Human brain cells, classified into different groups according to gene expression (each color represents a group), are mapped back to their original locations in the human brain. A detailed analysis of brain cell gene expression over time revealed the genetic origins of autism and glioblastoma at young ages. Image by Li Wang and Songcang Chen/Kriegstein Laboratory
UCSF scientists have discovered a new type of stem cell that helps young brains grow but is also capable of forming the cells found in tumors. The breakthrough could explain how adult brain cells take advantage of developmental processes to instigate the explosive growth seen in deadly brain cancers like glioblastoma.
The researchers made the discovery while surveying gene expression in human brain cells from the first two decades of life. The findings appear Jan. 8 in Nature.
“Many brain diseases begin during different stages of development, but until now we haven’t had a comprehensive roadmap for simply understanding healthy brain development,” said Arnold Kriegstein, MD, PhD, professor of neurology at UCSF and co-corresponding author of the paper. “Our map highlights the genetic programs behind the growth of the human brain that go awry during specific forms of brain dysfunction.”
The study measured gene expression in cells taken from donated brain samples. The researchers kept track of the original location of each cell to help explain how the brain creates connections.
In addition to the discovery of an early stem cell that could explain the genetics of glioblastoma in adulthood, the data contained hints about the origins of autism. The researchers have published the data as a resource for the field to use for understanding a wide range of other brain disorders.
“Our study paints one of the most detailed pictures of human brain development,” said Li Wang, PhD, postdoctoral researcher in Kriegstein’s laboratory and co-first and co-corresponding author of the paper. “Theories based on observations in the clinic and laboratory can now be tested against this hard data, and we’re excited to see what else the field can do with it.”
Samples reveal a treasure trove
Most studies of the developing brain are carried out in animal models, which are at best loose proxies for the human brain.