RESUMO
Transection and regeneration of the saphenous nerve on one side of a rat reduces the ability of the contralateral saphenous nerve to evoke plasma extravasation following antidromic nerve stimulation. It is proposed that a transneuronal signal--that is a signal that passes from injured neurones on one side of the body to intact ones on the other via the spinal cord--is involved in triggering this response. The present experiments have shown that the influence of this transneuronal signal is restricted to neurones of homologous nerves on the two sides of an animal, i.e. it passes from saphenous nerve neurones on one side to saphenous nerve neurones on the other; its influence does not seem to extend to neurones in other nerves, for example ones in either the ipsi- or contralateral sural nerves.