A comprehensive growth chart for the human brain

April 27, 2022

A Children’s Hospital Los Angeles researcher was part of an international project showing how the brain grows—and shrinks—over a lifetime, according to a news release.

An international team of researchers has created a different series of growth charts—for the brain. Children’s Hospital Los Angeles investigator Matthew Borzage, PhD, was among the co-authors of this pioneering effort, which has produced the first comprehensive growth charts for brain development. The team’s work—which was led by Children’s Hospital of Philadelphia/University of Pennsylvania and the University of Cambridge—was recently published in Nature.

While these growth charts, called BrainChart, won’t be coming to a pediatrician’s office anytime soon, they will provide scientists with an invaluable benchmark for future brain development studies.

Borzage explains what researchers have learned.

“Researchers have studied brain growth for a long time. But what we had before were a lot of smaller, individual studies, and no one knew if they were comparable to each other. You had different types of people and patients in each study, with scans from different MRI machines, etc. But no one had undertaken the Herculean task of bringing all of that data together and harmonizing it on a single platform,” Borzage said. “That’s what this project did. It’s the largest collection of data to answer the question: What is the size of your brain throughout your life? Because we now have more data, we can characterize brain growth and rates of brain growth in much more detailed, nuanced, and representative ways.”

What do the charts show about brain size over time?

“One of the cool things is you can compare brain volume milestones to a child’s development milestones. For example, the volume of gray matter—the active processing areas of the brain—grows at the fastest rate around age 6 months, at a time when babies are developing key motor skills. This volume then peaks just before 6 years of age,” Borzage said. “The volume of white matter—essentially, the brain’s connections—takes much longer to peak. It grows rapidly from mid-gestation through early childhood but doesn’t peak until the late 20s. Then there’s a very slow decline, and after age 50, that decline starts to accelerate.”

“This work also identified a previously unreported early growth period that takes place from 17 weeks post-conception to 3 years of age. During that time, the brain grows from 10% of its eventual size to 80%,” Borzage continued.

What happens next?

“Probably the coolest thing about this endeavor is that there’s an interactive component where researchers can upload new data to a special website. So, this project will continue to evolve,” said Borzage. 

“More data is particularly needed in the youngest children, including babies and even before birth. This is where the contributions of Children’s Hospital Los Angeles are especially important because we can provide this data and we have a very diverse patient population.”

“But the biggest thing that happens next is more research. These charts are really the ticket to entry for the next era of large-scale neuro analyses and imaging-based studies. They’re setting the stage for us to do research that’s a magnitude larger, and potentially more impactful, than anything we’ve done before,” Borzgae concluded.

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