Abstract
Previous brain imaging studies investigating the brain processing of scratching used an exogenous intervention mimicking scratching, performed not by the subjects themselves, but delivered by an investigator. In real life, scratching is a conscious, voluntary, controlled motor response to itching, which is directed to the perceived site of distress. In this study we aimed to visualize in real-time by brain imaging the core mechanisms of the itch-scratch cycle when scratching was performed by subjects themselves. Secondly, we aimed to assess the correlations between brain patterns of activation and psychophysical ratings of itch relief or pleasurability of scratching. We also compared the patterns of brain activity evoked by self-scratching vs. passive scratching. We used a robust tridimensional Arterial Spin Labeling fMRI technique that is less sensitive to motion artifacts: 3D gradient echo and spin echo (GRASE) - Propeller. Active scratching was accompanied by a higher pleasurability and induced a more pronounced deactivation of the anterior cingulate cortex and insula, in comparison with passive scratching. A significant involvement of the reward system including the ventral tegmentum of the midbrain, coupled with a mechanism deactivating the periaqueductal gray matter (PAG), suggests that itch modulation operates in reverse to the mechanism known to suppress pain. Our findings not only confirm a role for the central networks processing reward in the pleasurable aspects of scratching, but also suggest they play a role in mediating itch relief. Copyright:
| Original language | English (US) |
|---|---|
| Article number | e82389 |
| Journal | PLoS One |
| Volume | 8 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 6 2013 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Agricultural and Biological Sciences(all)
Cite this
Brain's reward circuits mediate itch relief. A functional MRI study of active scratching. / Papoiu, Alexandru D.P.; Nattkemper, Leigh A.; Sanders, Kristen M.; Kraft, Robert A.; Chan, Yiong Huak; Coghill, Robert C.; Yosipovitch, Gil.
In: PLoS One, Vol. 8, No. 12, e82389, 06.12.2013.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Brain's reward circuits mediate itch relief. A functional MRI study of active scratching
AU - Papoiu, Alexandru D.P.
AU - Nattkemper, Leigh A.
AU - Sanders, Kristen M.
AU - Kraft, Robert A.
AU - Chan, Yiong Huak
AU - Coghill, Robert C.
AU - Yosipovitch, Gil
PY - 2013/12/6
Y1 - 2013/12/6
N2 - Previous brain imaging studies investigating the brain processing of scratching used an exogenous intervention mimicking scratching, performed not by the subjects themselves, but delivered by an investigator. In real life, scratching is a conscious, voluntary, controlled motor response to itching, which is directed to the perceived site of distress. In this study we aimed to visualize in real-time by brain imaging the core mechanisms of the itch-scratch cycle when scratching was performed by subjects themselves. Secondly, we aimed to assess the correlations between brain patterns of activation and psychophysical ratings of itch relief or pleasurability of scratching. We also compared the patterns of brain activity evoked by self-scratching vs. passive scratching. We used a robust tridimensional Arterial Spin Labeling fMRI technique that is less sensitive to motion artifacts: 3D gradient echo and spin echo (GRASE) - Propeller. Active scratching was accompanied by a higher pleasurability and induced a more pronounced deactivation of the anterior cingulate cortex and insula, in comparison with passive scratching. A significant involvement of the reward system including the ventral tegmentum of the midbrain, coupled with a mechanism deactivating the periaqueductal gray matter (PAG), suggests that itch modulation operates in reverse to the mechanism known to suppress pain. Our findings not only confirm a role for the central networks processing reward in the pleasurable aspects of scratching, but also suggest they play a role in mediating itch relief. Copyright:
AB - Previous brain imaging studies investigating the brain processing of scratching used an exogenous intervention mimicking scratching, performed not by the subjects themselves, but delivered by an investigator. In real life, scratching is a conscious, voluntary, controlled motor response to itching, which is directed to the perceived site of distress. In this study we aimed to visualize in real-time by brain imaging the core mechanisms of the itch-scratch cycle when scratching was performed by subjects themselves. Secondly, we aimed to assess the correlations between brain patterns of activation and psychophysical ratings of itch relief or pleasurability of scratching. We also compared the patterns of brain activity evoked by self-scratching vs. passive scratching. We used a robust tridimensional Arterial Spin Labeling fMRI technique that is less sensitive to motion artifacts: 3D gradient echo and spin echo (GRASE) - Propeller. Active scratching was accompanied by a higher pleasurability and induced a more pronounced deactivation of the anterior cingulate cortex and insula, in comparison with passive scratching. A significant involvement of the reward system including the ventral tegmentum of the midbrain, coupled with a mechanism deactivating the periaqueductal gray matter (PAG), suggests that itch modulation operates in reverse to the mechanism known to suppress pain. Our findings not only confirm a role for the central networks processing reward in the pleasurable aspects of scratching, but also suggest they play a role in mediating itch relief. Copyright:
UR - http://www.scopus.com/inward/record.url?scp=84891954115&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84891954115&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0082389
DO - 10.1371/journal.pone.0082389
M3 - Article
C2 - 24324781
AN - SCOPUS:84891954115
VL - 8
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 12
M1 - e82389
ER -