Tracking neurons across days with high-density probes

Neural activity spans multiple scales from milliseconds to months. Its evolution can be recorded with chronic electrodes, and especially with high-density arrays such as Neuropixels probes, which measure each spike at tens of sites and record hundreds of neurons. These arrays often record units with consistent spike waveforms over time, but produce vast amounts of data that require new approaches for tracking neurons across recordings. To meet this need, we developed UnitMatch, an open-access pipeline that operates after spike sorting, based only on each units average spike waveform. We tested UnitMatch in Neuropixels recordings from the mouse brain, where it tracked neurons across weeks. In visual cortex, a neurons selectivity for visual stimuli and correlation with other neurons remained stable over days. In striatum, neuronal responses changed across days during learning of a task. UnitMatch is thus a promising tool to reveal invariance or plasticity in neural activity across days.