3D Brain Circuits

As you might know or have seen by the number of stories about it on this blog; I'm facinated by the human brain!

Especially because there is still so much to explore, discover, research and develop about the brain. The more we learn about our brain (e.g. how it functions, how to increase the volume of it, how to create an artificial brain, how to improve brain functions, how to boost it, how to integrate brain power with new technology, how brain music works, how to create robots with human brains, how to get the best out of it), the bigger the impact it will have on the advanced development of medical science and technology, which in the end will impact all of us as soon the new technology is being applied in consumer products & services.

So what is the brain? The brain is a black box. A complex circuitry of neurons fires information through channels, much like the inner workings of a computer chip. But while computer processors are regimented with the deft economy of an assembly line, neural circuits are impenetrable masses. Think tumbleweed.

The latest compelling brain development I heard and read about is a new '3D-type' of technology developed by the Harvard Medical School's Department of Neurobiology. They have developed a cool new technique for unraveling our complex brain masses. Through a combination of microscopy platforms, researchers can crawl through the individual connections composing a neural network, much as how Google crawls Web links.

"The questions that such a technique enables us to address are too numerous even to list," said Clay Reid, HMS professor of neurobiology and senior author on a paper reporting the findings.

The cerebral cortex is arguably the most important part of the mammalian brain. It processes sensory input, reasoning and, some say, even free will. For the past century, researchers have understood the broad outline of cerebral cortex anatomy. In the past decade, imaging technologies have allowed us to see neurons at work within a cortical circuit, to watch the brain process information.

But while these platforms can show us what a circuit does, they don't show us how it operates.
For many years, Reid's lab has been studying the cerebral cortex, adapting ways to hone the detail with which we can view the brain at work. Recently they and others have succeeded in isolating the activities of individual neurons, watching them fire in response to external stimuli.
The ultimate prize, however, would be to get inside a single cortical circuit and probe the architecture of its wiring.

Just one of these circuits, however, contains between 10,000 and 100,000 neurons, each of which makes about 10,000 interconnections, totaling upwards of 1 billion connections -- all within a single circuit. "This is a radically hard problem to address," Reid said.

Reid's team, which included Davi Bock, then a graduate student, and postdoctoral researcher Wei-Chung Allen Lee, embarked on a two-part study of the pinpoint-sized region of a mouse brain that is involved in processing vision. They first injected the brain with dyes that flashed whenever specific neurons fired and recorded the firings using a laser-scanning microscope. They then conducted a large anatomy experiment, using electron microscopy to see the same neurons and hundreds of others with nanometer resolution.

Using a new imaging system they developed, the team recorded more than 3 million high-resolution images. They sent them to the Pittsburgh Supercomputing Center at Carnegie Mellon University, where researchers stitched them into 3-D images. Using the resulting images, Bock, Lee and laboratory technician Hyon Suk Kim selected 10 individual neurons and painstakingly traced many of their connections, crawling through the brain's dense thicket to create a partial wiring diagram.

This model also yielded some interesting insights into how the brain functions. Reid's group found that neurons tasked with suppressing brain activity seem to be randomly wired, putting the lid on local groups of neurons all at once rather than picking and choosing. Such findings are important because many neurological conditions, such as epilepsy, are the result of neural inhibition gone awry.

"This is just the iceberg's tip," said Reid. "Within ten years I'm convinced we'll be imaging the activity of thousands of neurons in a living brain. In a visual circuit, we'll interpret the data to reconstruct what an animal actually sees. By that time, with the anatomical imaging, we'll also know how it's all wired together."

"How the brain works is one of the greatest mysteries in nature," Prof. Reid added, "and this research presents a new and powerful way for us to explore that mystery!"

For a verbal explanation of the research by Prof. Clay Reid on video, click HERE.
For a YouTube video about untangling the brain, click HERE.

Amazing to know that one of our vital organs is still a big mystery to science!

Warm regards,


Patrick