Before revision:  This application is however hindered by the use of visible light for fluorescence excitation , inducing unwanted visual stimulation that can only be partially overcome resorting to complex excitation geometries. On the other hand, two-photon (2P) LSF microscopy, owing to the use of invisible infra-red illumination, enables volumetric imaging of neuronal activity avoiding undesirable visual stimulation .
After revision:  This application is however hindered by the use of visible excitation light. The use of two-photon (2P) LSF microscopy, owing to the use of invisible infra-red illumination, enables volumetric imaging of neuronal activity avoiding undesirable visual stimulation .