The Memory of a Fly

I'm making an effort to write about more molecular stories, even though I have to read them several times to really get it, and so when I came across this one I thought it was just the ticket. While 'flipping through' PNAS recently I came across an article titled "PI3 kinase signaling is involved in Aβ-induced memory loss in Drosophila." Admittedly, I usually flip right past an article like this and go for one about ecosystem function, a new species find, or some new theory about food chains or something. But, remembering my new effort, I decided to read the abstract and then the article. Good thing I did because this is actually a pretty interesting story, once you get past all the genetics and molecular jargon.

The authors of the study conducted an experiment using fruit flies who suffered from brain issues similar to those seen in Alzheimer's patients. PI3 kinase is thought to protect an organism against the disease, and β-amyloid peptides are known to alter signaling proteins like PI3. The flies in the experiment were engineered to produce human β-amyloid which, in turn, caused them to develop Alzheimer's symptoms (memory loss, neurodegeneration, plaque accumulation). In their experiment, the researchers blocked the signaling pathway associated with these components.

A condition called long-term depression (LTD), where nerve signals get repressed for long periods of time, is known to be enhanced when β-amyloid is in the brain. The researchers found that this condition is worsened in flies that produce β-amyloid because of the related increase in PI3. Injections of PI3 kinase blocking drugs or by switching off the PI3 kinase gene restored nerve signals. The results suggest that this signal blockage lessened memory loss and decreased plaque buildup. That is a very short summary to say the least and so if you have access to the article (reference link below) I suggest taking a read.

So, once again, hooray for the fruit fly. Perhaps someone should send the article to Sarah Palin.

The study can be found here: http://www.pnas.org/content/early/2010/03/17/0909314107 (DOI: 10.1073/pnas.0909314107)

(image from academictree.org)