Researchers have developed a novel hardware design for recording neuronal activity across the three dimensions of a restrained zebrafish larva brain. This approach can help reconstruct the brain dynamics during sensory stimulation.
The new design uses a traditional multiphoton microscope with an 8-kHz resonant scanner. It integrates a remote focusing system upstream based on an electrically tunable lens. This layout enables neuronal activity recording from a brain volume of 800 × 400 × 180 μm3 with cellular resolution on about 80% of this volume.
The researchers present neuronal activity recordings from the RGC axonal projections of five days post-fertilization zebrafish larvae during visual stimuli presentation. They used a genetically encoded fluorescence-based reporter GCaMP6s. It is possible to reconstruct the activity from 45,000 to 52,000 cells within the brain of a larva with this configuration.
Researchers developed a raster scanning configuration incorporating an electrically tunable lens on a commercial multiphoton microscope equipped with an 8-kHz resonant scanner to reconstruct neuronal dynamics at cellular resolution in 3D. In their design, the ETL is placed upstream and near the galvo mirrors, in a position where the imaging beam fits without overfilling the optical window of the lens.
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