Kamal Ghorui
New Delhi: For many people, ageing brings small lapses in memory. A forgotten name, a misplaced key. For others, memory loss becomes something more serious. Yet, some in their 80s remain as sharp as they were decades earlier.A paper published in the journal, ‘Nature’, suggests one reason for this may lie deep inside the brain’s memory centre – in its ability to continue producing new cells even late in life. The study provides strong evidence that the adult human brain continues to generate new neurons in the hippocampus, the region crucial for learning and memory, though this process is disrupted by Alzheimer’s disease.
Using advanced single-cell genetic techniques, researchers analysed nearly 3,56,000 cells from postmortem hippocampus samples across age groups – from young adults to healthy elderly individuals, early Alzheimer’s cases, diagnosed patients and ‘SuperAgers’ – identifying neural stem cells and immature neurons and tracing a clear pathway from stem cell to mature neuron.Age alone did not shut down this process. Healthy older adults still showed neuron formation. But in Alzheimer’s, immature neurons were significantly fewer. Stem cells remained, yet their development into functioning neurons appeared impaired.Dr Manjari Tripathi, head of neurology at AIIMS, said this reflected neuronal plasticity – the brain’s ability to adapt and renew itself even in adulthood. According to her, this can be strengthened through exercise, balanced diet, adequate sleep, reduced stress, strong social networks and control of cardiovascular risks. Sleep, in particular, is crucial for memory consolidation and neuronal sprouting. She noted that many ‘SuperAgers’ stayed mentally active and socially engaged.Researchers detected early molecular changes in individuals with Alzheimer’s-related pathology but no symptoms, suggesting the disruption in renewal may begin years before memory decline appears.Dr Sudhir Kumar, neurologist at Apollo Hospital, Hyderabad, said adult neurogenesis occurred at a slower pace than in childhood but remain-ed functionally vital. New neurons are adaptable and help distinguish similar memories. He added if this regenerative capacity declined early in Alzheimer’s, future diagnostics may detect it before symptoms appeared. Treatment, he suggested, should focus not only on clearing toxic proteins like amyloid but also on stren-gthening the brain’s repair systems through targeted the-rapies and lifestyle measures.
