Fig. 5: Using Neuropixels Opto for optotagging.

a, We inserted two Neuropixels Opto probes in the striatum of Adora2a-Cre mice expressing the blue-sensitive opsin CoChR in D1 MSNs (using a D1-MSN-specific enhancer virus) and the red-sensitive opsin ChRmine in D2 MSNs (using a Cre-dependent AAV). Mice were free to run on a disc. After 20 min of recording, we ran the optotagging protocol (10-ms, 20-Hz, 100-µW pulses from each of 14 blue or red emitters, randomly interleaved). b, Recorded traces for one trial of light presentation, showing spike times (green and red dots) of two example units tagged by red light from emitter 3. Red shaded areas indicate the timing of the light pulses. c, Mean waveforms for the two units highlighted in b. d, Spike raster and peristimulus time histogram for 50 trials of stimulation from emitter 3, showing a consistent, low-latency response to each light pulse. e, Stacked rasters across 50 trials from all 14 emitters for five example units (including the two units from b–d). Red and blue shaded regions indicate the time of light presentation. Mean waveforms are shown above each raster. Key optotagging metrics are listed below each raster; units are considered tagged if they have a median latency below 8 ms, a reliability above 30% and a significant (Sig.) response to at least four pulses. Latencies are shown for comparison. f, Estimated location of all units passing quality control from a single recording, with units activated by blue or red light shown in blue and units activated by red light only shown in red. Large dots indicate units that pass quality metric thresholds for the complete session (ISI violations ratio <0.5, amplitude cutoff <0.1, presence ratio >0.8). Small dots indicate units that pass the ISI violations ratio threshold only for the prestimulus baseline interval (typical of units with low spontaneous firing rates that are strongly driven by light presentation).