Uses of coherent Raman scattering microscopy in neuroscience

Multiphoton microscopy allows the imaging of biological phenomena deep within brain tissues and has greatly advanced knowledge in neuroscience. However, many optical phenomena other than the multiphoton excitation of fluorophores in nonlinear optics are underrecognized. Coherent Raman scattering (CRS) uses multiple photons to boost weak Raman scattering. CRS has been used to enable molecular vibration-dependent contrast imaging of tissues and has been particularly useful for pathophysiological investigations of brain tissues. Recently, the combination of CRS with Raman-active bio-orthogonal chemical bonds or groups has proven particularly powerful for visualizing molecules not detectable by fluorescence imaging. This review introduces a new and exciting imaging strategy and its applications in neuroscience.