Central projection of rat sciatic nerve fibres as revealed by Ricinus communis agglutinin and horseradish peroxidase tracers.

The central projection of afferent fibres in the rat sciatic nerve has been studied by means of the suicide transport of a lectin, Ricinus communis agglutinin 60 (RCA 60), and the transganglionic transport of horseradish peroxidase (HRP). The results obtained from these two methods are similar; however, the RCA method gave a more consistent and better localisation of the primary afferent terminals than the HRP method. The present study has shown that primary afferents from the sciatic nerve project predominantly to the ipsilateral gracile nucleus. In addition, they also project to several other brainstem nuclei; these include the contralateral nucleus gracilis, the ipsilateral main cuneate nucleus, the external cuneate nucleus and the presumptive nucleus z.