Nature Methods Neuropixels Opto: combining high-resolution electrophysiology and optogenetics This paper introduces Neuropixels Opto, a prototype neural probe that combines high-density extracellular electrophysiology with optogenetic stimulation in a single device. The probe has 960 recording sites and two sets of 14 light emitters on a 70-μm-wide, 1-cm-long shank, enabling spatially targeted stimulation with blue and red light while simultaneously recording neural activity. In mouse cortex, Neuropixels Opto produced high-quality recordings and could selectively activate or silence neurons at different cortical depths. In the striatum and other deep brain regions, it enabled efficient optotagging and helped identify two cell types in parallel. The main advance is that Neuropixels Opto allows researchers to record, identify, and manipulate neuronal populations with high spatial and temporal precision using one integrated probe. This makes it a powerful tool for studying causal relationships in neural circuits. nature.com/articles/s41592-0…