(a) Section number #100. The yellow box indicates the region acquired at high resolution for the sections up to number #~3500 (see panel (c) for sections above #4000). (b) Montage of the high-resolution regions acquired. The corresponding indices are shown on the right. The insets numbered 1 to 4 are shown in panel (d). Insets 1, 2 and 3 are the only locations where vertical streaks resulting from sectioning were found. Inset 4 in section #~5000 is representative of the streak-free sectioning quality manually observed in all acquired high-resolution regions. The insets illustrating restart continuity (labeled e, f, and g) are shown below in panels with corresponding lettering. (c) Complete or partial sections collected after the restart. The yellow box shows the region acquired in section numbers above #4000. The nature of the cuts was observed through the binocular microscope simultaneously during the sectioning restart and is as follows (#1 refers to #~4000 + 1 and so on): #1, partial tissue; #2, partial tissue; #3, partial tissue; #4, partial tissue connected with partial magnet; #5, partial tissue connected with partial magnet (but disconnected during manual pickup, the magnetic and dummy parts remained stuck to the bottom of section #6); #6, partial tissue with disconnected partial magnet (the tissue/ magnet separation occurred immediately upon sectioning); #7, full tissue connected with full magnet (but disconnected during manual pickup, the magnetic portion is visible immediately to the right of the section); #8 to #15, full normal sections (not collected). (d) Insets 1, 2 and 3 from panel (b) showing (with yellow arrows) the only vertical streaks found after manual inspection among the entire high-resolution imagery from panel (b). Inset 4 from section #~5000 shows a representative image of the lack of image quality impairment that might occur due to a potentially damaged knife. (e– g) Four consecutive insets from the restart sections shown in yellow in panel (b). The interior of three small neuronal processes are painted in red, green and blue. There is no issue in tracing fine processes across the 20 hr long restart. The good continuity in panels (e–g) indicates that no material was lost despite the partial sections. Scale bars: (a) 200 mm; (b) 100 mm; (c) 500 mm; (d–g) 2 mm.