Retrograde axoplasmic transport of toxic lectins is useful for transganglionic tracings of the peripheral nerve.

Wallerian degeneration in the primary afferents consequent to death of parental root ganglion cells was successfully traced up to the level of the nucleus gracilis, following intraneural injections of ricinus communis agglutinin (RCA 60 or RCA 120) into the sciatic nerve or its branches. This method serves as a novel way of tracing primary afferents in the CNS in strict concordance with their counterparts in the peripheral nerve.