Paper Info
Title
Functional topography of the secondary somatosensory cortex for nonpainful and painful stimuli: an fMRI study.
Abstract
The regional activity of the contralateral primary (SI) and the bilateral secondary (SII) somatosensory areas during median nerve stimulations at five intensity levels (ranging from nonpainful motor threshold to moderate pain) was studied by means of functional magnetic resonance imaging (fMRI). The aim was to characterize the functional topography of SII compared to SI as a function of the stimulus intensity. Results showed that the galvanic stimulation of the median nerve activated the contralateral SI at all stimulus intensities. When considered as a single region, SII was more strongly activated in the contralateral than in the ipsilateral hemisphere. When a finer spatial analysis of the SII responses was performed, the activity for the painful stimulation was localized more posteriorly compared to that for the nonpainful stimulation. This is the first report on such a SII segregation for transient galvanic stimulations. The activity (relative signal intensity) of this posterior area increased with the increase of the stimulus intensity. These results suggest a spatial segregation of the neural populations that process signals conveyed by dorsal column-medial lemniscus (nonpainful signals) and neospinothalamic (painful signals) pathways. Further fMRI experiments should evaluate the functional properties of these two SII subregions during tasks involving sensorimotor integration, learning, and memory demands.
Year
DOI
Venue
2003
10.1016/j.neuroimage.2003.07.004
NeuroImage
Keywords
DocType
Volume
Functional magnetic resonance imaging (fMRI),Primary somatosensory area (SI),Secondary somatosensory area (SII),Median-nerve electrical stimulation,Pain
Journal
20
Issue
ISSN
Citations 
3
1053-8119
14
PageRank 
References 
Authors
2.54
5
8
Name
Order
Citations
PageRank
Antonio Ferretti17310.18
Claudio Babiloni210016.77
Cosimo Del Gratta3578.40
Massimo Caulo4396.37
Armando Tartaro5264.75
Lorenzo Bonomo6142.54
Paolo Maria Rossini76012.06
Gian Luca Romani824325.02