3x3D Imaging · Fast two-photon in vivo imaging and stimulation with simultaneous three-dimensional random-access scanning in multiple brain regions

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 millimeters. Our 3x3D system, which allows the simultaneous recording of neuronal activity in multiple, functionally connected distant brain volumes, is essential for understanding distributed brain computations. As each site can be scanned with sub-millisecond temporal resolution in several hundred user defined locations, the activity of single neurons in neuronal microcircuits or even neuronal compartments such as dendrites or axons will be followed. Furthermore, by combining imaging with powerful genetic methods and 3D photo-activation, we will not only record from identified circuits but also map connectivity between regions. We will validate the capability of our 3x3D system by simultaneously performing retinal, lateral geniculate nucleus, and cortical 3D imaging and photo stimulation. No currently available technology is able to achieve such multi-region 3D recordings of neuronal activity, considering not only products on the market but scientific publications as well. In the long term, the project leader SME will release a high-value added product family to the world market based on the methods and results that are realized and validated during this project. Despite steep competition from overseas laboratories, the first single region 3D 2P brain imaging was invented in Europe. Now, having similarly heavy competition this project attempts to realize the first multi-region 3D 2P brain imaging microscope.