Remote-Scanning Microscope Captures 25% of Zebrafish Brain Neurons at 200.8 Hz

3 articles · Updated · Nature.com · Aug 14

Researchers used a remote-scanning light-sheet microscope to record membrane voltage across about 85% of larval zebrafish brain volume, retaining 12,935 to 19,039 putative neurons per fish—up to roughly one-quarter of all brain neurons.
The system overcomes calcium imaging’s slower time resolution by scanning 30 planes over a 930 × 370 × 170 µm volume every 4.98 ms, using lightweight piezo-driven remote refocusing and dual ultrafast cameras to reach 200.8 volumetric Hz.
A key obstacle was blood-flow-driven stripe artifacts that could mimic spikes; the team mitigated them with transient heart arrest, resonant scanning, and mainly computational filtering that preserved 59% to 92% of segmented neurons.
In four fish exposed to 10-second UV stimuli, onset-responsive neurons formed a reproducible roughly 200-ms firing sequence across the optic tectum, with lateral neurons activating before medial ones.
The recordings also revealed stimulus-independent burst sequences in the cerebellum and medulla, suggesting the method can map millisecond-scale brain-wide dynamics and generate testable circuit hypotheses.