Introduction
pain
CORTEX, CEREBELLAR FUNCTION
The cerebellum is primarily known for its function in motor coordination, but its role in pain processing has been the focus of recent studies [Animal studies have shown that the cerebellum receives nociceptive input via nociceptive Aδ- and C-fibers [Therefore, modulation of cerebellar activity has been tried with the goal to influence pain processing. Transcranial direct current stimulation (t-DCS) offers a safe and noninvasive way to modulate superficial cortex areas, where anodal and cathodal stimulation usually lead to neuronal excitation and inhibition, respectively [To investigate if modulation of cerebellar function affects endogenous (including descending) pain modulation (as quantified by RIII reflex, offset analgesia, CPM effect) in addition to pain perception (pain ratings) and supraspinal nociception (as quantified by SEPs), we used anodal, cathodal, and sham cerebellar t-DCS in healthy subjects. Our hypothesis, based on the considerations above, was that anodal t-DCS would reduce pain perception and increase endogenous pain inhibitory mechanisms, while cathodal t-DCS would have opposite effects [