Residents
brain of the
Scientists turn
up startling
diversity among
nerve cells
By Laura Sanders
Peer out the window of a plane landing at LaGuardia Airport, and the tiny people scurry- ing around the streets of New
York City all look the same. But take a
stroll down Fifth Avenue and a new view
emerges: Up close, New Yorkers are very
different.
A street view of the brain also reveals
a new perspective: No two cells are the
same. Zoom in, and the brain’s wrinkly,
pinkish-gray exterior becomes a motley
collection of billions of cells, each with
personalized quirks and idiosyncrasies.
Powerful new techniques are giving
researchers a glimpse of this staggering
diversity — especially among nerve cells,
the brain’s information brokers. Even
nerve cells presumed to do the same
job come in a range of shapes and sizes
and display a host of behaviors, sending
their electrical messages in unpredictable ways, new studies reveal. The closer
scientists scrutinize nerve cells, called
neurons, the more differences turn up.
This cellular menagerie has left
researchers puzzling over how best to categorize what neuroscientist Rafael Yuste
of Columbia University calls these “living
creatures.” So far, systematic methods are
lacking. “Even after 100 years of research,
we have no clue how many classes of neurons there are,” says Yuste, a Howard
Hughes Medical Institute researcher. He
and other scientists are developing new
algorithms to automate neuron classification, in the hope of someday compiling
By classifying neurons based on shape
and behavior, scientists may get a han-
dle on which cells do what in the brain.
