Miniature microscopes for ultra-high frame rate imaging in freely moving animals

A new miniature microscope will capture brain cell activity at speeds ten times faster than current devices, letting scientists watch voltage changes in neurons as animals move freely. The problem is straightforward: the electrical signals that neurons use to compute and communicate happen in milliseconds, but existing miniature microscopes are too slow to see them. Researchers can either immobilise animals for high-speed imaging—which limits what they can learn about natural behaviour—or sacrifice speed for mobility. This project removes that trade-off by using Single Photon Avalanche Diode (SPAD) sensors, which are compact enough to fit on a rodent’s head yet fast enough to record both sub-threshold voltage shifts and action potentials. If successful, the microscopes will allow neuroscientists to link fast electrical signalling in genetically identified neurons to real behaviours like spatial navigation and decision-making. This is fundamental science: it will reveal how neural circuits compute in real time, not just where they are active. The technology could eventually extend beyond neurons to study electrical signalling in other tissues, such as heart or muscle cells. No immediate clinical application is claimed, but understanding how healthy brains process information is the foundation for future work on disorders where that processing goes wrong.