Dataset Information

Neural correlates of temporal summation of second pain in the human brainstem and spinal cord.

ABSTRACT: Temporal summation of second pain (TSSP) occurs when painful stimuli are presented repetitively (? 0.33 Hz) and results from a C-fibre evoked enhancement (or "wind-up") of the dorsal horn neurons. Based on electrophysiological studies in intact animals, windup is considered a purely central phenomenon. With advancements in functional MRI (fMRI), we can now probe the central mechanisms of this pain response in humans. The aim of this study is to characterize the fMRI responses in the healthy human brainstem and spinal cord that correspond to TSSP. Functional MRI of healthy female adults (N = 15) was conducted while brief, repetitive heat pain stimuli were applied to the right thenar eminence (C6 dermatome), and TSSP (0.33 Hz) and control (0.17 Hz) heat pain paradigms were employed. The stimulus intensity was adjusted to each participant's heat pain sensitivity. Data were analyzed by means of a general linear model, and region-of-interest analyses. As predicted, participants demonstrated significant behavioural summation of pain in the TSSP condition. FMRI results identified enhanced activity in the spinal cord dorsal horn at C6 in response to the TSSP condition. Additionally, multiple areas of the brainstem (RVM and PAG) showed greater responses with the TSSP condition. These results suggest that, in humans, increased pain perception in the TSSP condition is reflected by greater responses in the dorsal horn and in regions known to play a role in the descending modulation of pain, which may modulate the spinal cord response.

SUBMITTER: Bosma RL

PROVIDER: S-EPMC6869075 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Neural correlates of temporal summation of second pain in the human brainstem and spinal cord.

Bosma Rachael L RL Ameli Mojarad Elham E Leung Lawrence L Pukall Caroline C Staud Roland R Stroman Patrick W PW

Human brain mapping 20150914 12

Temporal summation of second pain (TSSP) occurs when painful stimuli are presented repetitively (≥ 0.33 Hz) and results from a C-fibre evoked enhancement (or "wind-up") of the dorsal horn neurons. Based on electrophysiological studies in intact animals, windup is considered a purely central phenomenon. With advancements in functional MRI (fMRI), we can now probe the central mechanisms of this pain response in humans. The aim of this study is to characterize the fMRI responses in the healthy huma ...[more]

PMID: 26366748

Similar Datasets

Project description:The spinal cord after injury shows altered transcription in numerous genes. We tested in a pilot study whether the nucleus raphé magnus, a descending serotonergic brainstem region whose stimulation improves recovery after incomplete spinal cord injury (SCI), can influence these transcriptional changes. Rats received 2 h of low-frequency electrical stimulation in the raphé magnus 3 days after an impact contusion at segment T8. Comparison groups lacked injuries or activated stimulators or both. Immediately following stimulation, spinal cords were extracted, their RNA transcriptome sequenced, and differential gene expression quantified. Confirming many previous studies, injury primarily increased inflammatory and immune transcripts and decreased those related to lipid and cholesterol synthesis and neuronal signaling. Stimulation plus injury, contrasted with injury alone, caused significant changes in 43 transcripts (39 increases, 4 decreases), all protein-coding. Injury itself decreased only four of these 43 transcripts, all reversed by stimulation, and increased none of them. The non-specific 5-HT7 receptor antagonist pimozide reversed 25 of the 43 changes. Stimulation in intact rats principally caused decreases in transcripts related to oxidative phosphorylation, none of which were altered by stimulation in injury. Gene ontology (biological process) annotations comparing stimulation with either no stimulation or pimozide treatment in injured rats highlighted defense responses to lipopolysaccharides and microorganisms, and also erythrocyte development and oxygen transport (possibly yielding cellular oxidant detoxification). Connectivity maps of human orthologous genes generated in the CLUE database of perturbagen-response transcriptional signatures showed that drug classes whose effects in injured rats most closely resembled stimulation without pimozide include peroxisome proliferator-activated receptor agonists and angiotensin receptor blockers, which are reportedly beneficial in SCI. Thus the initial transcriptional response of the injured spinal cord to raphé magnus stimulation is upregulation of genes that in various ways are mostly protective, some probably located in recently arrived myeloid cells.

Project description:The spinal cord after injury shows altered transcription in numerous genes. We tested in a pilot study whether the nucleus raphé magnus, a descending serotonergic brainstem region whose stimulation improves recovery after incomplete spinal cord injury, can influence these transcriptional changes. Rats received 2 hours of low-frequency electrical stimulation in the raphé magnus three days after an impact contusion at segment T8. Comparison groups lacked injuries or activated stimulators or both. Immediately following stimulation, spinal cords were extracted, their RNA transcriptome sequenced, and differential gene expression quantified. Confirming many previous studies, injury primarily increased inflammatory and immune transcripts and decreased those related to lipid and cholesterol synthesis and neuronal signaling. Stimulation plus injury, contrasted with injury alone, caused significant changes in 43 transcripts (39 increases, 4 decreases), all protein-coding. Injury itself decreased only four of these 43 transcripts, all reversed by stimulation, and increased none of them. The non-specific 5-HT7 receptor antagonist pimozide reversed 25 of the 43 changes. Stimulation in intact rats principally caused decreases in transcripts related to oxidative phosphorylation, none of which were altered by stimulation in injury. Gene ontology (biological process) annotations comparing stimulation with either no stimulation or pimozide treatment in injured rats highlighted defense responses to lipopolysaccharides and microorganisms, and also erythrocyte development and oxygen transport (possibly yielding cellular oxidant detoxification). Connectivity maps of human orthologous genes generated in the CLUE database of perturbagen-response transcriptional signatures showed that drug classes whose effects in injured rats most closely resembled stimulation without pimozide include peroxisome proliferator-activated receptor agonists and angiotensin receptor blockers, which are reportedly beneficial in spinal cord injury. Thus, the initial transcriptional response of injured spinal cord to raphé magnus stimulation is upregulation of genes that in various ways are mostly protective, some probably located in recently arrived myeloid cells.

Dataset Information

Neural correlates of temporal summation of second pain in the human brainstem and spinal cord.

Publications

Neural correlates of temporal summation of second pain in the human brainstem and spinal cord.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure