BIOTIN-DEXTRAN - FAST RETROGRADE TRACING OF SCIATIC-NERVE MOTONEURONS

We present evidence that biotin-dextran (BD) provides good fast retrog rade tracing in the rat sciatic nerve. Using BD injected distal to a c rush injury of either tibial or common peroneal nerves, spinal cord mo toneuron counts after 48 h compare favorably with counts obtained usin g horseradish peroxidase. Advantages of BD include fine staining of th e soma and its branches, increasing the reliability of motoneuron coun ting, as well as good staining of sciatic nerve axons 30 mm away from the crush site. BD, already demonstrated to be a good anterograde trac er in the central nervous system, is shown to be a good retrograde tra cer in a peripheral nervous system model.