scholarly journals Modulation of the N13 component of the somatosensory evoked potentials in an experimental model of central sensitization in humans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Di Lionardo ◽  
G. Di Stefano ◽  
C. Leone ◽  
G. Di Pietro ◽  
E. Sgro ◽  
...  

AbstractThe N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of dorsal horn neurons. In this neurophysiological study, we aimed to verify whether N13 SEP might reflect excitability changes of dorsal horn neurons during central sensitization. In 22 healthy participants, we investigated how central sensitization induced by application of topical capsaicin to the ulnar nerve territory of the hand dorsum modulated N13 SEP elicited by ulnar nerve stimulation. Using a double-blind placebo-controlled crossover design, we also tested whether pregabalin, an analgesic drug with proven efficacy on the dorsal horn, influenced capsaicin-induced N13 SEP modulation. Topical application of capsaicin produced an area of secondary mechanical hyperalgesia, a sign of central sensitization, and increased the N13 SEP amplitude but not the peripheral N9 nor the cortical N20-P25 amplitude. This increase in N13 SEP amplitude paralleled the mechanical hyperalgesia and persisted for 120 min. Pregabalin prevented the N13 SEP modulation associated with capsaicin-induced central sensitization, whereas capsaicin application still increased N13 SEP amplitude in the placebo treatment session. Our neurophysiological study showed that capsaicin application specifically modulates N13 SEP and that this modulation is prevented by pregabalin, thus suggesting that N13 SEP may reflect changes in dorsal horn excitability and represent a useful biomarker of central sensitization in human studies.

1997 ◽  
Vol 20 (3) ◽  
pp. 404-419 ◽  
Author(s):  
Terence J. Coderre ◽  
Joel Katz

This target article examines the clinical and experimental evidence for a role of peripheral and central hyperexcitability in persistent pain in four key areas: cutaneous hyperalgesia, referred pain, neuropathic pain, and postoperative pain. Each suggests that persistent pain depends not only on central sensitization, but also on inputs from damaged peripheral tissue. It is instructive to think of central sensitization as comprised of both an initial central sensitization and an ongoing central sensitization driven by inputs from peripheral sources. Each of these factors, initial sensitization, ongoing central sensitization, and inputs from peripheral sources, contributes to the net activity in dorsal horn neurons and thus influences the expression of persistent pain or hyperalgesia. Since each factor, peripheral inputs and central sensitization (initial or ongoing), can contribute to both the initiation and maintenance of persistent pain, therapies should target both peripheral and central sources of pathology.


2010 ◽  
Vol 112 (5) ◽  
pp. 1259-1265 ◽  
Author(s):  
Yuan-Xiang Tao ◽  
David S. Warner

Activation of synaptic N-methyl-D-aspartic acid receptor and its intracellular downstream signals in dorsal horn neurons of spinal cord contribute to central sensitization, a mechanism that underlies the development and maintenance of pain hypersensitivity in persistent pain. However, the molecular process of this event is not understood completely. Recently, new studies suggest that peripheral inflammatory insults drive changes in alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit trafficking via N-methyl-D-aspartic acid receptor-triggered activation of protein kinases in dorsal horn and raise the possibility that such changes might contribute to central sensitization in persistent pain. This review presents current evidence regarding the changes that occur in the trafficking of dorsal horn alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunits GluR1 and GluR2 under persistent inflammatory pain conditions and discusses the potential mechanisms by which such changes participate in the development and maintenance of inflammatory pain.


Pain ◽  
2007 ◽  
Vol 133 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Inhyung Lee ◽  
Hee Kee Kim ◽  
Jae Hyo Kim ◽  
Kyungsoon Chung ◽  
Jin Mo Chung

2010 ◽  
Vol 6 ◽  
pp. 1744-8069-6-44 ◽  
Author(s):  
James E Biggs ◽  
B Van Lu ◽  
Martin J Stebbing ◽  
Sridhar Balasubramanyan ◽  
Peter A Smith

Pain ◽  
2003 ◽  
Vol 106 (3) ◽  
pp. 241-251 ◽  
Author(s):  
Kristina S Vikman ◽  
Russell H Hill ◽  
Eva Backström ◽  
Brita Robertson ◽  
Krister Kristensson

2005 ◽  
Vol 94 (1) ◽  
pp. 35-48 ◽  
Author(s):  
J. M. Cuellar ◽  
P. X. Montesano ◽  
J. F. Antognini ◽  
E. Carstens

Herniation of the nucleus pulposus (NP) from lumbar intervertebral discs commonly results in radiculopathic pain possibly through a neuroinflammatory response. NP sensitizes dorsal horn neuronal responses, but it is unknown whether this reflects a central or peripheral sensitization. To study central sensitization, we tested if NP enhances windup—the progressive increase in the response of a nociceptive spinal neuron to repeated electrical C-fiber stimulation—a phenomenon that may partly account for temporal summation of pain. Single-unit recordings were made from wide dynamic range (WDR; n = 36) or nociceptive-specific (NS; n = 8) L5 dorsal horn neurons in 44 isoflurane-anesthetized rats. Subcutaneous electrodes delivered electrical stimuli (20 pulses, 3 times the C-fiber threshold, 0.5 ms) to the receptive field on the hindpaw. Autologous NP was harvested from a tail disc and placed onto the L5 dorsal root ganglion after recording of baseline responses ( n = 22). Controls had saline applied similarly ( n = 22). Electrical stimulus trains (0.1, 0.3, and 1 Hz; 5-min interstimulus interval) were repeated every 30 min for 3–6 h after each treatment. The total number of evoked spikes (summed across all 20 stimuli) to 0.1 Hz was enhanced 3 h after NP, mainly in the after-discharge (AD) period (latency > 400 ms). Total responses to 0.3 and 1.0 Hz were also enhanced at ≥60 min after NP in both the C-fiber (100- to 400-ms latency) and AD periods, whereas the absolute windup (C-fiber + AD − 20 times the initial response) increased at ≥90 min after treatment. In saline controls, windup was not enhanced at any time after treatment for any stimulus frequency, although there was a trend toward enhancement at 0.3 Hz. These results are consistent with NP-induced central sensitization. Mechanical responses were not significantly enhanced after saline or NP treatment. We speculate that inflammatory agents released from (or recruited by) NP affect the dorsal root ganglion (and/or are transported to cord) to enhance primary afferent excitation of nociceptive dorsal horn neurons.


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