Recent findings from neuroscientists reveal that the brain’s structure divides into five main stages throughout a typical person’s life, marked by four significant turning points from birth to death where the brain undergoes reorganization. Brain topology in children evolves from birth up to a crucial transition at age 9, then shifts into adolescence, which generally lasts until around age 32. In your early 30s, the neural wiring transitions to adult mode, marking the longest phase that extends for over 30 years. The third turning point occurs at about age 66, indicating the start of an early aging phase of brain structure, while the late brain phase begins around age 83.
Masry et al. Using a dataset of MRI diffusion scans, they compared the brains of 3,802 individuals aged 0 to 90 years. The dataset maps neural connections by tracking the movement of water molecules through brain tissue. Image credit: Mously et al., doi: 10.1038/s41467-025-65974-8.
“While we know brain wiring plays a crucial role in our development, we still lack a comprehensive understanding of how and why it fluctuates throughout life,” explained Dr. Alexa Mausley, a researcher at the University of Cambridge.
“This study is the first to pinpoint essential stages in brain wiring throughout the human lifespan.”
“These epochs offer vital insight into our brain’s strengths and vulnerabilities at different life stages.”
“Understanding these changes could shed light on why certain developmental challenges arise, such as learning difficulties in early childhood or dementia later in life.”
During the transition from infancy to childhood, strengthened neural networks emerge as the excess of synapses (the connections between neurons) in a baby’s brain diminishes, allowing only the most active synapses to thrive.
The brain rewires in a consistent pattern from birth until approximately age 9.
In this timeframe, the volumes of gray and white matter grow swiftly, resulting in maximal cortical thickness (the distance from the outer gray matter to the inner white matter), with the cortical folds stabilizing.
By the first turning point at age 9, cognitive abilities begin to evolve gradually, and the likelihood of mental health issues becomes more pronounced.
The second stage, adolescence, is characterized by an ongoing increase in white matter volume, leading to an enhancement in the sophistication of the brain’s communication networks, measurable through water diffusion scans.
This phase is marked by improved connectivity efficiency across specific regions and swift communication throughout the brain, correlating with enhanced cognitive performance.
“As expected, neural efficiency is closely linked to shorter pathways, and this efficiency increases throughout adolescence,” Mausley notes.
“These advancements peak in your early 30s, representing the most significant turning point in your lifetime.”
“Around age 32, the change in wiring direction is the most pronounced, and the overall trajectory alteration is greater than at any other turning points.”
“Although the onset of puberty is clearly defined, the conclusion is far harder to identify scientifically.”
“Based solely on neural structure, we found that puberty-related changes in brain structure conclude by the early 30s.”
Post age 32, adulthood enters its longest phase, characterized by a more stable brain structure with no significant turning points for three decades. This aligns with findings indicating an “intellectual and personality plateau.”
Additionally, the researchers observed a greater degree of “segregation” during this phase, indicating a gradual fragmentation of brain regions.
The tipping point at age 66 is more gradual, lacking dramatic structural shifts; however, notable changes in brain network patterns were found around this age on average.
“Our findings indicate a gradual reconfiguration of brain networks that peaks in the mid-60s,” stated Dr. Mausley.
“This is likely linked to aging, as white matter begins to decline, reducing connectivity further.”
“We are currently facing an era where individuals are increasingly at risk for various health conditions impacting the brain, such as high blood pressure.”
The final turning point arises around age 83, ushering in the last stage of brain structure.
Data from this stage is scarce, but a key characteristic is the shift from global to local connectivity as interactions across the brain diminish while reliance on specific regions intensifies.
Professor Duncan Astle of the University of Cambridge remarked: “In reflection, many of us recognize that our lives encompass distinct stages.”
“Interestingly, the brain also navigates through these phases.”
“Numerous neurodevelopmental, mental health, and neurological conditions are tied to the brain’s wiring.”
“In fact, variations in brain wiring can predict challenges with attention, language, memory, and a wide array of other behaviors.”
“Recognizing that structural transformations in the brain occur not in a linear fashion but through several major turning points can assist us in identifying when and how brain wiring may be vulnerable to disruptions.”
a paper detailing the study was published in the journal on November 25. Nature Communications.
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A. Mausley et al. 2025. Topological turning points across the human lifespan. Nat Commun 16, 10055; doi: 10.1038/s41467-025-65974-8
