Pain. 1985 Jul; 22(3): 235-42.

Thermal sensitivity in healthy subjects is decreased by a central mechanism after TNS.

Using the thermal sense as a model for nociception, the effects of conventional and acupuncture-like transcutaneous nerve stimulation (TNS) were tested on thresholds for warm and cold sensation in 8 healthy subjects. Photic stimulation did not change the thermically neutral zone (the warm-cold difference limen) from that seen under baseline conditions. However, the thermal difference limen usually increased with both types of TNS. The effect was ipsi- as well as contralateral, implying that a central inhibitory mechanism is activated by conventional and acupuncture-like TNS.