We propose to engineer and validate a novel random access three-dimensional two-photon (2P) laser scanning microscope which can simultaneously image three different brain regions in the three spatial dimensions (3x3D system), where each scanned volume can exceed cubic millimetres. We will validate the capability of our 3x3D system by simultaneously performing retinal, lateral geniculate nucleus, and cortical 3D imaging and photo stimulation.

Recording of neuronal activity in multiple, functionally connected distant brain volumes, is essential for understanding distributed brain computations.