Fig. 4.
Up-regulation of FasL in lumbar motoneurons of mutant SOD1 mice. (A) Transverse sections of L4 lumbar spinal cords of C57BL/6 (control), 75-day-old SOD1G93A, and 120-day-old SOD1G85R mice immunostained for Fas, Daxx, FasL, and choline acetyl transferase (ChAT). Fas and Daxx displayed a scattered expression pattern in various cell types of the gray and white matter. In control mice, FasL was mainly detected in dorsal and ventral horn neurons, including a few motoneurons. In SOD1G93A and SOD1G85R mice, a high proportion of motoneurons, as identified by ChAT staining on adjacent sections, was positive for FasL. (Scale bar: 100 μm.) (B) Histograms showing the percentage of FasL-positive motoneurons in serial sections of L4 lumbar spinal cord. Note the increased percentage of FasL-positive motoneurons in SOD1G93A and SOD1G85R mice as compared with C57BL/6 and SOD1WT mice. (C) Immunolabeling reveals coexpression of FasL and Fas in spinal cord motoneurons in a 75-day-old SOD1G93A mouse. (Scale bar: 50 μm.)