Fig. 29.

Adaptive optics enables high-resolution multiphoton microscopy at depth. (a) Wavefront distortion of the excitation light can be (b) corrected with a deformable mirror (DM) or liquid crystal spatial light modulator (SLM) to form a diffraction-limited excitation focus. Blue: wavefront. Red: excitation light. Orange: fluorescence. (c) 2P fluorescence images of dendrites and dendritic spines ($606-608\mu \mathrm{m}$ depth) in the mouse cortex. (d) 3P fluorescence images of a neuron ($414\mu \mathrm{m}$ depth) in the mouse spinal cord. (e) AO increases ${\mathrm{Ca}}^{2+}$ transient strength $\mathrm{\Delta }F/F$ and enables detection of orientation selectivity.