Fig. 1.

Experimental setup. A: high-frequency stimulation (HFS) was applied to the volar forearm of 1 arm. Test mechanical punctate stimuli and thermal stimuli were applied to the skin surrounding the area onto which HFS was applied as well as to the same skin area on the contralateral arm that served as a control. B: electrode used to deliver HFS consisted in 16 blunt stainless steel pins placed in a 10-mm diameter circle (cathode), surrounded by a concentrically located stainless steel anode. The heterotopic test area is shown in light grey. C: effect of HFS on the responses elicited by the test stimuli was assessed at 3 different time points: before HFS (T0), 20 min after HFS (T1), and 45 min after HFS (T2).