A novel study has shown that, in the brain region of the hippocampus, which is essential in learning and memory formation, SuperAgers make new neurons as fast as those of healthy youth, and 2.5 times faster than those of cognitively healthy older adults, and three times faster as those of those with Alzheimer's pathology.
Known as SuperAgers, the exceptional seniors (people older than 80) whose performance on episodic memory tasks is as sharp This indicates that the aging brain is able to regenerate, i.e. it is highly plastic, adaptable cells that have the ability to grow connections, integrate into neural circuits and support cognitive plasticity, said one of the co-authors of the study and a neuropsychologist at the Mesulam Institute of Cognitive Neurology and Alzheimer's Disease, Dr. Tamar Gefen, a professor of psychiatry and behavioral sciences at the Northwestern University Feinberg School of Medicine.
Their preservation of immature neurons with increased excitability is being exhibited by the SuperAgers, she said, they are bright-eyed and bushy-tailed and are about to fire. In addition to an increased production of neurons, SuperAger brains have a special supportive cellular environment in the hippocampus, which has also been termed as a resilience signature.
The supportive environment, worthy of nutrient-rich soil to a seedling is a biological confirmation that the aging brain also is plastic and can give birth to new brain cells and survive, contrary to years of belief in inevitable aging-related cognitive decline. In a research published in 2020, the program of SuperAger in the 7-year-old was found to have positive results, even though new neurons make up only a tiny portion of those in the hippocampal (about 0.01%), the neural structure is associated with retained memory functions.
A young neuron is the most adaptable and plastic type of brain cell, with more ability to grow, integrate and "wire itself into a brain," said Gefen, who helps lead the Northwestern SuperAging Program. "SuperAgers are showing the preservation of immature neurons with heightened excitability, they are bright-eyed and bushy-tailed and ready to fire," she said. "That is a more youthful brain."
The program of SuperAgers, which is currently 26 years old, previously identified characteristics of SuperAgers, including slower brain shrinkage, large key cells, less inflammation, and strong social connections.
The study, which was published in Nature has been titled as H human hippocampal neurogenesis in adulthood, ageing and Alzheimer disease.
The study led to the addition of a cellular mechanism to explain their cognitive advantage and opens the possibility to potentially develop interventions to stimulate healthy aging of the brain, and prevent Alzheimer disease.
