Superagers may have more new brain cells

A study of 38 donated adult brains found superagers had about twice as many immature neurons in the hippocampus as other healthy older adults, and people with Alzheimer’s showed reduced neurogenesis.

Researchers analyzed hippocampal tissue from 38 donated adult brains to assess signs of ongoing neuron formation and related gene activity. The samples came from five groups: young adults, typical older adults, superagers, people with preclinical Alzheimer's pathology, and people diagnosed with Alzheimer's. The team identified three developmental stages in single-cell nuclei and compared their prevalence across groups. The analysis found that superagers had notably higher numbers of immature neurons and distinct gene activity linked to synaptic strength and plasticity. Key findings: - The study examined 38 donated adult brains and analyzed 355,997 individual cell nuclei from the hippocampus. - Donor groups included eight healthy young adults (ages 20–40), eight healthy agers (60–93), six superagers (86–100), six with preclinical Alzheimer's pathology (80–94), and ten with an Alzheimer's diagnosis (70–93). - Superagers had roughly twice the number of immature neurons in the hippocampus compared with other healthy older adults. - The preclinical Alzheimer's group showed subtle molecular changes that suggested the neurogenesis-supporting system was beginning to falter. - Individuals with an Alzheimer's diagnosis showed a clear reduction in immature neurons, and superager neural cells had increased gene activity tied to stronger synaptic connections, greater plasticity, and higher brain-derived neurotrophic factor. Summary: The findings indicate that ongoing hippocampal neurogenesis and related gene activity may contribute to cognitive resilience in some older adults. The pattern of reduced immature neurons in people with Alzheimer's and early molecular changes in the preclinical group aligns with prior research linking neurogenesis to dementia. The research team notes that further studies could explore ways to support neurogenesis and investigate environmental or lifestyle factors associated with these differences. Undetermined at this time.