Get Rael-Science on Twitter: https://twitter.com/rael_science
A
new watershed study has mapped over 3,000 cell
types in the human brain.
Image
credit: Getty
Noa
Leach
Scientists
have long puzzled over the vast complexity of
the human brain. Now, researchers from across
the world have mapped its cellular make up and discovered
that there are over 3,000 cell types in the
human brain, including hundreds they
didn’t know existed.
Speaking
to BBC
Science Focus, Dr
Ed Lein, senior investigator and
neuroscientist at the Allen Institute for
Brain Science, said: “The brain is an
astonishingly complex cellular organ … and we
can now really define and map these cell types
across it.”
Previous
studies had only mapped the
brain cell types of particular regions in the
cortex (the outermost part of the brain).
These studies found over 100 different brain
cell types.
The
new research has expanded that mapping to
almost 100 regions across the entire human
brain – and found thousands of
different brain cells.
For
many parts of the brain, no-one has ever seen
this level of complexity and variety until
now. The researchers were surprised to
discover that even the oldest parts of the
brain (in evolutionary terms),
which were previously thought to be very
simple, are in fact highly complex.
In
the study, scientists at Allen Institute for
Brain Science used a technique known as
single-cell transcriptomics, which involves
studying all the genes switched on in
individual brain cell’s DNA.
They analysed post-mortem tissues from brains
donated to science, and healthy living tissue
donated by brain surgery patients.
The
study is part of a huge project to catalogue
the size and complexity of the human brain,
and is one of a suite of 21 papers released
simultaneously in Science, Science
Advances and Science
Translational Medicine.
One
of the other studies, also led by the Allen
Institute, found that the connections between
the 3,000 brain cell types are crucial to
making us unique individuals. Although “we all
share a common blueprint and set of building
blocks,” said Lein, there is “variation in how
those blocks are put together and the
properties of those blocks that make us unique
as individuals.”
In
a press release, Lein described the joint
discoveries as “a pivotal moment in
neuroscience”. The findings will help to
create more comprehensive atlases of the
entire human brain, as well as for brains of
other primates. These could improve our
understanding of brain diseases and disorders,
and our ability to treat them.
“This
is very much like the early stages of the
Human Genome Project,” Lein added to BBC
Science Focus. “We have now begun that
journey.”
About
our expert
Dr Ed Lein is the Senior Investigator and neuroscientist at the Allen Institute for Brain Science. His research has been published in PLOS Biology, Nature Biotechnology, and Nature Reviews Genetics.