TY - JOUR
T1 - Disentangling the spinal mechanisms of illusory heat and burning sensations in the thermal grill illusion
AU - Mitchell, Alexandra G.
AU - Ehmsen, Jesper Fischer
AU - Christensen, Daniel Elmstrøm
AU - Stuckert, Anna Villaume
AU - Haggard, Patrick
AU - Fardo, Francesca
N1 - Publisher Copyright:
© 2024 International Association for the Study of Pain.
PY - 2024/10/1
Y1 - 2024/10/1
N2 - The thermal grill illusion (TGI), a phenomenon in which the juxtaposition of innocuous warm and cold temperatures on the skin elicits a burning sensation, offers a unique perspective to how pain occurs in response to harmless stimuli. We investigated the role of the spinal cord in the generation of the TGI across 2 experiments (total n 5 80). We applied heat and cold stimuli to dermatomes, areas of skin innervated by a single spinal nerve, that mapped onto adjacent or nonadjacent spinal segments. Enhanced warm and burning ratings during the TGI were observed when cold and warm stimuli were confined within the same dermatome. Furthermore, we found the spatial organisation of warm and cold stimuli within and across dermatomes affected TGI perception. Perceived warmth and burning intensity increased when the cold stimulus projected to the segment more caudal to the warm stimulus, whereas perceived cold during the TGI decreased compared with the opposite spatial arrangement. This suggests that the perception of TGI is enhanced when cold afferents are projected to spinal segments positioned caudally in relation to those receiving warm afferents. Our results indicate distinct interaction of sensory pathways based on the segmental arrangement of afferent fibres and are consistent with current interpretations of the spread and integration of thermosensory information along the spinal cord.
AB - The thermal grill illusion (TGI), a phenomenon in which the juxtaposition of innocuous warm and cold temperatures on the skin elicits a burning sensation, offers a unique perspective to how pain occurs in response to harmless stimuli. We investigated the role of the spinal cord in the generation of the TGI across 2 experiments (total n 5 80). We applied heat and cold stimuli to dermatomes, areas of skin innervated by a single spinal nerve, that mapped onto adjacent or nonadjacent spinal segments. Enhanced warm and burning ratings during the TGI were observed when cold and warm stimuli were confined within the same dermatome. Furthermore, we found the spatial organisation of warm and cold stimuli within and across dermatomes affected TGI perception. Perceived warmth and burning intensity increased when the cold stimulus projected to the segment more caudal to the warm stimulus, whereas perceived cold during the TGI decreased compared with the opposite spatial arrangement. This suggests that the perception of TGI is enhanced when cold afferents are projected to spinal segments positioned caudally in relation to those receiving warm afferents. Our results indicate distinct interaction of sensory pathways based on the segmental arrangement of afferent fibres and are consistent with current interpretations of the spread and integration of thermosensory information along the spinal cord.
KW - Pain
KW - Spinal cord
KW - Thermal grill illusion
KW - Thermosensation
UR - http://www.scopus.com/inward/record.url?scp=85202463996&partnerID=8YFLogxK
U2 - 10.1097/j.pain.0000000000003352
DO - 10.1097/j.pain.0000000000003352
M3 - Journal article
C2 - 39185673
AN - SCOPUS:85202463996
SN - 0304-3959
VL - 165
SP - 2370
EP - 2378
JO - Pain
JF - Pain
IS - 10
ER -