Effect of carbamazepine and gabapentin on excitability in the trigeminal subnucleus caudalis of neonatal rats using a voltage-sensitive dye imaging technique
Biol. Res
;
48: 1-10, 2015. ilus, graf
Article
Dans Anglais
| LILACS
| ID: biblio-950800
ABSTRACT
BACKGROUND:
The antiepileptic drugs carbamazepine and gabapentin are effective in treating neuropathic pain and trigeminal neuralgia. In the present study, to analyze the effects of carbamazepine and gabapentin on neuronal excitation in the spinal trigeminal subnucleus caudalis (Sp5c) in the medulla oblongata, we recorded temporal changes in nociceptive afferent activity in the Sp5c of trigeminal nerve-attached brainstem slices of neonatal rats using a voltage-sensitive dye imaging technique.RESULTS:
Electrical stimulation of the trigeminal nerve rootlet evoked changes in the fluorescence intensity of dye in the Sp5c. The optical signals were composed of two phases, a fast component with a sharp peak followed by a long-lasting component with a period of more than 500 ms. This evoked excitation was not influenced by administration of carbamazepine (10, 100 and 1,000 µM) or gabapentin (1 and 10 µM), but was increased by administration of 100 µM gabapentin. This evoked excitation was increased further in low Mg²+ (0.8 mM) conditions, and this effect of low Mg²+ concentration was antagonized by 30 µM DL-2-amino-5-phosphonopentanoic acid (AP5), a N-methyl-D-as-partate (NMDA) receptor blocker. The increased excitation in low Mg²+ conditions was also antagonized by carbamazepine (1,000 µM) and gabapentin (100 µM).CONCLUSION:
Carbamazepine and gabapentin did not decrease electrically evoked excitation in the Sp5c in control conditions. Further excitation in low Mg²+ conditions was antagonized by the NMDA receptor blocker AP5. Carbamazepine and gabapentin had similar effects to AP5 on evoked excitation in the Sp5c in low Mg²+ conditions. Thus, we concluded that carbamazepine and gabapentin may act by blocking NMDA receptors in the Sp5c, which contributes to its anti-hypersensitivity in neuropathic pain.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Névralgie essentielle du trijumeau
/
Noyau spinal du nerf trijumeau
/
Carbamazépine
/
Acides cyclohexanecarboxyliques
/
Imagerie par colorant sensible au potentiel
/
Acide gamma-amino-butyrique
/
Amines
/
Anticonvulsivants
Type d'étude:
Etude diagnostique
Limites du sujet:
Animaux
langue:
Anglais
Texte intégral:
Biol. Res
Thème du journal:
Biologie
Année:
2015
Type:
Article
Pays d'affiliation:
Japon
Institution/Pays d'affiliation:
Ibaraki Prefectural University of Health Sciences/JP
/
Kanagawa Dental College/JP
/
Kitasato University School of Medicine/JP
/
Uekusa Gakuen University/JP
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