Indirect effect of sciatic nerve injury on the epidermal thickness of plantar glabrous skin in rats.

In patients with nerve injuries, the skin over the denervated part tends to atrophy. Few experimental studies have dealt with this issue. In this paper we examine the effects of nerve injury on the epidermis in plantar glabrous skin in rats. Analysis of paraffin sections showed that the epidermis becomes abnormally thin after sciatic neurotomy and suture or neurectomy, but not after nerve crush. Autoradiographic analysis showed a subnormal number of thymidine-labelled epidermal cells in plantar skin of rats subjected to sciatic neurectomy. However, after selective division of the sciatic foot branches, with preserved function of thigh and leg muscles, the number of labelled epidermal cells did not differ significantly between the side operated on and the control side. We conclude that the effect of sciatic nerve division on plantar skin in rats is caused by the motor deficiency in the foot rather than by deficient innervation of the skin.