Cold-sensitive and nociceptive neural pathways interact to shape the quality and intensity of thermal and pain perception. Yet, the central processing of cold-thermosensation in the human brain has not yet been extensively studied. Here, we used magnetoencephalography (MEG) and electroencephalography (EEG) in healthy volunteers, to investigate the time course (evoked fields and potentials) and oscillatory activity associated with the perception of cold temperature changes. Non-noxious cold stimuli consisting of Δ3°C and Δ5°C decrements from an adapting temperature of 35°C were delivered on the dorsum of the left hand via a contact thermode. Cold-evoked fields peaked at around 240 and 500 ms, at similar peak latencies as the N1 and P2 cold-evoked potentials. Importantly, cold-related changes in oscillatory power indicated that innocuous thermosensation is mediated by oscillatory activity in the range of delta (1-4 Hz) and gamma (55-90 Hz) rhythms, originating in operculo-insular cortical regions. We suggest that delta rhythms coordinate functional integration between operculo-insular and fronto-parietal regions, while gamma rhythms reflect local sensory processing in operculo-insular areas.
- cold evoked responses
- Copyright © 2016, Journal of Neurophysiology