Caudate Nucleus and Insular Activation During a Pain Suppression Paradigm Comparing Thermal and Electrical Stimulation
Arthur P Wunderlich1, Roland Klug2, Gregor Stuber1, Bernhard Landwehrmeyer2, Frank Weber3, Wolfgang Freund*, 1
Identifiers and Pagination:Year: 2011
First Page: 1
Last Page: 8
Publisher Id: TONIJ-5-1
Article History:Received Date: 21/7/2009
Revision Received Date: 4/11/2009
Acceptance Date: 16/11/2009
Electronic publication date: 18/1/2011
Collection year: 2011
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Pain modulation is an integral function of the nervous system. It is needed to adapt to chronic stimuli. To gain insights into pain suppression mechanisms, two studies concerning the suppression of the feeling of pain with different stimulation modalities (heat vs. electrical stimuli) but using the same stimulation paradigms were compared: 15 subjects each had been stimulated on both hands under the instruction to suppress the feeling of pain.
Anterior insula and DLPFC activation was seen in both single modality studies and seems to be a common feature of pain suppression, as it is absent in the interaction analyses presented here.
During the task to suppress the feeling of pain, there were no consistent activations stronger under thermostimulation. But during electrostimulation, there was significantly stronger activation than during thermal stimulation in the caudate nucleus bilaterally and in the contralateral posterior insula. This may be attributed to the higher sensory-discriminative content and more demand on subjective rating and suppression of the painful electrical stimulus, compared to thermostimulation. The caudate nucleus seems to play an important role not only in the motor system but also in the modulation of the pain experience.