Brain Atlas Maps Lifespan Changes in Brain Connectivity | Nature

The Evolving Brain: New Atlas Maps Lifelong Changes in Brain Connectivity

Scientists have created a detailed atlas charting how patterns of brain activity, known as functional connectivity, change throughout life. The research, drawing on brain scans from nearly 3,600 individuals from infancy to old age, provides a comprehensive guide to understanding brain development and aging. The findings, published today in Nature, could offer valuable insights into neurodevelopmental disorders and neurodegenerative diseases.

Understanding Functional Connectivity

The brain is a complex network where different regions constantly communicate and coordinate. Functional connectivity refers to the level of coordination between separate brain areas, even those physically distant from each other. These regions are considered functionally connected when their activity patterns correlate, suggesting they function together to support specific functions.

Researchers map this connectivity by plotting brain areas along functional axes based on their connectivity patterns. Study co-author Patrick Taylor, a computer scientist at the University of North Carolina at Chapel Hill, explains that there are three main functional axes. One key example is the sensory-to-association axis, which illustrates how brain regions transition from processing basic sensory information to engaging in complex thought processes. Brain regions along this axis exhibit similar connectivity patterns.¹

At one conclude of the sensory-to-association axis are regions heavily involved in sensory processing, primarily connecting with other sensory areas. At the other end are areas supporting higher-level information processing, connected to a diverse range of brain regions. Midway along the axis lie transition zones that link sensory input to abstract thought, functionally connecting both sensory networks and those involved in complex cognition.

A Lifespan Perspective on Brain Development

Even as previous research has explored brain tissue growth² and changes in functional axes during specific life stages, this study is the first to capture the development and evolution of all three main functional axes across the entire human lifespan. This comprehensive approach, according to study co-author Pew-Thian Yap, a radiologist at the University of North Carolina at Chapel Hill, is crucial for a deeper understanding of brain function.

The research team analyzed functional magnetic resonance imaging (fMRI) scans from 3,556 participants, ranging in age from 16 days to 100 years old. They tracked how the three functional scales developed and changed at different ages, revealing critical inflection points in the nonlinear growth curves of the connectome. The global mean of the connectome peaks in the late fourth decade of life, while the variance peaks in the late third decade.³

Implications for Neurological Research

Jakob Seidlitz, a neuroscientist at the University of Pennsylvania in Philadelphia, who was not involved in the research, believes this atlas is a significant contribution to the field. Such a guide could be instrumental in understanding the emergence of developmental issues and neurodegenerative conditions. The findings elucidate the lifespan evolution of the functional connectome and can serve as a normative reference for quantifying individual variation in development, aging and neuropsychiatric disorders.⁴

Key Takeaways

• A new brain atlas maps functional connectivity changes across the lifespan.
• The study analyzed fMRI scans from nearly 3,600 individuals, from infancy to old age.
• Researchers identified three main functional axes in the brain: sensory-to-association, and others not specified in the source.
• The atlas could aid in understanding neurodevelopmental and neurodegenerative disorders.