In a paper (subscription required) published this week in Nature, Cornell researchers demonstrated a new way of taking high-resolution, three-dimensional images of the brain's inner workings through a three-fold improvement in the depth limits of multiphoton microscopy, a fluorescence-based imaging technique.
The striking image above illustrates the technique and depicts a horizontal frame from three-dimensional reconstructed three-photon microscopy images in a mouse brain. Neurons are shown in red, blood vessels are labeled in blue and the dark holes are non-fluorescent neurons. A Cornell release offers more details about the work and the its significance from a basic research and clinical perspective:
Using a mouse model, the researchers have proved the principle of three-photon microscopy operating at a wavelength of 1,700 nanometers. This, in combination with the new laser specifically created for three-photon excitation, allows the researchers to perform high-resolution imaging of neurons at unprecedented depths within a mouse brain.
Pushing these depth limits is important for basic science and eventually could prove useful clinically, [senior author Chris Xu, PhD,] said. Depression and diseases like Parkinson's and Alzheimer's are associated with changes deep inside the brain, and finding the cures could be helped by subcortical neural imaging -- that is, below the gray matter of the brain and into the white matter and beyond, if the brain is visualized as stacked layers.
Photo by Xu Lab