It just keeps getting better. As well each of those sheets will also
be available for microscopic viewing if a comparable is called for.
This mapping should be almost the catalog. A decade of solid work
will end up mapping all brain activity generally and lead to
meaningful recognition of anomalies.
At worst, we can expect brain diseases to be easily identified at the
earliest stages.
I am sure we will have similar work for the rest of the body, before
we are finished, as well as additional comparables to check on the
range of possible variation.
Map of brain at
cellular level should aid Alzheimer, other neurological research
By Sheryl
Ubelacker
TORONTO - In what's
being called a landmark development for neuroscience, researchers
have created a 3D digital reconstruction of a complete human brain
that for the first time shows the organ's complex anatomy at the
cellular level.
Dubbed BigBrain, the
computer-based map of the brain provides a spatial resolution of
20 microns — smaller than the width of a single strand of human
hair and 50 times more refined than existing reference brains
available for scientific study.
The map permits
scientists to zoom into the brain to view various cells in the same
way Google Earth allows web users to zero in on a house on a
particular street.
"This allows us a
completely new level of insight into the brain's organization,"
said co-developer Alan Evans of the Montreal Neurological Institute
at McGill University.
"What this allows
us is to further examine the interaction between different brain
regions, the organization of the brain and how it observes behaviour
— how it underpins how our brains work and how we function as human
beings," said Evans, director of the Montreal Consortium for
Brain Imaging Research.
"So we have
raised the level of insight ... beyond what was possible at the turn
of the 20th century. This dataset will revolutionize our ability to
understand internal brain organization."
To construct BigBrain,
scientists studied the brain of an unidentified 65-year-old woman,
who had died with no evidence of neurological disease. The brain was
embedded in paraffin wax and cut into more than 7,400 slices using a
special large-scale tool called a microtome.
The
20-micrometre-thick sections — likened to small pieces of
plastic sandwich wrap — were mounted on slides and stained to
detect cell structures. The slices were then digitized with a
high-resolution scanner so researchers could construct the
high-resolution 3D brain model. Collecting the data took about 1,000
hours.
The result is an
online map that provides extremely fine details of the brain's
microstructure at the cellular level. Previously available reference
brains did not probe further than the macroscopic, or visible,
components of the brain.
While not every cell
can be seen, the map for the first time allows deeper analysis of the
brain's architecture and distribution of neurons and other cells in
sub-layers of the brain, something that wasn't possible before, said
Dr. Katrin Amunts, head of the Institute for Brain Research at
Heinrich Heine University in Dusseldorf, Germany.
The new reference
brain, which is part of the European Human Brain Project, "redefines
traditional maps from the beginning of the 20th century," she
said. "The famous cytoarchitectural atlases of the early 1900s
were simplified drawings of a brain and were based on pure visual
analysis of cellular organization patterns."
The finely detailed
anatomical resolution of BigBrain will allow scientists to gain
insights into the neurobiological basis of cognition, language,
emotions and other processes, the authors report in Thursday's issue
of the journal Science.
"You can look at
practically all the areas in the brain," said co-author Dr. Karl
Zilles, senior professor at Germany's Julich Aachen Research
Alliance. "For instance, when you are interested in a common
neurodegenerative disorder like Alzheimer's disease, you have the
first-ever brain model where you can look into details of the
hippocampus, which is the brain region extremely important for
memory.
"You can look
into brain regions which are connected with the hippocampus and play
a major role in this disease, but you can also study how many cells
you need to build up a cortical unit model in 3D.
"It is a common
basis for scientific discussions because everybody can work with the
brain model and speak about the same basic findings," he said.
"If you take one
brain here and another brain there, then you start to compare
differences, but what we need for answering principal and basic
questions in neuroscience is to have a common structure, which is the
basis for all our discussions."
Researchers worldwide
will be able to download brain sections from the BigBrain website at
www.bigbrain.loris.ca.
Evans said staff at
the Montreal Neurological Institute (MNI), where the brain slices
were digitized and compiled using advanced software, are already
using BigBrain.
Specialists such as
neuroanatomists and neurosurgeons at the MNI are "absolutely
ecstatic" over their ability to explore structures of the brain,
he said, explaining that an MRI can provide only a fraction of the
detail exhibited by BigBrain.
"So the surgeons
are all running in and out of the room trying to get at the data on
the very, very big screen that we have on a wall."
The map can help
surgeons performing deep brain stimulation (DBS) for such conditions
as Parkinson's and intractable epilepsy, for example, by allowing
greater accuracy in pinpointing which neurons are responsible for
certain symptoms. DBS involves implanting a pacemaker that sends
electrical impulses to specific parts of the brain.
Evans said BigBrain is
like a scaffold on which the visual data has been built, and new
information can be added as more is revealed about the microscopic
structures and intricate functions of the brain's various regions.
The scientists are
already in discussions with other research groups, including those at
the Allen Institute for Brain Science in Seattle, which has compiled
a number of its own specialized brain "atlases."
"We've been
working and speaking with scientists from the institute precisely
about this issue of integrating data that they are collecting into
the space of the BigBrain," said Evans.
"So we are
already on this case, and we are very excited about the possibility
of ... data integration into the BigBrain space."
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