Why Do Alzheimer’s Patients Wander? Researchers Look to the Brain’s Neurons
Researchers at Columbia Medical Center made a new discovery into the workings of the Alzheimer’s–a disease that affects nearly 1 in 9 Americans over the age of 65. Published in the journal Neuron, their research explains how a protein called Tau Alzheimer’s patients wander. Katherine Sullivan has more.
SULLIVAN: At the Riverstone Memory Center on 163rd street, patients with dementia sit in in rooms off a circular hallway. But Program assistant Martine Morales says you always have to be watching .
MORALES:I call it 24 eyes you have to have here.
SULLIVAN: Even those in the earliest stages of the disease need an escort.
MORALES: Because sometimes they get up to go to the bathroom, and there’s an exit sign saying go that way. You gotta redirect them.
SULLIVAN: Just down the street, a team of researchers is looking at the specific neurons that cause patients to wander. We’ve known for a long time now that in Alzheimer’s, a protein called Tau builds up, and creates a kind of tangle–But the new research shows these tangles happen in a region of the brain called the entorhinal cortex.
DUFF:If you look at someone face on and look behind their ears, the brain part that’s behind your ears is where the entorhinal cortex is located.
SULLIVAN: That’s Dr. Karen Duff–a lead author of the new study. This part of the brain helps orient us in space. It’s crowded with “grid cells” that fire rapidly as we move, helping us recognize our surroundings,
DUFF:They’re like the map for your GPS system. So if your map is distorted, your GPS system can’t tell you where to go.
SULLIVAN: Grid cells were only discovered two years ago, and Duff and her team are the first ever to study how they interact with a disease. To do it, they genetically modified mice brains to mimic the conditions of ALZ patients, and dropped them in the same maze as younger, healthy mice.
DUFF: Right, so the young mice could navigate and remember which way to turn in the maze. The older mice who had the pathology more advanced could not.
SULLIVAN: Duff says, This, along with other tests, showed that Tau tangles mess up our grid cells, killing off nerve cells, and leading to confusion–as if our Google map isn’t loading fast enough. Duff and her team are now looking at the exact type of neuron within the grid clusters that’s affected.
DUFF: Because if you can identify the type cell that is vulnerable, you develop therapeutics to prevent that cell from being vulnerable.
SULLIVAN: Dr. David Knopman, a clinical neurologist at the Mayo Clinic, says there’s still a long way to go.
KNOPMAN: I think it’s important to state that mouse models are not human disease.
KNOPMAN: But in the long run, this is actually very important for helping us understand the disease.
SULLIVAN: They agree Early screenings of the Entorhinal cortex could catch the emergence of ALZ long before memory starts failing. But Knopman says, once someone is diagnosed with ALZ–there’s not much they can do.
KNOPMAN: As of 2017, we don’t have any preventive treatments for ALZ, and therefore screening for it as no value from a therapeutic POV, it has value only for inducing fear.
SULLIVAN: Back at the Riverstone Memory Center, Morales and her fellow caretakers will stick to available therapies,
MORALES: I entertain them, I dance for them, I sing for them. (0:08)
SULLIVAN: Knopman says, There will need to be a lot more research like Duff’s before there are more treatments available. And this will be left largely to another uncertainty–government funding for scientific research.
Katherine Sullivan, Columbia Radio news.