3-D imaging enables deeper look into brain

Scientists have developed a new way of taking high-resolution, 3-D images of the brain using three-photon microscopy, according to an article published Jan. 20 in the journal Nature Photonics.

In the paper, lead author Chris Xu, an associate professor of applied and engineering physics at Cornell University, and colleagues described how they were able to use three-photon microscopy to image the subcortical region of a live, intact mouse brain. In doing so they surpassed the fundamental depth limit of two-photon microscopy.

According to an announcement from Cornell, Xu and colleague Watt Webb first demonstrated three-photon fluorescence imaging in 1995, but Xu said its advantages were not fully recognized at the time.

Now, the researchers said, three-photon fluorescence, combined with a longer excitation wavelength of the laser pulse, can overcome such obstacles as tissue scattering and absorption, which prohibit high-resolution imaging deep within biological tissues. This means three-photon microscopy makes for a better technology when it comes to deep tissue imaging.

The ability to image so deeply and in detail into a mouse brain suggests the imaging technology could lead to a better understanding of how the human brain works and help lead to cures for illnesses such as depression, and Alzheimer's and Parkinson's diseases, according to Xu.

"Brain mapping could be the so-called grand challenge within the next decade," he said. "With MRI, we can see the whole brain but not with the resolution we have demonstrated. The optical resolution is about 100 to 1,000 times higher and allows us to clearly visualize individual neurons."

To read more:
- see the article abstract in Nature Photonics
- read the announcement from Cornell