Relationship between Ependymal Cell-Derived Progeny, Axonal Growth-Modulating Molecules, and Axons in the Scar Tissue

(A–E) Chondroitin sulphate proteoglycans (CSPG), which are axonal growth inhibitory, are abundant in the scar tissue 2 wk after a dorsal funiculus lesion. CSPG are present in a complementary and nonoverlapping pattern to β-gal–expressing ependyma-derived cells. The extracellular matrix proteins fibronectin (A) and laminin (B and F), which are permissive to axonal sprouting, are widely distributed within the scar tissue and overlap with β-gal–expressing ependyma-derived cells. (C–H) Neurofilament (NF)-immunoreactive axons in the scar tissue are rarely present in CSPG⁺ areas (C–E) but are associated with ependymal cell progeny (C–H) and laminin (F–H) in the core of the forming scar tissue 2 wk after injury. Scale bars indicate 100 μm.