Super Neurons Found In SuperAgers Brain Enhances Memory

A new study conducted by the researchers of Northwestern Medicine shows that the neurons present in a particular area of the brain that influence the memory was considerably larger in SuperAgers than the rest of their contemporaries.

Super neurons or entorhinal cortex, which are responsible for memory, are detected in people who are aged above 80 years. Compared to their contemporaries who are 20-30 years younger and those who are diagnosed with an early stage of Alzheimer’s, the SuperAgers have larger neurons and thus much better memory.

Tau tangles, the nerves that are prominent in Alzheimer’s disease, were surprisingly nonexistent in the new super neurons.

“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. “We conclude that larger neurons are a biological signature of the superaging trajectory,” said Tamar Gefen, an assistant professor of psychiatry and behavioural sciences at Northwestern University Feinberg School of Medicine.

The study conducted by the team of researchers on SuperAgers with phenomenal memory exhibited a unique biological structure that consists of large and healthy neurons in the entorhinal cortex with an absence of tau tangles.

The unique trait of SuperAgers’ brains

Alzheimer’s disease, which affects the memory and behaviour of an individual, still remains a mystery to scientists. To this day, no cure has been discovered for the disease.

As we age, most of us experience a sharp decline in our memories. This is not the case for superagers, as some people can recall past events as efficiently as those in their 20’s.

Because of the presence of super neurons, the SuperAgers are pretty much immune to Alzheimer’s. Thus, scientists take this research very seriously as it could be the key to solving the memory-draining disease.

“To understand how and why people may be resistant to developing Alzheimer’s disease, it is important to closely investigate the postmortem brains of SuperAgers,” Gefen said.

The entorhinal cortex is one of the main locations where Alzheimer’s disease usually aims at. This is because it is the area that is responsible for our memory storage. Scientists also make it their top priority to learn more about it so that they can find a way to prevent it in the future.

It consists of 6 layers of neurons stacked on top of each other, layer after layer. Layer 2 is considered the vital hub of the brain’s memory circuit as it collects information from one memory centre to another.

The neurons that are free from the tangle formation are seen to keep their structural integrity while the tau tangles cause neuronal shrinkage. The SuperAger study was made possible only because of participants who were willing to donate their brains for research.

The brains of six SuperAgers, seven cognitively average elderly people, six young individuals, and five people with early stages of Alzheimer’s were examined by the scientists to reach the present conclusion that the former has larger neurons than any other.

They also measured and compared the size of neurons contained in layer 2 with that of those in layers 3 and 5.

“We expect this research to be amplified and more impactful through a $20 million expansion of the SuperAging Initiative, now enrolling five sites in the U.S. and Canada,” said Emily Rogalski, associate director of the Mesulam Center for Cognitive Neurology and Alzheimer’s Disease at Northwestern University Feinberg School of Medicine.

According to the MRI and PET scans, the SuperAger’s brain contains low aggregations of toxic brain plaques and tangles that are associated with Alzheimer’s.

“The remarkable observation that SuperAgers showed larger neurons than their younger peers may imply that large cells are present from birth and are maintained structurally throughout their lives,” said Gefen. “We conclude that larger neurons are a biological signature of the superaging trajectory.”