Fig. 6

Experimental setup. a: Locations of cutaneous nerve stimulating electrodes; the nerve stimulated are the superficial peroneal nerve (SPn), sural nerve (SRn), and the distal tibial nerve (DTn). b: An example of stimulus current control during pain threshold detection with 1Â s inter stimulus train interval (ITI). Each dot indicates delivery of a stimulus train. PainTup: stimulus current at which the stimulation became first painful. PainTdown: the last stimulus current at which the stimulation was painful. See text for detailed descriptions.