Spinal segmental and supraspinal mechanisms underlying the pain-relieving effects of spinal cord stimulation: An experimental study in a rat model of neuropathy
| Autor: | Björn A. Meyerson, Zhiyang Song, Sima Tchachaghian, Farah Shamaa, Bengt Linderoth, Jad Barchini, Nayef E. Saadé, Suhayl J. Jabbur |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Pain Threshold
Baclofen Time Factors Adrenergic beta-Antagonists Stimulation Bicuculline GABA Antagonists Rats Sprague-Dawley chemistry.chemical_compound medicine Animals Phentolamine Electrodes Adrenergic alpha-Antagonists Pain Measurement Analysis of Variance Methysergide business.industry General Neuroscience GABA receptor antagonist Spinal cord Propranolol Rats Disease Models Animal medicine.anatomical_structure Spinal Cord chemistry Hyperalgesia Dorsal column nuclei Neuropathic pain Transcutaneous Electric Nerve Stimulation Dopamine Antagonists Neuralgia Female Ketanserin Serotonin Antagonists Sulpiride medicine.symptom business Neuroscience medicine.drug |
| Zdroj: | Neuroscience. 215:196-208 |
| ISSN: | 0306-4522 |
| Popis: | Spinal cord stimulation (SCS) may alleviate certain forms of neuropathic pain; its mechanisms of action are, however, not fully understood. Previous studies have mainly been focused onto segmental spinal mechanisms, though there is evidence indicating a supraspinal involvement. This study aims to evaluate the relative importance of segmental and supraspinal mechanisms related to the activation of the dorsal columns (DCs). Rats were used to induce the spared nerve injury neuropathy and simultaneously subjected to chronic bilateral DC lesions at the C6-C8 level. Two pairs of miniature electrodes were implanted in each animal, with a monopolar system placed in the dorsal epidural space at a low thoracic level (below lesion) and a bipolar system placed onto the dorsal column nuclei (above lesion). Stimulation (50 Hz, 0.2 ms, 2-4V, 5 min) was applied via either type of electrodes, and tests for sensitivity to tactile and thermal stimuli were used to assess its inhibitory effects. Various receptor antagonists {bicuculline (GABA(A)), saclofen (GABA(B)), ketanserine (5HT(2)), methysergide (5HT(1-2)), phentolamine (α-adrenergic), propranolol (β-adrenergic), sulpiride (D(2)/D(3) dopamine) or saline were injected prior to the SCS. Rostral and caudal stimulations produced a comparable inhibition of neuropathic manifestations, and these effects were attenuated by about 50% after DC lesions. Pretreatment with the various receptor antagonists differentially influenced the effects of rostral and caudal stimulation. Our findings suggest that both supraspinal and segmental mechanisms are activated by SCS, and that in this model with DC lesions, rostral and caudal stimulations may activate different synaptic circuitries and transmitter systems. |
| Databáze: | OpenAIRE |
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