Wednesday, November 07, 2007

Taste the Brainbow

Stem cells may secret brain repair substance. What happens when you take a deficient rodent brain and inject it with stem cells? Brain rescue, at least in Alzheimer's-like mice models. This is a more elaborate variation on seminal work from last year.

Rather, the group speculates that the transplanted cells secreted protective neurotrophins, proteins that promote cell survival by keeping neurons from inducing apoptosis (programmed cell death).

What's interesting here is how malleable the system is. The brain is no different than the muscle or the skin in that it can respond to simple biochemical stimuli. Hook and levers, people, hooks and levers.

LaFerla's team genetically engineered mice to lose cells in their hippocampus, a region in the forebrain important for short-term memory formation. These mice were about twice as likely than unaltered rodents to fail a test of their ability to discern whether an object in a cage had been moved since their previous visit.

It would be interesting to see what kind of effect this model would have on the amygdala, the repository of emotional responses and almost always the first target of dementia diseases like Alzheimer's. However, I suppose it is difficult to tell if a mouse if more or less sad than the day before, and they aren't too forthright with that information.

The next step is to isolate this neurotrophin and throw it into a series of in vitro models, see what kinds of things pop up. A little combinatorial chemistry could begin to define what molecular appendage is the business end.

The chances of succumbing to a dementia like Alzheimer's has risen from about 1 in 6 to over 1 in 5 with our slowly creeping increase in life expectancy. With a tsunami of Baby Boomers turning 60, a sense of urgency is likely going to flock towards work of this nature very soon.

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