WEDNESDAY, March 19 (HealthDay News) -- A radically different
concept of how the brain's blood supply develops is outlined in a
study led by Massachusetts General Hospital researchers.
In experiments with mice, the researchers found that blood
vessels in the brain grow according to their own agenda beginning
early in fetal development. They also found that the vasculature of
an embryo's brain may actually guide later development of brain
cells and their connections.
The findings were published in the journal
Nature Neuroscience.
"Until now, it was believed that, as our brains grew and as
neuronal connections and nerve fibers formed, blood vessels
carrying oxygen and other nutrients grew passively to meet the
brain's metabolic needs," senior author Pradeep Bhide, director of
research for Massachusetts General Hospital Neurology and an
associate professor of neurology at Harvard Medical School, said in
a prepared statement.
"This new study calls for a complete revision of the model of
brain vascular development and places emphasis on genetic
mechanisms guiding the proliferation and migration of the cells
that make up blood vessels," Bhide said.
Bhide and his colleagues labeled endothelial cells (building
blocks of blood) with fluorescent markers and tracked their
movement as they created new blood vessels in the brains of fetal
mice. The endothelial cells' division, migration and assembly of
new blood vessels occurred in a highly coordinated and orderly
way.
The researchers concluded that the endothelial cells were
following their own genetic programs -- not those that govern the
formation of brain cells -- and that the endothelial cells weren't
simply responding to the growing metabolic needs of developing
brain tissue.
"In addition, we found that some of the genes that regulate
neuronal development also regulate endothelial cell development,
which unifies the principles of development of both cell types,"
Bhide said. "Our study also finds that endothelial cells in the
fetal brain may guide development of neuronal networks and places
the embryonic brain's vasculature in a position to play dual and
independent roles of supplying nutrition and carrying instructive
signals for brain development."
These findings may help improve understanding of brain
malformations and developmental disorders, the researchers
said.
More information
Zero to Three has more about
early brain development.
