Femoral motoneuronal(M) regeneration into saphenous nerve grafts(G) that are reinnervated simultaneously at the distal end with sensory axons(S) (MGS group), is 50% reduced compared to motoneuronal regeneration in grafts that are ligated distally (MGL group, Midha et al, SFN 1999). This maybe due to competition between sensory and motor axons for endoneurial pathways or an inhibitory influence of sensory axons on motoneuronal regeneration in sensory pathways. To test this, we evaluated the ability of motoneurons to regenerate into sensory nerve grafts at the same time as motoneurons regenerated into the graft from the distal end. In a rat model, a 4 cm saphenous autograft was interposed and sutured to the proximal stumps of the cut motor branches of both the left and right femoral nerves(MGM, n=4). 3 months later, the graft was sectioned in the centre, each end of the graft was exposed to 1 of 2 retrograde tracers (fluorogold or fluororuby). Rats were perfused 5 day later, the T11-L2 spinal segment removed...