RT Journal Article
SR Electronic
T1 Representation of Spatial Information in Key Areas of the Descending Pain Modulatory System
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4634
OP 4639
DO 10.1523/JNEUROSCI.4342-13.2014
VO 34
IS 13
A1 Christoph Ritter
A1 Martin N. Hebart
A1 Thomas Wolbers
A1 Ulrike Bingel
YR 2014
UL http://www.jneurosci.org/content/34/13/4634.abstract
AB Behavioral studies have demonstrated that descending pain modulation can be spatially specific, as is evident in placebo analgesia, which can be limited to the location at which pain relief is expected. This suggests that higher-order cortical structures of the descending pain modulatory system carry spatial information about the site of stimulation. Here, we used functional magnetic resonance imaging and multivariate pattern analysis in 15 healthy human volunteers to test whether spatial information of painful stimuli is represented in areas of the descending pain modulatory system. We show that the site of nociceptive stimulation (arm or leg) can be successfully decoded from local patterns of brain activity during the anticipation and receipt of painful stimulation in the rostral anterior cingulate cortex, the dorsolateral prefrontal cortices, and the contralateral parietal operculum. These results demonstrate that information regarding the site of nociceptive stimulation is represented in these brain regions. Attempts to predict arm and leg stimulation from the periaqueductal gray, control regions (e.g., white matter) or the control time interval in the intertrial phase did not allow for classifications above chance level. This finding represents an important conceptual advance in the understanding of endogenous pain control mechanisms by bridging the gap between previous behavioral and neuroimaging studies, suggesting a spatial specificity of endogenous pain control.