Millisecond two-photon optical ribbon imaging for small-animal functional connectome study.

We developed a high-speed two-photon optical ribbon imaging system, which combines galvo-mirrors for an arbitrary curve scan on a lateral plane and a tunable acoustic gradient-index lens for a 100 kHz-1 MHz axial scan. The system provides micrometer/millisecond spatiotemporal resolutions, which enable continuous readout of functional dynamics from small and densely packed neurons in a living adult Drosophila brain. Compared to sparse sampling techniques, the ribbon imaging modality avoids motion artifacts. Combined with a Drosophila anatomical connectome database, which is the most complete among all model animals, this technique paves the way toward establishing whole-brain functional connectome. (C) 2019 Optical Society of America