Extended Data Fig. 2: Analysis of tissue shavings and the workflow for mitochondrial colorimetric and respiratory assays.

a, Positions of collection sites of the four tissue shavings. Samples 1–3 were above the grey matter areas, while 4 was above a white matter area. b, Comparison of mitochondrial activities between the four ‘dust’ samples and corresponding tissue samples collected below after tissue voxelization. Values are mean ± SD. While all mitochondrial features (MitoD, TRC and MRC) were lower in all dust samples compared to tissue collected below, MitoD was less different between brain dust and tissue block. In sample 4, brain dust and voxels features appear to be very similar, but this possibly indicates that colorimetry and respirometry assays are at their detection limit when measuring mitochondria complex activities in the white matter. c, Brain voxel collection and preparation. d, Voxel plating and data collection for colorimetric mitochondrial assay and qPCR. e, Frozen tissue respirometry plate layouts derived from the assay plates on d to accommodate all samples and ran in duplicate. Samples were loaded into Seahorse plates at a constant volume rather than constant protein content. Parts c–e created in BioRender. Rosenberg, A. (2025) https://BioRender.com/k26p643.