Figure 7.

Expression of biomarkers for neural differentiation is consistent with the emergence of neuronal immaturity in addition to reactive astrocytes. a-e, Nestin expression is increased in contused specimens both 4 and 14 days after SCI. a, Increased nestin expression was observed throughout the grey matter, and in both the dorsal and ventral horns, in coronal sections of contused animals 4 days following injury. b-d, High magnification micrographs show nestin fiber tracts associated with small glial cells in the white matter/remnants of the dorsal horn (b), nestin positive cells along the interface between the ventral horn and white matter (c), and a large, nestin positive neuronal cell projecting into the white matter from the ventral horn (d). Arrows label nestin-labeled processes of the neuron, and an asterisk denotes the large nucleus; note the triangular shaped cell body and long axonal process. e, At 14 days post-surgery, contused specimens illustrated a higher level of nestin expression than that observed at 4 days, relative to sham controls. f-i, In addition to nestin, contused specimens also exhibited an increase in GFAP (f), but expression was largely confined to white matter (g, h) and GFAP and nestin did not co-localize exclusively. i, Large numbers of nestin+/GFAP- cells with long processes were observed within the lesion site, indicative of neuronal immaturity rather than reactive astrocytosis. Abbreviations, central canal (CC), dorsal horn (DH), grey matter (GM), ventral horn (VH), and white matter (WH). Scale bars, 500 μm (a, c, f-h), 200 μm (e, i) and 50 μm (b, d).