Random-access scanning microscopy for 3D imaging in awake behaving animals

Random-access line scanning enables neural activity to be monitored at high speed in neurons and dendrites that are sparsely distributed in three dimensions. The approach is demonstrated in behaving mice. Understanding how neural circuits process information requires rapid measurements of activity from identified neurons distributed in 3D space. Here we describe an acousto-optic lens two-photon microscope that performs high-speed focusing and line scanning within a volume spanning hundreds of micrometers. We demonstrate its random-access functionality by selectively imaging cerebellar interneurons sparsely distributed in 3D space and by simultaneously recording from the soma, proximal and distal dendrites of neocortical pyramidal cells in awake behaving mice.