OCCURRENCE OF EPIDERMAL NERVE-ENDINGS IN GLABROUS AND HAIRY SKIN OF THE RAT FOOT AFTER SCIATIC-NERVE REGENERATION

The occurrence and distribution of intraepidermal nerve endings in hai ry and glabrous skin of the rat foot was examined in normal cases and three months after sciatic neurotomy/suture or a crush lesion. The ner ve endings were visualized in cryostate sections with antibodies again st protein gene product 9.5. Normal glabrous skin exhibited 23.3 endin gs/mm length. Neurotomy/suture cases had 6.1 endings/mm. In rats with nerve crush injury the occurrence was normal, but the intraepidermal n erve endings tended to be abnormally short and occurred mainly in the basal layer of the epidermis. In sections from hairy skin countings we re not possible. Subjective evaluation indicated that the occurrence o f dermal and epidermal axon profiles usually was very deficient after neurotomy/suture and essentially normal after crush. Skin samples from the contralateral side of operated animals showed a normal occurrence and distribution of nerve endings. We also noted that cases subjected to neurotomy/suture showed increased numbers of protein gene product 9.5-immunoreactive intraepidermal cells and an abnormally thin epiderm is. We suggest that a highly deficient occurrence of intraepidermal ne rve endings may be one factor behind the unsatisfactory restitution of the sensory function of the hand typically seen in patients subjected to neurotomy and suture.