Figure 2.

Neuropixels penetrations through the brain. (a) Example recording vectors that can be achieved with single Neuropixels probes. Left, Oblique sections through a reference brain atlas with hypothetical probe tracks illustrated in white. Right, Locations of the sections (red) shown at left. VISp, primary visual cortex; LGd, dorsal lateral geniculate nucleus; MOp, primary motor cortex; CP, caudoputamen; PL, prelimbic cortex; BLA, basolateral amygdala. All scale bars 1 mm. The Allen Institute Common Coordinate Framework reference atlas was used to generate these images. (b) Histological reconstruction of an actual probe track, showing DAPI stain (blue) without (top) and with (bottom) overlay of the fluorescent indicator DiI (orange) used to coat the probe. Due to small shank dimensions (70 × 20 μm), Neuropixels probes must be localized with a dye or with functional signatures. (c) Example LFP recording and features that can be used to localize probe sites. Left, sample of raw LFP signal from a subset of channels with sharp-wave ripple indicated (red arrow) and zoomed-in (insert). Right, total LFP power averaged over the recording, showing peak in dentate gyrus. Panel c is reprinted with permission from Ref. [20^••].