Fig. 3

Enlarged extracellular spaces in the tissue surrounding syringomyelia cavities. Gross anatomical morphology of control (a) and PTS (b) tissue in semi-thin sections (750 nm) stained with methylene blue, displaying ventral median fissure and anterior penetrating vessel (VMF), central canal (CC), grey matter (GM), white matter (WM) and syrinx (S). The central canal in this PTS spinal cord (b) is dilated, but is not in direct communication with syrinx cavities. At the ultrastructural level, tissue appears normal in control animals (c). Enlarged extracellular spaces in the tissue surrounding syrinx cavities resembles edema and indicates increased water content in the spinal cord tissue (d). The syrinx border is lined by fragmented processes of astrocytes (euchromatic nuclei indicated by white arrows) and there appears to be a continuity (black arrows) between fluid in the cavity with the extracellular fluid and surrounding tissue (d–h). L, lumen. Magnification: ×3400 (c), ×1450 (d), ×4600 (e) ×2600 (f–h). Scale bars: 50 µm (a, b) 2  µm (c, e–h), 5 µm (d)