Study Highlights Unique Brain Activity in SuperAgers

Individuals in their 80s and 90s, referred to as “SuperAgers,” are found to generate twice as many young neurons as healthy adults, and 2.5 times more than those with Alzheimer’s disease, according to new research.

Dr. Tamar Gefen, a coauthor of the study and associate professor at Northwestern University’s Feinberg School of Medicine, emphasized the significance of these findings. “This indicates that the aging brain can regenerate — that’s groundbreaking,” she remarked.

Young neurons, which are particularly adaptable, contrast with stable mature neurons. Gefen, who contributes to the Northwestern SuperAging Program, noted that these young neurons have a remarkable ability to grow and connect within the brain. For over 25 years, researchers have been examining older adults with exceptional memory capabilities.

Gefen described SuperAgers as individuals who maintain lively, immature neurons that are more excitable. “They’re energetic and ready to connect — essentially a more youthful brain,” she stated.

The study also discovered that the hippocampus—an area crucial for memory—of SuperAgers possesses a stronger support system, nurturing young neurons much like a sapling thrives in rich soil.

Gefen mentioned that this research presents evidence that SuperAgers have a distinct cellular environment in their hippocampus that encourages neurogenesis. “It’s biological proof that SuperAgers possess more adaptable brains,” she added.

Neurogenesis, the process through which new neurons are formed, boosts brain plasticity. This plasticity is vital for the brain to heal itself, especially as it confronts aging and injuries.

Interestingly, SuperAgers exhibited more newly formed neurons than younger adults in their 30s and 40s. Senior author Orly Lazarov, a professor at the University of Illinois, described this resilience as an ability to cope with life’s inevitable changes.

While genetic predisposition may play a role, anecdotal evidence suggests that individuals who actively maintain good brain health can also stave off cognitive decline, according to Dr. Richard Isaacson, an Alzheimer’s prevention researcher from Florida.

Isaacson highlighted that lifestyle changes, like diet improvement, stress reduction, and regular exercise, can contribute to the growth of brain areas, including the hippocampus, and mitigate signs of Alzheimer’s such as tau tangles and amyloid plaques. “People often aren’t taught that brain cells can grow, but we’re seeing clear evidence from MRI scans of those who make brain-healthy choices,” he explained.

To qualify as a “SuperAger,” a person must be over the age of 80 and undergo comprehensive cognitive assessments that evaluate their memory capabilities, explained Emily Rogalski, a neurology professor at the University of Chicago. She assisted in developing the SuperAger program at Northwestern.

Rogalski indicated that SuperAgers exhibit exceptional episodic memory, which is the ability to recall daily life events and personal experiences. “It’s important to note that, when compared to their age-matched peers, SuperAgers have similar IQ levels, suggesting differences are not merely due to intelligence,” she added.

Common traits among SuperAgers include positivity and an active approach to learning, whether through reading or other activities. Many continue to work in their 80s, remain socially active, and often volunteer within their communities.

However, their lifestyle characteristics can be quite varied. “We have SuperAgers who struggle with heart disease or diabetes, who might not be physically active, and whose diets aren’t necessarily better than their peers,” Gefen pointed out. “Still, it’s the insights gathered from brains donated by SuperAgers that provide the most informative data.”

Examinations of brain tissue revealed that the cingulate cortex, responsible for attention and engagement, is thicker in SuperAgers compared to individuals in their 50s and 60s. Moreover, SuperAgers’ hippocampuses also displayed significantly fewer tau tangles, an Alzheimer’s indicator.

Another study highlighted that SuperAgers have particularly robust neurons in the entorhinal cortex—an area typically vulnerable in Alzheimer’s. Gefen found it remarkable that these neurons were larger than those from much younger individuals. “This finding suggests a remarkable structural integrity, almost like the support system within the neuron itself is more resilient,” she commented.

The recent study provides insight into how these neurons thrive, suggesting that the impressive size of entorhinal neurons may also be related to a supportive environment in the hippocampus. “These neurons are intricately linked,” Gefen concluded, hinting that this new research may clarify the reasons behind their increased size.

The study published in the journal Nature utilized advanced techniques to measure neuron development in various groups, including SuperAgers, healthy young adults, and those showing various stages of cognitive decline.

The innovative multiomic single-cell sequencing method allowed researchers to identify brain cells that support memory function as the hippocampus ages. Findings revealed that astrocytes and CA1 neurons play crucial roles in memory retention in SuperAgers.

CA1 neurons, essential for consolidating and retrieving memories, are commonly impacted by tau protein in Alzheimer’s. On the other hand, astrocytes, which vastly outnumber neurons, regulate blood flow and promote the formation of synapses crucial for brain function.

Gefen remarked that the relationship between astrocytes and CA1 neurons in SuperAgers enhances hippocampal function more than previously understood, creating a rich environment for immature neurons and synapse activity.