Memory decline is a normal part of ageing. As they age, people may notice that they do not remember information as well as they did: for example, many seniors often forget to take medicines on time or misplace spectacles and other personal articles.
However, standing out in this milieu are the super-agers – some people in their 80s and beyond whose memory and cognitive abilities do not seem to diminish with age.
Take the case of retired teacher Vanamala Kinikar from Solapur, a classical dancer since she was 12 years old. At 85, Kinikar runs a dance school and continues to dance. She easily recalls her childhood days and events.
“I clearly remember my first dance sequence which I choreographed in my seventh grade,” says Kinikar. “I like learning new things, cooking and doing household work,” adds the super-ager. Whereas it is quite common for many of her contemporaries to face memory and cognition challenges.
Super neurons
There are several other super-agers like Kinikar, and researchers are trying to find the factors underlying their age-defying brain functions.
Researchers at Northwestern University, Illinois, in the USA have a dedicated super aging research programme that is studying the neural mechanisms involved in the sharp memory and cognitive function among the 80-plus.
In a 2021 study published in Cerebral Cortex, Dr Tamar Gefen and her team at Northwestern University identified that the brain cells in super-agers did not have tau tangle and amyloid beta protein accumulation. They put out the hypothesis that it could be a reason for their preserved memory.
Continuing the research in 2022, they published another study in the Journal of Neuroscience. They examined brain scans of 24 deceased individuals of different age groups and conditions: six super-agers, seven cognitively average seniors, six individuals in the band of 30-40 years, and five others having early-stage Alzheimer’s disease.
In all these scans, they observed the tau tangle formations and measured the size of the neurons in the second layer of the middle region of the brain (entorhinal cortex). This region of the brain is responsible for the control of memory, navigation, and perception of time.
They noticed two remarkable aspects:
- The brain cells of the super-ager group were bigger and also had larger neurons compared to cognitive elders and 30-40 years old individuals participating in the study.
- In individuals having Alzheimer’s disease, the neurons were small due to the accumulation of tau tangle and amyloid beta protein in the brain.
The researchers observed that large neurons maintained their structures well. “One possible reason for the sharp memory in super-agers is that these large neurons are protected from the tau protein tangle accumulation,” Dr Gefen tells Happiest Health.
However, she adds, “I am not sure why neurons were larger in the super-agers or why these individuals are relatively protected from Alzheimer’s disease.”
‘What makes super-agers’ brains unique?’ and ‘How can we harness their biological traits to help the elderly stave off Alzheimer’s disease?’ are a few questions that the team is trying to answer.
Solutions in the future
This research has opened avenues for future studies – to understand how and why neuronal integrity is preserved in super-agers; and to focus on the metabolic, chemical, and genetic factors of these cells.
Sridharan Devarajan, associate professor, centre for neuroscience at the Indian Institute of Science, Bengaluru, explains, “Tau tangle formation is hypothesised to cause neuronal shrinkage, loss of neurons and communication between them. These may be key factors for developing diseases like Alzheimer’s.” He says if researchers can find answers to what makes these super neurons extraordinary, it can help find the solution for neurodegenerative diseases.
“The neuroprotective mechanism of the super neuron, when discovered, could have the potential to protect neurons in the brains of more vulnerable populations [from] dementia and early-stage Alzheimer’s disease,” says Dr Devarajan.
Sridharan Devarajan, associate professor at the Centre for Neuroscience at the Indian Institute of Science, Bengaluru, says that if researchers can find an answer to what makes these super neurons extraordinary, it can help to find a solution to neurodegenerative diseases.
Until a solution emerges, neurodegenerative diseases are currently managed with lifestyle changes and a few medicines for the symptoms. Staying active physically and mentally goes a long way in slowing disease progression.
Ask danseuse Kinikar about her nimble mind, and she says, “Activities like reading books, writing, and practising art help me to stay positive. Regular exercise and a nutritious diet keep me healthy.” One should perhaps take a leaf out of her routine to stay mentally young and agile.
