HONG KONG, April 9 (Xinhua) -- The University of Hong Kong (HKU) announced on Thursday that a super high-speed microscope developed by their researchers can effectively capture brainwave signals, offering further clues for the study of brain diseases.
This novel microscope, two-photon fluorescence microscope jointly developed by HKU and the University of California, Berkeley in the United States, can capture electronic signals and chemical transmission between neurons. It has successfully recorded the millisecond electrical signals in the neurons of an alert mouse.
At the heart of the high-speed microscope is an innovative technique called FACED (free-space angular-chirp-enhanced delay imaging) developed by HKU's research team. FACED makes use of a pair of parallel mirrors that generate a shower of laser pulses to create a super-fast sweeping laser beam at least 1,000 times faster than the existing laser-scanning methods.
In the experiment, the microscope projected a beam of sweeping laser over the mouse's brain and captured 1,000 to 3,000 full 2D scans of a single mouse brain layer every second.
Another important feature of the novel technique is that it is minimally invasive. The classical method for recording electrical firing in the brain is to physically embed or implant electrodes in the brain tissue. However, such physical intrusion could cause damage to the neurons, and can only detect fuzzy signals from a couple of neurons.
"We are working to further combine other advanced microscopy techniques to achieve imaging at higher resolution, wider view and deeper into the brain in the neocortex, which is about 1 millimeter," said Kevin Tsia, associate professor of the Department of Electrical and Electronic Engineering and Program Director of Bachelor of Engineering in Biomedical Engineering of HKU.
"This will allow us to probe deeper into the brain for a better and more comprehensive understanding of the functions of the brain," he added.
The result has recently been published in the academic journal Nature Methods.