The major caudal nerves of the rat provide an excellent model for longitudinal evaluation of nerve repair following a crush lesion. The surgical procedure and the method for testing sensory recovery are described in detail. Using this technique a clear, positive effect of ORG.2766 (an ACTH (4-9) analog) on the regeneration of sensory nerves could be shown. Results support the suggestion that ORG.2766 enhances the initial sprouting response, rather than exerting an effect on the growth rate of newly developed sprouts.