Researchers found a shift around age 24 in the dorsolateral prefrontal cortex, a region that supports planning and problem-solving, along with the reasoning behind decisions and working memory. Molecular activity rises again in later life, especially in cells that support and protect neurons.
The study was published in Nature on September 23. It analysed profiles of 1,307,674 cellular nuclei from 284 donors, ranging from childhood to age 97. The atlas tracks gene expression across the lifespan and shows how neuronal and glial populations behave in one impressive part of the cortex.
Mount Sinai describes the work as the first population-scale single-cell transcriptomic atlas of the dorsolateral prefrontal cortex across the human lifespan. Science Media Centre Spain said the study’s supporting materials described the 284 donors as neurotypical, allowing the atlas to focus on age-related molecular patterns rather than diagnosed brain disorders.
The strongest changes do not continue at the same pace throughout life. Most neuronal and glial subtypes undergo major remodelling during early development, with their patterns reaching relative stability around age 24.
That stability is real but incomplete. Some cell populations keep changing with age, including inhibitory neurons that express somatostatin and oligodendrocyte precursor cells. These groups remain biologically active beyond early adulthood.
The data show strong remodelling during early development, followed by relative stability in adult life. Molecular activity rises again in old age. During early development, neurons change their connections as brain circuits form and reorganise. After age 60, several glial populations show stronger changes, including astrocytes and microglia, along with oligodendrocytes.
The research materials also describe renewed remodelling after age 65. These age markers describe different parts of the same later-life shift.
Cellular stress and immune responses are linked to the later changes. The atlas also records weaker synchronisation in the circadian rhythms of some neuronal genes during old age. Ageing affects neurons as well as the cells that support them.
Juan Lerma, a CSIC researcher who contributed to the assessment circulated by Science Media Centre Spain, said the atlas makes it possible to identify changes in cellular composition. He also said it can help researchers examine possible periods of ability to recover and vulnerability during development. Marta Nieto likewise stressed the value of studying cells that support and protect neurons when analysing brain ageing.
Reuters separately described about age 24 as a transition point, after which most cell types in this region become more stable. Nature’s press material also says that midlife stability begins around 24, with slower changes in cell composition afterward.
The study examines molecular patterns in the dorsolateral prefrontal cortex using tissue from donors. It does not show that every part of every person’s brain finishes maturing at exactly 24. The age identified by the atlas marks a turning point in the measured cellular patterns, not a universal biological deadline. The findings apply to one cortical region rather than the whole brain.
The atlas does not give one age at which the entire brain becomes complete. It maps how cell types move from early development into adult stability, then show renewed molecular activity later in life.
By covering the period from childhood through advanced age, the work gives scientists a reference for studying development and ageing. It may also help them separate normal age-related change from possible changes linked to neurological and psychiatric disorders.
The evidence supports a more precise view of brain maturity: broad stability appears around 24 in this region, even as selected cell populations keep changing and ageing later reactivates molecular processes.
The finding does not mean that the brain suddenly finishes at 24. Nor does it mean development continues at the same pace forever. The atlas shows intense early remodelling giving way to adult stability. Molecular activity then rises again later in life.
