Figure 7.

Rostrally projecting VLF/LF neurons. Schematic ventral view of backfilling of cut VLF axon bundles with fluorescein dextran at the left lumbosacral junction is superimposed with a projected confocal image (40 of 65 optical slices, 8 μm each) of sacral neurons labeled through the cut VLF axons at the left lumbosacral junction in a whole mount transparent preparation of the spinal cord. Projected confocal images of 70-μm-thick cross sections through the S1, S2, S3, S4 and Co1 in one of the five labeling experiments performed in this series are shown to the right and below the image of the whole mount preparation. Calibration bars: 100 μm. The 3D histogram below shows the segmental and laminar distribution of the labeled VLF neurons. The numbers of neurons are means of five labeling experiments. For abbreviations, see Fig. 6A.