The MRI machine in Dr. Owen Carmichael's lab blares as it scans a subject's brain. Carmichael, Director of Biomedical Imaging at Pennington Research Center, studies those scans trying to understand how the brain ages.
Carmichael explains that "what you'll see on the MRI scan is the amount of brain tissue. And all of that brain tissue is part of that electrical circuitry that makes it possible for you to think." As we age, our brains tend to shrink. And as that tissue goes away, the harder it becomes to think.
He describes the young brain as a grape that's just been pulled from the vine, while "the elderly brain looks more like a raisin, in that it's deflated and smaller in size. And the person with Alzheimer's, that 'looking like a grape' goes even further, it's extremely shriveled up."
What makes the brain shrivel up? Carmichael thinks it could be in the heart. He's researching how managing things that contribute to heart health, like blood pressure and cholesterol, can help the brain.
"Staying physically fit, eating right, staying socially connected and staying intellectually stimulated, all those things help the brain age successfully," he said.
The real mystery for Dr. Carmichael is something called Cognitive Reserve. Some people whose brains have shriveled haven't lost their ability to think or remember. "There's something about these brains that make them resist, and it's a real mystery what that is. Why is that some brains are able to defy things like Alzheimer's disease?" he asks.
Carmichael is trying to figure out what those people did that blocked the cognitive decline. But he doesn't expect the solution to be a silver bullet. He wants "to know what all the pieces of silver buckshot are for those people that seem to defy Alzheimer's disease."
The next step for Carmichael is to conduct a study of blood pressure medications. He'll take brain scans over time of participants who successfully lower their blood pressure to see if the brain tissue is preserved.