Fast 3D imaging in behaving mice
Continuing our work on the 3D AO scanning technique, that can simultaneously read out neural activity on the somatic and dendritic scales, we have developed a novel method, 3D DRIFT AO microscopy. By this, we can drift the excitation spot quickly in any direction in 3D, while continuously recording fluorescence data. Therefore, we can extend the pre- selected individual scanning points to small 3D lines, surfaces, or volume elements to cover ROIs along with neighboring background areas or volume elements. In this way, we can preserve fluorescent information for motion artefact elimination, and, hence, to record spines, dendrites and networks form the moving brain of behaving animals. 3D DRIFT AO microscopy makes it possible to functionally image and stimulate large volumes of neural tissue: entire cortical columns, multiple separate cortical areas, or larger areas. Neuronal networks at multiple spatial scales, from small structures to the level of large neuronal assemblies (over 5000 neurons) can be now simultaneously imaged and activated in the V1 region and in higher order visual regions with high spatial (<500 nm, in the center) and temporal (>50kHz/ROI) resolution in several cubic millimeter volumes in 3D. This method can increase measurement speed and signal collection efficiency by several orders of magnitude (up to >10 000 000- fold; Szalay et al. 2016 Neuron, Chiovini et al. 2014 Neuron).