Understanding neural computation requires methods such as 3D
acousto-optical (AO) scanning that can simultaneously read
out neural activity on both the somatic and dendritic scales.
AO point scanning can increase measurement speed and signal-
to-noise ratio (SNR) by several orders of magnitude, but high
optical resolution requires long point-to-point switching
time, which limits imaging capability. Here we present a
novel technology, 3D DRIFT AO scanning, which can extend each
scanning point to small 3D lines, surfaces, or volume
elements for flexible and fast imaging of complex structures
simultaneously in multiple locations. Our method was
demonstrated by fast 3D recording of over 150 dendritic
spines with 3D lines, over 100 somata with squares and cubes,
or multiple spiny dendritic segments with surface and volume
elements, including in behaving animals. Finally, a 4-fold
improvement in total excitation efficiency resulted in about
500 x 500 x 650 mum scanning volume with genetically encoded
calcium indicators (GECIs).
