Blue Rats Walk Again

For decades, rumors have been spread about the magical powers of M&M's. Some claim that green M&M's act as an aphrodisiac. Sadly, researchers have yet to study the link between green dye and increased sexual desire. But someone did study the dye used for blue M&M's, and the findings might have a dramatic impact preventing spinal cord injuries.

The dye, known as Brilliant Blue G (BBG), resembles FD&C blue dye No. 1, which gives blue Gatorade and M&M's their garish hue. Researchers at the University of Rochester Medical Center discovered that if they injected BBG into rats who have suffered suffering paralyzing spinal cord injuries within the last 15 minutes, the rats would be able to walk again. Unfortunately, the rats walked with a limp and turned a little blue.

Maiken Nedergaard, one of the lead researchers, had previously discovered that when a spinal injury occurs, adenosine triphosphate (ATP) floods into the area surrounding the wound. Normally, ATP benefits human cells because it keeps them alive. But in the case of an injury, the sudden influx of ATP overstimulates otherwise healthy neurons and causes them to die of metabolic stress, often creating secondary injury and more spinal cord damage. The ATP cells flock to the spine because they're attracted to P2X7, or death receptors, found in abundance in spinal neurons.

Nedergaard and her colleagues needed a substance that would block the ATP and P2X7 from latching together. Oxidized ATP stopped the attachment, but had negative side effects. After serendipitously discovering that BBG, a P2X7R antagonist, is similar to FD&C blue dye No.1, researchers injected BBG into the rats' blood. The dye halted the cell deaths and rats that received the injection walked again. Rats that went without the shots never regained their ability to walk.