Researchers working with SuperAgers—people aged 80 and up with impeccable memory—reveal how their brains look decades younger. And compared to others their age, SuperAgers have nearly 90 percent fewer brain “tangles” linked to Alzheimer’s disease. The findings were published in the Journal of Neuroscience last week.
First identified in 2007, the so-called cognitive SuperAgers displayed memories as sharp as people 20 to 30 years younger than them. In a preliminary study, researchers found that a particular region of their cortex was thicker than that of middle-aged participants. Now, in a more detailed study, a Northwestern University team led by Tamar Gefen used MRI scans to image the brains of 31 SuperAgers, and they also conducted postmortem investigations with five who donated their brains to science.
Compared with 21 similarly aged people, as well as 18 volunteers aged 50 through 60, SuperAgers have an unusual brain signature characterized by three main components: a thicker, larger region of the cortex, significantly fewer neurofibrillary tangles (a marker of Alzheimer’s), and a huge supply of a neuron called von Economo, which has been linked to higher social intelligence.
That particular region of the cortex, called the anterior cingulate cortex, influences cognitive control, conflict resolution, and perseverance. And in SuperAgers, it contained 87 percent less tangles than recruits of the same age and 92 percent less tangles than individuals with mild cognitive impairment. These twisted fibers can strangle healthy neurons.
To the right, you can see Alzheimer neuropathology (APs and NFTs) in the cortex of an elderly control and an individual diagnosed with amnestic mild cognitive impairment. There are none in the 90-year-old SuperAger.
Furthermore, within this brain region, SuperAgers had up to five times more von Economo neurons, which likely play a key role in the rapid transmission of information during social interactions, “which is how they may relate to better memory capacity,” says study co-author Changiz Geula of Northwestern University. These neurons are also found in dolphins, whales, elephants, and some apes.
“The brains of the SuperAgers are either wired differently or have structural differences when compared to normal individuals of the same age,” Geula says in a news release. It could be the expression of a single gene or a combination of factors. Gefen adds: “Identifying the factors that contribute to the SuperAgers’ unusual memory capacity may allow us to offer strategies to help the growing population of ‘normal’ elderly maintain their cognitive function and guide future therapies to treat certain dementias.”
Images: shutterstock.com (top), T. Gefen et al., 2015 Journal of Neuroscience (middle)