Analgesic dorsal root ganglionic field stimulation blocks conduction of afferent impulse trains selectively in nociceptive sensory afferents. Pain 2020 Dec;161(12):2872-2886
Date
07/14/2020Pubmed ID
32658148Pubmed Central ID
PMC7669706DOI
10.1097/j.pain.0000000000001982Scopus ID
2-s2.0-85096203014 (requires institutional sign-in at Scopus site) 29 CitationsAbstract
Increased excitability of primary sensory neurons after peripheral nerve injury may cause hyperalgesia and allodynia. Dorsal root ganglion field stimulation (GFS) is effective in relieving clinical pain associated with nerve injury and neuropathic pain in animal models. However, its mechanism has not been determined. We examined effects of GFS on transmission of action potentials (APs) from the peripheral to central processes by in vivo single-unit recording from lumbar dorsal roots in sham injured rats and rats with tibial nerve injury (TNI) in fiber types defined by conduction velocity. Transmission of APs directly generated by GFS (20 Hz) in C-type units progressively abated over 20 seconds, whereas GFS-induced Aβ activity persisted unabated, while Aδ showed an intermediate pattern. Activity generated peripherally by electrical stimulation of the sciatic nerve and punctate mechanical stimulation of the receptive field (glabrous skin) was likewise fully blocked by GFS within 20 seconds in C-type units, whereas Aβ units were minimally affected and a subpopulation of Aδ units was blocked. After TNI, the threshold to induce AP firing by punctate mechanical stimulation (von Frey) was reduced, which was reversed to normal during GFS. These results also suggest that C-type fibers, not Aβ, mainly contribute to mechanical and thermal hypersensitivity (von Frey, brush, acetone) after injury. Ganglion field stimulation produces use-dependent blocking of afferent AP trains, consistent with enhanced filtering of APs at the sensory neuron T-junction, particularly in nociceptive units.
Author List
Chao D, Zhang Z, Mecca CM, Hogan QH, Pan BAuthor
Quinn H. Hogan MD Professor in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Action PotentialsAnalgesics
Animals
Electric Stimulation
Ganglia, Spinal
Neurons, Afferent
Nociception
Physical Stimulation
Rats
Sensory Receptor Cells
