Daijiworld Media Network - New Delhi
New Delhi, Mar 2: While ageing often brings mild memory lapses, new research suggests the human brain may continue to renew itself even in later years.
A study published in the journal Nature has found strong evidence that the adult human brain continues to generate new neurons in the hippocampus — the region crucial for learning and memory. However, this regenerative process appears to be disrupted in patients with Alzheimer’s disease.
Using advanced single-cell genetic techniques, researchers analysed nearly 3.56 lakh cells from postmortem hippocampus samples across various age groups — including young adults, healthy elderly individuals, early Alzheimer’s cases, diagnosed patients and “SuperAgers.” The team identified neural stem cells and immature neurons, tracing a clear developmental pathway from stem cell to mature neuron.
The findings revealed that age alone did not shut down neuron formation. Healthy older adults continued to show evidence of new neuron growth. In contrast, patients with Alzheimer’s had significantly fewer immature neurons. Although stem cells were still present, their ability to develop into functioning neurons appeared impaired.
Dr Manjari Tripathi, head of neurology at AIIMS, said the findings reflect neuronal plasticity — the brain’s capacity to adapt and regenerate even in adulthood. She noted that this ability can be strengthened through regular exercise, a balanced diet, adequate sleep, stress reduction, strong social engagement and effective control of cardiovascular risk factors. Sleep, she emphasised, plays a crucial role in memory consolidation and neuronal growth. Many “SuperAgers,” she observed, remain mentally active and socially connected.
Researchers also detected early molecular changes in individuals with Alzheimer’s-related pathology but without symptoms, suggesting that disruption in neuronal renewal may begin years before visible memory decline.
Dr Sudhir Kumar, neurologist at Apollo Hospital, Hyderabad, said adult neurogenesis occurs at a slower pace than in childhood but remains functionally important. He explained that newly formed neurons are highly adaptable and help distinguish between similar memories. If this regenerative capacity declines early in Alzheimer’s, he said, future diagnostic tools may be able to detect the condition before symptoms emerge.
He added that treatment strategies should not focus solely on clearing toxic proteins such as amyloid, but also on strengthening the brain’s natural repair mechanisms through targeted therapies and lifestyle interventions.