Deep Tissue Afferents, but not Cutaneous Afferents, Mediate Transcutaneous Electrical Nerve Stimulation-Induced Antihyperalgesia

Transcutaneous electrical nerve stimulation (TENS) is an accepted clinical modality used for pain relief. It is generally believed that TENS analgesia is caused mainly by cutaneous afferent activation. In this study by differentially blocking cutaneous and deep tissue primary afferents, we show that the activation of large diameter primary afferents from deep somatic tissues, and not cutaneous afferents, are pivotal in causing TENS analgesia.