Scientists making a circuit diagram of the human brain

January 28th, 2008 - 4:03 pm ICT by admin  

Washington, January 28 (ANI): Scientists at Harvard University are planning to create a circuit diagram of the human brain by using new machines that automatically turn brain tissue into high-resolution neural maps.

The researchers say that their main aim is to map every synapse in the brain, so that such a diagram could be created as would help understand the brain’s activity far better than most of the presently available advanced brain-monitoring tools, such as fMRI.

“You’re going to see things you didn’t expect. It gives us an opportunity to witness this vast complicated universe that has been largely inaccessible until now,” Wired News quoted Jeff Lichtman, a Harvard professor of molecular and cellular biology, as saying.

Lichtman reckons that a full set of images of the human brain at synapse-level resolution will contain about as much information as the total amount of storage in Google’s data centres.

For their work, the scientists will use a neuroscience gadget called the automatic tape-collecting lathe ultramicrotome (ATLUM), which is capable of cutting samples of fless into very thin slices. The prototype has already been used to collect more than a hundred half-centimetre-long sections of mouse brain.

Once the slices have been stuck onto a piece of transparent tape, the scientists use a scanning electron microscope to actually image the cells.

“We will go to each section of tissue that the ATLUM has deposited and identify the region of that section that contains the important information, like the wiring of the neurons. Then we’ll do a series of montage maps on each section,” said Lichtman’s lab partner Charles Nielsen, a product manager and vice president at the optical equipment company JEOL.

Scientists believe that a circuit diagram the brain may facilitate the detection of such wiring problems as underpin disorders like autism and schizophrenia.

“The ‘wiring diagram’ of the brain could help us understand how the brain computes, how it wires itself up during development and rewires itself in adulthood,” said Sebastian Seung, a computational-neuroscience professor at MIT.

Characterised as an automated brain peeler and imager, ATLUM uses a lathe and specialized knife to create long, thin strips of brain cells that can be imaged by an electron microscope.

“It works like an apple peeler. Our machine takes a brain, peels off a surface layer, and puts it all on tape. These technologies will allow us to get to the finest resolution, where every single synapse is accounted for,” Lichtman said.

The researchers hope that the new technology would enable them to find answers to some of the most fundamental questions about what happens when unprogrammed human beings are released into the world.

“When a dragonfly is born, it has to know how to catch a mosquito. But for us, none of this is built in. Our brains have to go through this profound education period that lasts until our second decade. What is changing in our brains?” Lichtman said. (ANI)

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