Distinct regulation of sodium channel types I, II and III following nerve transection.

We investigated mRNA expression of type I, II and III voltage-sensitive sodium channels in motoneurons following facial nerve transection by means of in situ hybridization histochemistry. Type I mRNA expression decreased markedly after nerve transection, while that of type III increased. Type II expression underwent no detectable change following nerve transection. These results suggest that type III sodium channels may be involved in regeneration and plasticity.