© Google/Lichtman LaboratoryAround 4000 nerve fibres connect to this single neuron
Google has helped create the most detailed map yet of the connections within the human brain. It reveals a staggering amount of detail, including patterns of connections between neurons, as well as what may be a new kind of neuron.
The brain map, which is freely available online, includes 50,000 cells, all rendered in three dimensions. They are joined together by hundreds of millions of spidery tendrils, forming 130 million connections called synapses. The data set measures 1.4 petabytes, roughly 700 times the storage capacity of an average modern computer.The data set is so large that the researchers haven't studied it in detail, says
Viren Jain at Google Research in Mountain View, California. He compares it to
the human genome, which is still being explored 20 years after the first drafts were published.
It is the first time we have seen the real structure of such a large piece of the human brain, says
Catherine Dulac at Harvard University, who wasn't involved in the work. "There's something just a little emotional about it."
This mammoth undertaking began when a team lead by
Jeff Lichtman, also at Harvard University, obtained a tiny piece of brain from a 45-year-old woman with drug-resistant epilepsy. She underwent surgery to remove the left hippocampus, the source of her seizures, from her brain. To do this, the surgeons had to remove some healthy brain tissue that overlaid the hippocampus.
Comment: See also: