TY - JOUR
T1 - Cortico-subcortical activation patterns for itch and pain imagery
AU - Mochizuki, Hideki
AU - Baumgärtner, Ulf
AU - Kamping, Sandra
AU - Ruttorf, Michaela
AU - Schad, Lothar R.
AU - Flor, Herta
AU - Kakigi, Ryusuke
AU - Treede, Rolf Detlef
N1 - Funding Information:
The authors thank Mr. Martin Dettling for technical support in the preparation of the pictures used in this study and the program to present the pictures. We also thank Prof. Sergij Goerdt and Dr. Yuichi Ogino for offering us pictures to evoke feelings of itch and pain. This study was supported by the Alexander von Humboldt Foundation and the Federal Ministry of Education and Research as part of the LOGIN consortium (01EC1010D, 01EC1010B); grants to H.F. and R.D.T. There is no conflict of interest for any of the authors.
PY - 2013/10
Y1 - 2013/10
N2 - The imagery of itch and pain evokes emotional responses and covert motor responses (scratching to itch and withdrawal to pain). This suggests some similarity in cerebral mechanisms. However, itch is more socially contagious than pain, as evidenced by the fact that scratching behaviors can be easily initiated by watching itch-inducing situations, whereas withdrawal is less easily initiated by watching painful situations. Thus, we assumed that the cerebral mechanisms of itch imagery partly differ from those of pain imagery in particular with respect to motor regions. We addressed this issue in 18 healthy subjects using functional magnetic resonance imaging. The subjects were instructed to imagine itch and pain sensations in their own bodies while viewing pictures depicting stimuli associated with these sensations. Itch and pain imagery activated the anterior insular cortex (aIC) and motor-related regions such as supplementary motor area, basal ganglia, thalamus, and cerebellum. Activity in these regions was not significantly different between itch and pain imagery. However, functional connectivity between motor-related regions and the aIC showed marked differences between itch and pain imagery. Connectivity with the aIC was stronger in the primary motor and premotor cortices during pain imagery and stronger in the globus pallidus during itch imagery. These findings indicate that brain regions associated with imagery of itch are the same as those involved in imagery of pain, but their functional networks differ. These differences in brain networks may explain why motor responses to itch are more socially contagious than those related to pain.
AB - The imagery of itch and pain evokes emotional responses and covert motor responses (scratching to itch and withdrawal to pain). This suggests some similarity in cerebral mechanisms. However, itch is more socially contagious than pain, as evidenced by the fact that scratching behaviors can be easily initiated by watching itch-inducing situations, whereas withdrawal is less easily initiated by watching painful situations. Thus, we assumed that the cerebral mechanisms of itch imagery partly differ from those of pain imagery in particular with respect to motor regions. We addressed this issue in 18 healthy subjects using functional magnetic resonance imaging. The subjects were instructed to imagine itch and pain sensations in their own bodies while viewing pictures depicting stimuli associated with these sensations. Itch and pain imagery activated the anterior insular cortex (aIC) and motor-related regions such as supplementary motor area, basal ganglia, thalamus, and cerebellum. Activity in these regions was not significantly different between itch and pain imagery. However, functional connectivity between motor-related regions and the aIC showed marked differences between itch and pain imagery. Connectivity with the aIC was stronger in the primary motor and premotor cortices during pain imagery and stronger in the globus pallidus during itch imagery. These findings indicate that brain regions associated with imagery of itch are the same as those involved in imagery of pain, but their functional networks differ. These differences in brain networks may explain why motor responses to itch are more socially contagious than those related to pain.
KW - Anterior insular cortex Craving Globus pallidus Itch imagery Motivation Pain imagery
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U2 - 10.1016/j.pain.2013.06.007
DO - 10.1016/j.pain.2013.06.007
M3 - Article
C2 - 23769719
AN - SCOPUS:84884285607
VL - 154
SP - 1989
EP - 1998
JO - Pain
JF - Pain
SN - 0304-3959
IS - 10
ER -