A half-millimeter probe listens to more than ten brain chemicals at once by turning living sensor cells into a microscopic optical array.
Neuromodulators rise and fall together, while most brain probes measure one molecule at a time. MORSE packs engineered living cells around a micro-endoscope and assigns each cell type a fluorescent sensor for a different chemical signal. Representative sixteen-sensor probes showed a median of eight active sensor types, and recordings tracked roughly 70 to 130 cells for as long as eight hours in aggregate. The system estimated norepinephrine and serotonin release in brain slices and detected spontaneous cerebrospinal-fluid serotonin elevations in three of seven mouse recordings. Its living hydrogel, intensity signals, and ventricular location set the current measurement boundary, while the central idea opens a path to following brain chemistry as a moving multichannel state.
If one tiny probe can follow a dozen chemical channels together, brain recording just shifted from isolated transmitters toward the composition of the fluid around neural circuits.