Research team from the University of Cambridge analyzed 3.802 MRT images brain and reconstructed neural connectivity patterns between birth and age 90. The data revealed a surprisingly clear picture: the structural organization of the brain does not take place continuously, but in five main phases, each of which is marked by significant milestones - around the years 9, 32, 66 and 83, he writes. Deutsche says.
"These periods of life provide important context for which stages our brains may be particularly capable or particularly vulnerable," highlights Alexa Mazley, lead author of the study and adds:
"We know that brain networking is critical to our development, but we lack a complete picture of how it changes throughout life – and why."
The first 9 years: building and reorganizing the brain
The first phase of brain development begins at birth and lasts until about the age of nine. During that period, the brain "connects" intensively. Countless new synapses are formed – connections between nerve cells – that form the basis for cognitive and motor development.
Already in early childhood, the brain begins to optimize these connections. Synapses that are not used are removed, while at the same time the information connections between the most important regions of the brain are strengthened. This stage is crucial for how efficient the brain will be in the following years of life.
The Great Brain Transformation from Age 9 to 32
Around the age of nine, the first turning point is announced. Then the brain begins to prepare for the changes that puberty brings. Hormonal changes cause the brain's white matter, responsible for the rapid transmission of information, to continue to grow.
At the same time, the network between key brain regions is optimized to make cooperation more efficient.
During this "building" phase, the typical problems of puberty often arise: From the perspective of adults, adolescents often behave irrationally and are prone to risky behavior. This is because the so-called prefrontal cortex is the last to develop – this region is responsible for planning and controlling impulses.
Since the brain is particularly sensitive to external and internal influences during this phase, mental health problems such as depression or anxious disorders often appear for the first time during puberty. However, after this transformation, the brain is ideally well connected and optimally prepared for adulthood.
Peak brain development around age 32
The next milestone at the age of 32 is, according to the study, the most significant in a person's entire life. The brain then reaches its peak. Intelligence and personality are fully developed, and neural networks function optimally in healthy individuals.
Over the next decades, the neural connections gradually disappear. The exact causes of this are still not fully understood.
It is suspected that external factors such as stress, family changes or professional pressures may play a role. It could also be a natural aging process that takes place independently of external influences.
While puberty marks a clear beginning, the end of adolescence is much more difficult to scientifically determine, explains study author Alexa Mazli. "Based solely on neural architecture, we found that the changes in brain structure typical of adolescence do not end until around the early thirties."
Such a structure remains relatively stable for three decades, until the next turning point is reached around the age of 66.
Reorganization of brain networks since 66
From the age of 66, the brain enters a new phase. Neural networks continue to thin out, making it difficult for different regions of the brain to cooperate. Similar to puberty, the brain is particularly vulnerable to disruption during this stage.
High blood pressure or other health problems can damage blood vessels in the brain, impairing cognitive abilities. The risk of neurodegenerative diseases such as dementia increases significantly during this stage of life.
The brain remains capable of learning even in old age
At age 83, the brain reaches a final milestone in its development. Neuronal connectivity continues to decline, and the brain increasingly struggles to compensate for the disruptions. However, current studies show that the brain possesses remarkable adaptability even in old age. For example, a research team from Tübingen and Magdeburg showed that even very old people can form new connections in the brain if they remain mentally active.
The study also confirms that the deeper regions of the brain can amplify weaker nerve signals and thereby partially compensate for the loss of neural networks. Mental activity and social interaction, therefore, can contribute to the preservation of brain functionality until old age.
Source: DW
