Transmission Electron microscopic evidence of neuronal apoptosis in the ventral horn of the spinal cord. The rabbit spinal cords were fixed by transcardial perfusion and removed at 48 h reperfusion, or operation for sham control and processed as described in Experimental Procedures. A, sham control (magnification × 10000); B-C, I/R control (magnification × 20000). I/R induced neuronal apoptosis, as demonstrated by specific morphological features. No apoptotic neurons were found in sham group sections. N, nucleus; nc, nucleolus; C, cytoplasm; M, mitochondria. Figures are representative of 3 separate experiments with similar results.