Like I expect most people would, I used to think that insulin was just something for diabetes. As a biology major I suppose I knew that it regulates how your body uses the sugars in your blood and built up energy reserves, but that was supposed to be it. Well yet again Neurochemistry went and ruined what I thought I knew. It turns out that insulin also has quite a few other roles, especially in the brain. Insulin and its cousin, insulin-like growth factor-1, are key players in neural development and survival. But great power and great responsibility, right? This means when they’re messed up they don’t just cause diabetes. Apparently they can also be involved in Alzheimer’s.
Their role in neural growth and survival make them important for making and keeping memories, so that’s fairly straightforward, but insulin is also important because it decreases inflammatory responses in our brains. And of all the places we want to avoid too much inflammation, the squishy organ in an enclosed space is probably at the top of the list. Not only that, but inflammation can interfere with the normal cleaning out of your brain so you can’t get rid of, for example, amyloid beta- a major player in Alzheimer’s. That’s in addition to your neurons lacking energy without insulin telling them how to eat, subjecting them to oxidative and mitochondrial stress—basically, burning themselves out—and both too much or too little insulin giving you hyperphosphorylated tau protein, another Alzheimer’s contributor. So your brain starts getting too big for its britches, your neurons are busy dying instead of keeping your memories like they’re supposed to, and why? Apparently due to insulin resistance, the same problem we have with diabetes. But on the bright side, we’ve got a little better view into Alzheimer’s disease, and one more way we might be able to treat it.
Adding Injury to Injury: Diabetes can make you more prone to Alzheimer’s?
