[Diffuse noxious inhibitory controls: theoretical aspects applied to the effects of regional administration of morphine].
Assuming a relatively high background activity of convergent neurons, we have suggested that their pain-signalling message could consist in the contrast between the high rate of firing in the segmental neuronal pool induced by the painful focus and the D.N.I.C.-mediated silence of the remaining neuronal population. This notion is substantiated by several observations in the rat regarding morphine analgesia: a clear lifting of D.N.I.C. is observed following systemic (0.1-1 mg/kg; i.v.), intraventricular (0.6-2.5 micrograms) or intrathecal (15 micrograms) morphine. All these procedures could restore the initial level of background activity, analgesia resulting from the attenuation of the postulated contrast.
Le Bars
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D
Unité de Recherches de Physiopharmacologie du Système Nerveux de l'INSERM (U. 161), Paris.
Bouhassira
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Villanueva
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D000818:Animals; D006801:Humans; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009433:Neural Inhibition; D009619:Nociceptors / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology*; D012018:Reflex / Q000502:physiology*
D009020:Morphine
Les contrôles inhibiteurs diffus induits par stimulations nociceptives (CIDN): aspects théoriques appliqués aux effets de l'administration régionale de morphine.