Hi everyone, I’m currently analyzing some spiking data from the Allen Neuropixels dataset and would like to cross-reference with the depth of each unit, provided as the dorsal-ventral (DV) coordinate registered to the CCF, if I understand correctly.

However, looking at the distribution of DV-coordinates for units labelled as V1/“VISp”, it starts at around 600 μm, while I would have expected it to start at 50-100 μm (or even closer to 0 μm) for units close to the surface. Am I misunderstanding something about the way the CCF system works? Is there some reference value for each session that I have to re-register to?

(The range of DV-coordinates goes from 600 μm to 1800 μm, so that seems reasonable, assuming a cortical thickness of 1000 μm and a non-perpendicular insertion angle.)

Thank you very much for your help!