Wednesday, September 23, 2009

The Color Blind Conundrum: Can you tell the difference between the red and green peppers?

Well, Sam and Dalton, two squirrel monkeys at the University of Washington, now can thanks to gene therapy.

Last week the science community was abuzz with research published in Nature (Mancuso, K. et al. Nature advanced online publication, doi:10.1038/nature08401, 2009) detailing the successful establishment of full color vision in two color blind squirrel monkeys at the University of Washington.
In a nutshell, researchers used gene therapy to insert the gene for red color vision into the eyes of male squirrel monkeys that previously lacked the gene. The result was the establishment of full color vision.

So why is this such a big deal?

Two reasons: For one, the gene therapy treatment worked - a huge advance for a technique that to date has held lots of potential, but few successful clinical applications.

More importantly, it gives researchers a bit more insight into the brain. Jay Nietz, one of the authors of the study, commented to Wired Science that colleagues did not believe that they would be successful because the research community generally accepts that there is a critical period during development during which neurons (the cells of the brain) make the necessary connections to perceive things like colors. The thinking is that if the brain wasn’t exposed to red early on, then it shouldn’t be able to register it later in life. Yet, in these monkeys, that wasn’t the case. Although they didn’t have the machinery (the red color gene) to perceive red when they were young, introduction of this gene later in life still resulted in them perceiving the color.

So really, what does this mean? It means that, at least when it comes to vision, the brain is more flexible than researchers thought. Even though it had never perceived red previously, when given the proper machinery, the red gene, it was able to make that distinction. So, for vision, the rules of neural connections are not as black and white as first thought.

What other systems might show this same “exception to the rule?” Perhaps other visual impairments, hearing deficits, maybe even systems outside the sensory realm? The clinical applications, should this be translatable to humans, could be astounding.

Take away points: Well, for one thing, science is constantly evolving, and as it evolves, its therapeutic potential increases. Another take-home lesson, sometimes the long-shot project fails, but other times, it doesn’t. When it doesn’t, it can mean great things for science and medicine. And maybe on a less universal note, but still important, if nothing else, the 1 in 12 men who are color-blind are one step closer to seeing red, and this sure would make their lives a little easier.

1 comment:

  1. This is so cool! I'm red-green color blind- maybe I can get that fixed some day in the future!