Figure 8. Necl4–Fc inhibits remyelination in vivo.

Demyelination of adult rat sciatic nerves was induced by lysolecithin followed by intraneural injections of human Fc (a) or Necl4–Fc (b) as described in “Material and Methods”. Eleven days post–injection, nerves were collected and longitudinal sections of the injected region were immunostained for MBP (green) and Na⁺ channels (red). The border between demyelinated and unaffected region is marked by a dotted line. Insets depict higher magnification images of selected nodes from remyelinated regions, many of which have binary clusters of Na⁺ channels. Circles mark the locations of representative regions shown in c–f: unaffected nerve regions (c), remyelinated (d) or inhibited (e) areas in nerves injected with Necl4–Fc, as well as in remyelinated regions of nerves injected with hFc (f). Regions of inhibited remyelination were only detected in the Necl4–Fc and not in the hFc control–injected nerves. (g) The number of Na⁺ channel clusters found in the various regions defined in c–f was counted and are shown as an average number (mean±SEM) per field of view (FOV a minimum of 10 FOV were counted for each region). Norm, normal; Re, remyelinated. Scale bar: (a–b) 100 µm; (c–f) 20 µm.