Reacción a "A study identifies five vital stages in the structure of brain connections"

Brain connectivity changes throughout life in complex and non-linear ways. Understanding when and how these changes occur is essential to gaining a deeper understanding of how brain structure and function develop and age. In their study, Mousley and colleagues use magnetic resonance imaging (MRI) scans of healthy volunteers aged between zero and 90 years. These images allow brain connections to be traced through white matter and brain networks to be constructed that can be analyzed using what is known as graph theory.

Their findings indicate that there are five key moments in which distinct changes in connectivity development occur:

• 0 to 9 years: the volume of gray matter (which contains neurons) and white matter (which contains connections) increases dramatically;
• 9 to 32 years: the increase in white matter continues and connections become more efficient;
• 32 to 66 years: a stabilization phase occurs;
• 66 to 83 years: the loss of connectivity begins to increase;
• from 83 years onwards, the different areas of the brain have more difficulty communicating.

This is a rigorous study based on a solid methodology applied to a large data set (more than 4,000 images), analyzed for the first time in such a wide age range. There are limitations acknowledged by the authors themselves, including the intrinsic difficulty of inferring brain connectivity from magnetic resonance imaging and the fact that the analyses are not separated by sex, as men and women may have different rates of development. Despite these limitations, it is a major contribution that has made it possible to identify turning points in development and could help us better understand the brain changes associated with neurodevelopmental disorders and dementia.

Although mathematical models use MRI data to identify “milestones” in brain maturation and aging, these times should not be interpreted as strict boundaries. In fact, the distinction between maturation and aging is relatively arbitrary. These are always continuous processes that describe the temporal evolution of the brain. Furthermore, it should be noted that the study focuses only on brain connectivity and does not analyze how cognitive aspects such as learning, memory, problem-solving ability, etc., change during these stages.