Using Blue Food Dye to Repair a Spinal Cord
The rat above was paralysed when its spine was damaged. This damage was methodical and deliberate. The rat's spinal cord was surgically cut, in order to test a new chemical treatment that it was hoped would minimise secondary damage, greatly reducing the disability of the rat.
This secondary damage occurs when ATP, the vital energy source that keeps our body's cells alive, quickly pours into the area surrounding a spinal cord injury, arriving within seconds, and begins to kill off the damaged cells. Paradoxically, when it comes to nerve cells, ATP acts without discrimination and kills off healthy cells in large numbers, in addition to the damaged ones.
This mass genocide of nerve cells quickly turns what would be a relatively minor injury into crippling damage, and it occurs every time the spine is damaged.
There have been ways to minimise this damage. Previous studies have shown that rats with damaged spinal cords who received an injection of oxidised ATP were shown to recover much of their limb function, to the point of being able to walk again, ambulating effectively if not gracefully. However, oxidised ATP has undesirable side effects in the body, and is not a compound that many doctors would be comfortable administrating to a human. Thus, the search was on to find a compound that had the same effect as oxidised ATP.
That rat above helped find it. Ironically it's a food dye, the same one as used to turn blue M&Ms blue. The compound Brilliant Blue G (BBG) stops the cascade killing of ATP cold, when it cuts through the neurons. Damaged cells still die, but anything with its membrane still intact tends to survive, as BBG retards ATP's effectiveness.
An additional major advantage is that BBP does not have to be injected into the spinal cord, which is an immensely painful process. As it is non-toxic, it can just be injected en masse into any vein, and the compound will make its way into all of the body's systems, colouring them blue for a time before fading. In the rats tested, the eyes took on a blue tint, as did the skin and nails. This faded within a week.
"While we achieved great results when oxidised ATP was injected directly into the spinal cord, this method would not be practical for use with spinal cord-injured patients," said lead researcher Maiken Nedergaard, M.D., D.M.Sc., professor of Neurosurgery and director of the Centre for Translational Neuromedicine at the University of Rochester Medical Centre. "First, no one wants to put a needle into a spinal cord that has just been severely injured, so we knew we needed to find another way to quickly deliver an agent that would stop ATP from killing healthy motor neurons. Second, the compound we initially used, oxidised ATP, cannot be injected into the bloodstream because of its dangerous side effects."
These side effects include of course, the bends, as oxygen bubbles form inside the bloodstream. Not a good idea.
A couple of weeks after the photo above was taken, the rat was killed. This sad event was necessary to visually investigate the damage to its spinal cord. That cord is shown on the right, and permanently retained the blue colouring around the damaged area. The rat had managed to regain the ability to walk after its spinal cord was cut, but never achieved the level of grace it had before, because BBP does not heal damaged neurons, only saves the undamaged ones from death. It also only works if injected within minutes of the initial spinal cord injury.
Thus, it is not the miracle cure that is sorely needed for reattaching or regrafting spines, however what it is, is a tool to prevent unnecessary surgical damage, limit the damage from accidents, and open up the possibility of experimental spinal operations - something that was simply unthinkable previously.