Scientists have examined lifelong cellular changes in the prefrontal cortex of the human brain, revealing that 2 main phases of brain activity are evident during adulthood.

For the research, more than 1.3 million cells obtained from the brains of 284 people aged from birth to 97 years were analyzed.

According to research, the most changes occur during brain development, but around the age of 24, the cellular structure of the prefrontal cortex becomes relatively stable, an area that plays an important role in planning, decision making and complex mental tasks.

This stability is maintained throughout most of adulthood, but after the age of 60, significant biological changes are again observed in the brain, particularly increased molecular activity in glial cells, which support and protect nerve cells and play a role in the brain’s immune response.

According to the researchers, the changes with age included factors related to inflammation, cellular stress and the brain’s internal biological clock. In young and middle-aged people, the 24-hour activity of nerve cells was more regulated, while after 60 years it became less prominent.

The researchers make clear that ages 24 and 60 are not precise or uniform stages of brain change, but are rather markers of broad biological trends revealed in the research.

The research also revealed that certain genes associated with schizophrenia and bipolar disorder were more active during early development, while genes associated with Alzheimer’s became more prominent in the glial cells of older adults.

According to the researchers, the findings further complicate the notion that the brain develops only in childhood and then ages continuously, instead showing rapid changes in the brain in early life, long periods of stability in adulthood, and a phase of biological changes again in later life.