FIGURE 4.

Representative images of choline acetyl transferase (ChAT) immunohistochemistry (IHC) showing surviving motor neurons in the contralateral (A) and ipsilateral (B) ventral horn at the C6 spinal cord level 6 weeks following avulsion only. This compares to ChAT IHC in the contralateral (C) and ipsilateral (D) ventral horn 6 weeks following avulsion with myelotomy. Notably, only very occasional ipsilateral surviving neurons were positive for the apoptotic marker Ab246, which detects a caspase-derived fragment of alpha-spectrin as shown in (E) at the C6 level. Indeed, the vast majority of cells were not immunoreactive for this marker (F) and appeared morphologically intact, indicating an absence of ongoing cellular degeneration. All scale bars = 50 µm.