Fig. 6.

Transverse sections of lumbar spinal cord from 29-d-old control (A) and pmn (B–F) mice showing the effects of neurotrophic factors on retrograde labeling of motoneurons 24 hr after application onto the sciatic nerve stump. Compared with untreated pmn mice (B), the number and the intensity of Fluorogold labeled cells were significantly increased after BDNF (C) or CNTF (E) application. In contrast, NGF (D) or GDNF (F) had no effect on retrolabeling rate. Occasionally strongly labeled cells are visible in NGF- and GDNF-treated or untreated pmn mice (F). Note also the punctate labeling in the cell bodies, which may indicate the trapping of Fluorogold in lysosomes and endosomes (Wessendorf, 1991). Scale bars: A–D, 90 μm; E, F, 60 μm.