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How Brain Mapping Works


The Brain Atlas: How We Use Brain Maps
Microsoft co-founder Paul G. Allen touts the completion of the Allen Brain Atlas on Capitol Hill in September 2006. The project studies the expression of genes in mouse brains.
Microsoft co-founder Paul G. Allen touts the completion of the Allen Brain Atlas on Capitol Hill in September 2006. The project studies the expression of genes in mouse brains.
Mark Wilson/Getty Images News

Neuroinformatics places all the data we have on the brain on the Internet in usable form. The data include images, models of neuron behavior and maps of the genes that are "turned on" in different brain regions. By making the data sharable and searchable, brain researchers can piggyback off of one another's studies and discover more.

Engineers are writing software to help brain researchers share and compare data. Software now analyzes, for instance, whether MRIs of Alzheimer's patients with different brain sizes and shapes have similar brain features. Are men with a certain brain architecture predisposed to bipolar disorder? This question, and many others, may one day be answered by computer programs that re-analyze images of past patients rather than by studying new ones.

Here are examples of brain atlases that researchers can mine for answers:

  • Allen Mouse Brain Atlas: The mouse brain expresses 21,000 genes. Researchers sliced up the brain and stained where each gene is expressed. Visitors can look at photos or 3-D models of the brain for their gene of interest [source: Allen Institute for Brain Science].
  • Allen Human Cortex Atlas: Our cerebral cortex allows us to think, reason and remember. Researchers have sliced this up as well. They have also stained where 1,000 genes -- and counting -- are expressed. You can even surf the pictures [Source: Allen Institute for Brain Science].
  • Whole Brain Atlas: Stores images of the human brain as it ages and fights diseases [source: Becker].

Images aren't the only source of information. Here are examples of databases brain researchers use:

  • NeuronDB provides diagrams of specific neurons in the human brain and tells you what inputs cause them to fire [source: Marenco].
  • ModelDB stores mathematical models of how neurons and neuron networks send electrical signals. "The collection of millions of cells doing that becomes movement, sensation, cognition, emotion, and human experience," says Wilson. "To make a model of the brain's function, we start with that" [source: Shepherd].

Now that we can map the human brain, how far have we gotten? Are we done yet? Are we even close? Find out on the next page.