one by one, to produce a virtual 3D model, according to the story.
But this can require days, sometimes even weeks, to process the results of just one examination, according to the story. “Even worse, mistakes can easily creep in and falsify the results,” the story reports, explaining that parts of individual nerve cells might get squashed during the process of slicing, “and the layers might be ever so slightly misaligned when set on top of each other.”
“Although this might not seem dramatic to begin with, it prevents us from establishing the length and extent of growth of single cells.” Frank Bradke was quoted in the story. Bradke and his team at the Max Planck Institute of Neurobiology have been investigating the regeneration of nerve cells following injuries to the spinal cord.
The team worked tirelessly to develop a new approach and a technique, based on a method known as ultramicroscopy was born, using a method that rendered the usually opaque cells to a more visible state.
The Max Planck neurobiologists and an international team of colleagues removed the water that makes up a cell, along with proteins, from a piece of spinal tissue and replaced it with an emulsion that refracts light in exactly the same way as the proteins, leaving them with a completely transparent piece of tissue.
“It's the same effect as if you were to spread honey onto textured glass,” Ali Ertürk, the study's first author, noted in the story. The opaque pane becomes crystal clear as soon as the honey has compensated for the surface irregularities, according to the story.
By using fluorescent dyes to stain individual nerve cells, scientists can now trace their path from all angles in an otherwise transparent spinal cord section, helping them figure out for once and for all whether or not these nerve cells began their growth following injury to the spine, according to the story, which notes this is an essential prerequisite for future research.
“The really great thing is the fact that this method can also be easily applied to other kinds of tissue,” Bradke was quoted as saying in the story. For example, the blood capillary system or the way a tumor is embedded in tissue could be portrayed and analyzed in 3D.
Deborah DiSesa Hirsch is an award-winning health and technology writer who has worked for newspapers, magazines and IBM in her 20-year career. To read more of her articles, please visit her columnist page.Edited by
Jennifer Russell
