According to science, the average person’s memory peaks in their 30s and then begins to decline thereafter. But a select group of elderly people (defined as those in their 80s and beyond) retain an unusually remarkable memory. These individuals’ have exceptional episodic memory that’s at least as good as that of an average person who’s 50 years younger. Now, a team of researchers has discovered how these individuals — also called SuperAgers — are able to keep their brains young — “super neurons.”
The science and other stuff to know
In an attempt to identify what makes the brains of SuperAgers different from typical elderly brains, a team of researchers from Northwestern University focused on the entorhinal cortex, a brain region responsible for memory and one of the first impacted by Alzheimer’s disease.
During the study, researchers studied six post-mortem SuperAger brains and found larger, healthier neurons in one of the six layers making up this region. These neurons were then compared to those in seven cognitively average elderly people, six young individuals, and five other persons with early Alzheimer’s, and were found to be significantly larger, according to a new study published in The Journal of Neuroscience.
“The remarkable observation that SuperAgers showed larger neurons than their younger peers may imply that large cells were present from birth and are maintained structurally throughout their lives,” said lead author Dr. Tamar Gefen, an assistant professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine, in a press release. “We conclude that larger neurons are a biological signature of the SuperAging trajectory.”
Moreover, the researchers discovered that the neurons of the SuperAgers did not have tau tangles, which are abnormal protein deposits that can accumulate inside neurons and impair them. These tau proteins are frequently a major indicator of Alzheimer’s disease.
When asked why SuperAgers’ neurons may be larger than those of their peers, Dr. Gefen said: “One possibility for the greater size is that these neurons are protected from neurofibrillary tangles — a hallmark of Alzheimer’s disease. We are not yet sure why these neurons were larger in SuperAgers or why they are relatively protected from disease.”
Most important of all, this study may hold a lot of promise for solving the mystery of what causes Alzheimer’s disease. Further research could enable researchers to identify early risk factors for Alzheimer’s disease and work toward developing an effective treatment, and possibly a cure. However, the real hope is for overall prevention, to discover why SuperAgers do not develop Alzheimer’s and how to prevent it from developing in the first place.
“Individuals with significant memory impairment due to Alzheimer’s disease showed nearly 100 times more tangles in the entorhinal cortex compared to SuperAgers,” Gefen said. “There is a strong relationship between tau-tangles and memory loss, and these findings in a unique SuperAging cohort could guide research in a new direction.”
Overall, the brain of SuperAgers seems to defy wear and tear better than that of an average person. By studying how SuperAgers are unique, researchers hope to unearth biological factors that might contribute to maintaining memory ability in advanced age, and surely, this study paves the way for additional research into the function of super neurons, both alone and in collaboration with other cells, nodes, and networks in the brain and body.