At Cornell University, Ithaca, NY, scientists have demonstrated a new way of taking high-resolution, 3D images of the brain's inner workings by a three-fold improvement in the depth limits of multiphoton microscopy, a fluorescence-based imaging technique.
A team of engineers demonstrated high-resolution, 3D imaging of the subcortical region of a live, intact mouse brain, breaking the previous depth limit of standard two-photon microscopy, which is a widely used imaging technology invented in 1990 at Cornell.
Their research describes three-photon fluorescence, combined with a longer excitation wavelength of the laser pulse, to overcome such obstacles as tissue scattering and absorption, which prohibit high-resolution imaging deep within biological tissues.
Using a mouse model, the researchers 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, which could eventually prove useful in imaging brains ofpeople with depression or Alzheimer's associated with changes deep inside the brain.
